-------
LIVING AND NON-LIVING RESOURCES
109
* I97O I97S I98O I9SS
FIGURE 7.—Projected nitrogen loads discharged to San Fran-
cisco Bay.
trace element contaminants (principally heavy met-
als) and hazardous and toxic chemicals which are
distributed by complex pathways encompassing es-
sentially all media and their associated ecosystems.
In estuaries the biological conversion to even more
toxic forms, e.g., organometallics and accumulation
in the aquatic ecosystems and sub-strates, under-
scores the importance of this pollution problem for
estuaries. The potential hazard of certain trace ele-
ments is demonstrated by the concentration factor
for shellfish (see Table 4).
Other sources of trace element emissions to the
environment are reasonably well identified; quanti-
tative estimates are available for air emissions from
different industries and the trace element contents
of wastewater from lead-zinc processing have been
calculated. Sludges and solid residues (tailings) also
constitute a source of trace element contaminants
Table 4.—Concentration factors for the trace elements composition of shellfish
compared with the marine environment
Encroachment factors
Silver
Cadmium,-
Copper
Iron
Manganese _
Nickel
Lead
Vanadium-
Zinc
Ag
Cd
Cr
Cu
Fe
Wn
Mo
Ni
Pb
V
Zn
Scallop
2 300
2,260 000
200 000
3 000
291 500
55,500
90
12 000
5 300
4 500
28 000
Oyster
j j_
18 700 1
318,000 '
60 000
13 700
68 200
4,000 ,
30
4 000
3 300
1 500
110 300
Mussel
3
100, C
320 0
3,C
196,0
13,5
14 0
4 0
2,5
9 1
330
100
100
)00
iOO
iOO
60
Source: Ketchum, B. H., editor The Water's Edge' Critical Problems of the Coastal
Zone. 1972. The MIT Press, Cambridge, Mass., Table 7.2: 150; based on Brooks, R. R.
and M. G. Rumsby. 1965. The Biochemistry of Trace Element Uptake by New Zealand
Bivalves. Limology and Oceanography 10:521-527.
in estuaries unless adequate storage or disposal is
practiced.
There are other major sources of trace element
contamination to water and land receptors in estu-
arine areas, notably automotive exhaust (lead),
leaching from municipal landfills, and incinerator
and land disposal of sewage sludge from municipal
wastewater treatment.46 Agricultural chemicals con-
tribute to heavy metal loads as nonpoint water
pollution, especially mercury, copper, zinc, cadmium,
manganese, and chromium.
The setting of air and water quality standards for
the various trace elements related to point and dif-
fuse sources of contamination requires the identifi-
cation of sources, forms of pollutants, pathways,
and the effects of each substance on the biological
communities in estuaries.
Effluent guidelines have been promulgated by
EPA for some 29 industries up to June 30. 1974
(see Appendix Table 5). Nevertheless, there is urgent
need for additional effluent limitation guidelines, for
EPA has identified a total of about 180 industrial
subcategories and 45 additional variances as requir-
ing distinct effluent standards.
In urban storm water discharges, PCB's and pesti-
cides have been identified as significant compo-
nents.47 Like the heavy metals, hazardous chemicals
—diethyl-stilbestrol, thalidomide, DDT, polychlori-
nated biphenyls, vinyl chloride, pesticides, and
phthalic acid esters—find their way into the estu-
arine environment along a variety of incredibly
complex pathways from many sources.48
Of all chemical classes, pesticides would appear to
pose the most difficult future pollution problem
since sources are diffuse and spread over millions
of acres in the 18 principal water regions of the
nation. Pesticide use in urban areas has increased.
The widespread presence and buildup of persistent
pesticides in water and in fish and marine mammals
are well documented. These characteristics make
pesticides and other hazardous and toxic substances
a major problem to resolve for the protection of the
health of man as well as for estuarine biological
communities.
46 Young, D. R. et al. February 1973. Source of Trace Metals from
Highly Urbanized Southern California to the Adjacent Marine Ecosystem.
Proceedings of a conference on Cycling and Control of Metals, sponsored
by EPA, NSF and BaKelle: 21-39. On December C, 1973, EPA promul-
gated regulations limiting the lead content of gasohne, allowable level of
lead is reduced to an average of 1.7 grams of lead per gallon in 1975, and
0.5 gram? of lead per gallon in 1979. This is the most significant and con-
trollable source of lead exposure. 38 Federal Register 3373-1, (1973).
" Sartor, J. D , and O. B. Boyd. November 1972. Water Pollution
Aspects of Street Surface Contaminants. 76-81 EPA-R2-72-081.
48 The pesticides aldrin, dieldrm, endrin and DDT and its derivatives
DDK and DDD were designated toxic water pollutants by EPA in July
1973. Sevm, chlordane, lindane, methyl parathion and parathion are cur-
rently being studied for possible inclusion m the list.
-------
110
ESTUARINE POLLUTION CONTROL
PETROLEUM LEAKAGE
IN ESTUARINE ENVIRONMENTS
Natural energy demand, even if stringent conser-
vation measures are in force, is expected to double
between now and 1985. The development of new-
energy technologies such as coal gasification, coal
liquefaction, oil, shale and tar sand processes, and
nuclear reactors is likely to have effects on aquatic
ecosystems in estuaries some 10 years in the future.
However, the impact of the increase in thermal
power stations could be expected to occur earlier
while the increase in domestic offshore oil production
and in oil imports can be expected to aggravate oil
leakage into the coastal zone.49
Within the next 10 years the United States' heavy
dependence on oil and gas to meet its energy de-
mands is not likely to diminish. In 1972, oil and
gas accounted for nearly 78 percent of U.S. energy
consumption. Expanded total energy needs were
forecast to require 28 million barrels of oil per day in
1985, nearly twice the consumption in 1970. Other
forecasts before the oil embargo indicated that oil
imports would likely increase to 15 to 20 million
barrels per day by 1985.50
National steps taken to reduce dependence on
foreign oil imports—federal legislation authorizing
construction of the trans-Alaska pipeline, expansion
of the leasing program for the outer continental
shelf, and a proposal to authorize construction of
deepwater ports—all have implications for increased
leakage of oil and petroleum products into the coastal
environment of states adjacent to offshore oil wells or
that have large refineries."'1
Approximately 60 percent of U.S. refining capacity
(seven million barrels per day, 1972) is concentrated
in the four coastal states of Texas, Louisiana, Cali-
fornia, and New Jersey. Production of oil from off-
shore reservoirs (over 8000 offshore wells in the
Gulf of Mexico alone) is expected to reach 30 to 40
percent of total oil and gas production by the early
1980's.
Accelerated imports increase the risks of potential
discharges from intentional or accidental tanker spills
outside or in port (estuary), while increased offshore
production adds to the potential hazard of major oil
49 The problems of energy supply and the impacts of heat disposal
from power plants in the coastal zone are discussed in Chapters 5, 7 and 8
of the Water's Edge. Critical Problems of the Coastal Zone, edited by
Bostwick H Ketchum, The MIT Press, Cambridge, Massachusetts, and
London, England. A major study to investigate the potential environ-
mental effects of offshore nuclear power plants wa;. initiated by the Council
of Environmental Quality in 1P73 Publication of this study is expected
in early 1975.
50 Joint Committee on Atomic Energy, 93rd Congress, 2nd Session.
1974. The Nation's Energy Dilemma.
sl Hypothetical drilling sites and development locations foi the Atlantic
outer continental shelves are offshore to Massachusetts, Rhode Island,
New Jersey, New York, Delaware, South Carolina, Georgia, and Florida
spills from blowouts.62 Coastal areas must provide
the space for receiving increased quantities of oil
carried by pipelines and tankers as well as additional
refineries.
Annual incremental spill volumes in U.S. coastal
areas have been estimated for different levels of
daily oil imports. In the absence of superports
and assuming continued deterioration of the U.S.
energy supply posture, approximately 800,000 bar-
rels of oil could be spilled by 1983.53
Petroleum leakage to the ocean and coastal zone
is not confined to tanker spills or blowouts from
offshore wells. There are many small chronic injec-
tions of oil and oil products into the marine en-
vironment near shore. Injections of oil and grease
result from sewage discharges and storm sewers,
filling station washdown operations, transportation
operations, and other domestic and industrial losses,
including hydrocarbons leaked from outboard
motors.54
It has been concluded that petroleum from pro-
duction, refining or transportation has penetrated the
marine food chain; however, an assessment of the
biological effects of petroleum from different sources
on the metabolism of organisms has not been
made.65 Little is known about the long-term effects
of oil in an estuarine environment. Spills and leaks
of oil cause a number of adverse effects in the estu-
arine environment, not all of which are well under-
stood.
Oil and components of oil can be lethal to or-
ganisms or inhibit normal feeding. The effects of oil
pollution of shoreline in estuaries depend partly on
the nature of the oil and partly on the means by
which it reaches the shore. The coating of rocks,
beaches, marshes can cause significant plant and
organism mortality. The nearshore marshes and
52 Over 17,000 wells have now been drilled in waters off the U.S. coast.
The potential impact of outer continental shelf oil development depends
m part on where oil released in the ocean travels and how it weathers.
The relative environmental iisks of oil and gas development in the Atlantic
and Gulf of Alaska outer continental shelves have been analyzed by the
Council on Environmental Quality in its report to the President, on
April 18, 1974, entitled, OCS Oil and Gas—An Environmental Assessment.
53 Basic data contained in the National Petroleum Council's U.S.
Energy Outlook, Report to NPC's Committee on U.S. Energy Outlook,
December 1972, "Polluting Incidents in and around U.S. Waters, Calendar
Year 1971," U.S. Coa.fi Guard, Washington, D.C., 1975. Estimates were
obtained by James E. Flinn and Robert S. Reimers. March 1974. Develop-
ment of Predictors of Future Pollution Problems. EPA Report 600/5-
74-005.
" An estimated 10 percent of outboard motor oil fuel mixture is un-
burned. Mussels exposed to water containing 50 parts per billion of these
hydrocarbons showed gill damage after 24 hours ol exposure, 66 peicent
died although they were removed after one day and placed in fresh water.
Fourteen percent of oysters tested died during the test period of 10 days.
Clark, R. C., Jr. and J. S. Finley. November 1974. Environmental Science
and Technology, Science News 106(211: 331. Since June 1973 Switzerland
has outlawed ordinary motor oil in boat engines and requires instead a
special oil that is emulsifiable and biodegradable. Communication by
Kohn, Henry H January 4, 1975. Science News 107 (1).3.
"Sanders, H L., J F. Grassle and G. R. Hampson. 1972. The West
Falmouth Oil Spill! Biology (Woods Hole, Mass.: Woods Hole Oceano-
grapluc Institute), Technical report No. 72-20.
-------
LIVING AND Nox-LiviNG
111
wetlands are the most biologically productive areas
of the estuary and are most sensitive to oil spills.56
Estimates of oil persistence indicate that oil
probably persists much longer in salt marshes with
soft sediments (up to 10 years) t-han on rocky shores
or coarse sediments (a few months). Oil even at low
concentrations threatens fish populations; fintish and
shellfish are very susceptible if oil enters spawning
and nursery areas. The cleanup procedure to hasten
the dissipation of visible oil by the use of dispersant
and emulsifying chemicals can be more damaging
to the shoreline environment than the oil.
In addition to the potential hazards from oil
spills, the development of superports to handle im-
ports and of offshore oil and gas leases whether on
the outer continental shelves or in the shallow in-
shore coastal zone (in Louisiana over 2.1,000 \\ells
are operated in this productive; fishery area) require
construction of major pipelines over coastal marsh-
lands. In Louisiana, coastal marshlands and estuaries
extend 20 to 40 miles inland from the Gulf of
Mexico. Physical and ecological effects in these un-
stable marshlands include erosion, release of toxic
substances from dredge spoils, turbidity, salinity,
and other ecosystem changes such as barriers to
nutrient flushing, to migration of estuarine organisms
and to tidal flow patterns that affect, aquatic life.
Canal erosion and pipelaying and marsh buggy
operations can destroy substantial areas of coastal
marsh.57
UPSTREAM ACTIVITIES AFFECTING
FRESHWATER INFLOWS
Trace element and toxic chemical contaminants
from production processes, municipal wastewater
treatment, and diffuse sources have been identified
as a major problem for the retention of productive
fishery habitat in urbanized estuaries. Another pro-
jected problem of national importance is the
potential hazard from greater leakages of petroleum
into the estuarine environment with the develop-
ment of offshore oil and increased imports. A third
broad category of activity which will impinge on the
estuarine fishery habitat might be termed "upstream
activities"—those removed from the seacoast but
•r>fi ior effects of 01) on estuarine eominuntftefi see Smith, Nei.-ori. March
21, 1972 Effects of the Oil Industiy on Shore Life in Estuaries. Pioceed-
mss of (he Hoval Society of London, Senes B. 180 (1001) 287-290 Also,
JDOE 1972. Baseline Studies oi Pollutants m the Marine Knvuoument
and Reseaich Recommendations. New York IDOL Baseline Conference,
May 24, 1972.
" AIcGmius, J. T. et :U. December 1972. Environmental Aspects of
Gas Pipeline Operations in the Louisiana Coastal Maishes, Report to
Offshore Pipeline Committee b> Battelie's Columbus Laboratories St.
Amant, L. S. 1971. Impacts of Oil on tho Gulf Coast. Trans. .30th American
Wildlife and Natuial Reso'itees Conference 206-219. St Aiiiant, 1971,
The Petroleum Industry as it Affects Marine and Estuarine Ecology.
Trans Society of Pet'oieum Engineers Meeting.
which importantly influence the quantity and quality
of fresh water entering the estuary.
Construction of dams, diversions of river flow
within a basin and from one drainage area to another,
control of floods, changes in land use such as in-
creased irrigation, and clearing and channelization
of forest and bottom land have in many instances
direct and significant effects on estuarine aquatic
habitat.
Modification of freshwater flows by dam con-
struction, diversion, and consumption affects the
extent of saltwater intrusion, the degree of mixing
of fresh and saltwater and the plankton and fish
populations.58 Reduction in freshwater flow increases
salinity in former brackish water areas and can
reduce the production of shrimp, oysters and other
marine life.
In the Sacramento-San Joaquin estuary the
changes that can be expected with modification of
normal flow patterns typify the effects that can be
expected in many estuaries. Losses of fish eggs and
young have to be; minimized when water is diverted
from the estuary; moderate not flow rates have to
be maintained to give1 positive downstream flows.
Maintenance of adequate freshwater flows from the
Delta into San Francisco Bay are required to main-
tain "suitable salinities for striped bass spawning
and for Xcomi/sis . . . for good survival of young
striped bass . . . for salmon migrations . . . for suffici-
ent turbidity . . . and for flushing pollutants from
diffuse source.-- out of the estuary." 59 Ail these
requirements should be accounted for in plans for
tipstream and delta \\atcr developments that would
modify flows. Already outflow from the Delta is
"only about half the natural lev! due to the com-
bined effect of upstream depletion storage and
pumped exports.'"'"
Increased population, industrial and municipal
usage, and the development of irrigated agriculture,
especially in river basins draining arid regions, will
continue to increase demand for storage and diver-
sion. The Texas Master Plan proposes to divert
most of the flow of the Sabine. Neches Nucces,
Trinity, Brazos and Colorado rivers for irrigation
use, while an even more ambitious scheme has been
discussed—the diversion of water from the mouth
of the Mississippi to the Texas High Plains.
ss Piitehaid, I) W. 1955. Ksmarme Circulation Patterns. Proceedings,
American Society of Civil Engineers 81 1-11 Ketchnm, B. II. 1951. The
Flushing of Tidal Estuaries Sewage. Sewage and Industrial Wastes 23(2).
198-209, Ketclium, B. H. Relation Rflweea Circulation and Planktonic
Population in Estuaries. Ecology 35. 191-200.
j9 California Department of Fish and Game Apul 1973. Maintenance
of Fish and Wildlife in the Sacramento-San .loaquin Estuary in Relation
to Water Development.
frl> California Department of Fish arid Game. June 1972. Ecological
Studies of the Sacramento-San Joaijum Estuary: A Decennial Report,
]901-1971:18.
-------
112
3500
3000
2500
2000
1500
1000
500
O1-
(328) ,
(203),'
100)
100)
1960
1980
Year
(199)
2000
ESTUAEINE POLLUTION CONTROL
500 -
400 -
300
200
100
90
2 8°
*„ 70
60
50
40
30
20
10
0
Rural +
irrigation
Industrial
FIGURE 8.-—Estimated future water withdrawal in the United
States. The figures in parentheses give percentage increase
over 1960 values. Source: Data of Murry, C. R. 1968. U.S.
Geological Survey Circular 556; Piper, A. M. 1965. U.S.
Geological Survey Water-Supply Paper 1797.
2000
FIGURE 9.—Estimated future water consumption in the
United States. Figures in parentheses give percentage of
estimated withdrawal. Source: Data of Murry, C. R. 1968.
U.S. Geological Survey, Circular 556; Piper, A. M. 1965.
U.S. Geological Survey Water-Supply Paper 1797.
problems of water quality and quantity at the inter-
face between rivers and the estuarine zone can be
expected to be exacerbated.
Projected future water withdrawals and con-
sumption represent substantial increases over pres-
ent-day totals (see Figures 8 and 9). Total water
withdrawal in the year 2000 is estimated to amount
to about 900 billion gallons per day, which compares
to a runoff of 1,400 billion gallons daily. Assuming
that consumption is 20 percent of total withdrawal,
we will actually be losing to the atmosphere 180
billion gallons daily, a small fraction of the runoff.
Recycling procedures can be developed to reduce
even further the percentage of runoff required to
be withdrawn. Consequently, there would appear to
be enough fresh water to meet future demands. The
pertinent question, however, is whether there is
sufficient fresh water in different drainage areas to
meet the respective demands and to maintain
productive fishery habitats in downstream areas. As
population pressures increase and urban activities
grow in both the hinterland and coastal zone, the
MANAGEMENT IMPLICATIONS
Land and water use in the coastal zone is inter-
related with that in the hinterland, both in actuality
and policy The state land use plans should therefore
incorporate plans for managing the lands along the
coast in such a way as to preserve the ecological
values of estuaries, other coastal waters, and marsh-
lands to the maximum practicable degree consistent
with essential uses for navigation, recreation, seafood
production, power plant cooling, and other uses.
The Coastal Zone Management Act of 1972 ad-
ministered by the National Oceanic and Atmospheric
Administration in its first year of operation has
provided assistance to all but one of 34 coastal
states and territories wishing to establish resource
management plans in defined coastal areas.
The management plans of the coastal zone (in-
cluding estuaries) should incorporate the flexibility
-------
LIVING AND NON-LIVING RESOURCES
113
to be compatible with comprehensive land use
planning measures as set out in the new administra-
tion bill drafted by the Secretary of the Interior.
Comprehensive plans for the use of the water and
land resources of the coastal zone should be based
on a careful classification of the coastal zone with
respect to uses and the degree of necessary public
controls over these uses. Provision should be made
for public acquisition of lands and interests in lands
required to preserve ecological values and provide
other public benefits.
Land and water practices and programs upstream
in the drainage area of an estuary importantly
influence the quantity and quality of fresh water
flowing into estuarine areas. Water management in
the estuaries and coastal zone must be integrated with
management of upstream water resources to achieve
comprehensive drainage basin management. The
planning of future developments and diversions up-
stream must recognize this crucial interrelationship
and provide facilities for mitigating losses and
preserving values in the estuaries and coastal zones.
Present Federal, state arid local processes for
making land use and development decisions as they
apply to the total estuarine system, including fresh-
water inflows, should be made adequate to the task.
Local governments cannot and should not be by-
passed. On the contrary, under an effective state
organization with strong regional bodies, local
governments should perform an indispensable role
in coastal zone management.C1
There is urgent need to improve environmental
impact statements required by Section 102 (c) of
the National Environmental Policy Act of 1970
(NKPA) for all the changes and activities affecting
estuarine areas. Improvement of impact assessment
procedures and analyses is required at all levels of
federal, state and local governments. This will
require a major commitment of resources lo attain
levels of competency and ensure that the evaluations
are thorough.
An early improvement in making the content of
environmental impact evaluation more relevant
could be brought about by re-establishing a co-
ordination arrangement between the Water Re-
sources Council and the Interagency Committee on
Marine Resources of the Federal Council for Science
and Technology, which is now responsible for the
policy coordination aspect of the National Marine
Sciences Program. This would assure that research
programs are designed to furnish the information
1)1 The principles drawn up b\ the California Advisory Commission on
Marine and Coastal Prso'jtcr, ^ropo<*
-------
114
ESTUARINE POLLUTION CONTROL
Council on Environmental Quality. 1971. Environmental
Quality. Second Annual Keport. Washington, D. C.
Council on Environmental Quality. April 18, 1974. OCS Oil
and Gas—An Environmental Assessment. Report to the
President.
Delise, G. October, 1966. Preliminary Fish and Wildlife
Plan for San Francisco Bay-Estuary. Prepared for the San
Francisco Bay Conservation and Development Commission.
Duke, T. W., and T. R. Rice. 1967. Cvcling of Nutrients in
Estuaries. Proceedings of Gulf and Caribbean Fisheries
Institute 19:59.
Flinn, James E., and Robert S. Reimers. March 1974. De-
velopment of Predictors of Future Pollution Problems.
EPA Report 600/5-74-005.
Gosselink, J. G., E. P. Odum, and R. M. Pope. 1974. The
Value of the Tidal Marsh. Publication No. LSU-SG-74-03.
Center for Wetland Resources. Baton Rouge: Louisiana
State University.
IDOE. March 24-26, 1972. Baseline Studies of Pollutants in
the Marine Environment and Research Recommendations.
IDOE Baseline Conference, New York.
Kahn, A. E. 1966. The Tyranny of Small Decisions: Market
Failures, Imperfections, and the Limits of Economics.
Dykos 19(1).
Ketchum, Bostwick H. 1972. The Water's Edge: Critical
Problems of the Coastal Zone. Cambridge, Massachusetts:
The MIT Press.
Ketchum, B. H. 1954. Relation Between Circulation and
Planktonic Population in Estuaries. Ecology 35.
Ketchum, B. H. 1951. The Flushing of Tidal Estuaries.
Sewage Industry Wastes. 23(2).
Kohn, Henry H. January 4, 1975. Letter to the Editor.
Science News 107.
Kutscher, Ronald. December 1973. Projections of GNP,
Income, Output, and Employment. Monthly Labor Review
96:3-42.
McGinnis, J. T., et al. December 1972. Environmental
Aspects of Gas Pipeline Operations in the Louisiana Coastal
Marshes. Report to Offshore Pipeline Committee by Bat-
telle's Columbus Laboratories.
McHugh, J. L. November 1968. Are Estuaries Necessary?
Commercial Fisheries Review 30(11).
Murray, C. R. 1968. U.S. Geological Survey Circular 556.
National Academy of Sciences 1972. Water Quality Criteria.
Washington, D. C.
National Petroleum Council. December 1972. U.S. Energy
Outlook. Report to NPC Committee on U.S. Energy
Outlook.
Odum, William E. 1970. Insidious Alteration of the Estuarine
Environment. Transactions of the American Fisheries
Society 4.
Piper, A. M. 1965. U.S. Geological Survey Water-Supply
Paper 1797.
Pomeroy, L. R., R. J. Reinold, L. R. Shenton, and R. D.
Jones. 1972. Nutrient Flux in Estuaries. Nutrients and
Eutrophication Edited by G. E. Likens. American Society
of Limnology and Oceanography. Special Symposium 1.
Pritchard, D. W. 1955. Estuarine Circulation Patterns.
Proceedings American Society of Civil Engineers 81.
St. Amant, L. S. 1971. The Petroleum Industry as it Affects
Marine and Estuarine Ecology. Transactions of the So-
ciety of Petroleum Engineers.
St. Amant, L. S. 1971. Impacts of Oil on the Gulf Coast.
Transactions 36th American Wildlife and Natural Re-
sources Conference.
Sanders, II L., J. F. Grassle, and G. R. Hampson. 1972. The
West Fallmouth Oil Spill! Woods Hole, Massachusetts:
Woods Hole Oceanographie Institute Technical Report
No. 72-20
Sartor, J. D , and G. B. Boyd. November 1972. Water Pollu-
tion Aspects of Street Surface Contaminants. 76-81 EPA-
R 2-72-081.
Smith, Nelson. March 21, 1972. Effects of the Oil Industry
on Shore Life in Estuaries. Proceedings of the Roval
Society of London. Series B 180 (1061).
U.S. Coast Guard. 1975. Polluting Incidents In and Around
U.S. Waters, Calendar Year 1971. Washington, D. C.
U.S. Congress. Joint Committee on Atomic Energy. 93rd
Congress, 2nd Session. 1974. The Nation's Energy Dilemma.
Washington, D. C.
U.S. Department of Commerce. National Technical Informa-
tion Service. Total Urban Water Pollution Loads. PB-
231/730. Springfield, Va.
U.S. Department of Commerce. Bureau of the Census. 1973.
Statistical Abstract of the United States: 1973. 94th edition.
Washington, D. C.
U.S. Department of the Army. Corps of Engineers. August
1971. National Shoreline Study, Shore Management
Guidelines. Washington, D. C.
U.S. Department of the Interior. August 1970. National
Estuarine Pollution Study. Report of the Secretary of the
Interior to the U.S. 91st Congress Pursuant to Public
Law 89-753. The Clean Water Restoration Act of 1966.
Washington, D. C.
U.S. Department of the Interior. Fish and Wildlife Service.
August 1970 National Estuary Study. Washington, D.C.
U.S. Environmental Protection Agency. April 1971. The
Economic and Social Importance of Estuaries. Estuarine
Pollution Study Series 2. Washington, D. C.
National Science Foundation. 1972. Patterns and Perspec-
tives in Environmental Science. Report prepared for
National Science Board.
U.S. Envirormental Protection Agency. April 1973. Guide-
lines for Developing or Revising Water Quality Standards.
Water Quality Division. Washington, D. C.
-------
LIVING AND NON-LIVING RESOURCES 115
U.S. Environmental Protection Agenc3T. Office of Water U.S. Environmental Protection Agency. March 1974. Water
Planning and Standards. August 1974. National Water Quality Strategy Paper. Washington, D. C.
Quality Inventory, 1974. Eeport to the Congress. EPA-
44019-74-001. Washington, D. C. Young, D. R., et al. 1973. Source of Trace Metals from
Highly Urbanized Southern California to the Adjacent
U.S. Environmental Protection Agency. 1973. Water Quality Marine Ecosystem. Proceedings of a Conference on Cycling
Criteria. Washington, D. C. and Control of Metals.
-------
APPENDIX A
TABLES
Appendix Table 1.—A summary of legislation relating to coastal and estuarine zones
Zone
Alabama - - -_ _ _i
Alaska
California
Connecticut
Delaware. » ,
Georgia
Hawaii ...
Maine _ __ ._
Comprehensive coastal zone
planning legislation
None at present — in the planning
stage.
stage.
Coastal Zone Conservation Act
(1972) — to develop plans and
control development Permits re-
quired for any development in the
coastal zone. The California Com-
prehensive Ocean Area Plan was
completed in 1972.
$3.5 million study of Long Island
Sound to develop a comprehen-
sive plan for this area.
Delaware Coastal Zone Act (1971)—
to control the location, type, and
extent of industrial development
in coastal areas, prohibition of
new heavy industries.
Management Act (1972): land de-
velopment regulations for "area
of critical state concern."
Legislation requiring a coastal plan
passed in 1973.
No coastal zone plan.
"Coastal Development Plan" being
prepared.
Wetlands
U.S. Army Corps of Engineers proj-
ects deemed harmful are refused.
Wetlands Protection Act— 1969
—Inventory of alt wetlands.
—No dredging or construction on
designated wetlands without a
permit.
Delaware Wetlands Act (1973)— per-
mits required for virtually all ac-
tivity in the wetlands.
Coastal Marshlands Protection Act
(1970)' "No person may remove,
fill, dredge, dram, or otherwise
alter any marshlands within the
estuarine areas without first ob-
taining a permit . . . ."
Wetlands Preservation Act (1967)—
State Wetlands Control Board can
impose any conditions regarding
Industries and power plant siting
mission regulates the location of
industries and domestic pollution
sources.
A power plant siting bill was passed
in 1974.
The state has banned heavy industry
within two miles of the coast, with
permits required for other uses.
Legislation to limit heavy industry on
coast is now pending.
Shoreline— recreation
demands on coastal zone.
finance the cost of recreation
lands.
Shoreline Setback Areas (1971).
Construction within 20 to 40 feet
from edge of vegetation growth is
prohibited without a special
permit.
dredging, filling, etc., on coast if
they feel it is in public's interest.
Maryland. ! Stil! being developed. A critical
j areas bill (S.B. 500) was enacted.
Wetlands Act (1970, amendment) no
dredging or filling without a permit
Shore Erosion Control Act (1970 as
amended)—provides loans for
shore erosion protection devices.
116
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LIVING AND NON-LIVING RESOURCES
117
Zone
Massachusetts
Mississippi —
New York
North Carolina
Oregon _- -
Puerto Rico
Rhode Island -
South Carolina
Texas j
Virginia
Washington -- „
Comprehensive coastal zone
planning legislation
A commission has been created to
develop a comprehensive plan for
estuarme area management.
Coastal zone management plan in
review stage.
Plan being formulated. Some
coastal zone land uses regulated
by 1973 law.
Plan being formulated. Coastal zone
authority influences land use.
Coastal Areas Management Act
(1974)— also a preliminary, com-
prehensive plan prepared De-
cember 1972. Land Policy Act
(1974),
Coastal Zone Management Plan Act
(1971) provides for a comprehen-
sive plan to be submitted to State
Legislature by 1975,
Comprehensive plan being devel-
oped.
Some coastal zone activities regu-
lated by state permit system.
No plan at present.
Coastal Puoltc Lands Management
Act (1976) provides for the com-
prehensive management of state-
owned coastal lands, and estab-
lishes permit system for con-
struction on coastal islands and
submerged lands.
The Texas Council on Marine Re-
lated Affairs was created in 1971,
to study and plan for marine re-
sources.
Plan being developed.
Shoreline Management Act (1971)
—sets responsibilities of state
and local areas for permit system,
and inventories.
Wetlands
Coastal Wetlands Protection Act
(1973)— designates the Marine Re-
sources Council as the regulatory
agency for activities on wetlands.
Wetlands Act (1967)— controls
dredging and filling of tidal areas.
Dredge and Fill Act (1971) promul-
gates rules and regulations for
dredging in tidal areas.
Wetlands Act (1970) permit required
for any dredging, filling, polluting,
butldmg, or otherwise altering wet-
lands—wetlands being mapped.
New York Wetlands Act (1971)— mo-
ratorium on wetland alterations.
Wetlands Protection Act (1971)—
authorizes the adoption of rules to
protect marshes and contiguous
lands. Dredge and Fill Act (1971)—
makes permits required.
Coastal Wetlands Act (1965), land
use restrictions in such areas.
Intertidal Salt Marsh Act(1965)-per-
mits needed to fill, dredge, etc.
Wetlands Act (1972)— a permit sys-
tem for wetlands regulation.
and river deltas are regulated
under the Shoreline Management
Act.
Industries and power plant siting
Power plant siting law was recently
enacted.
Power Plant Siting (1971)— sites
must be approved by PUC and not
environmentally detrimental.
Power plant siting law.
State has a power plant siting law.
As required under Federal Water
Pollution Control Act, no new mu-
nicipal or industrial discharges
without special authorization.
Thermal Power Plant Siting Act
(1970) — environmental and bio-
logical considerations will be main
guidelines in location of sites.
Shoreline— recreation
Multi-year study begun in 1971 in-
ventorying Long Island Sound
resources.
Oregon Land Use Law (1973)
regulating land uses. Beach
Access Act (1967)— citizen's right
to unrestricted beach use up to
vegetation line.
Coastal Management Council Act
(1971) to administer management
program for coastal areas.
No major legislation but increased
study and survey of coastal areas.
Public ownership of state beaches
up to vegetation line.
A coastal zone management program
is being undertaken.
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118
ESTTJARINE POLLUTION CONTROL
Appendix Table 2.—Major U.S. waterways
Appendix Table 4.—Major waterways: Reference level violations, 1963 to 1972
10 longest rivers
(miles)
Missouri (2,564)
Mississippi (2,348)
Rio Grande (1,885)
Yukon (1,875)...
Arkansas (1,450)
Colorado (1,450).. ...
Columbia— Snake (1,324) ..
Ohio (1 306)
Red (1 222)
Brazos (1,210)
10 rivers with
highest flows
(cubic feet per second)
Mississippi (620.000)1'2
Ohio (255,000)1
Columbia (235,000)'
Missouri (70,000)i
Tennessee (63,700)
Alabama-Coosa (59,000)
Red (57.300)1'3
Arkansas (45,200)'
Susquehanna (35,800)
Willamette (30,700)
Waters of 10 largest
urban areas
Hudson River— New York
Harbor
Los Angeles Harbor
Lake Michigan and other
waters of Chicago area
Delaware Rtver
(Philadelphia)
Detroit River and Detroit
area tributaries
San Francisco Bay and
Sacramento River
Potomac River
(Washington, D. C.)
Boston Harbor
Ohio River (Pittsburgh)'
Mississippi and Missouri
Rivers (St. Louis)1
1 Contained in first (or second) columns.
2 Includes Atchafalaya River (about 25 percent of flow).
3 Includes flow of Ouachita River.
Source' Environmental Protection Agency. 1974. National Water Quality Inventory
Report to Congress. Table 1-1.
Appendix Table 3.—Major waterways: Water quality trends 1963-72'.
Parameter
Suspended solids ._
Turbidity
Temperature _ _.
Color ..
Nitrate (as N)... .
Nitrite plus nitrate ...
Total phosphorus
Total phosphate
Dissolved phosphate
Dissolved solids (105° C).
Dissolved solids (180° C).
Chlorides..
Sulfates...
pH
Dissolved oxygen
Total cohforms (MFD)'...
Total conforms (MFI)2-..
Total conforms (MPN)>...
Fecal conforms (MPN)2...
Fecal conforms (MPN)2...
Phenols. __
Reference level and source1
80 mg/l-aquatic life
50 JTU-aquatic life
90° F-aquatic life
75 platinum-cobalt units-
water supply
0.89 mg/l-aquatic life
0.9 mg/l-nutrient
09 mg/l-nutnent
0.1 mg/l-nutrient
0.3 mg/l-nutrient
0.3 mg/l-nutnent
500 mg/l-watei supply
500 mg/l-watei supply
250 mg/l-water supply
250 rng/l-water supply
6.0-9.0-aquatic life
4.0 mg/l-aquatic life
10,000/100 mi- recreation
10,000/100 mi-recreation
10,000/100 mi-recreation
2,000/100 mi-recreation
2,000/100 mi-recreation
0.001 me/l-water supply
Percent of reaches
exceeding reference
levels
1963-67 1968-72
26 H
28 28
0 ' 0
0 0
16 6
12 24
18 26
34 57
30 41
11 22
25 18
28 , 12
12 9
12 12
0 0
0 0
24 13
50 30
23 20
45 21
17 43
86 71
Change
-12
0
0
0
10
+12
+8
+23
+11
+11
-7
-16
-3
0
0
0
-11
-20
-3
-24
+26
-15
' With the exceptions that follow, reference level designations are from "Guidelines
for Developing or Revising Water Quality Standards," EPA Water Planning Division,
April 1973, for ammonia, chlorides, sulfates, and phenols, "Criteria for Water Quality,"
EPA, 1973 (Section 304(a)(l) guidelines), and for nitrate (as N), "Biological Associated
Problems in Freshwater Environments," FWPCA, 1966, pp. 132-133.
Parameter
Suspended solids. .. . -^
Ammonia
Total conforms (membrane filter immediate)
T ? . h . ,
Number of
reaches
analyzed
28
29
9
25
31
23
20
33
9
28
34
31
23
5
34
12
12
18
33
11
16
32
5
27
30
19
17
28
Percent of
reaches
improved2
82
79
78
76
74
70
70
67
67
64
62
61'
61
60
59 •
58
58
56
55
55
44
41i
40
37
33
26
24
18
1 Based on median values at each reach. Reaches included only if they contain one
or more stations with at least seven samples each. Parameters included only if five
or more reaches were measured.
2 Except where noted, "improved" means that 1968-72 median concentrations are
lower than 1963-67 median concentrations at mean station.
3 "Improved" means higher concentration.
"Improved" means pH becomes higher (less acid).
Source: Environmental Quality Fifth Annual Report, Council on Environmental
Quality.
Appendix Table 5.— Published effluent guidelines for industries as of June 30, 1974
Industry Proposed
Fiberglass ; 8/22/73
Beet sugar 8/22/73
Cement... _. 7/7/73
Feedlots 9/7/73
Phosphates 9/7/73
Flat glass 10/17/73
Rubber ._ 10/11/73
Ferroalloys 10/18/73
Electroplating 10/5/73
Asbestos 10/30/73
Inorganics 10/11/73
Meats — - 1 10/29/73
Plastics and synthetics 10/11/73
Nonferrous metals 11/30/73
Cane sugar _; Up/73
Fruit and vegetables 11/9/73
Gram mills j 12/4/73
Soaps and detergents 12/26/73
Fertilizer , 4/8/74
Petroleum- ; 12/14/73
Dairy... . . 12/20/73
Leather... . . _' 12/7/73
Pulp and paper.. ._ ... . 1/15/74
Organics 12/17/73
Builders paper.. 1/14/74
Seafood 2/6/74
Timber. . 1/3/74
Iron and steel . 2/19/74
Textiles.. ... i 2/5/74
Steam and electric power . 3/4/74
Final
(effective date)
1/22/74
1/31/74
1/20/74
2/14/74
2/20/74
2/14/74
2/21/74
2/22/74
3/8/74
2/26/74
3/12/74
2/28/74
4/5/74
4/8/74
3/20/74
3/21/74
3/20/74
2/12/74
7/2/74
5/9/74
5/28/74
4/9/74
5/29/74
4/25/74
5/9/74
6/26/74
4/18/74
6/28/74
7/5/74
Not yet
published
Source. Environmental Quality. The Fifth Annual Report of the Council on Environ-
manfol Al.il,*., 107* Tlhio 9 nonn 1*1
-------
APPENDIX B
Principles for
Coastal Zone Management
Drawn up by
California Advisory Commission
on Marine and Coastal Resources
1. FINDINGS AND DECLARATIONS
a. Legislative findings should be brief and directed toward
the positive aspects of the regulatory scheme.
2. STATE COASTAL ZONE MANAGEMENT
a. The state should provide leadership in assisting local
governments in the planning and management of the coastal
b. Coastal zone management legislation should designate
a single state organization to provide leadership in the plan-
ning and management of the coastal zone.
c. The state organization to be selected to administer the
plan of regulation should be directed by a board consisting of
persons qualified and experienced in the development, con-
servation or use of marine and coastal resources (e.g , con-
cerned with environmental quality, conservation and
recreation, living marine resources, land use planning and
coastal development, and economics and law of natural
resources) and persons not required to have specialized
knowledge.
d. The state organization should be required to establish
continuing liaison and coordinate its activities with all other
major state and private agencies directly interested in the
administration of the coastal zone.
e. The state organization should be empowered to require
periodic review and updating of all local and regional plans.
f. The state organization should be designated as the state
coastal zone authority for all purposes stated in any federal
coastal zone management legislation and be given the au-
thority to administer any statewide program of research and
planning peitaining thereto.
g. The state organization should be a clearinghouse for
planning information pertaining to the development and con-
servacion of the marine and coastal resources of the state.
h. The technical ad-, isorv committee shouH tons-ist of the
California Advisorv ('ommis.si.jii on Marine and Coastal
Resources (-'CMC"").
i. The advisory committee should be given the responsi-
advise the state organization either when requested
when deemed appropriate by the committee.
by it or w
2. REGIONAL COASTAL /ONE M
a. Coordination of this planning and management function
will require regional entities, encompassing aggregations of
several local governments.
V>. Regional boards should be designated to supervise the
implementation of the program.
c. Regional areas should be designated following county
lines and be functionally related to resource planning.
d The governing boards for the designate-l urea? should
consist of persons qualified and experienced in the develop-
ment, conservation or use of marine and coastal resources
(e.g., concerned with municipal government, county govern-
ment, water use, environmental quality, recreation and con-
servation, land use and land use planning, living marine
resources, and economics and law of natural resources).
4. LOCAL GOVERNMENT COASTAL ZONE MANAGEMENT
a. The planning and management of the coastal zone is
primarily the responsibility of local government.
b. Planning and management of the coastal zone located
within the boundaries of units of local government are and
should remain primarily the responsibility of units of local
government in accordance with state criteria
c. Local governments should coordinate their planning and
management within overall state policy and should administer
the coastal zone under the state's certification.
5. PERMIT AREA BOUNDARY
a. The state organization selected should have legally
precise and ascert ainable boundaries.
b. Any administrative discretion to expand the coastal zone
should be of short duration.
c. The practicability of the plan of regulation should be
considered in determining the extent of the defined coastal
zone, it being more desirable to have a coastal zone with
numerous exceptions based upon imquantified considerations.
6. COASTAL ZONE POLICY AND CRITERIA
a. The state organization selected should formulate and
adopt state policy for coastal resources conservation ard
development.
b. Criteria for ceitification of local plans and programs
should be established an'! administered by the state.
c To the extent practicable, principles underlying criteria
to lie applied by any new state coastal zone management
should be established prior to or concurrently with the imple-
mentation of I ho regulatory aspects of that system.
d. The criteria to be developed should include components
for all lawful uses of the coastal zone and none should be
generically prohibited.
e. The criteria to bf developed should facilitate an optimum
combination of all lawful uses in thv 'oastal zone by a con-
sideration of all private and public benefits and costs re.v.jlf ing
from them.
119
-------
120
ESTUARINE POLLUTION CONTROL
f. Special consideration in forming criteria should be given
to uses which cause irreversibility in potentially permanent
flow (e.g., renewable) resources.
g. The staff of the state organization selected should be
given the responsibility of preparing recommended planning
criteria.
h. A technical advisory committee should have the respon-
sibility to review and comment upon recommended planning
criteria.
7. COASTAL ZOSE PLAN DEVELOPMENT
a. The state organization selected should ultimately in-
corporate the Comprehensive Ocean Area Plan ("COAP")
into the state plan.
b. The state organization selected should integrate regional
plans developed by the regional boards into the state program.
c. Regional boards should be required to prepare regional
plans incorporating coastal elements developed by units of
local government to the extent that the same are consistent
with the criteria developed by the state organization.
d. Regional planning entities should provide a compre-
hensive format for coordinated planning and management in
accordance with state policy objectives.
e. Primary responsibility for management of marine living
resources should not be affected by coastal zone management
legislation.
f. The state organization should certify coriformance of
regional plans to state policy.
8. LAND USE PERMIT SYSTEM
a. Units of local government should be required to give
notice to the regional boards of permits granted for regulated
uses of the coastal zone with supporting data for the decision
made, and the regional boards should have the power to
review the same within a designated period of time (e.g.,
30---60 days) to determine whether the decision meets with the
relevant criteria. If a regional board does not give notice of
nonconformance with such criteria within such period, the
permit shall be effective.
b. Regional boards should have the power to issue orders
to units of local government or their permittees to rescind
permits issued for uses not conforming to relevant criteria.
c. Regional boards should have the power to obtain injunc-
tions and other appropriate legal relief.
d. Where the matter is of regional concern, regional boards
should also have the power to hear appeals from denials of
permits by units of local government and to confirm or rescind
such action.
e. The state organization should upon petition of an
aggrieved person, public agency, unit of local government or
its own motion review any action or failure to act by a regional
board with respect to any requested use of the coastal zone
considered not in accordance with state criteria.
f. State agencies should be required to give notice to the
appropriate regional board of regulated uses of the coastal
zone proposed to be made by them and of permits proposed
to be granted for such uses with supporting data for the
decision made with respect thereto. The appropriate regional
board should have the power to review the decision within
the designated period of time (30-60 days) to determine
whether the same meets with the relevant criteria of the
regional plan. If the appropriate regional board does not give
notice of nonconformance with such criteria within such
period, the proposed use shall be deemed approved.
9. ECONOMICS AND FINANCING
a. The legislation should provide funding for all affected
governmental agencies at all levels to enable them to perform
assigned responsibilities in an adequate and timely fashion.
b. The state organization should be structured so as to
take maximum advantage of existing organization, personnel
and equipment.
c. The state organization selected should allocate to the
regional boards from funds appropriated to it such monies as
may be necessary for their professional staffing and other
administrative expenses.
d. The legislation should recognize private property rights
in the coast al zone and require payment of fair compensation
in the event that any taking is effected thereunder.
e. The legislation should give appropriate recognition to
the effect of the plan of regulation of units of local government
and should provide a means for equalizing benefits as well as
costs incurred in environmental maintenance or sustaining
low densitv uses.
-------
THE EXTRACTIVE INDUSTRIES
IN THE COASTAL ZONE OF
THE CONTINENTAL UNITED STATES
STANLEY R. RIGGS
East Carolina University
Greenville, North Carolina
ABSTRACT
The extractive industries in the coastal zone consider all known mineral sources excluding
petroleum, that presently occur or may occur in the future within the estuaries, the nearshore
continental shelf waters, and the adjacent land areas within continental United States exclusive
of the Great Lakes. This includes all activities in the recovery of natural materials from the sedi-
ments and rocks of the earth's crust and from the water column and the preparation and treat-
ment of these natural materials in order to make them suitable for use.
Mineral extraction, excluding petroleum, is presently nonexistent in most estuaries and very
limited both in commodities and quantities in the few estuaries where extraction is taking place.
Any consideration of estuarine and offshore mining must deal with the potential. To develop
an adequate inventory of the resource potential of the United States coastal areas will necessitate
a massive and coordinated detailed study of the surface and subsurface geology. Most extractive
industries, whether in, adjacent to, or distantly remote from an estuarine system will have some
impact upon the pollution of the coastal zone; however, no two extractive industries will have
similar effects or degrees of pollution impact upon the estuarine systeu .
A basic knowledge of the mineral reserves and the general economic value to man is essential
prior to (he development of any land and water use management plans involving the continued
development of our coastal scone. Economics of a given mineral resource may change dramatically
in response to new technological advances, discoveries of new ore deposits, or as industrial and
social demands change through time. Such changes can have drastic effects upon the same manage-
ment programs which define land and water uses. The resulting dilemma becomes of paramount
importance: the need to protect a delicately balanced estuarine system, upon which mar is de-
pendent, sitid at the same time dramatically increase ils use and modification for materials which
man is also dependent upon.
INTRODUCTION
This report on the extractive industries in the
coastal zone considers all known mineral resources
excluding petroleum, that presently occur or may
occur in the future within the estuaries, the near-
shore continental shelf waters, and the adjacent land
areas within continental United States exclusive of
the Great Lakes. Also, it does not directly consider
the consequences of dredging, particularly as related
to channel and harbor dredging and maintenance.
Tin; estuarine y,one or coastal zone, as used in this
report, refers to the geographic region including the
coastal counties between the landward limit of tidal
influrji'-ij and the three-mile limit to son ward ("Na-
tional Rsf.ii.'trme j'oiluii'.n Studv," 1970, p. '>).
The esitiarim- ;:oiuj is HU ecosystem. That is, it is an
fnvironment of land, water, an 1 air inhabited by plants
arid anmi<,'!b (hat have spceiiic relationships to each
other Thi> pai !ic alar <-:osys*eip is !he interface between
lu;;i,'«'i (-ocu'U ip 8;
In order to evaluate the mineral resource potential
of the coastal zone, one must first establish what the
mineral resources are. Any naturally occurring
material, whether it be an individual mineral, an
aggregate of minerals combined into unconsolidated
sediments or consolidated rocks, or a natural ma-
terial in the; form of liquid or gas is a mineral re-
source if its physical or chemical characteristics
make it a desirable ingredient in man's technological
society. Since almost all natural materials may be,
usable resources in some form and at some time or
other, whether it be for general land fill, beach re-
plenishment, construction materials, or as a source of
some metal or fuel, all of the materials bounding arid
occurring within the coastal zone become potential
resources.
The extractive industries includ" ai! forms of re-
covery of natural materials from the sediments and
rocks of the earth's crust and from the water column
comprising the oceans and estuaries. More specifi-
cally these Inriu.ie (! , b-takjix? of *>o surface «•;:
in order to extract nar ural materials; (2) aii activities
or processes involved in the extraction of natural
-------
122
ESTTAIUNE POLLUTION CONTROL
materials from their original location; and (3) any
preparation and treatment of these natural materials
in order to make them suitable for use. This broad
array of activities associated \\ith the mineral ex-
traction industries range from the exploration and
mining activities, to the processing and treatment
plants, to the complex transportation systems in-
volving pipelines, channels arid harbors. The poten-
tial conflict with other coastal uses and the potential
impiier, of these activities upon the delicate balances
of the fragile and limited estm'.rine zone have given
binh tti a eiileiuma that is slo\\i\ growing ro prohibi-
tive proportions.
Various geologists have projected that the major
mineral reserves in the United States, which are pres-
ently derived from land, will be exhausted by the
year 2000 (Moore, 1972). If this is the case,' then
where are the future resources to come from? — the
coastal areas and the continental shelves! Since the
shelves are geologically nothing more than sub-
merged portions of the continent, MeKelvey (19(58)
believs thar it is logical to assume that the mineral
potential should be roughly comparable to that
which has already been found on land. Partly for
these1 reasons, Moore (1972) projects a truly large-
st-ale undersea mining industry by 19SO with com-
plete1 dependence upon this source by the year 2000.
The fact that the United States Department of the
Interior Itys recently issued a "Draft Environmental
Impact St.itement" in connection with undersea
mining, as well as a set of proposed regulations for
the actual K using and mining of undersea hard rock
minerals, underscores the anticipation of the in-
creased develop/merit of these presently poorly known
resources.
Hove. v or, the total present world production of
minerals fyom the sediments aid locks comprising
the sea ilooj of the continental margins, excluding
oil and gas is only about $470 million annually or
2 percent of the on-land production of these minerals.
Anothct >il;j million \\orth of minerals arc pres-
ent 1\ e\tr;<;:ted from seuvater making the present
value oi all extractive resources from the marine
environmuit a minor part of the total mineral pro-
duction (liigg, 197.")!. However, to date o.ily a very
small percentage of the coa&ta! and shelf eiu'iron-
rnents have even been explored for anything other
1hnn pors'blv petroleum Tf 'he major thrust for
oil. rt n inei; ! tvsouices is .>u ihu "ontment.-d shelf,
li''.'!: i iic coask.'ii zotie .''ill pisu an t ver increasing
role in th.< extractive industries. This role will in-
clude °ome mining its<-'if, but probably of greater
".ill
lem and processing oiaiits r.ccebsan for the offshore
extractive industries.
At the present time, it is nearly impossible to
describe accurately or completely the location and
size of existing extractive industries in the coastal
zone, to say nothing about the mineral reserves. In
fact, the mineral resource potential of the estuaries
and continental shelves, with few exceptions are at
best only superficially known. The reasons for this
are: (1) the geologic and mining agencies that moni-
tor these industries do not differentiate the extrac-
tive opeiutious that ate related to the r-o, stal zone
troiu am other region: ('.'.< for competitive reasons,
the same agencies generally arc not able <~o relate
production statistics and rarely do they have access
to good reserve information if it is even known; and
(3) detailed geologic investigation, exploration, and
research in the coastal zone is extremely expensive,
technologically difficult, and generally a relatively
•'new1' science.
Kecent inquiries by the author, to the geological
surveys of the coastal states, underscored both the
lack of knowledge of the resources and the meager
effort to monitor any existing mineral extraction
within or adjacent to the estuaries or the offshore
areas. In fact, much of the existing published data,
such as Table IV.2.8 entitled "Major Exploitation of
Coastal Mineral Resources" in the ''National Estu-
arine Pollution Study" (p. 124, 1970). is extremely
misleading. The table states that in 1907 there were
1,479 coastal operations in the United States ex-
ploiting $373,192,000 worth of minerals including 168
metal operations, but excluding all petroleum and
other mineral fuels. These numbers are only correct
if one include^ all of the inland coastal plain areas.
A study of the case histories of specific (stuarme
zones within the same publication, as we!1 as in
"The Economic and Social Importance of Estuaries"
(Environmental Protection Agency, 1971) and the
"National Estnarine, Pollution Study''' (United
States Department of the Interior, 1970, suggest
that mineral extraction is actually nonexistent in
most estuaries and very limited both in commodities
and quantities in the few estuaries wlu;re extraction
is taking place. To adequately know and inventory
the resource potential of the United States coastal
areas \\il nccessitaN a ma^ne and co"rdin,"t"eld de-
tailed stueh of the surface and subsurface ge ohig/--a
mainmot1! undertaking. Oni\ t-io-.v, iso'.'iied. and
individual pn.irns-, is presentiv !»'ing IM~\-\.- n this
direction
Consideration of esluarin;1 a/iCt off-thon alining
must deal with the p"tentia! since the present min-
eral production from below the x ;i is limited to
'ii 1\' ': !e A" C'i %uu<'(hl ies. the niiii< r ''ii • be Mig oe~t''< >-
. >;;.n ll-nvi ;•.:',• j,-< -> nt •• i ,1,,i, ,, '..
-------
LIVING AND XoN-LlVING RESOURCES
123
the current efforts within the rapidly changing off-
shore petroleum exploration and development. Those
include: (in a rapid annual increase in the number
of holes drilled; ('h^ an expansion into deeper waters
further from shore; (o) a complementary increase
in the size and capabilities of the offshore1 drilling
rigs; and (d) an increasing sophistication of under-
water operating facilities and pipeline systems. As
the petroleum industry continues to expand its
exploration and operations into the coastal and
offshore areas, there will be an increase in the dis-
covery arid recovery of associated minerals that can
be recovered by pumping and solution mining;. Such
minerals as sulfur and potash occur in salt domes,
which are major petroleum reservoirs. The sophis-
ticated technology necessary for the exploration and
mining of other types of mineral deposits from the
sea floor will quickly follow.
The United States' economy needs over 4 billion
tons of raw mineral supplies to produce $17r> billion
worth of domestically produced energy and processed
materials of mineral origin annually; the demand
still far exceeds the domestic production of both
raw materials and processed minerals (Morgan,
1974). The Secretary of the Interior issued in mid-
1973 his "Second Annual Report Under the Mining
and Minerals Policy Act of 1970," in which he stated
that the "development of domestic mineral resources
is not keeping pace with domestic demand,''for nine
major reasons (Morgan, 1974):
1. Mineral imports have an unfavorable impact upon
Die "United States' balance of trade and upon the United
States' balance- of payments'
2. Expropriations, confiscations, and forced modifica-
tions of agreements have severely modified the flow to
the United States ot some foreign mineia! materials
produced by United States firms operating abroad, and
have made other material*- more costly;
3. United States industry is encountering greater com-
petition from foreign nations and supranational groups
in developing new foreign mineral supplies and in assur-
ing the long-term flow of minerals to the United St-ites;
4. Development of the United States iransportation
net is not keeping pace with demand, thus seriously
affecting the energy and minerals industries;
5. Removal of billions of tons of minerals annually from
the earth contribute^ to a variety of disturbances,
6. The United States mining, minerals, metal, and
miner-il reclamation industries are encountering increas-
ing difficulty in financing needed expansion ot capacity
and the in! rod net ion of new improved technology,
7 Management of the resources of the public lands,
including the continental shelve?, must be improved;
8. The factual basis for the formulation and implementa-
tion of environment ai legulations must be improved, so
that man and nature are properly protected with
ruinimum dislocation of important economic activities;
and
9. The United States Government information base foi
the conduct of its mineral responsibilities r-- grossly
inadequate.
Morgan also points out that the world economy has
grown faster recently than the United States' econ-
omy has: this has resulted in increased competition
for needed raw materials. Likewise, it is becoming
increasingly dilh'cuit tu sell manufactured articles
in world markets to pay for imported raw matx'riaJs.
Thus, the United States is faced with an ever-in-
creasing need for self sufficiency in mineral resources.
Most extractive industries, whether in, adjacent,
to, or distantly remote from an estuarine svstem
will have some impact upon the pollution of the
coastal zone. Since most of the drainage systems
from the land ultimately end in the estuaries, (tie
drainage network funnels a great variety of con-
taminants into the coastal system. These contam-
inants are derived from a multitude of sources includ-
ing the extractive industries, agriculture, urhan, and
industrial wastes. Consequently, coal becomes part
of the sediment load entering the Potomac River,
dissolved phosphorus enriches (he waters of the
Famlico River in North Carolina, and dissolvtd
metals reach San Francisco Bay from ihe mir.es in
the Sierras.
On the other hand, no two extractive industries
will have similar effects or degrees of impact. For
example, a sand and gravel quarry adjacent to an
estuary can be completely sealed so that no sediment
reaches the estuarine waters, while a mercury mine
many miles from the estuarine zone may contribute
minute but lethal concentrations of dissolved mer-
cury to the bottom muds. Unless the extractive in-
dustry is directly within the estuary, the processing-
plants and allied industries utilizing the recovered
commodity will often have a greater potential or
actual long-term pollution effort upon the estuarine
system than the mechanical or the chemical extrac-
tion in an adjacent land or offshore area will have
The economic value and demand for a given com-
modity is determined by ('d} the specific qualities r.f
that material which in turn determine^ the tech-
nological uses; (b) the availability and concentra-
tion of the material; (e) by the cost of recovering
and processing the commodity; (dj transportation
of the ore for processing as well as the- distance to
markets; and (cj time delays resulting fron1. possible
restraining orders, hearings, and court litigations.
Knowledge of these parameters is essential prior to
the development of any land and water use manage-
ment plans involving th< continued dcvtlopiurnr of
our coastal zone. However, the economies of a given.
mineral resource may change1 draimtieaJh in re-
sponse to new technological advances, discoveries
of new ore deposits, or as industrial and social de-
-------
124
ESTUARINE POLLUTION CONTROL
mands change through time. Such changes can have
drastic effects upon the same management programs
which define land and water uses.
As we begin to go to the sea for more of our mineral
resources to offset dwindling onshore supplies,
spiraling prices, and satisfy the increasing need for
national independence, new pressures will develop.
These new pressures, when combined with the exist-
ing pressures of growing technology and population,
can only have significant increased pollution impact
upon an already environmentally overstressed
coastal system. According to the "National Estu-
arine Pollution Study" (1970, p. 20), the coastal
counties of the United States contain 15 percent of
the land area; however, they carry 33 percent of the
population and 40 percent of all manufacturing
plants in the United States—and they continue to
grow. Thus, man's dilemma continues to grow—the
need to protect a delicately balanced natural system,
upon which man is dependent, and at the same time
dramatically increase its use for materials on which
man also depends.
Before discussing the specific extractive industries
in the estuarine zone, the interrelationship of man
and mineral resources should be put into proper
perspective. This interrelationship is summarized by
T.S. Levering (1969, p. 110):
Whether a particular type and grade of mineral con-
centrate at, a particular location in the earth's crust is
or can become an ore (a deposit that can be worked at
a profit), moreover, depends on a variety of economic
factors, including mining, transportation, and extractive
technology. The total volume of workable mineral
deposits is an insignificant fraction of 1% of the earth's
crust, and each deposit represents some geological
accident in the remote past. Deposits must be mined
where they occur—often far from centers of consumption.
Each deposit also ha.s its limits, if worked long enough it
must sooner or later be exhausted. No second crop will
materialize. Rich mineral deposits are a nation's most
valuable but ephemeral material possession—its quick
assets. Continued extraction of ore, moreover, leads,
eventually, to increasing costs as the material mined
comes from greater and greater depths or as grade
decreases, although improved technology and economics
of scale sometimes allow deposits to be worked, tem-
porarily at decreased costs. Yet industry requires
increasing tonnage and variety of mineral raw materials;
and although many substances now deemed essential
have understudies that can play their parts adequately,
technology has found no satisfactory substitutes for
others.
THE EXTRACTIVE INDUSTRIES
AND THEIR POLLUTION IMPACT
UPON THE COASTAL ZONE
Table 1.—Categories of extractive resources and their development potential
within the coastal zone
Resource
category
Extractive
resources
Resource potential
Surface deposits
Unconsohdated to
partially consolidated
sediment-.- j Total sediments
i Shell gravel:,
I Quartz and lock
, gravels
I Light mineral sands
Heavy mineral sands
Salt
Clay minerals
Phosphate
Peat
Consolidated Rock [ Rock aggregate
Limestone
Subsurface deposits
Pumpable materials
Gas and fluids j Oil
Natural gas
I LPG
Geothermal energy
Soluble solids
Slurry solids,. .
Partially consolidated to
consolidated rocks.-_
Aqueous deposits
Sulfur
Potash
Salt
Phosphate
Gfaucontte
Sand
Phosphate
Fuels (coal, uranium,
etc)
Metals (gold, silver.
copper)
_____
Chlorides
Magnesium
Bromine
Fresh water
Other materials
**
*
*
NP
NP
NP
NP
NP
NP
•'"
**
***
***
*
NP
**# #**
*# *#*
**
*** ***
* *
* *#
** ; **#
** **#
** i #*:£
* . *
##* ***
* *
*** ***
* **
KEY: NP—No known production
*— Minor source or potential
**—Moderate source or potential
***—Major source or potential
deposits (Table 1). Each category of deposit has its
own type of materials and problems associated with
recovery and consequently, will be considered
separately.
Surface Deposits
The extractive industries that occur either within
the estuaries, on the nearshore continental shelf, or
adjacent land areas can be placed into three general
categories: the surface, subsurface, and aqueous
The natural materials occurring within or con-
stituting the surficial deposits of the estuarine zone
are not only extremely varied in composition, but
also in their potential use (Table 2.). In general, the
-------
LIVING AND XON-LIVING RESOURCES
Table 2.—Utilization of surflclal sediment deposits
125
Land fill, construction, beach maintenance
Lime for cement
Agricultural lime
Construction and road foundation aggregate
Beach foundation
Poultry grit
Oyster foundation
High silica sand
Building and paving sand
Feldspar sand
Beach replenishment sand
Titanium (rutile, ilimenite, and leucoxene)
Zirconium (zircon)
Rare earths (monozite, xenotime)
Refractories (kyanite, sillimamte)
Valuable metals (gold, tin, platinum, chromium)
Phosphate
Ceramic industries
brick, tile, earthenware, stoneware, refractories, etc.
Soil improvement, horticulture, etc.
materials in this category are unconsolidated or
poorly consolidated sediment which are capable of
being dredged directly without the problems of
removing overburden sediments or breaking up
consolidated materials. These materials are generally
only renewable over extended periods of time. Under
local high energy conditions, and if there is an ad-
equate source and supply, some sediment deposits
can be rapidly renewed; examples of such deposits
are sands and gravels associated with inlets, near
shore shoals and capes, and river mouths.
For the most part the deposits considered here are
low value commodities (the exceptions being some of
the heavy minerals, Table 2.) that require very
modest, if any, benefaction or preparation prior to
use. Also, because of this low unit value, the com-
modities have limited and often local markets that
are dictated by the very high transportation costs.
Consequently, most operations are very small scale,
low budget, and temporary depending on the highly
variable local markets and economies.
The surface deposits represent the most widely
exploited group of mineral resources within the
coastal waters today, with the major exception of
petroleum. The present and future importance of
these surface resources and the resulting pollution
potential to our estuarine system, will be considered
in more detail. The surficial deposits include the
following commodities: sand and gravel, heavy and
light minerals, shells, cla3', peat, and total sediment
for land fill.
SAXD AND GRAVEL
The rising demand for sand and gravel is reflected
in the total United States consumption which has
accelerated from 500 million tons in 1954 to 980 mil-
lion tons by 1970, with a projection of 1,670 million
tons by 1985 and 2,530 million tons annually by
2000 (Grant, 1973). The rate of consumption of
sand and gravel during 1970 amounted to 5 tons per
capita, which is greater than all other mineral com-
modities except water (McKelvey, 1968). Most of
this sand and gravel conies from the land, even so,
sand and gravel probably represent the most im-
portant commodities recovered from the coastal
zone in terms of both volume and value. However,
since no records are kept of production in the estu-
arine zone, the commonly quoted values are highly
suspect. Nevertheless, the explosive urban and
industrial growth in the coastal areas, which demand
an ever-increasing amount of construction aggregate,
is rapidly depleting the known land supplies in
nearby areas or is burying them in their urban
sprawl. Since most of the cost of these essential low
unit-value commodities is in transportation, a proxi-
mal location to the market is essential. However,
since such large reserves and acreages are necessary,
faced with strong urban zoning restrictions, resource
development near the markets in metropolitan areas
becomes essentially prohibitive. Thus, as transporta-
tion costs rise and as laud supplies dwindle, the ex-
tensive and high quality deposits of submarine sand
-------
126
ESTUAIUNE POLLUTION CONTROL
and gravel occurring in the coastal zone become
increasingly more attractive. England has already
been forced to the sea to supply over 13 percent of
the required aggregate, utilizing 75 ocean-going
dredges representing 32 companies (Hess, 1971).
Manheim (1972) estimated that 400 billion tons
of sand grading 75 percent or more are present in the
upper three meters covering 20,000 square miles of
the continental shelf off the northeast United States
coast. Pings and Paist (1970) have estimated that
sand deposits cover about 50,000 square miles of the
Atlantic shelf and areas about half as large on both
the gulf and Pacific shelves Extensive gravel de-
posits have been outlined north of Barmount Bay
off the New Jersey coast (Schlee, 1968), within
Massachusetts Bay, the Gulf of Maine, and on the
Florida shelf (Rigg, 1974). Pings and Paist (1970)
believe that the offshore sand and gravel industry is
still in its infancy and will grow and develop ex-
tremely rapidly due to the abundance of suitable
deposits in shallow water near markets and the
relative ease with which materials can be recovered,
classified, and transported by barge. This will be
particularly true in the Boston to Norfolk megalop-
olis. Detailed studies are already underway in the
coastal and offshore areas of most other coastal states
to define the potential of these resources with the
U.S. Army Corps of Engineers doing much of this
work through the Coastal Engineering Research
Center.
In addition to the massive needs of aggregate for
the construction industries, another important use
is emerging for the submarine sands and gravels.
During 1973, mil lions of cubic yards of sand were
pumped from Cape Hatteras, N.C., to the nearby
beaches by the National Park Service. This major ef-
fort to replenish 2.2 miles of lost beach with sand
is only temporary since shoreline recession in this
area has averaged 9 meters per year for the past 100
years ( Dolan, et al, 1973). This is becoming an ever
increasing problem around the entire country as the
rate of shoreline development spirals. The Corps
of Engineers estimates that about 7 percent of the
United States shorelines are experiencing critical
coastal erosion while an additional 36 percent are
experiencing slight to moderate erosion (1971).
Where is the sand going to come from if the beaches
are to continue to be replenished, particularly when
the sand has to be of a certain grain size which is in
equilibrium with that particular energy regime? This
resource problem is a little more difficult than locat-
ing construction aggregate.
HEAVY \ND LIGHT MINERALS
Many of the sand resources of the coastal area
contain varying concentrations of heavy and light
minerals that have significant economic value. The
heavy minerals (minerals with high specific grav-
ities) include the titanium and refractory minerals,
zircon, monazite, and the less common minerals
such as gold, tin, platinum, chromium, and diamonds
(Table 2.). These minerals occur concentrated
in placer deposits in drowned river channel deposits,
modern beaches, and old beaches on both the ad-
jacent coastal plain and continental shelf that were
formed during fluctuations in the sea level. These
minerals are commonly mined from similar types of
deposits on the land, but rarely have they been
successfully mined in the offshore zone. In spite, of
the lack of past economic development of these
coastal deposits within the United States, heavy
minerals are extremely popular and have been and
are presently being extensively studied in the marine
sediments in most coastal states. Many of these
studies have been in connection with the heavy
metals program of the. United States Geological
Survey, which was initiated in 1960 to stimulate
domestic production of a small group of critical
metals including gold. Some of these metals, such
as gold, tin, platinum, and chromium, will probably
be dredged from the United States sea floor in the
near future simply because they are in considerably
short supply. The Pacific shelf has known deposits
of gold off California and Oregon, chromium off
Oregon, arid gold, tin, and platinum off the Alaskan
coast.
The light minerals (minerals with average or less
than average specific gravities) include pure quartz
or high silica sand or feldspar-rich sands which can be
used as a source of potash (Table 2.). Both of these
commodities are of considerably less value than the
heavy metals, and are very abundant on land; con-
sequently, the potential of these commodities being
economically extracted from the sands in the marine
environment probably lies sometime in the future
yet.
SHELL
Shell aggregate is commonly dredged from shallow
estuarine waters and adjacent land areas in several
portions of the United States coastal zone. The shell,
mostly from old oyster reefs, is primarily used for
aggregate in road building and concrete, the manu-
facture of Portland cement and lime, and in small
amounts, for miscellaneous markets such as poultry
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LIVING AND NoN-LlVING RESOURCES
127
grit and cultch material for modern oystering.
Generally, the total land resources of calcite (CaC03)
in the United States are presently adequate. How-
ever, in local metropolitan regions, this resource is
often unavailable or lacking^ then transportation
arid land values again become the, controlling factors
and the estuarine shell deposits become an alternate
supply.
The largest production of shell comes from the
gulf coast states including Texas, Louisiana, Missis-
sippi, and Alabama with lesser amounts produced in
Florida and California. Some minor production has
come from the mid-Atlantic states of Virginia,
Maryland, and New Jersey. The State of North
Carolina is presently carrying out a shell survey
within some estuaries. Extensive shallow Pleistocene
oyster reefs and marine shell beds underlie the estu-
aries and the mainland areas adjacent to the estu-
aries in northeastern North Carolina (Riggs and
O'Connor, 1972). Since extensive limestone deposits
outcrop along most of the North Carolina coast, the
muddy shell deposits are only locally mined for land-
fill purposes. Most of the central and south Atlantic
coastal states have a similar geologic setting with
abundant limestone just inland from the coast.
Consequently, the need for and the probability of
developing the estuarine shell resources in these
areas is minimal. The north Atlantic states have only
minor shell deposits due to the occurrence of ex-
tensive glacial sand and gravel deposits throughout
the coastal zone.
In contrast to the Atlantic coastal plain, the Texas
coastal zone has limited limestone, gravel, and
crushed stone reserves to supply the needs for con-
structional aggregate, cement, and the large chemical
industrial complexes. These massive needs are sup-
plied largely by the extensive shell dredging indus-
try in the shallow Trinity, Galveston, and San
Antonio Bays, about 75 percent of current produc-
tion coming from the latter. The shell occurs as
distinct reefs either at the bay bottom, which sup-
port living oysters, or buried at varying depths
within the bay muds. Shell production began in the
late 1800's and continued slowly until the 1950's,
reaching peak levels during the last 15 years (Fisher,
et al, 1973). In 1971, production began to fall off
considerably, due to both rapidly diminishing re-
serves and increasing environmental pressures.
CLAY
Clay is another low unit cost commodity critical to
the construction industries and therefore is related
to the metropolitan markets; thus, transportation
costs and land values are again the critical parame-
ters. Clay is primarily used in the ceramic industries
for building bricks, refractories, tiles, et cetera.
Since clay deposits are extremely common and
widespread on the land there is little need to develop
submarine clays. Nevertheless, clay is a major
sediment type which is being deposited in the modern
estuaries, as well as occurring in the older Pleistocene
sediments. Riggs and O'Connor (1974) have de-
scribed extensive clay wedges in the estuaries of
northeastern North Carolina. The proximity of these
clay deposits to the Norfolk metropolitan area which
is a great distance from the nearest brick factories
has provided some potential economic value to an
otherwise noneconomic sediment. Similar Pleistocene
clay deposits in the Myrtle Beach, S.C., area are
presently being exploited as raw material for brick.
PEAT
Extensive peat deposits commonly occur in the
protected estuarine intertidal salt marshes and
freshwater swamps. These low energy transitional
zones from water to land represent areas of rich
organic growth which produce the thick peat ac-
cumulation of partially decomposed organic matter.
This peat is used in horticulture for soil improve-
ment; however, this market is both local and some-
what limited. Consequently, most peat extractive
industries are very small operations.
TOTAL SEDIMENT
Probably the most common form of extractive
industry in the estuaries is the dredging of sediment
for adjacent land fill and shoreline modification
purposes, in which case the sediment itself has a low
unit value. This whole category seems to be a very
gray zone that nobody claims, acknowledges, or
considers as a legitimate part of the minerals indus-
tries within any of the coastal states. This total
sediment dredging includes everything from landfill
itself to beach replenishment, ditching for mosquito
control, drainage of marshes for agriculture and
logging, stream channelization, harbor development,
and finally, into channel dredging and maintenance.
This extractive industry represents by far the great-
est volume of material extracted directly from the
estuaries. As a result, it probably has a far greater
pollution impact upon the estuaries than all other
forms of mineral extraction.
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128
ESTUARINE POLLUTION CONTROL
POLLUTION EFFECTS
The pollution effects resulting from the extraction
of the surface sediments by mine dredging are no
different than those from conventional channel and
harbor dredging. In fact, the latter probably rep-
resents by far the single most important form of
"estuarine mining" that takes place in our coastal
waters. The subject of channel dredging is being
treated in considerable depth independently within
the study of estuarine pollution. In general, the
pollution effects of the extraction of mineral resources
from the surface sediments within the coastal zone
can be summarized as follows:
1. Since there is often very little processing other
than washing and sizing, surface sediment operations
are less likely to contribute chemical pollution to the
coastal system. Likewise, they generally contribute
minimal amount of dissolved metals and substances
to the coastal waters.
2. Extraction operations of surface sediments on
the land areas adjacent to the estuaries can generally
be carried out in shallow closed systems so that little
deleterious sediment escapes into the coastal waters
and there is minimal impact upon the groundwater
system of the region.
3. On the other hand, the extraction operations
within the estuarine waters can produce vast amounts
of sediment pollution and have a dramatic impact
on the physical-chemical character of the estuaries.
More specifically, these include the following:
a. Large amounts of sediment will be suspended
producing increased water turbidity. This tends
to decrease organic productivity by affecting
light penetration and the resulting photosyn-
thesis. More importantly however, these in-
creased suspended sediments can drastically
change the bottom sediment patterns and the
resulting benthic floral and faunal populations.
In a study by Riggs and O'Connor (1974) in
the nearshore area off Pinellas County, Fla.,
the effects of the high amount of organic rich
suspended sediments derived from landfill dredg-
ing in Boca Ciega Bay had a drastic effect upon
the nearshore environments around John's Pass.
The suspended sediments in the murky estuarine
waters are pulled out of suspension primarily by
"filter-feeding benthic organisms (mostly poly-
chaetes) and excreted as fecal pellets which
then accumulate in extensive ephemeral de-
posits." The resulting pelletal muddy sand
populated by polychaetes is rapidly displacing
the "more desirable" populations including the
beautiful and extensive "sponge gardens" and
associated invertebrate and fish populations
which occur throughout this nearshore area.
b. The removal of materials from the estuarine
bottoms and the disposal of spoils produces
great modifications of the bottom topography.
Such changes have dramatic effects upon the
remainder of the estuarine system which include
circulation and the resulting water chemistry
(salinity, dissolved oxygen, et cetera.) The
deepening of the water and the steepening of
slopes will also increase wave-induced erosion
of the adjacent estuarine shorelines.
c. In addition, these extraction processes pro-
duce temporary disruption of the productive
habitat and oftentimes a permanent change in
the type of habitat. For example, generally a
greater area will have deeper water and steeper
slopes after the dredging than existed prior to
dredging, thereby producing a net loss of the
more productive shallower water environments.
This would result in major changes to the bio-
logical population inhabiting the area as well
as a loss of the shallow breeding grounds.
4. Most extraction operations of the surface sedi-
ments on the continental shelves could probably be
carried out with a smaller immediate and less far-
reaching pollution impact upon the estuaries than
direct estuarine mining itself. However, since there
are so many variables such as geographic location,
character of the sediment, local current system and
energy levels, et cetera, each specific circumstance
must be considered independently. For example, a
recent effort to extract gravels from the shelf in
Massachusetts Bay was temporarily halted because
of the sediment dispersal patterns from the dredge
site (Nelson, 1974).
In summary, the extraction of surficial deposits in
the estuarine zone has extremely variable effects
upon the estuarine system. Exploitation of land
deposits adjacent to the estuaries should be allowed
to fully develop to supply the local needs, however,
only with strong controls for handling and dis-
charging surface waters, effluent control, and recla-
mation. Exploitation of the vast potential resource
wealth in the offshore area should be encouraged,
but again, only with strong controls which allow
each deposit or operation to be evaluated indepen-
dently. On the other hand, extraction of the surface
deposits within the estuary itself should not be
allowed. The resources in the surficial deposits are
usually stimulated by local economic development
and are absorbed into the local urban development
and do not spawn significant new industrial and
-------
LIVING AND NON-LIVING RESOURCES
129
Table 3.—Relationship of type of mineral resource to the general resource value and cost of production within the coastal zone
Value
Resource category
Surface Deposits
Unconsolidated to partially consoli-
dated sediment
Consolidated rock
Subsurface Deposits
Pumpable materials
Gases and fluids
Soluble solids^. ._ _ _ _ _
Unconsolidated sediment
Consolidated sedimentaryand crystal-
Ime rocks
Examples
Sancf, gravel, shelf, etc.
Crushed rock and limestone
Oil, gas, LPG
Sulfur, potash
Phosphate
Phosphate
Coal, iron, oil shales, metals (gold,
silver, copper, etc.)
Mining method
Dredge
Explosives and dredge
Drill hole (pumping)
Drill hole (solution mining)
Dredge (island damming and open
Pit)
Drill hole (slurry mining)
Hard rock underground mining
methods
Present status
Abundant Production
_. „_
No Production (only for channel
dredging, pipelines, etc.)
Very Abundant Production
_ _ _ _ _
Abundant Production
No Production (technology being
developed)
Moderate Production
No Production (technology available
for working from adjacent land
areas or artificial islands)
\
Cost
o »
3 o>
= S
~ 8
O -*
1
economic development. Also, most often these com-
modities can be replaced with other low unit cost
alternative materials, including natural, manmade,
and waste products. The short-term gains of low
unit value materials cannot justify the increased
pollution and modification problems in an already
highly stressed system which plays such an important
role in the productivity of the oceans.
Subsurface Deposits
The extraction of natural materials from the sub-
surface is a much more expensive operation which
requires more sophisticated technology and equip-
ment than the extraction of surficial materials.
Consequently, the types of materials that can be
recovered from the subsurface are the glamor com-
modities which include the fuels, the metals, and the
higher unit cost rum-metallic resources (Table 3.).
The deeper in the ground or the further to sea one
has to go to recover these commodities, the higher
the cost and the more "glamorous" the material has
to be. Also, the technical problems and the cost of
recovery increases dramatically as we move from
the materials that can be pumped to the surface, to
Unconsolidated sediments, to consolidated rock
(Table 3.). These three categories represent a
logical approach to discussing the extraction of
specific materials and their resulting pollution poten-
tial upon the coastal system.
PUMPABLE MATERIALS
Quantitatively, the most important materials in
this category are natural gas, oil, LPG, ground
water, and geothermal energy. Because of the ex-
treme importance and size of the extractive indus-
tries associated with these commodities, they will be
considered separately in another report.
The other natural materials included here are the
soluble solids which include sulfur, salt (NaCl), and
the various potash minerals. All three of these
materials are associated with evaporite deposits and
the resulting salt domes, which are in themselves a
very important reservoir trap for petroleum. Since
salt domes commonly occur in the coastal zone and
on the continental shelves, and because of the rapid
increased exploration and development of offshore
petroleum, the future increased extraction of these
commodities in coastal areas is pretty much assured.
Presently, sulfur is the only soluble solid being
produced from the coastal zone in the United States ;
however, salt and potash are being produced by
solution mining from inland Canada. The presently
known deposits of sulfur occur in the Texas and
Louisiana estuarine zone, with present production
coming from only one offshore area in Louisiana.
The extraction of sulfur is from many wells located
on fixed, above-water platforms. Utilizing the Frasch
method of solution mining, the sulfur is then pumped
through heated pipelines to processing plants on
land.
The pollution problems associated with solution
mining in the coastal zone can be summarized as
follows:
a. The problems of leaks, breaks, and effluent
(hot water, brines, drilling mud, et cetera) associated
with solution mining and pipeline operation;
b. The problems resulting from the operation and
maintenance of the big equipment associated with
drilling, pumping, and transportation;
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ESTUARINE POLLUTION CONTROL
c. The most important problem, particularly with
petroleum, of the allied industries which are estab-
lished in nearby coastal waters.
UNCONSOLIDATED TO PARTIALLY
CONSOLIDATED SEDIMENTS
This category would include any mineral resource
that occurs in the subsurface in soft or unconsolidated
sediments that are diggable. The major resources
that presently fit into this category are phosphate
and possibly coal and oil shale. Coal is mined from
below coastal waters in many places around the
world; however, in the United States the underwater
coal potential does not appear to be very great and
oil shale is probably down the road some. On the
other hand, both the Atlantic and Pacific coastal
waters have vast phosphate reserves which occur
primarily in the subsurface with only small surface
concentrations.
The outer coastal plans, estuaries, and nearshore
shelf areas of North Carolina, South Carolina,
Georgia, Florida, and California have tremendously
large and extensive beds of phosphorite sediments
that occur under from 10 to several hundreds of
feet of overburden sediments. In Beaufort County,
N.C., the Pungo River Formation is presently being
strip-mined directly on the banks of the Pamlico
River estuary. Three million tons of phosphate have
been produced annually for the past eight years
from a 50 foot bed below 90 feet of overburden. The
operating company is presently doubling its plant
capacity while another company has just recently
announced its plans for opening a new mine next
year. The projection for the new mine is to produce
4 to 5 million tons a year by 1977. The operating
company controls 30,000 acres which contain over
2 billion tons of phosphate reserves. Of this, 10,000
acres occur on a state mining lease below the
Pamlico River estuary. In fact, this very rich
phosphate bed underlies not only several large
counties in eastern North Carolina, but hundreds of
square miles of the Pamlico Sound and Neuse and
Pamlico River estuaries. The existing phosphate
mining operation has had a very small direct impact
upon the adjacent estuaries. Hobble, et al (1972)
reported that the addition of phosphorus in the
estuary resulting from the adjacent phosphate mine
was irregular, but small, producing only slightly
higher concentrations than normal. The periods of
high photosynthesis within the estuary are a direct
function of nitrate fluctuations coming from up-
stream and not the phosphorus. There have also
been only very minor effects upon the major fresh
watei aquifer directly beneath the phosphate bed,
due to the need for heavy pumping to dewater the
large open-pit mine.
Similar extensive subsurface deposits of phos-
phorite occur in the coastal areas extending from
Charleston, S.C., to south of Savannah, Ga. An
attempt by a major mining company in 1966 to
mine part of the 7 billion tons of phosphate reserves
occurring under the coastal marshlands and estuaries
of Chatham County, just east of Savannah lead to
a major study by the University of Georgia System
(1968). This report studied the geology and economic
potential of the deposit, as well as the effects of
mining upon the ground-water system. Even though
the report was generally favorable, mining was com-
pletely blocked by the environmental aspects of the
potential oppn-pit dredge mining. Furlow (1972,
p. 226) said that:
. . . public opinion, aroused by conservation groups two
years ago, is still so adamantly opposed to mining
marshland and disrupting ecological chains that I can
foresee no time in the future when marshland mining
will be allowed. These conservation groups have only
to point to phosphate mining areas in Florida as prime
examples of what would happen to the Savannah area.
Drill hole information from the Georgia Depart-
ment of Mines, Mining, and Geology suggests that
the Chatham County deposit extends offshore at
least 10 miles and possibly as much as 20 miles with
small overburdens, high grades, and large tonnages.
Furlow (1972, p. 228) concludes that the:
. . . future of phosphate mining in Georgia lies entirely
in the offshore area rather than in the marshlands.
Offshore dredge mining, while more difficult and ex-
pensive than onshore mining, can be accomplished with
present or presently developing technology. Last, but
certainly not least of mining considerations, conservation
and ecologically-oriented groups would have far less
objection to offshore mining than they would to mining
in the unspoiled marshes of Chatham County.
The California Continental Shelf also has extensive
deposits of phosphate sediments. In fact, these
deposits were planned for development in 1961; the
United States Geological Survey subsequently sold
its first and only hard mineral lease on the con-
tinental shelf in April 1974 (Rigg, 1974). However,
this sale involving six tracts and totalling 30,000
acres, was subsequently cancelled by the United
States Geological Survey when it was learned that
there was a World War II munitions dump on the
lease site.
The exploitation of the unconsolidated sediments
from the subsurface generally represents tremendous
earth moving operations utilizing open-pit strip
mining techniques with massive equipment. Vast
acreages are involved in both recovering the exten-
sive beds of reserves and treating and disposing of
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LIVING AND NON-LIVING RESOUKCES
131
the waste materials. It has been demonstrated in
North Carolina that such operations can safely take
place on the lands adjacent to the estuaries with
only very minimal pollution and direct environmental
impact upon the estuaries. However, .similar mining
operations in central Florida, 120 to 50 miles inland
from the coastal zone, have been extremely damaging
to the estuaries; upon occasion the wall of a slimes
pond will fail, sending millions of tons of mud
downstream.
Similar types of mining operations are technically
feasible within the estuarine waters; the shallow
waters can be filled, or even diked and drained
allowing for either open-pit dry mining or under-
water dredge mining. However, due to the extremely
large land requirements, the vast amounts of earth
movement, and the problems of the resulting waste
materials, there is a tremendous permanent modifi-
cation of the estuarine environment and system.
Also, a great potential exists for massive estuarine
damage resulting from broken dikes during major
storms and storm tides.
Offshore mining of these deep phosphate reserves
is technologically and economically questionable at
the present time. The two greatest factors are
probably the high energy levels of the Atlantic and
the economic factors of ore dilution with dredge
mining. With respect to the potential effect upon the
adjacent estuarine systems, each situation \vould
have to be individually evaluated as with offshore
surface mining.
The technology which would allow surface mining
of phosphates utilizing a subsurface pumping method
is actively being tested on the deep phosphate
deposits in Xorth Carolina. If this pumping proce-
dure can be adequately developed, it could provide
a satisfactory alternative to open-pit mining for
recovering the vast estuarine and offshore phosphate
deposits with minimal estuarine damage.
CONSOLIDATED KOCK
Because of the high cost of hardrock mining in
the subsurface, the only potential mineral resources
that can be economically considered in this category
are the glamor metals (gold, silver, copper, lead,
zinc, et cetera) and the fuels such as coal and
radioactive minerals. Extensions of underground
mines from adjacent land areas have been producing
about ,30 million tons of coal per year from under
the sea in eight different countries for a long time
(McKelvey, 1974). The fact that there are at
present no such undersea mines in the United States
does not indicate the potential. Since the continental
shelves are merely the submerged portion of the
continents, they can be expected to contain similar
mineral resources as the continents. For example,
a copper and zinc deposit below the tide flats of
Penobscot Bay in Maine was originally mined from
three underground shafts (Smith, 1972). More
recently, a 90-acre salt marsh was dammed and
drained for a short-lived open-pit operation. The
environmental pollution problems included salt
water encroachment into the fresh water aquifer,
silting and water turbidity, and heavy metal con-
tamination in the estuary.
Technology presently exists for mining below the
estuary from shafts on the mainland or from man-
made islands within the estuary. The technology
already exists for using a lock tube seated in a shaft
cored by a big-hole drill supplying vertical hole
entry with an open air underground mine. This
would allow for the use of the same mining tech-
niques as used on land (McKelvey. 190S). To date,
this technology has not been put into operation in
the nearshore ocean environments. This, however, is
not too far in the future. Moore (1972) believes that
the technology will exist and the need will be great
enough to support large-scale mining of noble and
base metals from the shelf by 19SO with almost total
dependence upon this source by the year 2000.
A pretty firm basis has already been well established
for such a prediction—the present transition of the
major petroleum reserves to the coastal arid offshore
shelf environments. Another important factor that
is involved here is that at present only a very small
percentage of the coastal and inshore shelf has been
explored for anything other than petroleum.
The potential impact upon the estuaries of sub-
surface hard rock mining on land i.s extremely
variable and is only partially dependent upon its
proximity to the estuary. Regardless of its location,
resulting heavy metal contamination of the estuarine
waters and bottom muds is common. On the other
hand, those operations which are in close proximity
to the estuarine system could also have a more
direct impact upon both the ground water and
estuarine waters.
POLLUTION EFFECTS
The potential pollution impact resulting from sub-
surface mining within the estuary and nearshore
environments is probably not as great as surface
mining in the same areas would be. This type of
extractive operation would cover smaller areas, move
smaller volumes of material, and would not be
directly connected with the water column, which
means that it generally would be :i cleaner operation.
The major impact would be associated with the
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ESTUARINE POLLUTION CONTROL
barge transportation of the ore and the necessary
processing plants located on the nearby coastal area.
The potential chemical and sediment pollution
resulting from hardrock-metal benefication plants
and smelters is generally very great.
Aqueous Deposits
Most of the elements known on the earth's surface
can be found in seawater. These various chemical
constituents comprise an impressive Hi.") million tons
of dissolved solids per cubic mile of sea water in
the world's oceans. This amounts to a total mineral
reserve of oO X 1015 tons for the 330 million cubic
miles of sea water, thus forming the largest con-
tinuous ore body available to man (Shigley, 1968).
However, the concentration of most of the elements
is so low that only very few are presently and
probably will be economically exploitable in the near
future. Four groups of commodities are presently
being extracted, or recently have been extracted,
from sea water in the United States; these include
the chlorides (including common salt), the mag-
nesium compounds and magnesium metal, bromine,
and water. In addition to these, the ocean waters
may some day yield the most important source of
energy for the long-term solution to the ever-
increasing energy needs—deuterium. Deuterium is
a heavy isotope of hydrogen useable in the process
of fusion; the ocean waters contain 25 trillion tons
of deuterium (McKelvey, 1974)—so much that
only 1 percent would supply about ;100,000 times
the world's initial supply of fossil fuels; the total
could supply the world's energy needs for 120 million
years at 40 times the 1968 level, (Holdren and
Herrera, 1971.) It also appears that deuterium can
be extracted from sea water without any ill effects
upon the water and biological system.
Technological processes have been developed for
recovering all of the major elements and many of
the minor elements dissolved in sea water. However,
only four groups of materials arc presently being
economically extracted on a large scale. A brief
discussion of each of these groups follows.
SODIUM AND CALCIUM CHLORIDES
These two commodities are presently being pro-
duced by solar evaporation behind extensive diked
flats in the estuaries of San Francisco Bay, Calif.
Recently, salt was also produced in similar evapora-
tion flats in Newport and San Diego Bays, Calif.
However, due to the extensive acreages of estuarine
flats necessary for this operation and the extreme
urban pressure for development, the latter two have
closed. It is not likely that future fields will be opened
since salt is readily available from brines, rock-salt
mines, and as byproducts of potash mining. The
environmental pollution resulting from the salt
operations is very poorly known and is generally
thought to be minimal. This is pointed out by the
recent establishment of a National Wildlife Refuge
in San Francisco Bay which includes 12, 243 acres
of salt company lands, most of which is used for
salt production. The company has been assured,
however, that continued salt production is con-
sidered compatible with the Refuge (Davis and
Evans, 1973). However, the diking of the estuarine
flats, along with the resulting bitterns from the salt
operations, definitely does modify the geometry,
chemistry, and the biota of the coastal environment.
MAGNESIUM COMPOUNDS AND METAL
Many of the various compounds of magnesium
produced in the United States are derived from sea
water in eight coastal plants operating in six states
(Table 4.). The remainder of the magnesium is
produced from well brines and magnesium minerals.
The process involves adding the sea water to lime
solutions, forming a magnesium hydroxide precipi-
tate. The lime is generally derived from oyster shells
which an; dredged from the estuaries. Magnesium
metal is also produced from sea water at the Dow
Chemical Company plant in Freeport, Tex. In 1972,
they produced 120,000 short tons of metal utilizing
chemical and electrochemical processes. The produc-
tion of the magnesium compounds itself produces
very minor estuarine pollution; however, since the
production of the metal is a chemical process, it has
a greater potential chemical impact upon the estu-
arine system.
Table 4.—Domestic producers of magnesium compounds from sea water in 1972
(from Minerals Yearbook for 1972, United States Department of the Interior,
Bureau of Mines, v. 1, p. 748)
Company
Location
Basic Magnesia, Inc [ Port St. Joe, Fla.
Barcrott Company [ Lewes, Dela.
Chorchem, Inc.- | Pascagoula, Miss.
Dow Chemical Company j Freeport, Texas
FMC Corp ] Chula Vista, Calif.
Kiser Aluminum & Chem. Corp I Moss Landing, Calif.
Merck & Company, Inc j S. San Francisco, Calif.
Northwest Magnesite Company Cape May, N. J.
Capacity
(short tons
MgO equiv.)
100,000
5,000
40,000
250,000
5,000
150,000
5,000
100,000
655,000
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LIVING AND NON-LIVING RESOURCES
133
BROMINE
This element was economically produced from
seawater in combination with other extraction proc-
esses. For example, in 1967 the Dow Chemical plant
in Freeport, Tex., produced large amounts of bromine
as a byproduct of magnesium extraction. Also, the
solar salt pans at Newark, Calif., produced bromine
as a byproduct of the evaporite bitterns. These
extraction operations required chemical plants lo-
cated directly at the water's edge and, therefore,
produced minor amounts of chemical pollution. How-
ever, by 1971, all of the bromine produced in the
United States was from well brines in Arkansas and
Michigan and lake brines in California (United
States Department of the Interior, 1973).
WATER
The desalinization of seawater to produce usable
fresh water is an old idea that is becoming increas-
ingly important in the world today and locally it is
even becoming an economic extractive industry. In
1966, there were 153 seawater desalinization plants
in the world with daily capacities greater than
24,000 gallon per day (Shigley, 1968). He believes
that: . . . "the rate of growth of desalinization has
been about 30 percent per year for the past 10 years;
it is now predicted that the installed capacity will
be about one billion gallons per day by 1978."
Since 1958, when the United States Office of
Saline Waters authorized the construction of five
pilot plants to test different desalinization processes,
three coastal based plants have been desalinizing
seawater. These plants are located at Wrightsville
Beach, N.C., Freeport, Tex., and San Diego, Calif.
Today the costs of water production in these specific
plants averages between 75 cents to $1 per 1,000
gallons as compared to the average freshwater costs
of 30 to 35 cents per 1,000 gallons for industrial and
municipal use and about 5 cents per 1,000 gallons
for agricultural uses (Cargo and Mallory, 1974).
Since the effluents of desalinization are more valuable
as a source of minerals than the average seawater,
the development of the necessary technology could
play an important role in changing the economics
of the entire extractive industries from ocean water,
including fresh water. Indeed, due to increasing
demands for limited ground water plus the rapidly
increasing pollution of our water resources, these
plants will become more important and abundant
in the near future.
Several critical areas in the United States where
desalinization could become economic very soon are
portions of South Florida, the Outer Banks of North
Carolina, South Texas, and Southern California. Con-
sequently, the estuarine impact of this extractive
process will only increase with time in the United
States. The impact resulting from the effluents
derived from desalinization is local and relatively
small as compared to other extractive industries.
The effluents are about equal in volume to the
amount of fresh water produced, and they have
about twice the concentration of the original sea-
water (Shigley, 1968). Of far greater impact is the
associated urban, industrial, and agricultural devel-
opment that would follow, particularly in the areas
that presently are deficient in fresh water resources.
POLLUTION EFFECTS
The environmental impact of those industries
extracting from aqueous deposits upon the associated
estuarine systems appears to be less than some of
the other extractive industries. Since these are land
based operations, the physical intrusion is limited to
the adjacent shoreline area. However, all of the
extractive industries described in this section produce
brines with increased heavy metal contents, often
heat, and in some cases chemical effluent. Discharge
of these effluents, unless properly monitored and
controlled, could produce significant local estuarine
pollution. Probably the greatest impact that this
group of extractive industries has upon the estuarine
system is indirect, resulting from the stimulation of
and interdependence upon numerous other indus-
trial, commercial, and residential activities. Shigley
(1968), pointed out that the combination of raw
materials and location at Freeport, Tex., has stimu-
lated the development of a large chemical manu-
facturing complex, of which seawater processing
activities are only a part. Because the seawater
processing activities share raw material overhead,
and research with over a 100 other products in such
an industrial confine, what would otherwise be either
a marginal or uneconomic operation, can become
economic and viable.
CONCLUSIONS
The relationship between mineral resource utiliza-
tion and the coastal system is presently and will
continue to produce an ever-increasing dilemma with
respect to estuarine pollution. This basic dilemma
can be summarized with the following conclusions:
1. Our growing technological society is totally
dependent upon a myriad of basic mineral resources
which are the raw materials for the technical machine.
The value of, and demand for any of these basic
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134
ESTUARINE POLLUTION CONTROL
resources is dictated by the industrial technology
and economic considerations at any given time, both
of which are highly changeable and volatile controls,
2. Extraction of minerals has to take place where
the minerals occur; the location of resources cannot
be legislated or decreed. Since the coastal zone does
contain a myriad of potential resource commodities
necessary for our technological society and since
these commodities do have an economic value,
society demands exploitation.
3. Even though there is considerable mineral
resource potential within the coastal zone, there is
a dramatic lack of information pertaining to the
occurrence, distribution, and concentration of spe-
cific materials. This is absolutely essential informa-
tion which is prerequisite to any form of coastal zone
management.
4. The potential environmental and pollution
problems associated with resource extraction, prep-
aration, and transportation, which are prerequisite
to their use, are often exceedingly great. The
processes of extraction of these resources are often
messy operations that are capable of physically,
chemically, and biologically disrupting and/or modi-
fying the fragile coastal and estuarine system. The
resulting effects may be either direct or indirect,
local or broad scale, temporary or permanent, and
of varying degrees of severity, all depending upon
the commodity itself and the methods of extraction
and processing. In addition, a myriad of satellite
industries develop in the coastal zone in response to
a given extractive industry; often these industries
have a greater potential cumulative impact upon
estuarine pollution than the extractive industry
itself. Some extractive and satellite industries are
not compatible with other legitimate uses of the
estuarine system.
5. Some resource materials have alternate sources
from which the necessary raw materials can be
supplied and many have substitute materials that
can be made available or developed. This is par-
ticularly true of the low unit cost aggregate materials.
Other materials, however, do not have alternate
sources or substitutes. Consequently, attitudes to-
wards and necessity for the recovery of the mineral
resources within the estuaries and offshore areas
vary between the two opposite1 extremes of complete
abstinence to complete development.
6. The estuarine system of the United States
occupies a very narrow transitional zone between the
land area and the continental shelf; the total extent
of this system represents an extremely small but
manifestly important percentage of the United
States. The estuaries, for the most part, are the
terminal mixing basins of the freshwater drainage
systems with the ocean's waters. Therefore, they
receive the cumulative residue, waste, pollution and
sediment resulting from all man's and nature's
activities within each drainage system, subsequently
funneled into the estuaries.
7. Socially, industrially, and demographically, the
United States has evolved, in a manner that appears
to be continuing, with disproportionate concentra-
tions within the coastal zones. This continual en-
croachment and the mounting intensity of develop-
ment and use of the estuarine zone has produced a
highly stressed system which is resulting in major
and potentially devastating changes within this
fragile and important transitional area.
If one can accept these statements as valid, then
there is no alternative but to establish a moratorium
on all estuarine activities that will continue to add
stress to an environment that represents such a vital
part of the earth system and which presently sits in
a very precarious balance. The extractive industries,
to a large extent, fall into this situation. Develop-
ment of the mineral resources on the adjacent lands
and the offshore continental shelf areas should be
encouraged with the proper setback lines from the
shore, environmental controls, and a viable monitor-
ing system. However, the question of mineral extrac-
tion from within the estuaries themselves should be
seriously reevaluated. The age old question of which
is the most valuable to man, provokes the honored
response—the old "trade-off" game. But as man's
needs grow, the "trade-offs" grow and pretty soon
we're "trading off the trade-off." Man can no longer
afford this sort of approach to the continued develop-
ment of some small part of the system which in its
totality is a critical resource that has well denned
limits. The need is to start evaluating the natural
systems, upon which man is so dependent, from a
long-term basis of interdependence and not the
immediate1 short-term dollar value. Multiple use and
estuarine management are fine concepts that satisfy
quarreling factions, but all too often they amount
to little more than a sophisticated land grab—like
the old miners staking their claims. One must
approach the continued use and development of the
estuaries as a single complex interacting ecosystem
which has finite limits—these limits must be defined
now.
RECOMMENDATIONS
In order to meet the objective of the, overall study
considering the status of pollution in the nation's
estuarine zone with respect to the mineral extraction
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LIVING AND NON-LIVING RESOURCES
135
processes, I propose the following recommendations:
i. Establish a moratorium on any further develop-
ment of the extractive industries within the estuaries
until the proper background resource information
can be obtained to set up a viable management
program. After a national resource priority base has
been developed, establish stringent sets of procedures
that define what resources can be extracted from the
estuarine system, where, and by what methods.
2. An extensive and exhaustive study should be
initiated by Congress and placed under the direction
of the U.S. Geological Survey, to map the geology
and inventory the mineral resource potential of the
United States coastal zone in a similar fashion to
the extensive U.S. Geological Survey-Woods Hole
Atlantic Continental Shelf study or the U.S. Geo-
logical Survey heavy metals study. Such environ-
mental and geologic mapping is an absolutely essen-
tial first step for any resource management program
which will consider the multiple use by conflicting
interests. One cannot plan the destiny of a system
without an intimate knowledge of the composition
and processes operating within the system. Use
evaluations and trade-offs cannot be made until the
total resource potential is known.
3. A mechanism should be set up within the
geological surveys in the coastal states under the
direction of the U.S. Bureau of Alines to monitor the
extractive industries within the coastal zone of their
state. This monitoring system should include: (a)
the volume and values of annual production and the
reserve situation of each specific mineral commodity;
(b) the extraction methods and disruptive effects
of each specific mining operation upon the estuarine
system; and (c) the processing and transportation
methods of each mining operation and its actual and
potential disruptive impact upon the estuarine
system.
4. Establish rigid stress limits to stabilize the
disproportionate growth and development of the
estuarine systems throughout the United States. This
should include delineation of the type as well as the
amount of growth and development.
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oceans—Part I: Mineral Industries Bull., Colorado School
of Mines, Golden, Co., v. 13, no. 2, p. 1-18.
Rigg, J. B. 1974. Minerals from the sea: Ocean Industry, v. 9,
no. 4, p. 213-219.
Riggs, S. R., and M. P. O'Connor. 1974. Relict sediment
deposits in a major transgressive coastal system: East
Carolina Univ., Greenville, N.C., Sea Grant Pub., UNC-
SG-74-04.
Schlee, J. 1968. Sand and gravel on the continental shelf off
the northeastern United States: U.S. Geol. Survey Circ. 602.
Shigley, C. M. 1968. Seawater as raw material: Ocean In-
dustry, v. 3, no. 11, p. 43-46.
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136
ESTUARINE POLLUTION CONTROL
Smith, P. A. 1972. Underwater mining—insight into current
United States thinking: University of Wisconsin, Madison,
Wise., Sea Grant Pub. no. WIS-SG-72-330.
U.S. Army Corps of Engineers. 1971. National shoreline
study including the report on the national shoreline study,
nine regional inventory reports, shore protection guidelines,
and shore management guidelines: Washington,-&C., U.S.
Government Printing Office.
U.S. Dept. of the Interior. 1973. Minerals yearbook for 1972:
Bureau of Mines, v. 1.
1970a. The national estuarine pollution study: U.S.
Senate Document no. 91-58, 91st Congress, 2nd Session,
Washington, B.C.
1970b. National estuarine study: Fish and Wildlife
Serv., U.S. Government Printing Office, Washington, D.C.,
7v.
University System of Georgia. 1968. A report on proposed
leasing of state owned lands for phosphate mining in
Chatham County, Georgia: Advisory Committee on
Mineral Leasing, Athens, Ga.
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FISHERIES
-------
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STATUS OF
ESTUARINE ECOSYSTEMS
IN RELATION TO
SPORTFISH RESOURCES
JOHN CLARK
Conservation Foundation
Washington, D.C.
ABSTRACT
In< rea.sing numbers of anglers—ten million at this time—fish along the coastal shores, an estimated
57 percent of them in the estuaries. Factors affecting the ecosystem are discussed. Recommenda-
tions are made to meet management needs, on the federal, state, and local levels.
INTRODUCTION
Ten million American anglers fish in coastal wa-
ters ; they catch nearly one and a half billion pounds
of fish each year. This massive recreational activity
is supported by fish resources that are dependent
on the continued health of estuarine and coastal
ecosystems.
The number of people fishing in coastal areas has
increased 50 percent since 1960, while the average
yearly catch per angler has declined somewhat. The
causes for the decline in catch—an indicator of fish
population size—have not been determined with ac-
ceptable scientific validity and because of the envi-
ronmental complexities of coastal ecosystems they
may never be. In the following account we have had
to work with skimpy circumstantial evidence to
explore the causes and effects.
All in all, marine fish resources appear to be in
surprisingly good shape. Atlantic stocks are improv-
ing after a period of general depletion during the
1960's. This may in part reflect the results of the
recent national effort to clean up our waters and
protect the environment. Further gains will depend
upon how well fish harvest management and eco-
system protection can be combined into effective
federal, state and local programs and how well
societal goals for use of the resources can be defined
and implemented.
THE COASTAL SPORT FISHERY
The ten million coastal anglers spread their efforts
rather ovenly along the U.S. shoreline, as shown for
1970 in Table 1, the latest year of record (from the
National Marine Fisheries Service).1 While there is
reason to believe that the catches may be somewhat
over-estimated by the inherent biases in the angler
interview-recall system used, they can be assumed
to give a reliable indication of the distribution of
catches.
Anglers fish in both estuaries (tidal rivers, bays,
lagoons, sounds) and oceans (surf and offshore wa-
ters) , with 57 percent of the fish taken in estuaries.
They spend about $100 each on fishing gear and
other expenses per year.2
Coastal angling is a widespread attraction. Half
the anglers have family incomes of less than $10,000
(1970 data) .2 Twenty-two percent are women. Most
come from rural areas, towns, and suburbs rather
than from large cities.
National surveys in 1960, 1965, and 1970, show
that coastal fishing has increased by 50 percent in
the span of one decade.1'2 As the number of anglers
increased from 6.2 to 9.4 million, the yearly average
catch dropped from 102 fish to 87 fish per year per
angler. This reduction is most likely a consequence
of reduced carrying capacity of fishing waters, a
possible natural reduction of fish stocks, or more
fishing pressure on the stocks than can be accommo-
dated at the same high catch rate.
The national sport-fishing surveys are not ade-
quate to provide a statistical basis for examining
trends in abundance because they are done so in-
frequently (5-year intervals) and because they con-
tain inherent biases typical of poll (interview-recall)
systems of data collection. A somewhat more sensi-
tive indicator of abundance trends is the commercial
catch which is recorded by the National Marine
Fisheries Service through collection and tabulation
of dealers' records. Example trends shown by com-
mercial catch records are depicted in Table 2 for
139
-------
140
ESTUARINE POLLUTION CONTROL
Table 1.—Estimated number of anglers and catch for 19701
Region
North Atlantic
Middle Atlantic.- _.|
South Atlantic
South Pacific
North Pacific „ ^
Number of
anglers
1,700,000
1,800,000
1,800,000
1,500,000
900,000
900,000
1,300,000
Catch (millions of fish)
Ocean
35.3
69.5
112.2
42.4
47.2
34.7
8.3
Estuary
81.7
98.7
72.0
146.6
50.5
2.5
15.8
Table 3.—The estimated total U.S. angler catch of certain estuarine dependent
species groups for Atlantic and Gulf States combined.' Catch in millions of fish
four of the major Atlantic and Gulf of Mexico sport
fish species.
The pattern is different for the various species,
reflecting differences in biological, environmental
and economic factors that affect their populations
and their fisheries. Common to all, however, is a low
point in catch in the late 60's, centering in 1967,
followed by an upward swing into the 1970's, a
trend not discernible in the 5-year national surveys
of sport fishing catches (Table 3).
It is quite possible that the upswing of the latter
60's is partially due to a general lessening of pollu-
tion impacts and an improvement in water quality
in coastal areas. For example, Edwin Joseph sug-
gests that the increase in sea trouts may have been
caused by decreasing agricultural use of DDT.3
After World War II, DDT use rapidly increased in
shorelands draining into estuaries where the spawn-
ing and nursery areas of the sea trouts are located.
Lethal doses of DDT lodge in the yolk oil of many
species causing death to embryos. Then after the
middle 60's DDT use began to drop off. As it did,
Table 2.—The total commercial catches of certainestuarine dependent species
groups for the Atlantic and Gulf States combined. (Source: National Marine
Fisheries Service; 1972 statistics are preliminary)
Year
1955
1955. ..
1957
1958 ..
1959
1960
1961
1962_ ..
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
Millions of Pounds
Bluefish
4.2
4.1
4.8
3.3
3.8
3.5
3.7
5.9
5.9
4.6
5.0
5.5
4.3
5.4
6.0
7.2
5.6
6.3
Croaker
47.3
56.8
19.0
24.7
11.9
6.9
5.2
3.3
2.7
2.*
3.5
3.4
2.5
4.7
6.7
8.4
10.6
16.6
Flounder
63.4
65.1
69.3
77.3
75.0
79.4
85.5
104.5
125.5
129.0
133.7
127.7
112.5
114.0
115.0
123.0
125.0
128.0
Sea trouts
16.4
15.5
14.1
12.8
10.6
9.9
10.2
10.0
9.3
10.1
11.9
10,7
9.5
12.0
11.4
14.9
18.7
21.0
Year
1960
1965
1970 .
Bluefish
23 8
31 0
36 0
Croaker
46 0
51 0
66.0
1 ~ T
Flounder |
50 6
54.6
57.4 :
Sea trouts
83.8
89.4
107.0
breeding likely was restored to normal. Reduction
of other chemical and industrial pollution is un-
doubtedly a factor in recent fisheries improvement.
Although these improvements are encouraging,
many threats remain; vigilance is necessary, and a
much higher potential is realizable. This potential
is particular^" high for reducing damage from effects
such as urban drainage and physical destruction of
estuarine systems, effects that do not originate with
point source pollution (pipe discharges). To correct
these, there usually must be control of land uses in
the watersheds and along estuarme shores coupled,
of course, with the control of point discharges. Such.
combined land and water ecosystem management
programs are necessary to maintain the vitality of
estuarine fish populations.4
THE ESTUARINE ECOSYSTEM
An estuary is a constricted coastal water body
that connects to the sea and has a measurable quan-
tity of salt in its waters. For management purposes,
the following rule of thumb, which is based upon
the degree of confinement, may be used to distinguish
between estuarine and open coastal areas: An estu-
ary is a waterbody that has a basin circumference
in excess of three times the width of its outlet to
the sea.4
The exceptional natural value of the estuarine eco-
system comes from a beneficial combination of phys-
ical properties that separately or in combination
perform such functions as those listed below4:
1. Confinement: Provides shelter which protects
the estuary from wave action, which allows plants
to root, clams to set, and fragile small animals to
exist; and permits retention and concentration of
suspended life and nutrients.
2. Shattowness: Allows light to penetrate to plants
on the bottom; fosters growth of marsh plants and
tideflat biota; encourages water mixing; arid dis-
courages large oceanic predators which avoid shallow
waters.
3. Salinity: Freshwater dilution deters ocean pred-
ators and encourages estuarine forms; precipitates
sediments; and provides buoyancy and physiologi-
cally beneficial salt concentrations. Freshwater flow
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FISHERIES
141
over saltier, bottom water typically induces benefi-
cial stratified flow.
4. Circulation: Tidal and wind forces plus strati-
fied flow set up a beneficial system of transport for
suspended life, enhance flushing, and retain orga-
nisms in favorable habitats.
5. Tide: Tidal energy is a major driving force of
circulation; tidal flow transports nutrients and sus-
pended life, dilutes and flushes wastes; tidal rhythm
acts as a regulator of feeding, breeding, and other
functions.
6. Nutrient storage: Trapping mechanisms store
large amounts of nutrient within estuary; marsh and
grass beds store nutrients for slow release as detritus;
richness induces high accumulation of available nu-
trients in animal tissue.
About two thirds of the Atlantic and Gulf of
Mexico species of coastal sport fish depend upon
the special life giving properties of the estuaries for
sanctuaries, or nursery areas for their young. Fewer
Pacific than Atlantic species are critically dependent
upon estuaries.4
The estuarine dependent species include those
that spawn in the ocean, along the beaches, in the
inlets, within estuaries, and up the tidal rivers. The
young of all these converge in the estuaries for food,
refuge, and suitable water. Most estuarine depend-
ent fishes are ocean or coastal migrants who spend
only part of their lives in the shallow estuaries. But
this one period may be the most crucial part of the
survival of the species. Three major categories of
estuarine dependency are shown below with exam-
ples for each species:5
Adults found
mostly in the
estuaries, some
only seasonally.
Flounder (winter
flounder)
Spotted trout
Tarpon
Croaker
(hardhead)
Snook
(lafayette)
"White perch
Adults found
partially in the
estuaries, some
only seasonally.
*Stnped bass
(rockfish)
Fluke (summer
flounder)
Porgy (soup)
Red drum (redfish
or channel bass)
Black drum
Mullet
Adults found
mostly along the
open coast.
Bluefish
Tautog
(blackfish)
King whiting
(kingfish)
*Alewife (river
herring)
*Shad
Atlantic mackerel
Menhaden (bunker,
pogy)
*Anadromous species: Living as adults in salt or brackish water but
spawning m fresh or nearly fresh water.
Estuaries and their adjacent shorelands are easily-
accessible for urban or industrial development. Use
pressures are heavy in urban areas adjacent to
estuaries and the pollution potential is high. The con-
finement and shallowness of estuarine water basins
allow pollutants to pervade their waters, particu-
larly those that have poor flushing characteristics.
There is irony in all this. The most urbanized
estuaries which often suffer the highest environmen-
tal stress are at the same time potentially subject to
the highest sport fishing demand because of the
human populations concentrated there. Therefore,
the very water bodies that should carry the greatest
sport fish resources may actually carry the least.
Because of the variety of man-caused disturbances
that affect estuarine waters and because of year to
year natural changes in the environment that affect
species, it is nearly impossible to establish any
scientifically valid correlation between the type of
pollutant, or other disturbance, and the status of
any fish population. There does not exist in the sci-
entific literature one scientifically convincing cause
and effect relation between a single disturbance and
a single effect. Therefore, one must look broadly at
complete ecosystems in all their complexity and try
to judge the multiple effects of multiple disturb-
ances upon carrying capacity limiting factors.
CARRYING CAPACITY LIMITING FACTORS
The potential fish yield of any estuarine water
body is governed by its carrying capacity for the
species it supports. Carrying capacity in the strict
scientific sense is the number of a particular species
that can be supported per acre, or other measure of
size. However, we use it here in a more general sense
as the amount of life that a habitat can support.
Exactly what makes good fishing waters has al-
ways been a bit of a mystery. However, science has
unraveled enough of the mystery to understand
what environmental disturbances degrade good fish-
ing waters and generally how they do it. Each type
of disturbance reduces carrying capacit}r in a spe-
cific way and a combination of them causes a
combination of carrying capacity reductions.
The National Pollutant Discharge Elimination
System (NPDES) and related provisions of the
1972 Water Act should provide adequate control
of disturbances arising from point sources of pollu-
tion (pipe discharges) including industrial and mu-
nicipal wastes by the mid-1980's. This alone should
considerably improve the carrying capacity of estu-
aries for fish. But controlling point sources is only
part and perhaps the easiest part of the much larger
job of restoring the carrying capacity of the nation's
estuaries. Controlling non-point pollution may pre-
sent a far greater challenge. For example, a primary
source of non-point pollution discharge to estuaries
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142
ESTUAKINB POLLUTION CONTROL
is urban runoff—water from city streets, industry
sites, parking lots, and other developed areas—
which often carries massive loads of pollutants into
estuaries. The following amounts might be expected
from a typical city of 100,000 population following
a one-hour storm (in Ib./hr.) :6
Street Raw Secondary
surface sanitary plant
runoff sewage effluent
Suspended solids 500,000 1,300 130
BOD6 5,600 1,100 110
COD 13,000 1,200 120
Nitrogen (Kjeldahl) 800 210 20
Phosphates 440 50 25
Erosion from disturbed land surface often pro-
duces massive amounts of sediment that may be
transported to estuaries, as shown by the following
estimates -7
Activity
Sediment Produced
(tons/sq.mi./yr.)
Construction 48,000
Cropland 4,800
Grassland 240
Forest 24
Disturbed Forest (not clear-cut) 24,000
Active Surface Mines 24,000
Abandoned Mines 2,400
This erosion may also bring excessive nutrients,
toxic matter, and bacteria down to the estuaries to
reduce carrying capacity for sport fish populations.
In the following sections we first describe each
major natural factor that limits the total carrying
capacity of an cstuarine fish habitat. Second, we
discuss the point and non-point pollutional disturb-
ances that lower carrying capacity. And third, we
relate the disturbances to specific human activities.
Oxygen
Of the various gases that are found dissolved in
coastal waters, oxygen is of the most obvious impor-
tance to fish and other animal life. They need ample
oxygen to survive and even more to grow and func-
tion well—the federal water standa.rd is a minimum
of 4.0 ppm (parts of oxygen per each million of
water).
When sewage and other wastes with high BOD
(biochemical oxygen demand) pollute coastal waters,
bacteria multiply to enormous abundance and de-
plete the water of oxygen faster than it can be
replaced by either plants or the atmosphere. Fish
may be killed by a sudden oxygen drop but more
often the problem is a persistent and pervasive lack
of oxygen which reduces carrying capacity and re-
pulses fish. For example, low oxygen from industrial
and municipal wastes has eliminated striped bass
spawning in the Delaware River and oxygen deple-
tion from papermill waste disrupted salmon runs in
Bcllingham Bay, Wash. Oxygen levels are depressed
to low levels in Florida canals built for seaside
housing developments where fine sediments accumu-
late and water becomes stagnant—a half pound of
organic wastes per day (.e.g., grass clippings) is
enough to contaminate a 100-foot length of canal,
reducing oxygen from an acceptable 4.5 to an un-
acceptable 3.8 ppm.9 In August 1971, all bottom
fish deserted the western part of Long Island Sound
around Glen Cove because of oxygen depletion
caused by pollution.10
Temperature
Temperature controls life in the coastal ecosystem.
Migration, spawning, feeding efficiency, swimming
speed, embryological development, and basic meta-
bolic rates of fish are controlled in large part by
temperature. Temperature increase, such as that
caused by power plant effluents may disrupt these
basic life processes. (Power plants also suck fish in
with cooling water and kill them in the pumps and
pipes.) Where multiple power plants are placed on
an estuary, temperatures can increase to damaging
levels over extensive, areas, such as the striped bass
breeding grounds shown in Figure 1 or the vital
grass bed nursery area shown in Figure 2 where 91
percent of the grasses were killed.
Fresh Water Inflow
The volume of fresh water supply not only gov-
erns the salinity of estuaries, but also controls circu-
lation patterns (circulation strongly influences the
abundance and the pattern of distribution of fish
and other life in the estuary).
Some fish require different salinities at different
phases of their life cycle such as those provided by
runoff, summer drought, et cetera. Alterations af-
fecting freshwater inflow may upset the natural
salinity regime, upsetting habitat conditions to
which the fish are naturally adapted and lowering
carrying capacity. Salinity throughout the coastal
ecosystem fluctuates primarily with the amount of
dilution by freshwater inflow and the extent of
evapotranspiration. The inner ends of estuaries may
become so salty in summer when fresh inflow water
is diverted for other uses that the water becomes
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FISHERIES
143
FIGURE L—Temperature of the Hudson from Troy, N.Y., to the ocean at three tidal times with five power plants in full
operation.11
virtually uninhabitable for sport fish—for example,
Tomales Bay, Calif. (39 ppt salinity),13 and Rookery
Bay, Ha., (to 40 ppt).14
Sedimentation
Also related to the volume of runoff inflow is the
amount of sediment carried down into the estuary.
Uncontrolled development in estuarine watersheds
creates adverse effects by reducing the capability
of the land to filter and hold back storm water
runoff and to cleanse it of sediments as well as
nutrients and a wide variety of other contaminants
from the land surface. Therefore it is a fundamental
goal of estuarine resource management to protect
water bodies against excess loading of polluting
materials by achieving control of damaging activities
in the watershed.4
Accumulation of sediment on the bottom of an
estuary results in shoaling of the basin and the
creation of a soft, shifting, and basically unsuitable
habitat for bottom life. These sediments also trap
pollutants that are harmful to water quality when
resuspended by wind, currents, or boat traffic. Vir-
tual elimination of bottom life—as has now hap-
pened in the New York Harbor estuary—seriously
degrades the ecosystem and dismantles the food
chain of fishes.
An example of gros.s pollution from agricultural
drainage and clearing is the estuarine system of
Back Bay, Va., and Currituck Sound, N.C., which
was loaded with silt which killed bottom vegetation,
created high turbidity, and lowered the carrying
capacity.16 Sedimented and degraded estuaries with
reduced carrying capacity for sport fishing are found
along all sections of the U.S. coastline.
Corrective measures require control of: (1) erosion
from land clearing and site preparation in the water-
OBSERVATIOM
STATIONS
FIGURE 2.—Profiles of isotherms above ambient (°T) in
Biscayne Bay during summer—the Turkey Point plant was
subsequently fitted with an alternate cooling system.12
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144
ESTUARINE POLLUTION CONTROL
shed; (2) dredging activity in estuarine basins;
(3) municipal and domestic pollution which creates
organic sediments; and (4) boat traffic (which re-
suspends sediments).
Water Circulation
The circulation of water through an estuary is a
key factor in carrying capacity. It transports nu-
trients, propels plankton, spreads "seed" stages,
(planktonic larvae of fish and shellfish), cleanses
the system of pollutants, controls salinity, shifts
sediments, mixes water, and performs other useful
work. The fish populations and the entire dynamic
balance of an estuary revolve around and are strongly
dependent upon circulation. Channel dredging and
filling alter the flow patterns of estuaries as does
the construction of bridges, causeways and piers
which impede circulation.
Light
Sunlight is the basic force driving the ecosystem.
It is the fundamental source of energy for plants
which in turn supply the basic food chain which
supports all fish. Sunlight must be able to penetrate
the water so as to foster growth of the plants.
Estuarine waters are normally more cloudy (tur-
bid) than ocean waters, being more laden with silt
and richer in nutrients and phytoplankton. Excess
turbidity reduces penetration of sunlight into water
and thus depresses plant growth. This may be caused
by excavation in water basins, by the discharge of
eroded soil with runoff, by nutrients in the runoff
or by sewage or industrial waste discharges which
stimulate the growth of algae and lead to clouding
of the water.
Nutrients
In addition to light, nutrients must be present to
support the food chain. The amount of nitrate dis-
solved in the water is generally believed to be the
primary nutrient control on abundance of estuarine
plants. Nutrients continuously trickle out of the
estuarine system and must be replaced by minerals
in the inflow of land runoff. This supply should not
be diminished.
Conversely, the ecosystem may be unbalanced by
an excessive and unnatural supply of nutrient chem-
icals from septic tank leaching, discharge of sewage
effluent, industrial organic wastes, contaminated
land runoff water, and so forth. The result is over-
fertilization (eutrophication) which involves rapid
"blooms" of phytoplankton followed by mass death
and decay, clouding the water, fouling estuarine
bottoms and depleting oxygen.
While sewage has been the usual suspect for over-
fertilization of natural waters, the potential damage
by fertilizer runoff has increased dramatically—the
amount of nitrogen used in agriculture in the United
States increased fourteenfold in 25 years.16 Fertilizer
runoff can jeopardize the carrying capacity of estu-
arine systems, particularly poorly flushed ones.4
Water Suitability
Protection of water quality for fish life involves
more than just avoiding lethal concentrations of
pollutants—the water must be suitable beyond bare
survival. There are definite limits below which ani-
mals desert an area or survive in very reduced
abundance. Sensitive oceanic migratory fishes may
be particularly affected by water suitability and
abandon coastal areas with bad water. The result
may be failure of a fishing area and decrease of the
overall carrying capacity for the excluded species.
A variety of substances from industrial discharges
or sewage effluent—heavy metals, oil, organic sub-
stances—are repelling to fish; for example, salmon
avoid water with copper in very small amounts
(0.0024 mg/1)17 such as comes from fertilizer run-
off.14 Such repellents are probably responsible for
the general avoidance or apparent virtual abandon-
ment by oceanic sportfish species of many estuarine
and nearshore ocean waters such as Boston Harbor,
the Savannah River, and the Hudson Estuary. Elim-
ination of all significant discharge of pollutants
would restore the abundance of fishes in many of
these areas.
Toxic Substances
It is not possible to determine the amount of
damage done to sport fishing resources by the dis-
charge of toxic chemicals into estuaries, but the
damage appears to have been extensive; e.g., the
severe reduction of the sea trout previously dis-
cussed. In another circumstantial example, the vir-
tual disappearance of the California sardine (an
important forage for pelagic game fish) is correlated
with increasing DDT use after World War II (Fig-
ure 3).18 DDT use is banned in California but a
50-square mile area off the Los Angeles sewer plant
discharge (Palos Verdes area) has a persisting de-
posit of about 200 tons of DDT in the surface
sediments on the bottom of the continental shelf.19
The same area has also received toxic metals from
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FISHERIES
145
3456
Millions of oounds of DDT
PIGOEE 3.—The decline of the Pacific sardine from the mid-
40's to the early ,50's and the amount of DDT used in Cali-
fornia in the same period.18
the discharge, leading to fish diseases19 and wide-
spread reproductive failure of marine species of the
area. But now there are signs of a comeback as
young stages of species missing for decades are re-
appearing in the area indicating a water quality
improvement.20 Because of the ocean outfall, water
quality of the harbors is better in certain respects
than that of the ocean, a reversal of the usual
situation.
The NPDES program of EPA has an important
role to play in eliminating the discharge of toxic
substances to estuarine and coastal waters. The
potential benefits are supported by encouraging re-
sults of pollution abatement efforts to date.
Severe disease (fin rot) of estuarine and coastal
fishes is caused by municipal waste discharge. In
the New York harbor area 22 species were affected
by fin rot, including both pelagic fishes (e.g., blue-
fish, striped bass) and bottom fishes (e.g., flounder,
hake) ,20 In the Los Angeles area about 50 percent
of sole, rockfish, croaker, and other bottom fish
sampled were affected.19
Vital Habitat Area
Vital habitat areas are particularly critical ele-
ments of thf I'cosystem whose protection is essential
to prevent degradation of the system, including
depletion of fish. In the profile of the shorescape,
wetlands are the ureas above the mean high tide
mark and below the yearly high storm mark. Wet-
lands, vegetated with a combination of salt-tolerant,
wet-soil, plants—grasses and rushes—often grade
into some combination of fresh water marsh plants
at the upland edge. Vegetated tidelands are the
swamps and marshes from mean high tide down to
the low water mark.
Wetlands and tidelands vegetation converts nutri-
ents in land runoff and estuarine waters to basic
food for aquatic life, a sort of floating humus of
small particles (detritus). It also removes excess
nutrient, sediment, and other dissolved and sus-
pended matter. The marsh and swamp areas provide
critical habitats for many species as well as stabilize:
shorelines, prevent erosion, and buffer the force of
storms arid floods
If the wetlands-tidelands vegetation is elimi-
nated, carrying capacity of the ecosystem for fish
is reduced—about 50 percent in a typical case.22 Re-
duction of freshwater inflow to tidelands or canaliz-
ing or bulk-heading tidelands may also significantly
reduce estuarine fish resources. Therefore, fishery
management programs should require that wetlands
be protected from obliteration, alteration, or degra-
dation by pollution and by drainage or dredge-arid-
fill projects which reduce the area of the wetland
or disrupt the natural water flow patterns—as is
addressed under Section 404 of the 1972 Federal
Water Act Amendments.
Submerged grass beds convert and provide detrital
nutrient to the system, add oxygen (during day-
light), and stabilize" bottom sediments. They usually
attract an abundance and diversity of life and are
nursery areas for young fishes and crustaceans. Grass
beds are vulnerable to turbidity, which screens out
light and prevents growth of the grass, and to fine
sediments (mud) which create unstable bottom con-
ditions wherein the grasses often cannot anchor.
Heated power plant effluent (along with induced
turbidity) may destroy local grass beds; for exam-
ple, in the Patuxent River, Md., and Southern
Biscayne Bay, Fla.12 Boat traffic over grass flats
may compound the problem by stirring up sedi-
ments and ripping out plants.4
MANAGEMENT NEEDS
Fishing success depends upon the abundance of
fish which in turn depends upon the current carrying
capacity of the aquatic ecosystem. Carrying capacity
itself is governed by specific limiting factors. These
limits in turn are depressed by adverse ecologic
impacts from development and human occupancy.
Therefore, coastal sport fisheries management should
incorporate ecosystem management aimed at opti-
mizing carrying capacity.14
Secondly, it should be directed toward optimizing
the social benefits from the resource. This requires
that goals and policies for management be based
upon a realistic evaluation of social, economic, and
ecologic factors.
It is customary for states to regulate coastal fish-
-------
146
ESTUARINE POLLUTION CONTROL
cries. Stronger roles for both federal and local govern-
ments should be considered if successful integrated
programs of fisheries management are to be imple-
mented. Local governments sometimes regulate
shellfish and less often, a herring run or other spe-
cial situation. But local government plays an im-
portant role in controlling access to fishing, via
roads, parking lots, beaches, piers, boat ramps.
The states have the leading role partly because
fish migrate between local fishing areas. A species
may spawn in one area, feed in another, and winter
somewhere else again, making it impossible for any
local government to act effectively. In addition, the
water moves from one locality to another bringing
one town's wastes to another's shores. Therefore,
the states are better equipped to deal with manage-
ment of fisheries.
There is clearly a Federal role for management of
coastal migratory fish and for protection of inter-
state environments. No state can do the whole job
alone because both fish and water move from state
to state. For the most part interstate commissions
have proved ineffective in coordinating fishery man-
agement of the states into successfully integrated
programs.
Typical state fisheries management programs have
dealt only marginally with the coastal environment.
Fish regulations are usually aimed at allocating fish
to fishermen by limiting the type of gear, size of
fish, time of year, number of fish taken per day, and
so forth. This passive portioning out of the catch
is usually done without any attempt to scientifically
optimize the yield from the ecosystems involved.
In state management the target usually is a single
species. Rules are laid down for the species without
regard for other species that share the ecosystem—
species that may be prey, predator, competitor, or
eooperator. The rules are applied through the politi-
cal process in state legislatures or by appointed
state commissions, under heavy lobbying pressure
from fishing organizations. Opinion* of state fishery
biologists may be ignored because their case has
not had the funds or manpower to be developed
with scientific certainty. Most stafes have no salt
water sportfish license to provide an internal source
of funds for management or research on sport fishing
problems. Stale commissioners and the general con-
stituency of the fishery agency want to see money
spent for visible structures—boat ramps, artificial
reefs, and so forth—rather than advance planning,
research, or administration. Consequently, the agen-
cies are under-financed and short handed.
As a result, coast sport fisheries management is
typically a series of ad hoc responses to immediate
situations. In only a few states, such us California,
Florida, and Massachusetts, is there any continuing
management research program to serve as the basis
for longer-term strategies that include environmental
protection. If there is to be an effective strategy for
comprehensive coastal fisheries management, there
must be clearly defined long-term goals. The goals
must be translated into policies consistent with social
needs as determined through the political process.
The following planning framework suggests major
elements that need to be considered:
1. Resource optimization: Devise a system of estua-
rine resource management that involves both harvest
control and ecosystem management. Harvest control
includes: bag limits, size limits, gear restriction,
access limits, and closed areas and seasons. Eco-
system management includes: control of chemical
and industrial pollution, protection of vital habitat
areas, control of land clearing and site preparation
in shorelands, maintenance of freshwater inflow,
control of dredging and filling, and control of boat
traffic.
2. Access: Provide a system of access that will
guarantee an optimum pattern of fishing activity-
consistent with economic, sociologic, and ecologic
constraints. Physical development should incorpo-
rate roadways and public transportation as well as
beaches, bridges, piers, marinas, ramps, and charter
boats. Social factors to be balanced should include:
geographic distribution, income level, race, and
availability of alternative recreation opportunity.
3. Allocation: Plan for a balanced pattern of allo-
cation of fish resources including. (]) competing
user groups such as commercial anglers, skin diving,
and foreign fishermen; (2) the various demographic
elements (see 2); (3) preferred sizes of the catch;
and (4) preferred times and areas of fishing.
4. Monitoring: Design a system for measuring
catch and monitoring user satisfaction to guide the
management program.
.">. Revenue: Examine the recreational fishery
(along with commercial) to determine the revenues
gained for different patterns of use and for different
levels of production.
C>. Institutional: Determine the optimum mix of
federal, state and local jurisdiction.-., and the best
methods of implementation of management actions
through existing and new legislation.
It appears- that this is an appropriate time for
each coastal state to review its situation, to examine
federal-state-local jurisdictions, to decide; upon a
unified set of goals, and to establish a clear set of
policies for use and protection of coastal fishery
resources.
-------
FISHERIES
147
The Federal government would need to partici-
pate in this process whore migratory fishes and inter-
state environments are involved, and to provide a
mechanism for coordinating activities of all federal
agencies dealing with the coastal environment and
coastal resources. There is now no federal policy or
program on migratory fish resources. Such a role
must be suitably defined by Congress through legis-
lation, funding, and study.
The new federally sponsored Coastal Zone Man-
agement program would seem a logical framework
for such a cooperative planning study, providing
that sufficient importance and funds are given to
the individual states to conduct comprehensive plans
for land and water resource management. It is
clear that only through this kind of comprehensive
planning can recreational fishery resources be prop-
erly maintained and equitably shared among all
Americans.
REFERENCES
1. Deuel, David G. 1973. The 1970 Salt-Water Angling
Survey. U.S. Dept. of Comm., Ntl. Mar. Fish. Serv.,
Current Fishery Stats. No. 6200
2. U.S. Bureau of Sport Fisheries and Wildlife (undated).
National Survey of Fishing and Hunting 1970. U.S.
Dept. of the Int , Bur. Spt. Fish, and Wildlife, Res.
Publ. 95.
3. Personal communication. Edwin A. Joseph
4. Clark, John. 1974. Coastal Ecosystems: Ecological Con-
siderations for Management of the Coastal Zone. The
Conservation Foundation, Washington, D.C.
5. Clark, John. 1966. Fish and Man: Conflict in the Atlantic
FjStuaries. American Littoral Society, Special Publica-
tion No. 5
6. Sartor, J. D. and f). B. Boyd. 1972. Water Pollution
Aspects of Street Surface Contaminants. USEPA, Env.
Prot. Tech. Serv. EPA R2-72-081.
7. Midwest Research Institute. ]973. Methods for Identify-
ing and Evaluating the Nature and Kxterit of Non-
point Sources of Pollutants. Draft Report. USEPA.
Contr. No 08-01-1839.
8 CopeUuui, B. J , H, T. (Mum, and Frank \. Mosely.
1974. Migratory Subsystems Chapter F, Coastal
Ki'ological Systems of the United States, edited by H T.
Odum, B, J. Copeland and K. A. McMahari. Volume
III. pp. 422-453
9. Personal Communication. Timothy Stuart, Florida De-
partment of Water Pollution Control, Tallahassee, Fla.
10. National Marine Fisheries Service. 1972. Druid's Island
Phase I: A short-term ecological survey of Western
Long Island Sound. U.S. Dept. of Comm.' NOAA, Nat.
Mar. Fish. Serv., Sandy Hook Marine Laboratory.
(See Table 37).
11. Simon-tov, M. 1973. Testimony to U.S.A.K.C. Licensing
Board Hearing—Indian Point No. 2, Feb. 8, 1973.
12. Roessler, Martin A. and Joseph C. Zieman. 1969. The
effects of thermal additives on the biota of Southern
Biscayne Bay, Fla. Proc. of Gulf and Carib. Fisheries
Inst , 22nd Session, pp 136-145
13. Smith, Edmund H., et al. 1971. Physical, chemical,
microbial, and hvdrographic characteristics of Tomales
Bay. Final Kept, to KPA. Project No. 18050 DFP.
August, 1971.
14. Clark, John. 1974. Rookery Bay: Ecological Constraints
on Coastal Development. The Conservation Founda-
tion, Washington, D.C.
15. Sincock, John L., et al. 1962. Back Bay—Currituck Sound
Data Report, U.S. Bureau of Sport Fisheries and
Wildlife. 4 Volumes (Mimeo).
16. Commoner, Barry. 1970. Threats to the Integrity of the
Nitrogen Cycle: Nitrogen Compounds in Soil, Water
Atmosphere and Precipitation. In Global Effects of
Environmental Pollution, S. F. Singer, ed. (D. Reidel
Publishing Co., Dordrecht, Holland), pp 70-95.
17. Sprague, J. B. 1971. Measurement of pollutant toxicity
to fish. III. Sublethal effects and "safe" concentrations.
Water Research, 5: No. 6, pp 245-266.
18. Unpublished information supplied by Walter Thomsen,
previously with the California Dept. of Fish and Game.
19. Information supplied by David Young, The Southern
California Coastal Water Research Project, Los
Angeles, Calif.
20. Personal communication, Rimmon C. Fay, Pacific
BioMarine Supply Co., Venice, Calif.
21. Mahoney, John B., Frederick H. Midledge and David
G. Deuel. 1973. A fin rot disease of marine and euryha-
line fishes in the New York Bight. Trans. Amer. Fish.
Soc , Vol. 102, No. 3: pp 596-603.
22. Personal communication, Richard Williams, Smithsonian
Institution.
23. Anderson, Richard R. J969. Temperature and Rooted
Aquatic Plants. Chesapeake Science, Vol. 1, Nos. 3
and 4: pp 157-J04.
-------
-------
LIMITING FACTORS
AFFECTING COMMERCIAL FISHERIES
IN THE MIDDLE ATLANTIC
ESTUARINE AREA
J. L. McHUGH
State University of New York
Stony Brook, New York
ABSTRACT
Landings of fish and shellfish by domestic commercial fishermen in the Middle Atlantic Estuarine
Area (Rhode Island-Virginia inclusive) nearly doubled in weight from 1969 to 1973, from about
586 million to more than 1,074 million pounds. The increase was not accompanied by a similar
increase in fishing effort, but by distinct increases in abundance of certain coastal fishes like
menhaden, weakfish, summer flounder, and bluefish. In the area north of Chesapeake Bay blue
crab was more abundant than it has been for more than a decade and scup also was more plentiful.
It is tempting to attribute these increases to pollution abatement, but no direct proof is available.
For example, the return of blue crab to the New York Bight area may have been made possible by
the decline in use of DDT. All these species are known to vary widely in abundance from natural
variations in environmental factors and it is difficult to separate natural from manmade causes.
The only certainly adverse effects of water pollution on abundance or catches of living marine
resources are those which produce obvious and measurable effects, usually catastrophic, or which
result in closure of shellfish beds. Because so many important living resources use the estuaries as
spawning, nursery, or feeding grounds it is prudent to avoid additional deterioration of water
quality and, where possible, to reduce dumping of wastes.
INTRODUCTION
This review of the fisheries of the Middle Atlantic
Estuarine Area includes estuaries and coastal waters
from Cape Cod to Cape Hatteras and out to the
edge of the continental shelf. This area (Figure 1)
lies between latitudes 41°20' N. Lat. and 35°15' N.
and extends seaward to the 200m. depth contour.
The offshore boundary is approximately where
the shelf meets the continental slope. Although this
is not exactly the definition given in section 104 (n)
(4) of Public Law 92-500, it is the only rational
definition for adequate consideration of the living
resources upon which the fisheries of the Middle
Atlantic Bight depend. Most commercial fishery
resources in the area are highly migratory, and
perform extensive seasonal movements east and
west as well as north and south. Thus, many living
resources of the area are about equally dependent
upon the inshore and the offshore estuarine environ-
ment. In winter and spring many of the major
migratory living resources are concentrated in rela-
tively deep water at the edge of the shelf, some ap-
parently favoring the major canyons. Conditions
along these outer boundaries must play an important
role in determining future abundance and availa-
bility of these resources to the inshore fisheries.
The definition of the Middle Atlantic Estuarine
Area adopted here is similar to the definition of the
Middle Atlantic estuarine region used in the "Na-
tional Estuarine Pollution Study" (Anon. 1970a),
although that study did not include Chesapeake
Bay, but considered it as a separate region. "The
National Estuary Study" (Anon. 1970b) defined
the Middle Atlantic Estuarine Zone as the estuaries,
bays, and coastal waters from Cape Cod to Cape
Charles, Va. Chesapeake Bay was considered sep-
arately, and the area from Cape Henry, Va. to Cape
Hatteras was included with the South Atlantic
Estuarine Zone. None of these arrangements is
entirely satisfactory for a fishery study because basic
data on domestic commercial landings are recorded
by states, whereas foreign and recreational catches
are recorded by broader regions. The fishery re-
sources of Chesapeake Bay are sufficiently different
from those to the north that it is best to examine
them separately. Because North Carolina fishery
resources are transitional between Middle and South
Atlantic Estuarine Areas, the commercial fisheries
of North Carolina have been omitted. Thus, the two
subareas of the Middle Atlantic Estuarine Area con-
sidered in the present study are Rhode Island to
Delaware inclusive, and the Chesapeake states,
Maryland and Virginia.
149
-------
150
77°
ESTUARINE POLLUTION CONTROL
75° 74° 73° 72° 71"
^ BLOCK
LONG ISLAND ^ISLAND
SOUND
NEW YORK BIGHT
70°
FIGURE 1.—The Middle Atlantic Estuarine Area of the United States. Not all place names mentioned in the text are included.
The long narrow east-west peninsula near the southeast end of Long Island and the similar north-south peninsula at the north
end of the New Jersey seacoast are Rockaway Point and Sandy Hook, respectively. A line drawn between these points separates
Greater Raritan Bay from New York Bight. The Potomac River is the large river entering Chesapeake Bay from the west. The
Maryland-Virginia boundary follows its southern bank. The Patuxent River lies immediately north of the Potomac and the
Rappahannock River immediately south.
Within waters under national jurisdiction, from
inland limits of estuarine waters to seaward limits
of domestic fishery control, living marine resources
are subject to many natural and manmade hazards.
Subtle or catastrophic natural environmental vari-
ables can alter abundance and availability of the
resources to fishermen. Various stresses created by
man include not only relatively uncontrolled fishing,
but also domestic and industrial wastes and engineer-
ing works which alter the environment, usually for
the worse. Farther out on the continental shelf,
especially at or near the edge, many of these re-
sources remain concentrated for several months in
winter and early spring. Here they are highly vulner-
able to fishing, mainly by foreign fleets, but less
susceptible to water pollution and other indirect
human influences.
The fishery resources of the area from Cape Cod to
Cape Hatteras provided a domestic commercial
catch in 1973 of about 1.6 billion pounds1, for which
1 To convert millions of pounds to metric tons, multiply by 453.6.
-------
FISHERIES
151
American fishermen received about $119 million.
The retail value of this catch could be $300 million or
more. They also provided 820 million pounds to
fishing fleets of at least 10 other nations. Not to be
ignored is the substantial recreational catch. Surveys
of saltwater sport fisheries have not been made every
year, but in 1970 recreational fishermen were re-
ported to have taken about 447 million pounds from
the same community of resources, and the sport
catch in the area probably was larger in 1973. The
distribution of catch and fishing effort on individual
stocks varies between recreational, domestic com-
mercial, and foreign fisheries. Not included in the
recreational catch are clams, bay scallop, crabs, and
some other invertebrates taken in large numbers by
non-commercial fishermen. The recreational catches
of invertebrates have never been assessed for the
area as a whole. These three segments of the fisheries
of the Middle Atlantic Estuarine Area have been
taking about 2.9 billion pounds of fish and shellfish
annually, and perhaps more.
This essay reviews briefly the status of the com-
mercial fisheries of the Middle Atlantic Estuarine
Area in 1969, when the report pursuant to the re-
quirements of Public Law 89-753 was completed
("National Estuarine Pollution Study'-'), and makes
a comparison with the situation five years later, in
1974. The comparison considers what has happened
in the interim, what improvements and adverse
developments have been noted, what important
issues need attention, what the future may bring,
and what are the chances for improved management
of the resource. Particular attention has been given
to the effects of estuarine pollution, as directed by
Public Law 92-500, section 104(n), but it has not
been possible to ignore other sources of variation in
condition of the commercial fishery resources. This
has required, among other things, brief attention to
the saltwater sport fisheries, which are properly the
subject of another chapter in this volume. Assuming
that other sources of attrition are, or will be. under
control, continued productivity of the coastal fisher-
ies will still depend upon appropriate control of all
forms of fishing.
perhaps some migratory species of limited scope,
like blue crab, white perch, tautog, and some stocks
of winter flounder (category Ee in Tables 1 and 3"!;
2) migratory coastal species that do not move off-
shore in significant numbers beyond national fishery
jurisdiction, like menhaden, croaker, and weakfish
(Em);
3) artadromnus and catadronious species, which
spawn in fresh water but spend most of Their lives
at sea. cr vice versa, like American -'had, ak"\i;'e.
striped bass, and American ee! (A >;
4) living resources i)f the continental shelf, which
at the harvestable stage either arc immobile on or
under the sea bed or are unable to move except in
constant physical contact with the sea bed or the
subsoil, like surf clarn or rock crab (S) ;'2 and
5) highly migratory resources that move seasonally
not only north and south, but also inshore-offshore
between estuarine waters proper and the outer con-
tinental shelf, like red and silver hakes, summer
flounder, scup, and butterdish (Om). A sixth cate-
gory in this arrangement might be made up of truly
oceanic species, like tunas and the great whales,
which penetrate waters of the inshore estuary seldom,
if at all (0).
Most of these living resources are subject to man-
made stresses in the inshore estuarine environment,
some throughout life, others at important stages.
Assessment and control of the effects of water pollu-
tion, engineering works, and other human environ-
mental influences, including fishing, upon the living
resources is extremely difficult because at least four
other major complicating forces may be operating
at the same time: 1") natural variations in environ-
mental quality, sometimes subtle, like changes in
water temperature or salinity-—sometimes catastro-
phic, like the effects of hurricane winds or heavy
rains; 2) self-generated (endogenous) oscillations
within individual stocks; 3"! complicated and major
effCcts of fishing operations; and 4! opinions, emo-
tions, and political pressures geneiated by the effects
of natural and man made phenomena indiscrimin-
ately, which influence the regulatory process
THE RESOURCE
Coastal fishery resources can be subdivided use-
fully into several categories, based not onlv on their
value to man and to the ecosystem, but also on their
geographic distributions, migratory habits, and
vulnerability to maninado environmental change.
One such arrangement might \n~:
1) endemic resources, like oyster, hard clam, and
Status of the Resource in 1969
Judged by the total weight <-f fish and shelltibh
lauded in the Middle Atlantic Estuarine Area in
3909 at- compared \vitli the past, the domestic •Com-
mercial fisheries of the area had never been in worse
condition. Total weight of landings was at an ail-
time low in recorded historv, less than 37 percent of
2 American lobster lias been derl'ired by tht! United State* C >ngrcss a
creature of the sheif, but it does not fit the definition.
-------
ESTFARIXE POLLVTION CONTROL
the 1956 high of 1.59 billion pounds. But for most of
the period up to 1956 and for some years after, in-
dustrial fish and shellfish (used for purposes other
than human food) had dominated the catch, thus
trends in total landings reflect principally the for-
tunes of the industrial fisheries, harvesting mostly
menhaden for manufacture of oil and meal. When
edible species are considered separately, the peak in
landings came about 1030. By 1969 landings of food
fish and shellfish, all species combined, in the area
had been dropping fairly steadily for about 40 years.
The 1930 maximum in production of edible fish
and shellfish came shortly after it was discovered
that many of the resources which migrate into
Middle Atlantic estuaries in spring and summer
move outward to the edge of the continental shelf
and southward in late fall and winter. A winter trawl
fishery rapidly developed offshore to take advantage
of this discovery. Major disturbances in the long-
term trend since 1930 came when prices and landings
dropped sharply during the economic depression of
the early 1930s, rose sharply toward the end of the
second world war when acute shortages of red meat
at home and abroad increased the demand for pro-
tein from the sea, and fell again in the 1950s. In 1968
total weight of edible fish and shellfish landed in the
Middle Atlantic Estuarine Area was lower than in
any year on record except 1933, when the full force
of the depression had hit the fisheries, with adverse
effects on demand and prices. Total landings of
edible fish and shellfish were only moderately higher
in 1969 than in the low year 1968*
RHODE ISLAND-DELAWARE SVBAKEA
Major species by weight in 1969 landings in this
subarea are listed in Table 1. Surf clam dominated
the edible catch, accounting for 35.6 percent by
weight of all food fish and shellfish. Xext in order
were yellowtail flounder, hard clam, American
lobster, scup, and winter flounder. Together, these
six species made up nearly 82 percent of the total
weight of edible fish and shellfish.
By landed value (Table 2) hard clam dominated
the edible catch (nearly 29 percent of the total'),
followed in decreasing total landed value by lobster,
surf clam, and oyster. The first four species by landed
value were shellfish, and they made up 68 percent of
the total landed value including industrial species.
Major edible fmfish species by landed value were
scup, yellowtail flounder, summer and winter floun-
ders, striped bass, and butterfish. The 10 leading
species by landed value, including shellfish and in-
dustrial species, produced a gross income to domestic
commercial fishermen of over $30 million, nearly
Table 1.—Major species in domestic commercial fishery landings in the Middle
Atlantic Estuarine Area 1969-1973 (Rhode Island to Delaware inclusive). Weights
in millions of pounds. Shells of molluscan shellfish not included. Species with
total annual catch 50,000 pounds or less not included. Symbols: Ee = estuarlne
endemic; Em = estuarine migratory; A = anadromous or catadromous; S =
creatures of the continental shelf; Om = oceanic migratory, usually moving
between international and territorial waters; 0 = truly oceanic
Species
Menhaden ,
Surf clam. i
Yellowtaii flounder
Sliver hake - - !,
American lobstei
Butterfish
Atlantic cod
Squids
Summer flounder
Bluefish
Weakfisti
Atlantic mackerel
American oyster
Red hake ------
Sea scallop - ^
Conch-
American shad
Tilefish
Bluefin tuna
Sea mussels----
Subtotals ,.
Grand totals
Em
S
Om
Ee
Om
Om
Om
Om
Om
Om
Om
Om
Om
Om
Om
Ee
Om
Em
Om
r
Om
0
Om
Ee
1969
43 8
42.2
13 5
11.4
8.9
8.0
7.4
7.2
3.6
3 4
2.3
2.2
2.0
2.0
1.9
1.4
1 . 4
1 2
1.1
0.9
0.6
0.5
0.5
0.5
0.1
0.1
0.2
168 3
r
231.9
1970
40.6
52.6
15.4
11.9
8 0
9.3
7.4
8.1
2.2
3.8
1.4
3.2
3.1
2 4
1.7
2.3
1.5
1.6
1.2
0.7
0.5
0.5
0.5
0.4
0.1
3.1
0.2
183.7
2'24.2
1971
80.4
40.3
20.8
12.5
8.2
9.0
6.2
8 1
2.7
3.1
1.3
3 2
2.5
4.8
1.6
1.7
2.1
1.3
2.2
0.5
0.5
0.5
0.4
0.4
0.1
2.0
0.3
216.7
253.5
1972
158.3
32.7
28.0
12.1
10.9
6.3
7.4
6.6
1.2
2.7
1.9
3.2
2.2
5.6
1.7
2.8
3.4
1.6
4.0
0.5
0.5
0.6
0.5
0.6
0.3
2.2
0.5
298.3
326.0
1973
172.5
31.6
25.1
10.2
11.5
5.4
9.4
6.6
3.0
3.4
2.8
5.6
2 7
4.3
3.6
2.8
3.3
1.9
5.0
0.6
0 4
0.5
0.6
0,9
0.8
1.3
0.7
316.5
379.7
1972-73
as % of
1969-70
392
68
184
96
133
68
114
86
72
85
127
170
96
225
147
151
231
125
391
69
82
110
110
167
550
109
300
175
155
86 percent of the landed value of the entire domestic
commercial catch from this subarea* in 1969. This
probably represents a retail value of $100 million
or more.
Although landings in Rhode Island to Delaware
in 1969 were almost t he lowest on record, they might
have been even lower if commercial fishermen had
not constantly shifted to new resources as the supply
of traditional resources declined. Outstanding ex-
amples of such declines were menhaden landings,
which fell f-oni a maximum of over one billion pounds
in 1956 to a 1966 low of orly 22 million pounds. By
I960 the menhaden catch in the subarea had in-
crea^ed to about 46 million pounds. The American
oyster, which was reportrd to have produced a
maximum of about 60 million pounds of meats in the
early part ;>f the 20th century dropped from about
35 million pounds in 1929 to a low of one million in
196.5, and in 1969 had recovered only slightly to
about 1.4 nilhon pounds of meats. Scup was the
dominant food finfish for almost two decades, reach-
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FISHERIES
153
Table 2.—Major species in domestic commercial fishery landings in the Middle
Atlantic Estuarine Area 1969-1973 (Rhode Island to Delaware inclusive). Landed
values (price paid to fishermen) in millions of dollars, not adjusted to standard
dollars. * = $50,000 or less
Species
1969
1970
1971
1S72
~T
1973
Hard clam
American lobster „
Surt clam
Amstican oyster....
Scup
Yellowtai! flounder
Sea scarfc;
Menhaden _ ._ _ , _.
Silver hake ___
Winter flounder .,
Bulterfish
Bay scallop
Biuefish
Squids .- . . ,
Weakfish . _.,
Atlantic mackereL
American shad _ „
White perch , _
Subtotals _-.
Grand totals „
i 10. 3
I 7.4
., ' 5.0
: i 5
1.4
1 1.0
. -! 0.8
I 0 8
0.7
J 0.7
j 05
j 0.5
J 0.4
J 0.3
i 0 1
4 02
i 0 1
0.1
i 0.1
J 0.1
-1 0.1
j 0.1
—I 0.1
! 0.1
J 34.3
i 35.6
11.5
9.5
6.1
2.0
1 8
1.7
0.9
0.7
1.2
0.8
0.9
0 4
0.4
0.5
0.4
0 3
0.2
0.2
0.2
0.2
0.1
0.1
0.1
0.1
0.1
0.1
0.1
40.6
42 5
i r
13.5 1 1
10.2
5.4
?.8
1.7 \
2 1
0.8
0.3
1.2
0.7
1.0
0.5
0.5
0.3
0.4
0 3
0.2
0.2
0.4
0.5
0.1
0.1
0.1
0.1
0.1
0.1
43.6 5
46.7 ! 5
6.0 13.9
8.7 8.5
4.2 3.9
4.4 5 1
1.7 2.7
3.7 4.4
1.0 J.I
2.5 4,3
1,3 2 3
0.9 1.4
1 1 1.2
0.6 1.2
0.3 0.7
0.2 0.5
0.5 0.6
03 03
0.3 0.6
0.2 04
1.0 1 3
0.7 0.7
0 1 0.2
0.2 J 02
0.1 ! 01
0.2 0.2
0.1 ! 0.1
01 0.1
01 01
0.4 ! 56.1
3.0 58.6
ing a maximum oi over 34 million pounds in 1960
and a minimum of 6.2 million in 1971. Landings of
scup in 1969 were near this minimum, at about 7.4
million pounds. Several other species, like weakfish,
had produced relatively large catches earlier and had
i alien to minima in or about 1969.
To balance these substantial declines commercial
fishermen turned to other species, notably surf clarn.
This fishery was negligible prior to the mid-1940s,
but bepan to grow in 1945 off Long Island, N.Y.
Landings from \\ aters off Long Island reached a
peak quickly and the center of operations shifted to
the NV\v Jersey coaut, By 1968 and 1969 landings
in New Jersey hud declined slightly from a peak of
over 43 million pounds of meats in 1900, and the
fishery had ju.-it begun to shift to beds off the Dela-
ware aim Mar vim id coasts. The histm v oi this fishery
has been on< of heavy exploitation of known clam
stocks, entry of more capital and labor, substantial
reduction of thv sto.-ks, exploration for unexploited
segments of I he resource, raid a constant shifting
toward t'-u '•••lath 'rhf -urf H un industry provides
an (j>.(-t;li -in casi hii-to; •-, oi' what happen,-' to a living
resource when harvesting is essentially unregulated.
CHESAPEAKE SUBAREA
Total domestic commercial landings in the Chesa-
peake Bay states in 1969 were lower than they had
been since 1953. As in the area to the north, indus-
trial fisheries have dominated the catch, but the
1969 catch was not an all-time low, as it was from
Delaware to Rhode Island. The smallest reported
total weight of landings in the Chesapeake subarea
\\ii-; in 1942, at just over 200 million pounds, and the
trend has been upward ever since.
Landings of edible fish and shellfish in the Chesa-
peake area reached a peak by weight in 1930, as they
did farther north, then declined, but reached even
higher levels in the middle 1940s, with a maximum of
about 205 million pounds. An unusual abundance of
croaker and weakfish, coupled with high demand for
food fish during the war and immediately after, were
largely responsible for this second peak. Blue crab,
alewife, and oyster dominated the edible catch in the
Chesapeake subarea in 1969, accounting for about 67
percent by weight of all edible fishery products.
Next in order by weight were soft clam, striped bass,
surf clam, northern puffer, American shad, scup,
hard clam, and white perch (Table 3).
Together, these1 11 major species made up over 90
percent of total edible landings. By landed vahie
(Table 4) the first five species were shellfish, ac-
counting for nearly S3 percent of all edible species
by value.
A steady shift from one resource to another, al-
ready noted in landings in the Rhode Island—Dela-
ware subarea, was characteristic of the Chesapeake
subarea also. Catches of the following species de-
clined substantially prior to 1969: Atlantic croaker,
down from a maximum of 57.7 million pounds in
1945 to a low of about six thousand pounds in 1968;
scup down from a peak of 13.5 million pounds in
1960 to about 2.5 million in 1968; sea bass from a
maximum of 10.1 million pounds in 1952 to about
1.9 million in 1969; weakfish from a 1945 peak of
24.7 million pounds to a low of d.7 million in 1967;
and American oyster from over 100 million pounds of
meats before the turn of the century to a record low
of 18.3 million in 19f>3. Countervailing upward
trends occurred in landings of other species: men-
haden from a low of about 64 million pounds in 1942
to record highs in the late 1950s and early 1960s,
then a decline to about 180 million in 1969; striped
bass, an upward trend since 1934, tvh'T the catch
was only 0 6 million pounds, to a maximum of 7.8
million in 1969; blue crab from a low of 30.2 million
pounds 111 1942 to a high of 94 million in I960; and
soft dam from insignificant cai ch.es prior to the.
second world v.,it to a
of meats in J9(>4.
if ov IT S n
pountl
-------
154
ESTUAIUNE POLLUTION CONTROL
Teble 3.—Major species in domestic commercial f> the area as a whole
since -1111)9 utal landings have almosi doubled (Ta-
bles 1 an-1 0,1, from about .">S."> million to 1.0.34 mil-
lion pounds Most of this inert/IM- has come about
"hiough ;». substantial ''i< rea- • in menhaden landings.
v inch !•• M'7 > we; ; lifetime- -':• !'J'>H caicn.. Tl-t-
remainder o1' *he increase \\ as mmi" up <>f r-ubst mtiul
Table 4.—Major species in domestic commercial fishery landings in the Middle
Atlantic Estuarine Area 1969-1973 (Chesapeake Bay). Landed values (price paic
to fishermen in millions of dollars, not adjusted to standard dollars). * =
$50,000 or less
Species
1969 i 1970
197!
1972
1973
American oyster - _. _ 14.0 1
Blue crab 7 0
Menhaden . 2 8 '.
Soft clan- . ?.8
Hard clam-. ... 1.7
Sea scallop ' 1 5
Stnpec hass ! 4
Surf clam_- . 09
Alewife 0 7
Summer flounder 0 5
White perch 0 4
Scup ... . 04
Black sea bass.. _. . . 0.3
American shad... 0.3
Catfish and bullheads 0.2
American eel ._ 02
Northern puffer 0 2
American iobstei 0 1
Weakfish.... . . 0.1 i
Butterfish 0.1
Spot . *
Conch | •
Bluetiih... ' *
Atlantic croaker . . *
i
Subtotals . 35 6 »
Grand totals ' 36.1 ', 4
5 1 16.0 15.2 15.9
55 7.2 74 7.7
76 6.5 9.3 20.6
?,4 1 3,0 1.0 35
1.1 1.6 1 ? ' 1.3
10 08 1.9 13
12 1.1 15 2.Z
1 6 I.b 3.7 5.9
04' 03 03 03
07 06 07 1.0
03 0 3 02i 0.2
0.4 ' 02 0.2 0 2
C.'t 0.2 02 0.4
0.4 0.3 0.3 I 0.5
0.2 0.2 0.3 0.3
0.3 0 4 0.2 0.1
01 * * *
02, 0.2 11 0.3
0.3 0.3 0 3 0.7
0.2 0.1 01 *
OS' 0 1 ! 0. 3 ' 0.4
01 * * • O.I
01 0.1 0.1 i 0.2
O.I ' 0.2
0 2 41.0 45.6 60.3
0 5 41.5 45.9 60.7
growth in catches of surf clam, yellow tail flounder,
•weakfish, summer flounder, oyster, bluefish, and
home other species like croaker and tilelish for which
the increase in pounds was relatively small hut the
percentage increase was large. Landings of Atlantic
croaker, for example, were 1-1 times as large in 1973
as in 19t>9, and according to a recent report young
croaker are exceedingly abundant in Chesapeake Baj
in 1974, which suggests that catches will continue to
increase. The relat ively large increase in tilelish land-
ings was caused by recent development of a special-
ized iisherv out of Xew .Jersey. These substantial
increases were partially offset by decreased landings
of other resources. Included in this group were ale-
wife, soft clam, northern puffer, American lobster,
hard clam and a few others. Xo substantial increases
in domestjf fishing effort or techniques have occurred
in the ")-ytar period, except pevhap.^ for menhaden.
This knowledge, and other Unes of evidence e.g.
increased r-creaiioMni catchis and person:;! oh,-,eiva-
Tions, can '>e taken as strongly suppor'i.ig, (he vie\\
("hat there has been a real increase in abundance ol
some species of the estuaries and a real decrease in
nth'-rs For species like ale\>ire the decline in do-
n, -.ti'1 ian-linji,- uas bala.a'C'.i l.\ inc/e-is, o foreign
cat dies.
-------
FISHERIES
155
RHODE ISLAND-DELAWARE SVBAKEA
Landings in this subarea increased by about 55
percent from 1969 to 1973 (Table I}. .Menhaden
landings increased nearly fourfold and fairly large
gains were recorded also for yellowtail flounder, blue
crab, summer flounder, silver hake, weakfish, scup,
oyster, and striped bass. The.se increases were parti-
ally offset by declines in landings of surf clam, Amer-
ican lobster, and a few other species. The decline in
lobster catches may have been a result of decreasing
fishing effort.
CHESAPEAKE PVHAREA
Domestic commercial fishery landings in this sub-
area almost doubled from 1969 to 1973. The major
increase here was also in menhaden landings, which
almost tripled in this subarea. The increase in total
landings had been even greater in 1972, from about
354 million pounds in 1969 to about 735 million,
more than doubling the 1969 catch. Food fish and
shellfish landings were moderately higher in the
Chesapeake subarea in 1973 than in 1969, largely
because surf clam production rose by more than 43
million pounds of meats, almost a sevenfold increase.
But this substantial increase was partially offset
by a major drop in alewife catches, catastrophic
declines in production of soft clam and northern
puffer, and moderate drops in catches of several
other species (Table 3).
PROBABLE CAUSES OF CHANGES
Most living resources of the coastal zone fluctuate
widely in abundance from natural causes. Natural
changes in environmental conditions at critical
stages in the life history obviously affect survival and
future abundance, but our understanding of cause
and effect is very poor and probably always will be.
When the fortunes of the fisheries are viewed against
this background of natural change it is difficult to
determine the relative contributions of fishing, water
pollution and other manmade effects, and natural
environmental variations. The effects of fishing can
be measured if accurate information is available on
catches and amount of fishing effort over a reason-
ably long period of time. But similar information on
most other manmade effects, and on naturally-
caused changes in abundance, is not available. Thus,
conclusions about the causes of changing abundance
of living resources are likely to be largely intuitive.
To assess the reasons for the changes observed
between 1969 and 1973 in commercial fisherv land-
ings in the Middle Atlantic Estuarine Area it is
helpful to retreat to the narrower and more com-
monly used definition of an estuary: a semi-enclosed
coastal body of water having a free connection with
the open sea and within which the sea water is mea-
surably diluted with fresh water derived by land
drainage. It is in such bodies of coastal water (hat
effects of human activities are most pronounced.
This includes Long Island and Block Island Sounds,
Greater Raritan Bay (inside a line joining Rockaway
Point and Sandy Hook), Delaware Bay, Chesapeake
Bay, and all estuaries and bays lying inside the
fringe of barrier beaches along the south shore of
Long Island and the ocean coasts of New Jersey,
Delaware, Maryland, and Virginia. Because it Las
been a major waste disposal site for many years, the
apex of New York Bight is also included, although
it does not fit the conventional definition.
This separation of estuarine and shelf waters
eliminates some major living resources in Tables 1 to
4 from consideration insofar as strictly estuarine
processes are concerned. These resources are: surf
clam, yellovvtail flounder, cod, haddock, Atlantic
mackerel, sea scallop, tile-fish, blue/in tuna, and
probably a part of the lobster resource. It is assumed
for the purposes of this study that these essentially
oceanic species, and perhaps some others which do
not reside in coastal waters close to shore for any
great length of time, are not presently affected
significant!}" in abundance by human alteration of
the estuarine environment. However, it must be
remembered that large oceanic fishes like tunas and
billfishes have been shown to accumulate relatively
large residues of heavy metals and other contami-
nants which may have corne from estuarine sources
via the food web. Changes in abundance of these
species must be assumed to be caused by natural
environmental changes, or by the effects of fishing,
or both. This leaves about 25 sueeies, more or less,
depending upon how one defines importance to the
domestic commercial and recreational fisheries-,
about which we should be particularly concerned
with respect to the effects of manmade environ-
mental modification. These resources have been
identified by code letters in Tables 1 and 3.
Species Which Have
Produced Major Changes
in Landings 1969-74
Of this group of about 25, nine have shown con-
siderable increases in landings in the area as a whole,
and these increases are almost certainly associated
with real increases in abundance, for reasons already
given. Another eight, or perhaps nine, have shown
-------
156
ESTUARINE POLLUTION CONTROL
considerable declines in landings, some of which have
been associated with real decreases in abundance.
Two additional species have produced major in-
creases in landings in the Rhode Isla.nd-Delaware
subarea only, and another three have declined only
in the Chesapeake subarea. Before discussing specific
environmental alterations which may have been
responsible it is helpful to examine briefly most of
these species to find out whether it is possible to
identify all or some of the reasons for the major in-
creases and declines.
AMERICAN OYSTER
The oyster industry of the area now produces
much less than it once did, but this still is the most
important oystering area in the nation. In the late
1950s and early 1960s one calamity after another hit
the industry, first a massive invasion of sea stars in
Long Island Sound, then specific diseases of oysters
in Delaware Bay and later in Virginia. It is not
known whether reduced water quality was a factor
in these epizootics, but it is possible that the new
stresses exerted on the resource by manmadc en-
vironmental changes may have made the oyster
more susceptible. These outbreaks almost destroyed
the industry in all major producing areas from New
York to Chesapeake Bay except in Maryland. The
relatively low-salinity waters of the northern part of
Chesapeake Bay are particular)} favorable for oyster
growing, and a massive rehabilitation program, con-
sisting mainly of replanting shell and transplanting
live oysters, by the State of Maryland on public
oyster grounds has more than doubled production
there1 since the low year 1963. This has demonstrated
that oyster production can be increased if govern-
ments are willing to spend the time and money to do
so. Whether this has contributed any increased
revenue to the local economy apparently has not
been demonstrated.
In the New York and Chesapeake areas some suc-
cess has been attained at raising seed oysters in
hatcheries. At this stage, however, opinion is divided
as to whether this is an economically sound method
of resolving the problem of highly variable natural
seed production. In the other Middle Atlantic states
private enterprise, sometimes with help from the
states, has been improving oyster production slowly.
In the area as a whole landings have increased about
15 percent from 1969 to 1973. tn Maryland the in-
crease has been more than 19 percent in the 5-year
period, but this and the modest gains in other states
have been partially off-set by a drop in Virginia
oyster production.
Much of the blame for the long-term decline in
oyster production has been attributed to careless
oystering practices, but water pollution also has
hurt the industry by forcing closure of more and more
areas for public health reasons, and by adversely
affecting survival of larvae and young. But aside
from setbacks by severe storms, and severe out-
breaks of predation or disease, industry and govern-
ment probably will be able to continue improving
the volume of oyster production to satisfy existing
demand.
HARD CLAM
Hard clam is harvested in all states in the Middle
Atlantic Estuarine area, but New York now is by
far the largest producer. Most of this production
comes from Great South Bay on Long Island. From
1929 to 1957 Rhode Island and New York vied for
first place in volume of hard clam landed, but since,
1957 landings have been rising in New York and
falling in Rhode Island. The decline in Rhode Island
probably has been caused by over-harvesting, but
the rise in New York landings almost certainly has
represented a large increase in abundance in Great
South Bay over the past 15 years. In both states the
industry has been plagued by water pollution,
which has led to progressive closing of productive
clam beds, especially on Long Island, where the
human population is growing more rapidly than in
any other area of the United States. Large areas of
clam bottom are closed or restricted along the New
Jersey coast, as in other states of the area. AVhere
clam digging is permitted the harvest is intense
because demand is good and prices high.
Many experienced baymen believe the available
resource is being overharvested. That conclusion is
hard to escape with respect to the Rhode Island
hard clam industry, which now produces only about
20 percent of the catch of 20 years ago. The harvest
in New York reached a peak in the period 1969 to
1973 and this is reflected in the record of landings
for the subregion (Table 1). Clam diggers in Great
South Bay report that they now must work harder
to make the same catch. Clam fisheries in the area
generally are subject to a negative form of manage-
ment, in which water quality is checked frequently
and grounds are closed to harvesting when coliforrn
bacteria numbers exceed minimum values. This is
important, but is not likely to maintain yields of
clam resources when the total catch needs to be con-
trolled also. The towns that have jurisdiction over
clam beds in Great South Bay, especially the town
of Islip, are now beginning to develop model re-
search and management programs based on im-
proved law enforcement, better understanding of
-------
FISHERIES
157
the dynamics of the resource, and transplantation
from polluted to clean areas. They dcservo to bp
encouraged and supported adequately.
SOFT CLAM
The soft clam industry of the area developed in
Maryland waters in the 1950s to supply markets
that could no longer be satisfied by a declining catch
in New England. The abrupt decline in landings
from 1971 to 1972 and 1973 (Table 3) was caused
by the effects of tropical storm Agnes, in June1 1972,
which brought down such a load of contaminants
from land drainage after heavy rains that the State
of Maryland found it necessary to prohibit harvest-
ing in the interest of public health. Before water
quality had recovered to safe levels, low salinities
and high water temperatures had killed most soft
clams in commercial clamming areas. Restrictions
were placed on the catch in 1972 and 1973 because
it was feared that the sharply-reduced resource
could not withstand an intense fishery. It was ex-
pected that landings would be considerably better in
1974, and monthly statistics received to date have;
borne this out.
WHITE PERCH
This species also is most abundant in the Chesa-
peake segment of the area. Commercial landings in
Chesapeake Bay have dropped to almost one-third of
the 1969 level, but this may not have been a conse-
quence of declining abundance. White perch is taken
in large quantities by sport fishermen in the area,
especially from New Jersey south, and the estimated
recreational catch is much larger than the commer-
cial catch. White perch is endemic to the inshore
estuary, and in Maryland waters of Chesapeake Bay
it is considered to be underexploitcd. The decline of
the commercial fishery there probably has been
caused by overcrowding and slow growth, which
has affected prices. In Virginia, on the other hand,
the species is believed to have been affected ad-
versely by water pollution, especially in the James
River.
NORTHEBN PUFFER
The major fishery for puffer in the area also has
been in Chesapeake Bav. Peak landings were reached
in 1965, and landings have been erratic and generally
downward since that time. The initial decline was
caused by excessive catches in 1965, and in 1966 a
considerable supply of puffer was held over in cold
storage from the previous year. The species is notably
variable in abundance, apparently from wide varia-
tion in success of spawning, which is especially evi-
dent in short-lived species; but, as with other species,
the causes of fluctuation are not known. Commercial
landings dropped from 4.6 million pounds to less
than 50,000 from 1969 to 1973 (Table 3). Consider-
able numbers are taken by sport fishermen in the
area as a whole, and the recreational catch has
dropped sharply in Now York and New Jersey as
well as in Chesapeake Bay.
SPOT
This is a fish of estuaries and inshore coastal
waters. It was once fairly important along the west-
ern end of Long Island and the New Jersey coast,
but commercial catches have been relatively minor
since the middle 1940s. The reason for the decline is
not known. Spot is a short-lived fish, and wide varia-
tions in success of spawning are reflected in catches
almost immediately. The increase of about 1.5 mil-
lion pounds in the commercial catch from 1969 to
1973 probably merely reflects such variations, for the
1970 catch was much higher (Table 3).
ELITE CKAB
The blue crab fishery has been centered in Chesa-
peake Bay, and landings to the north have histor-
cally been much smaller. Abundance and catches
have varied widely in the Chesapeake, but the long-
term trend in landings has been upward since the
1930s, although the peak catch of about 97 million
pounds in 1906 has not been exceeded. From Dela-
ware north the maximum catch was 6.6 million
pounds in 1950, and fluctuations have been relatively
much wider north of Chesapeake Bay. The northern
fishery declined after about 1957 and in New York
no commercial catch has been reported since 1961.
In the 1970s blue crab began to increase in abun-
dance in bays along the south shore of Long Island,
and although commercial fishing has not resumed in
New York, recreational catches of blue crab are
reported to have been substantial. Similar increases
have occurred in New Jersey and Delaware also.
The increased commercial catches in those states are
shown in Table 1.
It has been speculated that recovery of the re-
source in New York has been caused by the ban on
use of DDT and other chlorinated hydrocarbons for
mosquito control. Suffolk County, New York, was
reputed at one time to have the most massive spray-
ing program in the country. Partial recovery of the
-------
158
ESTUARINE POLLUTION CONTROL
fi,sher\ in New Jersey and Delaware also might have
had the same cause, but there is no proof that this
was so in any state. Whatever the cause, landings
by commercial and recreational fishermen north of
Chesapeake Bay have certainly increased substan-
tially, and the reported commercial catch has now
recovered to about 70 percent of the all-time high.
Because the recreational catch probably is much
larger now, the condition of the resource probably is
better than indicated by commercial landings alone.
ATLANTIC MENHADEN
The 5-year increase in landings of menhaden north
of Chesapeake Bay was substartial, but 1973 land-
ings were still far short of the maximum reached in
1956. In the Chesapeake subarea. however, men-
haden landings in 1972 were the highest on record.
in 1973 second highest. The 1970 Chesapeake catch
was the third best year on record and 1971 the sixth.
The intense fishery in the Chesapeake subarea now
takes mostly l-and-2-year-old immature fish, and
allows relatively few to survive long enough to
migrate farther north. The increased catch to the
north may have been related to greater abundance
in the south, or survival from local spawning may
have been hotter because competition from migrating
southern menhaden had been largely eliminated for
a while. That the menhaden resource has been able
to produce1 bumper crops despite the very heavy
drain on the stock by commercial fishing is reason-
ably good circumstantial evidence that levels of
water pollution in the area and other manmade
environmental changes have not been great enough
to affect the menhaden resource. If water pollution
or other human influences have affected the resource
in the past, it could be assumed that conditions have
improved recently as far as menhaden is concerned.
Virtually nothing is known about the environmental
variables thai control the size of the menhaden stock.
It is difficult to understand how this resource has
been able to survive such a heavy fishery, and indeed
produce such large catches after it appeared that the
stocks of menhaden had Seen seriously overfished.
It has been noted by several workers that just before
a fish stock collapses it may produce one or more
very large year classes. Xo explanation has been
advanced, except speculation that in some way the
internal regulatory mechanisms of the stock break
down. Thus, the recenr large catches of menhaden
in the area may be more a matter for concern than
for optimism. Event,- in the fishery in the last five
year:-; illustrate as well as any case history of a fishery
how poor is our capability to explain and predict
what is happening. Among other things it elso dem-
onstrates why it is so difficult 1 o assess the effects of
a specific pollutant, or even of water pollution gen-
erally. If pollution control is able to prevent further
deterioration of the estuarine environment; or even
better, if estuarine pollution can be reduced; the
inevitable decline of the menhaden fisheries of the
area, when it comes, will most likely be caused by
overfishing, abetted by the effects of natural en-
vironmental changes. A decline is assumed to be
inevitable if the present high demand for the product
continues, and the fishery remains essentially un-
regulated.
STRIPED BASS
Abundance and catches of striped bass in the area
have been following an upward trend for some 40
years, although the Chesapeake catch appears to
have leveled out for the past decade. This trend
shows in commercial and recreational landings, and
there is no good reason to doubt that abundance has
increased substantially, although the evidence is
circumstantial, as it is for most of the species under
discussion. This upward trend may not be evident
to the short-term observer, and it is not clearly
evident in the period 1969 to 1973 (Tables 1 and 3),
because the trend is superimposed upon a back-
ground of wide variations in spawning success which
have caused large short-term fluctuations in abund-
ance. Thus, in any period of a few years landings
are about as likely to be dropping as they are to be
rising.
The long-term trend in commercial landings can
be recognized clearly in the progression of highs and
lows. Since 1930 each major high in commercial
landings in the area as a whole has been higher than
the previous one, and each low also has been succes-
sively higher. It is very unlikely that this increasing
commercial harvest reflects only an increase in fishing
effort, for striped bass historically has been a popular
food fish. Sport catches also have been trending up-
ward, although a part of this increase must have
been associated with the demonstrated increase in
sport fishing effort.
It has been suggested that, because they spend the
first two years of their lives in the estuaries, striped
bass have been able to take advantage of the in-
creased nutrient supply contributed by domestic
wastes. This is only an hypothesis, which cannot be
confirmed by existing evidence that links cause and
effect. ^Nevertheless, it seems that, striped bass has
so far been able to cope successfully with human
alterations of the environment, as well as with con-
tinued intensive fishing.
This is not cause for complacency, however, for it
-------
FISHERIES
159
is not known for certain why striped bass apparently
h. s been increasing in abundance for more than a
quarter-century, nor even why, along with this
trend, abundance has fluctuated so widely in the
short run. It explains nothing to say that such fluc-
tuations are to be expected in resources which live in
a rich but highly variable and sometimes hostile
environment, although a more rational approach
toward fishery management might be possible if this
fact of variation were more clearly recognized. It
would be a matter of concern, of course, if the magni-
tude of such fluctuations were to increase. Nor is it
cause for complacency, even if proof were available
that added nutrients had favored striped bass abun-
dance, for the process is likely to be reversible if the
nutrient supply continues to increase.
ALEWIFE
Of all species which have declined in commercial
landings in the area since 1969, alewife landings
have dropped most sharply. In the Middle Atlantic
Estuarine Area the species is important commercially
only in Chesapeake Bay. Recently, from 80 to 90
percent of the catch is landed in Virginia, Chesapeake
landings of alewife dropped from about 34 million
pounds in 1969 to slightly more than 11 million in
1973, largely because large quantities have been
taken by foreign fleets offshore. As a consequence,
the United States, by negotiating bilateral agree-
ments with some nations, has imposed strict quotas
on some catches. There is no evidence that manmade
environmental changes other than fishing have
affected the resource in this area, but anadromous
species like alewife are especially vulnerable to estu-
arine water pollution.
AMEKICAN SHAD
The decline in landings of shad in the area, espe-
cially north of Chesapeake Bay, does not necessarily
signify a decline in abundance of the species. It is
known that economic factors rather than a scarcity
of fish have been the primary cause of the recent
decline of the Hudson River shad fishery. Modern
transportation and preservation facilities have made
it easier to ship shad from early runs to southern
rivers for marketing in New York at high prices.
By the time shad runs begin in the Hudson River
local demand has been sated because shad tradi-
tionally has been a short-term seasonal delicacy,
which forces the price too low for profitable fishing.
Actually, it is reported that water quality in the
Hudson River has improved in most areas, and off-
flavors of shad are less prevalent now. Like other
anadromous species, shad always will be vulnerable
to environmental deterioration. Foreign catches of
shad have not been reported.
MIGRATORY COASTAL FOOD FISHES
Several once important food fishes have made
encouraging recoveries in abundance in the period
since 1969, although commercial landings of these
species are still far below historic maximum levels.
Included are scup, weakfish, bluefish, summer floun-
der, and Atlantic croaker. All five are important
recreational species as well, and the saltwater sport
fisheries have benefited particularly from this partial
recovery. The magnitude of the recover}' probably
was greater than commercial landings suggest, be-
cause although statistics are not available on recrea-
tional catches of these species in the area except for
1970, it is demonstrated that the popularity of salt-
water sport fishing has been increasing. It must be
recognized that increased commercial or recreational
landings do not by themselves demonstrate an in-
crease in abundance, for increased catches may
simply signify greater fishing effort or improved
availability of fish to fishermen for some reason.
Assumption beyond reasonable doubt that these
species, and some others, have truly increased in
abundance comes from personal experience, con-
versations with scientists and fishermen, and in-
numerable reports in trade magazines and sport
fishermen's publications. Bluefish apparently have
been particularly abundant recently, as demon-
strated by large sport catches, and by unusual num-
bers taken by commercial and research trawlers
offshore. Croaker have been appearing again off the
coasts of Delaware and New Jersey, where they have
been virtually absent for years. As mentioned al-
ready, recent reports suggest that croaker catches
may increase dramatically in 1975 and subsequently.
Wide variations in abundance of all these species
have been noted several times in the past. No one
has identified the reasons for these fluctuations, and
no one can predict what will happen in the future.
The recent increase in weakfish abundance appears
already to have been temporary, as might be ex-
pected from past expedience. Weakfish appear to be
scarcer in 1974. All spend important parts of their
lives in the inshore estuary throughout the area,
and it can be assumed that they are affected in vari-
ous ways by what man does to the estuarine environ-
ment, but the extent of such effects is not known
except when major kills of obvious origin occur. Two
of the five, scup and summer flounder, are highly
vulnerable to foreign fishing. All, however, are taken
-------
160
ESTUABINE POLLUTION CONTROL
by domestic commercial and recreational fishermen
at all seasons, in various places, and by various gears.
Present laws and regulations, and the means to en-
force them, are totally inadequate to manage these
fisheries effectively, even if the necessary scientific
knowledge were available. It is theoretically possible
to regulate the harvest to maintain optimum yields,
but it is questionable whether the necessary public
cooperation and adequate funds will be available.
SILVER HAKE
Rather surprisingly, domestic commercial landings
of this species have increased since 1969 in the area.
For several years the International Commission for
the Northwest Atlantic Fisheries (ICNAF) has
been concerned about the stocks of silver hake and
has placed quotas on the catch. The species is not
abundant south of New Jersey, and commercial
catches from the area are determined more by the
market than by the supply of raw material. The in-
crease of about 2.5 million pounds in area landings in
the 5-year period cannot be interpreted necessarily
as an indication of increased abundance. Demand for
silver hake as human food is limited, and the price
is highly sensitive to market conditions. The in-
centive to fish for this species varies accordingly.
However, successful spawnings in 1971 and 1972 had
led to predictions of increased catches later.
AMERICAN LOBSTEK
The lobster harvest south of Cape Cod has been
growing for about a decade. This has been attributed
to two developments, a southward shift of lobster
stocks and increased abundance to the south in re-
sponse to declining coastal water temperatures, and
new fisheries on hitherto under-exploited lobster
stocks in relatively deep water on the continental
shelf. As -with so many popular explanations based
on observations of general environmental change,
the drop in water temperature and the increase in
lobster abundance were real, but the cause and effect
hypothesis has not been proven. Many lobstermen
think that the harvest has been too intense and that
the resource has been overfished. This is quite likely,
for in common with most other fisheries of the area,
the states have many fishery laws and regulations,
but there has been no control on the amount of
fishing. Uncertainty about the catch of lobster by
foreign fleets and by recreational fishermen further
complicates the problem.
Others think that a reversal of the environmental
trend that originally led to the growth of the fisheries
south of Cape Cod is now responsible for declining
catches. There is no evidence that manmade changes
other than fishing have affected lobster abundance in
the area. It is to be hoped that the relatively new
federal-state lobster research and management
program will help to answer these questions and
prevent overharvesting of lobster. Whatever the
cause, landings in the area by domestic commercial
fishermen dropped from a reported 8.2 million to 5.6
million pounds from 1969 to 1973 (Tables 1 and 3).
WINTER FLOUNDER
This coastal species does not make extensive
migrations, and it tends to be subdivided into local
populations which do not intermingle freely. It has
a history of wide fluctuations in abundance which
appear to have been caused by natural environmen-
tal changes. Winter flounder is not very abundant
south of New York. The decline in commercial land-
ings since 1969 (Table 1) has no great significance in
terms of abundance of the resource.
BUTTERFISH
In the late 1960s butterfish was considered to be a
very much underharvested species. Foreign fleets,
especially those seeking squid, now are taking in-
creasing quantities, and it is believed that the har-
vestable surplus is now being fully utilized. Under
such circumstances it could be expected that domes-
tic catches will be smaller than before, and this may
explain the drop of about 1.5 million pounds in
domestic commercial landings since 1969 (Tables 1
and 3). Possible effects of estuarine pollution cannot
be ruled out, however.
Estuarine Pollution
Water pollution probably shares top place with
uncontrolled fishing as the most serious threat to the
economic well-being of the domestic commercial
fisheries. The sessile endemic resources, like oyster,
clams, and mussels, are particularly vulnerable be-
cause, once the free-swimming larvae have settled to
the bottom, these resources are non-migratory. For
practical purposes conch also falls in this category.
Other estuarine endemic species can to some extent
avoid gross pollution unless they become trapped
for some reason. Little is known about sublethal
effects, although there is evidence that they can be
serious.
The most obvious damaging effects of estuarine
pollution to living resources and to commercial and
-------
FISHERIES
161
recreational fishing are the threats to human health
caused by intake and retention of human pathogens
by molluscan shellfish. The principal reason is that
shellfish such as oyster and hard clam frequently are
eaten raw. Many formerly productive shellfish
grounds in Rhode Island, along the Connecticut
shoreline, around the coast of Long Island, along
ocean coasts from New Jersey to Virginia inclusive,
and in Raritan, Delaware and Chesapeake Bays,
are now closed to shellfishing, or are open only under
special permit to take shellfish for further processing.
The areas so restricted include substantial parts of
coastal waters of the seven states in the Middle
Atlantic Estuarine Area, and the total area closed is
still increasing. The State of New York controls
about 425,000 acres of shellfish bottom, of which
about 100,000 acres are closed because water quality
does not meet minimum standards. Thirteen percent
of these waters were closed in 1973. This not only
progressively reduces the area of bottom approved
for shellfish harvesting and therefore the potential
yield, but also increases the likelihood that consump-
tion of shellfish taken illegally will cause outbreaks of
hepatitis or other human disease. Such outbreaks
not only are dangerous to public health, but also
can have disastrous immediate and long-term effects
on the economy of the industry through erosion of
consumer confidence. Oysters and clams to be eaten
raw bring the highest prices, so are harvested selec-
tively. Thus, the economic threat to the industry
is ever-present and very great. In the period 1969 to
1973 molluscan shellfisheries of the inshore estuaries
of the Middle Atlantic Estuarine Area produced a
harvest for which fishermen received more than
$35 million a year, on the average, which was more
than 38 percent of the landed value of all fish and
shellfish caught commercially in the area.
In addition to these non-migratory resources,
several other species remain within the inshore
estuaries throughout their lives, and thus may be
more vulnerable to water pollution than the highly
migratory species which come and go. Blue crab is
the most important of these, especially in Chesa-
peake Bay, where it is the most important edible
species by weight and second most important in
landed value. Among the highly migratory species,
the anadromous fishes are especially vulnerable
because the young are born in those parts of the
estuaries most susceptible to pollution. Included
are such valuable species as striped bass, alewife,
and shad. Sublethal effects in the natural environ-
ment are extremely difficult to detect and their
influence on the living resources difficult to evaluate.
Thus, it should not be assumed that such effects
are insignificant.
Mass mortalities of menhaden and other species
sometimes occur in estuaries. Such mortalities in
Chesapeake Bay often have been associated with a
natural deficiency in dissolved oxygen content of the
water in the central part of the bay and in the lower
parts of the major rivers in that area, especially the
Rappahannock, Potomac, and Patuxent. Domestic
and industrial waste disposal has aggravated this
natural condition by creating an additional oxygen
demand. A similar condition, which has become more
serious as the human population has grown, exists
in summer in the western part of Long Island
Sound. Interpretation of the effects of these man-
made changes is very difficult for at least two rea-
sons, both of which have been demonstrated dra-
matically in Chesapeake Bay in the 1969-1973 per-
iod. Hurricane Agnes in 1972 caused heavy mortality
of molluscs, partly, but not entirely, from intensifica-
tion of natural conditions. Unusually great abun-
dance of certain species, such as menhaden, will per se
increase the numbers of fish killed, and perhaps the
frequency of kills, even if the environment has not
changed. These interactions of natural and man-
made forces make it extremely difficult to measure
cause and effect, because we do not know specifically
how these factors operate individually, or how they
interact.
At some places in the area, e.g. in Barnegat Bay,
N.J., and Long Island Sound, N.Y., waste heat
from power plants has had beneficial effects on
sport fishing. Species such as bluefish, striped bass,
white perch, menhaden, and others become en-
trained in the warm plume of discharged cooling
water and support recreational fisheries in winter
where none existed before. Plant shutdowns or sud-
den weather changes sometimes cause sudden mor-
talities. The power companies arc seldom praised
for such fortuitous creation of new sport fisheries,
but they are immediately vilified when a kill occurs.
It seems unlikely that such kills can have significant
permanent or even immediate effects on the re-
sources involved, although local effects can be
catastrophic.
In summary, the only certainly identifiable effects
in the natural environment of estuarine water pol-
lution on the living resources and their fisheries are:
1) transfer of human pathogens; 2) closure or re-
striction of harvesting on molluscan shellfish beds;
and 3) catastrophic releases of pollutants in which
cause and effect are obvious.
It follows that we have no positive explanation
why many important species in the Middle Atlantic
Estuarine Area have increased substantially in abun-
dance in the period 1969-1973, and thus cannot
attribute these recoveries to pollution abatement,
-------
162
ESTUAKINE POLLUTION CONTROL
where abatement has occurred. However, many lab-
oratory studios and some controlled field studies
have shown that all species studied are affected
adversely by many components of water pollution.
This is sufficient to support the conclusion that
many pollutants are deleterious to fishery resources
and to human health.
Domestic Management of the Fisheries
A primary objective of fishery management is to
maintain the resource in a condition to produce the
optimum sustainable yield, which means economic
as well as biological health. Despite the short-term
increase in landings from 1969 to 1973, which ap-
parently was not the result of an equivalent increase
in fishing effort, it is fairly obvious from the long-
term record that we have not achieved effective
fishery management in the Middle Atlantic Estu-
arine Area. The declining total catch of food fish
and shellfish, despite constant and progressive shift-
ing from resource to resource, is sufficient evidence
of that. There has been no dearth of opinion as to
what i . wrong with the fisheries of the area and
what are the remedies. Many of these views have
been translated into laws, and all of the states have
voluminous codes of fishery statutes, few of which
have any basis in fact.
The only exceptions in the seven-state area are
the oyster and soft clarn management programs of
the State of Maryland, already mentioned. These
have more than doubled oyster production in that
state in 10 years, 25 percent of which increase oc-
curred from' 1969 to 1973 (masked in Table 3 by a
concurrent drop in Virginia) ; and are bringing about
recovery of the soft clam resource and fishery. In
New York State the town of Islip, which controls
about one-third of the bottom of Great South Bay,
has embarked on a promising program to manage
the hard clam resource. If successful, these programs
will be models for other local communities and states
to follow. The difficulties should not be underesti-
mated, however. Not the least of these is the extreme
difficulty and cost of law enforcement associated
with resources in shallow water, near shore, and
easily accessible to the public generally. Without
adequate enforcement, the best program in the
world will fail.
Foreign Fishing
Fishing by other nations on the continental shelves
surrounding the United States has become the major
concern of domestic fishermen. It has overshadowed
all the other problems of the coastal fisheries of the
nation and of the Middle Atlantic Estuarine Area.
This dominance of foreign fishing over all other
fishery problems probably occurred because it pre-
sented an obvious "villain" which could be blamed,
rightly or wrongly, for most of the ills of the domestic
commercial and recreational fisheries. This scapegoat
has no means of fighting back at the domestic level.
Foreign fishing has seriously affected some tradi-
tional American fisheries, such as Georges Bank
haddock and Pacific halibut, to name only two.
Foreign fishing as a serious problem for the domestic
fisheries of the area began in 1965 and 1966, when
the Soviet Union took a large harvest from the
strong 1963 year class of haddock on Georges Bank,
and then began to extend its operations to the south
and west. As early as 19(53, however, the USSR did
some fishing south of Georges Bank. Now at least
10 nations besides the United States are fishing in
the Middle Atlantic Bight.
Of some 47 major species in the domestic commer-
cial and recreational fisheries of the Middle Atlantic
Estnarine Area, IS are also being taken by foreign
fleets on or over the continental shelf. The other 29
domestic species either do not enter the high seas
beyond the 12-mile zone of national fishery jurisdic-
tion or do so in such small numbers or for so short
a time that incidental catches by foreign fishermen
would not be a serious problem. The only exceptions
are menhaden, which sometimes are found beyond
12 miles in substantial numbers, especially off Vir-
ginia and North Carolina in winter, and surf clam,
which is widely distributed on the continental shelf
in the area. It does not seem likely that specialized
foreign fisheries for these species will develop. The
surf clam has been declared a creature of the conti-
nental shelf under the provisions of the 1958 Geneva
Convention, which thus reserves this resource to the
United States.
Table 5 shows reported landings of the 18 species
or groups of species fished jointly by domestic arid
foreign fleets in the area. The foreign catches are
probably higher than they should be for direct com-
parison, because they include Georges Bank. Virtu-
ally none of the domestic landings listed comes from
Georges Bank.
Some of the species migrate between waters over
Georges Bank and the Middle Atlantic Estuarine
Area (e.g. Atlantic herring and mackerel), others,
such as winter flounder, probably do not. The ale-
wife resources of Chesapeake Bay definitely have
been affected by the foreign fisheries, as the decline
in domestic landings illustrates. Foreign catches of
scup have been relatively small, but even these small
catches are of concern because the scup resource has
-------
FISHERIES
163
Table 5.—Domestic (upper row) and foreign (lower row—ICNAF subareas 5z and 6) commercial catches of major species taken by both groups in Middle Atlantic
Estuarine Area 1966-73. Weights in millions of pounds. * = 50,000 pounds or less. — = no catch reported
Species
Alewife
Scup
Yellowtai! flounder - -
Silver hake _ _
Winter flounder . ..
Atlantic herring
Butterfish.
American (o6ster._ ,.
Black sea bass
Squids..- _ __ . ._-
Atlantic mackerel ,
Red hake
Atlantic cod. „ ,
Tf/ensn
Sharks
1966
34.4
25.9
2.0
9 8
9.5
0.2
9.2
472.4
9.2
0.2
7.4
305.1
5.4
8.6
4.0
3.2
2.6
2.4
15.0
1.5
239.4
1.2
90.8
0 9
3.1
0.9
0.9
19.4
0 5
1967
30.7
14.3
18.6
1.8
8.1
11.4
0.2
11.0
195.4
9.0
0.2
1.7
479.5
4.9
5.1
4.8
2.5
2.9
2.1
41.9
1.4
117.5
2.2
52.0
0.6
1.1
0.1
0.5
5.3
3 2
1968
36^5 1
49.1
13.9
5.1
6.3
12.3
0.2
9.7
132.0
7.6
0.2
0.8
822.1
3.4
11.9
6.5
2.4
3.0
3.7
2.9
123.7
1.1
29.3
2.9
61.5
0.5
19.8
0.1
0.4
8.8
0 2
1969
33.9
79.8
10.3
1.1
3.9
13.5
42.1
9.0
166.4
7.7
15.0
0.1
674.4
4.7
33.0
8.2
2.4
2.7
15.6
1.7
239.8
1,2
108.5
3.4
46.7
0.1
4 2
0.1
0.2
19.2
0.1
1970
21.1
43 6
9.5
0.4
5.7
*
15.4
6.8
8.1
72.6
8.2
1.1
*
540.8
3.8
19.8
9.5
2.1
1.8
33.0
2.6
450.6
1.6
16.1
3.8
23.8
*
0.1
0.1
12.3
3.1
•
1971
13.1
47.8
8.1
2.2
5.2
1.5
20.8
4.6
8.3
162 0
8.2
3.7
2.5
570.3
3.4
13.9
9.3
0.2
1.2
1.7
44.7
1.8
517.5
1.3
59.3
3.1
26.0
*
1.8
0.1
0.1
24.2
2.0
1.1
1972
12.1
27.5
8.7
3.7
5.3
0.9
28.0
12.1
10.9
233.0
6.6
5.5
0.7
377.8
1.5
12.3
7.2
0.4
1.6
2.2
104.5
2.9
843.0
1.6
162.4
2.7
25.8
*
8.1
0.3
0.1
46,3
2.2
0.4
1973
11.3
14.0
10.2
3.9
9 3
*
25.1
1.4
11.5
254.7
6.6
3.4
0.4
435.9
3.2
39.3
5.6
0.5
2.4
3.0
121.4
2.8
836.3
1.9
137.7
3.4
28.0
*
6.2
0.8
0.1
33.8
1.3
0.2
decreased sharply in abundance since the 1950s.
Summer flounder catches by foreign fishermen also
have been small, but foreign catches may be larger
than reported because some summer flounder may
have been included in unclassified catches. Relatively
large foreign catches of yellowtail flounder have led
to quota limits on this species by ICNAF, but the
effects on the fisheries of the Middle Atlantic Estu-
arine Area are not evident in the record of domestic
landings. Yellowtail flounder in the area probably
belong to a distinct stock, and catches on Georges
Bank probably would not affect this stock. Although
landings of yellowtail flounder in the area from 1969
to 197,3 do not reflect it, this flounder has been
seriously reduced in abundance.
Catches of silver hake by foreign fleets in the area
have been very large. This fishery also is regulated
by ICNAF quotas. Domestic landings show no ap-
parent effects from foreign fishing, but the catch of
silver hake is determined more by demand than by
abundance of the resource, and thus commercial
catches will not reflect variations in abundance.
Since foreign fishing began in the area, catches of
winter flounder have been relatively small, although
pulse fishing produced a large foreign catch in 1969
and a fairly large catch in 1972. The decline in
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164
ESTUARINE POLLUTION CONTROL
domestic catches of winter flounder may have been
a consequence of foreign fishing, but the demon-
strated existence of local stocks and wide natural
variations in abundance make such a conclusion
questionable. The domestic fishery for Atlantic her-
ring in the area is negligible because there is little
demand for adults of the species. The large foreign
catches are apparently of little importance to the
domestic fisheries, although it is not certain that
the Maine sardine fishery \vill be unaffected. It would
be interesting to know whether this large catch of
an abundant species has had any indirect effects on
other living resources of importance to the domestic
fisheries. It appears that the domestic fisheries have
been harvesting only a small fraction of the butter-
fish resource, but with the development of large
foreign fisheries the resource1 now is believed to be
fully utilized.
Reported foreign catches of northern lobster have
been relatively small, but it has been suspected that
incidental, unreported, catches are larger. Lobster
supports an important traditional American fishery,
and any foreign catch is a matter of concern. Recent
declaration of lobster as a creature of the continental
shelf by the United States may correct the situation,
if other nations are willing to accept the rather
strained definition as it applies to this species.
No foreign catches of black sea bass have been
reported, except in 1964, when about l.oOO metric
tons were listed, but sea bass migrate to the outer
continental shelf in winter and incidental catches
are suspected. Demand for squid is very limited in
the United States, and this species has been much
underexploited by the domestic fisheries, but squid
are important in the diet of many resources of major
interest to domestic fishermen. The large recent
foreign fishery is of relatively minor concern to the
domestic fisheries at present. Al least 50 percent.
and perhaps a greater proportion of the catch of the
foreign squid fleet is butterfish.
Atlantic mackerel, like Atlantic herring and squids,
is not in great demand in the United States. It has
been a part of domestic strategy in negotiating with
other nations that fish off this area to encourage
them to concentrate on such abundant species of
minor value to Americans. This strategy probably
is less palatable to American recreational than com-
mercial fishermen.
The domestic harvest of red hake probably is
much underestimated b}r official catch statistics.
This is the major species in the industrial trawl
fisheries of Nantuckot Shoals, i catch which is not
reported by species. Red hake also supports a minor
sport fishery. Most of the foreign catch of Atlantic
cod comes from Georges Bank and north. In total
catch domestic landings in the area have shown no
obvious effects of foreign fishing. Sea robins are not
of great importance to the domestic commercial
fisheries of the area, but are apparently much more
important in the sport fisheries. Only small catches
of tilefish have been reported by foreign fleets, but
the species occupies a very specialized habitat at
the edge of the; continental shelf, and incidental
foreign catches are suspected. The domestic com-
mercial fishery for sharks is small, but sharks are of
interest to sport fishermen. The effects of the rela-
ti\el\ large foreign catch on the sport fisheries are
not known; the relatively large recent fisheries for
bluefin tuna in the North Atlantic Ocean have
brought that resource to a dangerously low level.
Vigorous attempts now are being made to limit
catches stringently.
In summary, it is clear that foreign fishing in the
area has had measurable adverse effects on some
fishery resources of interest to domestic commercial
and recreational fishermen, and that foreign catches
of some others are a matter of concern. In addition,
as long as foreign fishing continues in the area,
incidental catches of some resources will reduce to
some extent the probability of measuring the effects
of other variables on the abundance arid condition
of estuarine stocks. On the other hand, it must be
noted that a number of important fishery resources
of the area are not subject to foreign fishing, and
that stocks of some of these, like soft clam and
northern puffer, have declined in the last five years
much more sharply than some which arc taken
by foreign fleets. This is not to say that foreign
fishing is not having its effects, but it does empha-
size the complexity's of the situation and the need
to pay more serious attention to domestic fishery
management.
Social-political Issues
In the United States, the individual states, and
sometimes counties or even towns, have broad juris-
diction over fisheries in adjacent waters. Local gov-
ernments make the, laws and regulations and arc:
responsible for surveillance and enforcement. Federal
jurisdiction over fisheries is restricted to inter-
national waters or to interstate commerce in fishery
products. In the Middle Atlantic Estuarine Area
the federal government takes the lead in ICNAF
affairs and bilateral negotiations as they relate to
the fisheries of the area, but this places many migra-
tory resources under double jurisdiction, because
important species like scup, summer flounder, sea
bass, and others move seasonally between territorial
and international waters.
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FISHERIES
165
International fishery management in the area has
been criticized as inadequate or ineffective, but in
reality this is too extreme a view. For one thing, it
ignores what should be obvious, that domestic fishery
management, which among other things includes
pollution control, has failed almost completely. In-
ternational agreement is difficult to achieve, and
arrangements under ICNAF and the various bi-
lateral agreements that apply to the area have not
been perfect. However, it cannot be denied that the
fisheries would have been in much worse condition
today if the federal government had not entered
into negotiations with other nations fishing off this
section of the coast. The results of these arrange-
ments have shown that the interests of the United
States fisheries have been served best when we can
present reasonable scientific evidence that a problem
exists. Scientific research has been the basis of most
of our international fishery agreements, but scien-
tific evidence has played a very small role in deter-
mining fishery policy or in developing laws and
regulations for most fisheries of territorial waters.
This most important point has not been clearly
recognized by many.
State and sometimes local governments in the
area support scientific research on fishery resources
and their environment. Some of the information
developed has been used as a basis for regulating
domestic fisheries, but usually fishery laws and regu-
lations have been based on opinion rather than fact,
and are much more likely to be concerned with who
makes the catch than how the catch should be
limited. In other words, domestic fishery manage-
ment in estuarine waters is much more likely to be
based on struggles between vested interests than
on scientific objectivity. This contrast between inter-
national and domestic management strategies does
much to explain why international arrangements,
difficult as they are, have been much more success-
ful than domestic.
Many state and local fishery laws and regulations
tend to perpetuate inefficiency and prohibit or re-
strict efficient harvesting methods. This adds to
the cost of catching fish, which is already relatively
high because vessel construction, fishing gear, repair
and maintenance, insurance, and other costs are
greater than anywhere else in the world. In addi-
tion, most of the domestic fisheries suffer from
overinvestment of capital and labor, another form
of economic inefficiency. In the absence of scientifi-
cally-based catch quotas, or better still, limitations
on numbers of fishermen and units of gear, there is
no effective management of the resource. This, cou-
pled with wide natural variations in abundance of
individual resources, makes it virtually impossible
to detect the effects of other manmade environmen-
tal changes.
Communication Between Fishery Interests
Commercial fishery interests in the United States
have many protagonists and some antagonists. Com-
mercial fishermen, processors, and distributors have
many organizations, local, state, and national, which
represent their interests in various ways. These in-
clude groups of fishermen, boat owners, unions, and
trade organizations of various kinds. At the political
level, commercial fisheries have surprisingly strong
support, especially in such key fishing areas as the
Pacific Northwest, Alaska, New England, and the
Gulf of Mexico. In fact, some believe that in certain
regions political interest and support at the national
level is far greater than the economic value of the
industry warrants.
On the administrative side the National Marine
Fisheries Service of the Department of Commerce
has the major federal responsibility for fishery re-
search, development, and services to the commercial
fishing industry and to recreational saltwater fishing
interests. Other responsibilities reside in the Depart-
ments of State, Interior, Treasury, Agriculture,
Labor and other departments and specialized agen-
cies. Each state has an agency with prime responsi-
bility for marine fishery management and research.
Some coastal states have separate agencies for fin-
fish and shellfish management, and often jurisdiction
over anadromous fisheries is divided between coastal
and inland fish and wildlife agencies. As already
mentioned, research and management are sometimes
further complicated by delegation of certain respon-
sibilities to local governments.
In the Middle Atlantic Estuarine Area efforts
have been made to coordinate research and manage-
ment between states through the Atlantic States
Marine Fisheries Commission (ASMFC), an inter-
state organization of more than 30 years standing,
to which all 15 Atlantic coastal states belong. The
Commission has made progress in certain directions,
but has not yet succeeded in getting the states to
cooperate in effective fishery management programs.
The compact which created the Commission named
the Fish and Wildlife Service of the Department of
the Interior as its primary research agency. When
the National Oceanic and Atmospheric Administra-
tion was created this function was transferred to the
Department of Commerce. All of these agencies,
groups, and key individual members exert influence
in a variety of ways, through the communications
media, by serving on advisory committees or com-
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166
ESTUARINE POLLUTION CONTROL
missions, testifying before congressional or state
assembly committees or at public hearings, lobby-
ing, and so on. Vested interests and inadequate or
out-of-date information often stimulate controversy
rather than solutions. It would be interesting to
determine how much human energy and economic
resources have been devoted to these ends, to no
avail.
Sources of Information
Knowledge about the fisheries and the living re-
sources and their environment resides in various
forms in all individuals and groups described above,
in conservation organizations, in universities, in the
staffs of international fishery commissions, and in
the United Nations family of organizations, espe-
cially FAO and UNESCO. The amount of knowledge
available through such diverse groups is consider-
able, but it varies widely in accuracy, quality, and
breadth, depending on the experience, competence,
and interests of individuals and groups, and on the
amount of information and expertise readily avail-
able to them. Between them, these individuals and
institutions know, or have access to information
on, abundance, distribution, and biology of the re-
sources, including latent or underutilized species;
the condition of those resources and the effects of
manmade or natural environmental variables; fish-
ing grounds and fishing methods; markets, prices,
and economic structure of the industry; processing,
distribution, and consumption of fishery products;
imports and exports; the world fishery picture; and
major problems of the marine fisheries.
None of this information is complete, and its
adequacy and accuracy vary between resources and
between specific fisheries. Much of it has been
gathered by indirect methods and by scanty sam-
pling and it may be difficult or impossible to esti-
mate levels of accuracy. For example, statistics of
commercial fishery landings published by the federal
government, sometimes in cooperation with individ-
ual states, are generally considered to underestimate
the catch, whereas the national surveys of saltwater
sport-fishing probably have produced overestimates
of the sport catch. Some attempts have been made
to measure the accuracy of these estimates, and
these have tended to confirm th<' statements made
above, but these attempts have been confined to
limited regions and short periods of time.
The literature on pollutants and their effects on
fish and shellfish is voluminous, and has been accu-
mulating at an accelerating pace. Experimental
studies in the laboratory have demonstrated that
manv constituents of domestic and industrial wastes
do specific damage to estuaririe organisms. Such
substances may kill fish and shellfish directly or
exert less obvious, but sometimes much more damag-
ing, effects on the resource as a whole, including
modification of spawning habits, decreased growth
and increased mortality of larvae and young, reten-
tion and transfer of human pathogens, concentration
of heavy metals and pesticides, and increased inci-
dence of deformities such as fin rot and crooked
vertebral columns. It has been shown conclusively
that DDT and other pesticides, developed to kill
insects, are particularly harmful, in very low con-
centrations, to marine animals related to insects,
such as crabs and shrimps. But pesticides kill or
otherwise affect other invertebrates and fishes too.
When it comes to measuring the effects of pollutants
on fish and shellfish in the natural environment the
problem is much more difficult because natural en-
vironmental variables, some seasonal, some longer-
term, and fishing as well, have substantial effects
on abundance. Against this background of fluctuat-
ing abundance it is nearly impossible to detect the
effects of a single factor. Laymen are prone to be
much more positive about cause and effect than
scientists, but some scientists have further compli-
cated the issues by making hasty judgments or by
drawing unwarranted conclusions.
Much published work on effects of water pollu-
tion or of specific pollutants on fish and shellfish
resources is fragmentary and inconclusive and not
of much help for interpreting what is happening in
the natural environment. Many agencies and indi-
viduals are doing research and gathering data. Some
of the work is good, some mediocre, some trivial.
Better coordination and review would be desira-
ble. Since 1969 several useful reviews have been
published An example is "The Water's Edge,"
sponsored by the Institute of Ecology and the Woods
Hole Oceanographies Institution in 1972. This and
some other pertinent publications are listed in the
bibliography, which makes no pretense of being
comprehensive. The conclusions and recommenda-
tions in this report are worth study. Too often such
documents are published and then forgotten.
Factors of natural human origin that affect sur-
vival, abundance, and general health of fish and
shellfish in the natural environment are probably
so numerous, and reinforce or buffer each other in
so many complicated ways, that it probably is un-
realistic to pretend that our understanding of cause
and effect will ever be very clear. This is not neces-
sarily a deterrent to effective control. If we know
from laboratory studies that DDT or other similar
compounds are lethal in small doses to blue crab
or shrimps, then that should be sufficient cause to
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FISHERIES
167
decide that DDT should not be allowed to contami-
nate the waters of the Middle Atlantic Estuarine
Area or anywhere else. If we know from laboratory
studies and from analysis of animals collected in
the natural environment that heavy metals, pesti-
cides, and other toxins are concentrated in living
tissues at levels higher than concentrations in the
environment, that should be sufficient cause to pro-
hibit additions of such substances to the waters of
the coastal zone. If we know that addition of oxygen-
demanding substances to a body of water will reduce
the dissolved oxygen content to levels below that
necessary for survival or for normal biological func-
tioning, then that should be sufficient cause to
prohibit excessive manmade oxygen demand in fish
and shellfish spawning, nursery, or feeding areas.
Available data for understanding the effects of
water pollution on commercial fishery stocks are
reasonably good for some species or stocks of fish
and shellfish. For example, it cannot be denied that
water pollution destroyed the oyster industry of
Greater Raritan Bay in New Jersey and New York,
and is responsible for closure of most of the clam
beds there. In the early 1960s a serious outbreak of
hepatitis was traced to clams illegally harvested
from Raritan Bay. There is no question that water
pollution played a role in reduced marketability of
shad from the Hudson River. In some places in the
area it is clear that water pollution was at least
partially responsible for declining runs of shad and
other anadromous fishes. Aside from clear-cut exam-
ples like these, or accidents in which cause and
effect is beyond reasonable doubt, presumption of
pollution-associated effects on commercial fisheries
is largely hypothetical. It is just as logical to suppose
that the long-term upward trends in abundance of
striped bass and blue crab in Chesapeake Bay were
caused by nutrient enrichment from domestic wastes,
as that the decline and recovery of blue crab stocks
in New Jersey and New York were caused by heavy
use and then prohibition of use of DDT. Data do
not exist to support or to deny these hypotheses,
and it is difficult to conceive of ways in which direct
confirmation could be obtained.
SUMMARY AND CONCLUSIONS
In the 5-year period since the "National Estuarine
Pollution Study" was completed landings of domes-
tic commercial fish and shellfish in the Middle At-
lantic Estuarine Area have almost doubled in weight.
Although landings alone are not a very accurate
index of abundance of the living resources of an
area, other evidence demonstrates beyond reasonable
doubt that, although the supply of some resources
in the area has declined substantially since 1969,
others are much more abundant today. Generally,
the domestic commercial fisheries in the area appear
to be in better condition now than they were five
years ago, but this may be transitory and more
apparent than real. Certainly, many stocks are much
less abundant than they were. It has been demon-
strated that the total living weight of fishery re-
sources in the ICNAF area is substantially less than
it was a decade ago.
It is tempting to attribute this general increase in
abundance and catches to the beneficial effects of
estuarine pollution control and abatement. Although
there is no evidence to refute this hypothesis, neither
is there evidence to support it. The short-term im-
provement in commercial fishing in the area must
be reviewed against a long-term decline in catches
of most food fish and shellfish, in which short-term
fluctuations often have masked long-term trends.
Among the most important sources of short-term
fluctuations are some partly-understood and many
unknown natural variations in the environment, the
effects of which cannot be distinguished from the: ef-
fects of manmade changes. Also unknown for most
species are the effects of essentially unregulated
domestic commercial fishing, and of deliberate or
incidental catches by foreign fleets. Totally un-
known, but certainly important, are the effects of
removals of fish and shellfish by recreational fisher-
men. Sport catches of some species, such as bluefish
and striped bass, are many times as great as the
commercial catch. Unless these fishery-associated
sources of attrition can be brought under control,
the odds are high that domestic catches of traditional
fishery resources will continue t o decline in the long
run, and that commercial fishing will continue to
shift to underutilized resources. Such latent resources
are not limitless, and they probably are underutilized
either because markets are limited or the cost of
harvesting is too high.
The extreme difficulty of measuring the effects of
water pollution or pollution control on the commer-
cial fisheries of the area as a whole need not be a
deterrent to positive action. Molluscan shellfish are
an important segment of the commercial fishing
industry in this area, and they are worth preserving
and enhancing. The molluscan shellfish resources
also are important because they can be considered
as endemic resources in the waters of each state,
and therefore can be managed unilaterally without
the need for interstate or international cooperation.
Theoretically, management of these resources should
be relatively easy, but as a practical matter it obvi-
ously has not been in most states of the area. In
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168
ESTUARINE POLLUTION CONTROL
some of the states it is not certain that a real
incentive exists.
The area of bottom closed to shellfishing, and
trends in closures or reopenings of such areas, may
be a useful index of the condition of estuarine
waters. If effective management of mqlluscan shell-
fisheries can be achieved, and the effects of natural
environmental change and economic trends in the
shellfish industries are sufficiently well understood,
it may then be possible to evaluate the benefits of
pollution control by monitoring estuarine shellfish
grounds and measuring the condition of the living
resource. In this connection, a better index of envi-
ronmental quality on shellfish beds is needed, to
replace the standard coliform bacteria count now
in use.
It is possible that nutrient enrichment from waste
disposal has increased the biological productivity of
certain estuarine fishery resources in the area. If
this is so, it was entirely serendipitous. The experi-
ence of the oyster industry in Great South Bay,
N.Y., has demonstrated that uncontrolled additions
of nutrients can also destroy an estuarine commer-
cial fishery. For these reasons, and in the interest
of public health as well, control and abatement of
estuarine water pollution must have high priority.
At the same time, the possibility of benefits to
commercial and recreational fisheries from controlled
addition of nutrients merits investigation. Where
deliberate enrichment has been tried elsewhere, the
results have been promising.
AUTHOR'S NOTE
Since this paper was written, information about
commercial fishery landings in 1974 has become
available. The figures are preliminary, and for some
states have not yet been published, but it is clear
that the upward trends noted for some estuarine
species are continuing, especially for scup, summer
flounder, and blue crab. In New York State com-
mercial landings of blue crab were reported in 1974
for the first time in eleven years, and direct observa-
tions confirm the increased abundance of this species.
Increasing abundance of summer flounder has been
confirmed by a recent study of sport catches and
effort in New Jersey (Festa, 1975). Black sea bass
can be added to the list of resources increasing in
abundance. The commercial catch of this species
north of Chesapeake Bay has almost tripled since
1970, and sport catches are increasing also (Berra-
fato, 1975). On the other hand, the effects of foreign
fishing on yellowtail flounder were first noted south
of Cape Cod in 1974. Landings of this species
dropped sharply from Rhode Island south.
Recovery of the blue crab resource may not be a
good omen for the hard clam industry. Blue crab is a
serious clam predator. Interactions between species,
as populations wax and wane, create a shifting back-
ground against which the effects of water pollution
are difficult to measure.
An encouraging note was sounded in July 1975
when the New York Department of Environmental
Conservation announced that it would reopen some
9,200 acres of shellfish bottom in Long Island Sound
because water quality has improved.
REFERENCES
This is not intended to be an exhaustive list of pertinent
literature. It contains principally references to publications
from which supporting data or statements were drawn and
a few papers which seemed to cover broadly the subject of
water pollution and fisheries. Other sources may be found in
the literature cited by these papers, and in the other papers
in this volume.
Anonymous. 1970a. National Estuarine Pollution Study.
U.S. Dept. Interior, Fed. Water Poll. Control Agency,
Washington, D.C.: ix+633 p.
Anonymous. 1970b. National Estuary Study. U.S. Dept.
Interior, Fish & Wildl. Serv,, Washington, D.C., 7 volumes.
Anonymous. 1974. New Jersey Landings, Annual Summary
1973. U.S. Dept. Commerce, NOAA, Natl. Marine Fish.
Serv. & N.J. Dept. Envir. Protect., Div. Fish, Game &
Shellf: 7 p. and earlier reports in this series for 1971 and
1972.
Anonymous. 1974. New York Landings, Annual Summary
1973. U.S. Dept. Commerce, NOAA, Natl. Marine Fish.
Serv. & N.Y. Dept. Envir. Conserv.: 8 p. and earlier
reports in this series for 1971 and 1972.
Anonymous. 1974. Virginia Landings, Annual Summary 1972.
U.S. Dept. Commerce, NOAA, Natl. Marine Fish. Serv.,
Va. Marine Resources Comm., & Potomac River Fish.
Comm.: 9 p. and 1971 report in this series.
Berrafato, Frank. 197S. Return of the sea bass. Long Island
Fisherman 10(28), July 1975:16.
Boone, Joseph. 1974. The hardheads are back. Comm. Fish.
News, Md. Dept. Nat. Resources 7(6) :3.
Brey, William L. 1974. Maryland Landings, Annual Summary
1972. U.S. Dept. Commerce, NOAA, Natl. Marine Fish.
Serv., Md, Dept. Chesapeake Bay Affairs, and Potomac
River Fish. Comm.: 11 p. and 1971 report in this series.
Butler, P. A. 1971. Influence of pesticides on marine eco-
systems. Proc. Roy. Soc. London B177-.321-329.
Calabrese, Anthony. 1972. How some pollutants affect
embryos and larvae of American oyster and hard-shell
clam. Marine Fish. Rev. 34(11-12) :66-77.
Davis, Dr. Jackson. 1974. Telephoned information about soft
clam, alewife, croaker, and northern puffer in Chesapeake
Bay. Va. Inst. Marine Science, Gloucester Point, Va.
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FISHERIES
169
Deuel, David G. 1973. 1970 Salt-Water Angling Survey.
U.S. Dept. Commerce, NOAA, Natl. Marine Fish. Serv.,
Current Fish. Statistics No. 6200:iii+54 p.
Dewling, It. T., K. H. Walker, and P. T. Brezenski. 1972.
Effects of pollution: Loss of an $18 million/year shell-
fishery. In: Marine Pollution and Sea Life. M. Ruivo (ed.)
Fishing News (Books') Ltd., London: 624 p.
Festa, Patrick. 1975. Creel census of the summer flounder
sport fishery in Groat. Bay, New Jersey. N J. Dept. Plnvir.
Protection, Div. Fish, (lame and Shellf., Nacote Creek
Research Sta., Prog. Kept, for 1974.
Gates, John M. and Virgil J. Norton. 1974. The benefits of
fisheries regulation: A case study of the New England
yellowtail flounder fishery. Univ. R. 1. Marine Adv. Serv.,
Tech. Kept, 21:35 p.
Ginter, Jay J. C. 1974. Marine fisheries conservation in New
York State: Policy and practice of marine fisheries manage-
ment. N.Y. State Assembly Scientific Staff and N.Y. State
Sea Grant Program: vi+64 p.
Grosslein, M. D., F-. G. Heyerdahl, and H. Stern, Jr. 1973.
Status of the international fisheries off the Middle Atlantic
coast. Tech. Ref. Doc. prepared for the bilateral negotia-
tions of USA with USSR and Poland, May 1973. Natl.
Marine Fish. Serv., N.E. Fish. Center, Lab. Ref. No.
73-4:117 p. (xerox'.
Hamons, Frank L., Jr. 1973. Survey indicates threefold in-
crease in clamming areas for 1974 season. Comm. Fish.
News, Md. Dept. Nat. Resources 6(6):i-2.
Fodder, V. M. 1975. Statistical Bull Vol. 23 for the year
1973. Internatl. Comm. Northwest Atl. Fish., Dartmouth,
Canada: 277 p. and earlier reports in this series since 1966.
Jensen, Albert C. 1974 Managing shellfish resources under
increasing pollution loads. Proc. Gulf & Caribb. Fish. Inst
26th Ann. Sess., Oct. 1973: 173-180.
Jensen, Albert C. 1974. New York's fisheries for scup, summer
flounder and black sea bass. N.Y. Fish & Game J. 21(2) :126-
134.
Ketch urn, Bostwick H. (ed). 1972. The Water's Edge.
Critical problems of the coastal zone. MIT Press, Cam-
bridge, Mass: xx-f-393 p.
Knapp, William E. 1974. Marine commercial fisheries of New
York State: An analysis by gear. Unpublished M.S.
Research Paper Marine Sciences Research Center State
Univ. of N.Y., Stony Brook, N.Y.: 108 p. + appendices
(to be published).
Medeiros, William Henry. 1974. Legal mechanisms to re-
habilitate the Hudson River shad fishery. N.Y. State
Assembly Scientific Staff and N.Y. State Sea Grant
Program, Albany, N.Y.: xiv+65 p.
Murphy, William J. 1974. Rhode Island Landings, Annual
Summary 1972. U.S. Dept. Commerce, NOAA, Natl.
Marine Fish. Serv., and R.I. Dept. Nat. Resources, Div.
Conserv.: 11 p. and 1971 report in this series.
Rice, T. R. and J. P. Baptist. 1974. Ecologic effects of radio-
active emissions from nuclear power plants. Chap. 10 in:
Human and Ecologic Effects of Nuclear Power Plants.
Leonard A. Sagan (ed). Charles C. Thomas, Publisher,
Springfield, 111.: 373-439.
Riley, Frank. 1974. Personal communication: information on
domestic commercial fishery landings 1971-1973. National
Marine Fisheries Service, Gloucester. Mass.
Schaaf, W. E. and G. R. Huntsman. 1972. Effects of fishing
on the Atlantic menhaden stock: 1955-1969. Trans. Am.
Fish. Soc. 101(2) :290-297.
Slobodkin, L. B. 1973. Summary and discussion of the sym-
posium. In: Fish Stocks and Recruitment. B. B. Parrish
(ed). Cons. Int. Expl. Mer, Rapp. Proe.-Verb., 164:7-14.
Waldichuk, Michael. 1974. Coastal marine pollution and
fish. Elsevier Pub. Co., Ocean Management 2(]):1-60.
Wheeland, Hoyt A. 1973. Fishery Statistics of the United
States 1970. 'U.S. Dept. Commerce, NOAA, Natl. Marine
Fish. Serv., Stat. Dig. 64:489 p. and earlier reports in this
series by various authors in various predecessor agencies
back to'1880.
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OUR ESTUARIES
AND COMMERCIAL
FISHING TRENDS
GORDON C. BROADHEAD
Living Marine Resources, Inc.
San Diego, California
ABSTRACT
The estuarine habitat of fish and shellfish is eroded by both natural and man-caused environ-
mental changes. Shrimp and menhaden are discussed principally, noting the effects on them
of salinity, temperature, and turbidity. The soft-bottomed embayments peripheral to the estuaries
offer preferred living conditions. They are more productive—and more vulnerable—than the
open waters of the estuaries. Recommendations are made for preserving these estuarine habitats.
INTRODUCTION
Coastal marshes arc among the most productive
areas of the world, largely because they function as
nutrient traps, occupy stable areas which are shel-
tered from destructive wave action and are nearly
free of desiccation hazards. Nourishment is supplied
by freshwater rivers and streams carrying loads of
rich silt. At the same time, highly dependable tidal
currents remove undesirable wastes and bring in
larvae and oxygen-rich waters. Because of these
characteristics, our coastal estuaries support a great
variety and abundance of organisms. Perhaps even
more important is that estuarine areas function as
nurseries for a great many fish and other marine
animals—including many commercial species—which
spend most of their adult lives in deeper, offshore
waters.
During 1973, the United States landings of sea-
food items totaled 4.7 billion pounds, valued at just
over $900 million to the fishermen. Many of the
important species of commercially important fish
and shellfish depend significantly upon estuarine
environment during at least a portion of their life
cycle. Various authors have estimated that about
two-thirds of our total commercial fish harvest is
made up of estuarine-dependent species. The list is
lengthy and, therefore, I am confining my examples
to two important fisheries, penaeid shrimp and
menhaden, which each support commercial opera-
tions along the east and gulf coasts of the United
States. 1'Jach of these resources has residence in
estuarine areas during portions of their life history,
and are thus exposed to the potentially detrimental
effects of estuarine degradation.
THE RESOURCES AND
THEIR ENVIRONMENT
Shrimp
There are three commercially important species of
shrimp in the gulf and south Atlantic areas: the
brown shrimp, Penaeus aztecus; the white shrimp,
P. setiferus; and the pink shrimp, P. duorarutn. Two
lesser important species are the seabob, Xepho-
penaeus kroyeri and the royal red shrimp, Hymen
openaeus robustus.
During 1973, the gulf and south Atlantic landings
of penaeid shrimp were 207 million pounds, valued
at $199 million to the fishermen.
Adult penaied shrimp spawn offshore. The eggs
hatch within hours and the nauplii become part of
the zooplankton. Within three to five weeks the
young shrimp enter the bays and estuaries as post-
larvae and there they grow rapidly, moving seaward
and into the commercial fisheries within months.
In the estuaries, shrimp form part of the mobile
benthos. Brown and white shrimp prefer soft muddy
substrate, while pink shrimp prefer the firmer sandy
bottoms. The species are omnivorous, eating plants,
animals and organic and inorganic detritus. Penaeid
shrimp are essentially an annual crop with only a
small percentage of individuals surviving more than
one year.
A number of factors influence the occurrence and
success of spawning and the subsequent growth and
survival of the young shrimp. Unseasonally low
temperatures which occur following spawning are a
significant factor in the survival of metamorphosing
shrimp and postlarval shrimp in the estuarine nur-
sery areas.
171
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172
ESTUARINE POLLUTION CONTHOL
Salinity appears to be a dominant factor in the
distribution and growth of bro\\n shrimp in the
estuarine systems, llairifall is the primary factor
which influences bay and upper estuarine salinities.
Runoff is the major factor influencing salinities in
the lower estuaries. Barrett and Gillespie (1973)
showed that years of above average discharge of the
Mississippi River have been associated with poor
production years for brown and white shrimp, while
below average discharges resulted in good produc-
tion years for the species. They noted that rainfall,
combined with river water, may dilute estuarine
and near-shore salinities to below the tolerance
limits for penaeid shrimp and, therefore, substan-
tially limit available optimum nursery areas. Other
environmental factors such as turbidity, unseasonal
meteorological conditions and pollution may affect
shrimp populations.
No definitive studies have been conducted which
relate the effects of turbidity to shrimp abundance
and distribution. However, casual observations by
several authors suggest that bays and coastal areas
which are turbid produce the greatest concentrations
of shrimp. Ingle (1952) and Viosca (1958, cited
in Mackin, 1961) have both mentioned the fact
that shrimp are apparently attracted to the turbid
waters near shell dredges in Louisiana and Alabama.
Kutkuhn (I960) felt that turbid estuaries and bays
provided shrimp with both a supply of nutritive
detritus and protection from predation. Lindner and
Bailey (1969) established a qualitative relationship
between turbid plumes and shrimp in the Gulf of
Mexico using Gemini spacecraft photography and
commercial catch statistics for the brown shrimp in
the northwestern Gulf of Mexico. Their conclusions
were conjectural because of the Lick of "ground-
truth" data on the fishing grounds.
Mock (1966) noted that the abundance of small
white and brown shrimp was substantially greater
along a natural coastline than along an adjacent
area altered by bulkheading.
Menhaden
The United States landings of menhaden are com-
prised of four species: Brevoortia tyrannus and B.
smithi on the Atlantic coast and B. patronus, B,
quentri and B. smithi in the Gulf of Mexico. B.
tyrannus dominate the catches in the Atlantic and
B. patronun in the gulf. During 1973, menhaden
landings for the Atlantic and gulf coasts totalled
1.9 billion pounds, valued at $73 million.
Commercial landings of menhaden in the Gulf of
Mexico are largely 1- and 2-year-old fish. These
ages also dominate in the Atlantic landings, although
there are considerable volumes of 3-, 4- and 5-year-
old fish in certain years.
Menhaden are curyhaline. The adults spawn off-
shore during the fall and winter and the larvae
migrate inshore and live in the estuaries for five to
10 months, at which time they retiirn to the offshore
waters for further growth, followed by sexual matu-
rity and spawning. Their early life history pattern is
remarkably similar to that of the penaeid shrimp.
Reintjes (1970) noted ''menhaden are an im-
portant component in an estuary. After they trans-
form from the slender, transparent larvae to juve-
niles, they become filter feeders. They swim about
in schools, usually with their mouths gaping open,
to filter the small planktonic animals and plants from
the water. They have a complex gill apparatus that
forms a basketlike sieve that removes all but the
smaller particles from the water. As the bulk of the
organisms eat algae or the remains of higher plants,
menhaden are principally herbivores. Menhaden are
one of the few fishes (mullet is another) that live by
grazing on the plants in the- estuaries. They arc at
one of the lowest trophic levels near the bottom of
the food chain and provide food, in turn, for nearly
all the carnivores that are large enough to oat them.
This then forms both sides of the coin: The role of
estuaries in the life cycle of menhaden and the role
of menhaden in the ecology of estuaries."
Reintjes and Pacheco (1966) discussed physical,
chemical and biological factors affecting the survival
and growth of young menhaden. Mass mortalities
have been attributed to sudden temperature changes,
low concentrations of dissolved oxygen, very high
salinities, and toxic pollutants.
Gunter and Christmas (I960) noted that surface
temperatures of coastal waters are a major factor
in the migration patterns of menhaden. Harper
(1973) stated that menhaden indicated a preference
for clear water. However Tagatz and Wilkeiis
(1973) found that more juvenile menhaden, were
caught in clear water estuaries at night than during
the day while there was no such diurnal difference in
turbid waters. They suggest that the turbid waters
offer the young menhaden protection against preda-
tion. Kroger and Guthrie (1972) found indications
of higher predation rates on young menhaden taken
in clear water estuaries than in turbid areas.
Kemmerei et al. (1973) Mi
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FISHERIES
173
determined. However, the relationship is a well-
known phenomenon that is utilized extensively by
the fishermen and their spotter aircraft pilots in
locating schools of menhaden.
Spotter pilots report that schools of menhaden
are capable of creating turbid clouds ("dragging
mud") as they pass over muddy bottoms. The fact
that these clouds appear in water as deep as 100 feet
as well as in shallow water, suggests that this
behavior may be either a feeding response or a
protective measure (Lichtenheld, 1970). Thus, in
the shallow area of the Mississippi Sound, men-
haden schools could have been responsible for the
turbid plumes observed by Maughn and Marelstein.
The Estuaries
The destruction of estuarine zone wetlands as a
result of natural processes and the activities of man
is a continuing and serious problem. Except for L
few estuaries in Alaska, every one of the nation's
estuaries has been modified by man. Twenty-three
percent have been severely modified, 50 percent
moderately modified and 27 percent slightly modified.
"The National Estuary Study," carried out by the
United States Department of the Interior, concluded
that the destruction of estuaries is proceeding at a
rate that will spell their end within a few decades.
The most severe adverse environmental impact
to estuaries has resulted from sewage pollution,
dredging and filling to create land, channel dredging
for navigation, industrial wastes, and ditching and
draining wetlands. Additionally, there is river im-
poundment and flow control, pesticide pollution,
solid waste disposal, seawalls, dike and levee con-
struction to prevent flooding, mining and oil pollu-
tion. Chapman (1972) noted that for the south
Atlantic, Caribbean and Gulf of Mexico estuarine
regions, about 50 percent of the area has been
moderately impacted and in the gulf, 34 percent has
been seriously impacted. Important legislative steps
have been taken in recent years to halt this irrevers-
ible trend.
PROBLEMS IN DETECTION OF
ADVERSE EFFECTS
Despite documented degradation of the estuaries,
there are few examples where changes in the overall
productivity of shrimp and menhaden can be related
directly to these environmental changes. One case
may be the sharp decline in(the shrimp production of
Sabine Lake, Tex., concurrent with the completion
of the Toledo Bend Dam on the Sabine River.
A substantial portion of the runoff to the shrimp
nursery grounds in the Sabine Lake area was reduced
during late 1966 and 1967 during the filling of the
reservoir. During the 5-year period following the
closure of the dam, river discharge as measured at
Ruliff, Tex., was one-third lower than an earlier
5-year period, 1955-1959, prior to closure. In addi-
tion, the seasonal pattern of runoff was altered sub-
stantially with the peak period occurring in April
rather than May, The discharge data and catch
information are shown in Figure 1. Shrimp catches
from Calcasieu Lake, an adjacent estuary not under
the influence of the Sabine drainage, are included for
comparative purposes. There, the shrimp production
has been maintained while the Sabine Lake produc-
tion has fallen to near zero.
Such relationships are extremely difficult to isolate
and verify on a real time basis. The measurement of
the abundance of commercial species of fish and
shellfish is, at best, a very crude science.
Measures of apparent abundance are always in-
direct. That is, an index of commercial fishing vessel
success, adjusted for seasonality and standardized
for vessel efficiency, becomes the standard for year-
/ 1 Mean Five Years
/ \ 1955-1959
1962 19G4 1966 1968 1970 1972
FIOUBE 1.—River discharge and shrimp production.
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174
110 -j
100-
90-
ESTUARINB POLLUTION CONTROL
80-
70-
60-
50-
40-
30-
20-
10-
1
1974
1958 1960 1962 1964 1966 1968 1970 1972
FIGUKK 2.—Landings of brown and white shrimp, Gulf of Mexico ports, 1957-74.
to-year comparisons. However, the abundance of
marine fish and shellfish populations are influenced
by a complex of factors:
• Broad natural changes in marine climatology.
• Short-term variations in spawning and survival
of young due to changes in ocean and estuarine con-
ditions.
• Commercial fishing operations.
• Manmade changes in estuarine habitat.
National Alarine Fisheries Service maintains long-
term historical series on catch, effort and apparent
abundance for gulf menhaden and shrimp fisheries.
Changes in overall shrimp production levels are
complex to analyze, as there are three principal
species, taken by thousands of vessels, on a number
of fishing grounds. Figure 2 depicts the historic
catches of brown and white shrimp along the gulf
coast since 1957. The 19-year trend in production is
upward. However, substantial year-to-year fluctua-
tions make it difficult to detect any real change in
the average level of productivity until long after
such a change has occurred.
The most recent data for menhaden is shown in
Figure 3 (from Anonymous, 1974). Several im-
portant points are illustrated. First, there is a good
long-term correlation between the amount of fishing
effort and the resulting catch. Second, there appear
to be cyclical deviations, since 1956, of the individual
years about this average relationship. These fluctua-
tions are about eight years' duration and are
ESTIMATED AVERAGE MAXIMUM SUSTAINABLE YIELD (MSYJ
GULF MENHADEN PURSE SEINE FISHERY
,,,-"7"
70<' / /*
;"' ><
/ /_ (478,QOQ TONS)
(460,000 UNITS)
100 200 300 400
EFFORT (THOUSANDS OF VESSEL TON-WEEKS)
FIGURE 3
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FISHERIES
175
probably the result of changes in ocean and estuarine
climate on the spawning and survival of the very
voung menhaden. The extreme values (1957, 1958,
1961, 1962, 1967 and 1971) exhibit an average
deviation of 35 percent from the line of best fit. Thus,
the trend in population abundance after the 1968
season suggests that the definite downtrend in
catches since 1961 was signaling overfishing or
detrimental effects of habitat degradation or a com-
bination of both. However, the following year,
catches began to increase again and peaked in 1971.
With much the same level of effort, catches have
been substantially lower in the 1971—1974 period.
Is the present decline part of the cycle or is the
decline signaling problems with the population?
Obviously, we will not be able to say until four or
five more years of information have been added to
the data base.
The instability of marine populations has been
noted by Longhurst et al. (1972). They emphasize
the difficulties in sorting out and identifying the
myriad of factors affecting marine fish populations.
They also demonstrate that these changes can only
be revealed and measured by deliberately mounted
and well-sustained monitoring programs. They note
a real lack of understanding that pollution monitor-
ing schemes, in the ocean, can succeed only if the;
natural effects of the changing physical environment
are both monitored and understood on a continuing
basis. Natural fluctuations are often incorrectly
ascribed to the effects of pollution; conversely, the
effects of a modified environment frequently pass
undetected in the system.
Erosion of habitat on a broad scale is gradual in
nature and thus direct effects upon populations of
commercial species of fish and shellfish are almost
impossible to detect on a real time basis, amid the
noise of short-term variability and long-term effects
of fishing pressure and climatic change. Thus, we
may be faced with the fact that these habitat
modifications are completed and nonreversible by
the time we can measure and document specific
relationships for important species.
WHAT SHOULD WE DO
It is obvious that major research studies designed
to document the direct relationship between estu-
arine habitat degradation and the deterioration of
our major fisheries for shrimp, menhaden and other
commercially important species will not be too
useful in preventing these losses, but will prove
largely an interesting historical documentation for
later analysis.
What is required is an approach which states
flatly that the shallow, turbid, soft-bottomed em-
bayments in the interior of marsh areas around the
periphery of the estuaries are the preferred habitats
of many important migrating marine animals. These
areas are much more productive per unit area than
the open waters of the bays and estuaries. They
represent about 30 percent of the total of 26 million
acres of estuarine waters in the United States.
These shallow areas, mostly less than six feet in
depth, are the most vulnerable to man's activity.
Fishery dollar values per acre of nursery ground
must be computed and adj usted for their renewability
and for their direct and indirect impact upon our
economy. Commercial values must consider not only
the initial revenue to the fishing vessels (the tradi-
tional reporting method) but also the ripple economic
impact upon the broad supporting infrastructure of
the industry. Economists project that each dollar of
primary industry income results in fivefold impact
on our nation's economy. A dollar of landed catch
value is divided among fishermen, shipyards, equip-
ment and machinery suppliers, fuel dealers, provi-
sioners, the insurance industry, the financial com-
munity, and many other smaller support elements.
Sport-fishing and recreational values are more dif-
ficult to compute and compare with commercial
values which are primary in nature. They are large,
nevertheless, and the dollar impact (discounting the
aesthetic values) is at least equal to that of the
commercial industry.
Tihansky and Meade (1974) provide an excellent
review of the problems associated with measurement
of the economic values of estuaries to United States
commercial fisheries.
The placing of a real fishery value, per acre, on the
critical shallow estuarine areas, is not an easy task
but it should and can be done on a region-by-region
basis, utilizing currently available information. A
research team of fishery biologists and marine econo-
mists, with practical business orientation, could
expect wide-scale fishing industry cooperation, both
commercial and sport, in such an endeavor. The
results would provide agencies, legislature, and in-
dustry with a sound basis for decisions with respect
to estuarine zone usage where conflicts of interest
arise.
REFERENCES
Anonymous. 1974. A Discussion Paper on the Current Status
of the Gulf Menhaden Fishery and Some Resource Manage-
ment Issues. Report to Gnif States Mar. Fish. Comm. by
NMFS Atlantic Estuarine Fisheries Center.
Barrett, B. B., and M. C. (Jillespie. 1973. Primary Parlors
Which Influence Commercial Shrimp Production in Coastal
Louisiana. Tech. Bull. No. 9., La. Wildl. and Fish. Comm.
-------
176
ESTUARINE POLLUTION CONTROL
Chapman, Charles R. 1972. The Impact on Estuaries and
Marshes of Modifying Tributary Runoff. Proceedings
Second Symposium 1972. Coastal Marsh and Estuary
Management. LSU Division of Continuing Education,
Baton Rouge, Louisiana, p. 235-258.
Gunter, G., and J. Y. Christmas. 1960. A Review of Literature
on Menhaden with Special Reference to the Gulf of Mexico
Menhaden, Brevoortia patronus Goode. U.S. Fish Wildl.
Serv., Spec. Sci. Report Fish. 363.
Harper, D. E., Jr. 1973. Effects of Siltation and Turbidity on
the Benthos and Nekton, In: Texas A & M Research
Foundation, Environmental Impact Assessment of Shell
Dredging in San Antonio Bay, Tex., Vol. 5, Appendix D5.
Ingle, Robert M. 1952. Studies on the Effect of Dredging
Operations Upon Fish and Shelfish, Technical Series No. 5,
October, 1952. State of Florida Board of Conservation, the
Division of Oyster Culture, Tallahassee, Fla.
Kemmerer, Andrew J., Joseph A. Benigno, Gladys B. Reese
and Frederick C. Minkler. 1973. Summary of Selected
Early Results from The ERTS-1 Menhaden Experiment.
Fishery Bulletin Vol. 72, No. 2, 1974, p. 375-389.
Kroger, Richard L. and James F. Guthrie. 1972. Effect of
Predators on Juvenile Menhaden in Clear and Turbid
Estuaries. Marine Fisheries Review, Nov.-Dec., 1972. Vol.
34, Nos. 11-12. p. 79-80.
Kutkuhn, Joseph H. 1966. The Role of Estuaries in the
Development and Perpetuation of Commercial Shrimp
Resources. A Symposium of Estuarine Fisheries, American
Fisheries Society Special Publ. No. 3; p. 16-36.
Lichtenheld, Richard W. 1970. Schooling and Migratory
Behavior. U.S. Fish Wildl. Serv. Circ. 350. p. 26-29.
Lindner, Milton J., and James S. Bailey. 1969. Distribution
of Brown Shrimp (Penaeus aztecus aztecus IVES) as
Related to Turbid Water Photographed from Space. U.S.
Fish Wildl. Serv. Fish. Bull: Vol. 67, No. 2. p. 289-293.
Longhurst, Alan, Michael Colebrook, John Gulland, Robin
Le Brasseur, Carl Lorenzen, Paul Smith. 1972. The In-
stability of Ocean Populations. New Scientist, 1 June, 1972.
Mackin, John G. 1961. Canal Dredging and Silting in Louisiana
Bays. In: Publications of the Institute of Marine Science,
Univ. Texas, Port Aransas, Tex. Vol. 7. p. 262-314.
Maughn, Paul M., and Allan Marmelstein. 1974. Application
of ERTS-1 Data to the Harvest Model of the United States
Menhaden Fishery. For: Goddard Space Flight, Center,
Greenbelt, Md. p. 1^9.
Mock, Cornelius R. 1966. Natural and Altered Estuarine
Habitats of Panaeid Shrimp. Proc. of the Gulf and Carib-
bean Fisheries Institute, 19th Annual Session, p. 86-98.
Reintjes, John W. 1970. The Gulf Menhaden and Our
Changing Estuaries. Proc. Gulf and Caribbean Fisheries
Institute, 22nd Annual Session, p. 87-89.
Reintjes, John W., and A. L. Pacheco. 1966. The Relation of
Menhaden to Estuaries. In: R. F. Smith, A. H. Swartz
and W. H. Massmann (editors), A Symposium on the
Estuarine Fisheries, p. 50-58. Am. Fish. Soc. Spec. Pub. 3.
Tagatz, Marlin E., and E. Peter H. Wilkens. 1973. Seasonal
Occurrence of Young Gulf Menhaden and Other Fishes
in a Northwestern Florida Estuary. NOAA Tech. Rep.
NMFS SSRF 672.
Tihansky, D. P., and N. F. Meade. 1974. Estimating the
Economic Value of Estuaries to United States Commercial
Fisheries. Manuscript.
Viosca, Percy, Jr. 1958. Report of the Seafood Section,
Oysters, Water Bottoms and Seafood Division, Seventh
Biennial Report. Wildl. and Fish. Comm. 1956-1957, p.
96-106.
-------
LIMITING FACTORS
AFFECTING THE
COMMERCIAL FISHERIES
IN THE GULF OF MEXICO
SEWELL H. HOPKINS
SAM R. PETROCELLI
Texas A&M University
College Station, Texas
ABSTRACT
The gulf coast, with 13 percent of the U.S. coastline producing one-third of the Nation's fisheries
catch, is enriched by the Mississippi and many smaller rivers. The same river water that brings
in food and fertility also brings pollutants from cities, industries and agricultural areas. So far,
this pollution has not provably affected the commercial fisheries, except that closure of some
bay areas by health authorities has hurt the oyster fishery. Hut over 95 percent of gulf fisheries
production is based on species that depend on estuarine nursery areas and are therefore vulner-
able to pollution and other man-made changes in estuaries. Fish kills and decreased reproduction
in some areas warn of what could happen if conditions get worse. Research is needed on the
costs as well as the benefits of man's activities, including pollution and pollution control, as
population increases.
DESCRIPTION OF THE COAST
OF THE GULF OF MEXICO
Inshore Waters and Estuaries
Some 1,000 miles of the gulf coast has an excess
of precipitation over evaporation, and all of the
nearshore gulf waters are strongly diluted by fresh
water from floods or heavy local rains. All gulf coast
rivers together flow into the gulf at the average
rate of approximately 829,000 cubic feet per second
or roughly 600,000,000 acre-feet of fresh water annu-
ally. Approximately 80 percent of this flows into
the gulf on the Louisiana coast. Alabama contributes
8.3 percent, Florida 6 percent, Texas 4.4 percent,
and Mississippi 1.3 percent of the fresh water enter-
ing the northern Gulf of Mexico.
The northern gulf is dominated by the Mississippi
River, which flows into the gulf at the average rate
of 620,000 cubic feet per second. The river water
brings with it large quantities of dissolved nutrients,
suspended organic matter, and nutrients absorbed
on clay and silt particles, so that there is a broad
area (over 400 miles) of enriched estuarine water
surrounding the mouth of the Mississippi. Gunter
(1963, 1967) called this the "Fertile fisheries Cres-
cent" and pointed out that 21 percent of the total
fisheries catch of the United States was landed
within this area. The percentage is higher now.
Estuarine waters on the gulf coast include large
areas of low marsh that are flooded by fresh water
in rainy weather and by salty water during high
tide periods. Also, estuarine waters do not end at
the "passes" (bay mouths), but continue into the
gulf for variable distances. St. Amant (1973) esti-
mated the gulf coast estuarine area, including only
areas with water of salinity 5 parts per thousand
(ppt) or higher, at 7.84 million acres (12,250 square
miles). Chapman (1973) gave a figure of 12.4 million
acres (19,375 square miles). Gunter (1967) counted
33 "bay systems and sounds" averaging about 550
square miles, or a total of 18,150 square miles, but
pointed out, that the actual area of estuarine waters
normally includes parts of the gulf that have low
salinities, and varies according to season and weather
conditions from 17,000 to 20,000 square miles (10.88
to 12.80 million acres'). (See Fig. 1.1
Commercial Fisheries
of the Gulf States
Although it makes up only 13 percent of the total
coastline of the United States, the gulf coast in 1972
produced 32 percent of the total U.S. fisheries catch,
based on value, and 34 percent of the volume. In
1973, gulf coast fishermen landed 1,229 million
pounds of marine and estuarine fish worth $63
million, and 246 million pom ids of,salt i\ater shellfish
worth $170 million. The total value of gulf fisheries
landings was $223 million in 1972 and $233 million
in 1973, based on prices paid fishermen at the dock.
177
-------
178
ESTUAKINE POLLUTION CONTROL
I
o
"o
o
W
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FISHERIES
179
(Of course the wholesale value was higher, and the
value of processed fishery products was much higher;
retail value is roughly three times dock value.)
Several features of the gulf coast commercial catch
are worth noting here.
(I) It is dominated by the shellfisheries, and espe-
cially by shrimp, crabs and oysters, usually worth
three to four times more than the much greater
volume of finfish.
(2) The finfish volume is dominated by menhaden.
This industrial fish, which is processed to produce
oil, fish meal and solubles worth ultimately many
times the original value of the catch, is the number
one fish of the United States in volume and among
the top five in value. Approximately 60 percent of
the U.S. menhaden catch is landed on the gulf coast.
(3) Nearly all of the gulf coast catch, including
practically all of the menhaden, is made within the
waters of the United States, or in international
waters within a few miles of the U.S. coast. Of the
important commercial fishes, only groupers and red
snappers are caught mainly beyond the 12-mile
limit, and they make up only 1 percent of the
volume and 2 percent of the value of the total gulf
coast catch.
(4) As Gunter (1967) has pointed out, 97.5 per-
cent of the total commercial fisheries catch of the
gulf states is made up of fishes and shellfishes that
spend all or part of their lives in estuaries. A few
species, such as the commercial oyster, live their
entire lives in estuarine waters.
(f>) Because gulf coast commercial fisheries are
based on species that are mostly estuary-dependent,
they are especially vulnerable to pollution. The
fresh water of gulf coast rivers brings in residues
of pesticides, defoliants, fertilizers, et cetera, used
to produce crops on millions of acres of farmland.
On the- way to (he gulf the rivers receive discharges
from many city sewage systems and industrial
plants, drainage from oil fields and mines, and so
forth. So far, these contaminants do not seem to
have reached the gulf in concentrations sufficient
to conspicuously harm commercial fisheries, but
that seems possible in the future if pollution con-
tinues to increase.
The typical gulf life cycle involves spawning in or
near the gulf, in \\ater of near-oceanic salinity, mi-
gration of the nculy hatched juveniles to estuarine
waters, then growing up in the shallows where young
fish are protecteu from predators lv, vegetation, by
poor visibility due to muddy water, or by salinity
too low for most predacious fishes. These estuarine
shallows are known as nursery areas. Some fishes
leave the btvs before becoming mature and others
spend all or almost all of their lives in estuarine
waters. The commercial fisheries can be maintained
only by keeping the nursery areas productive.
Gunter (19G7) and others have pointed out that
most of the gulf commercial catch is made close
inshore (inside the 12-mile limit, or within sight of
shore), in waters that can be considered estuarine
since they are affected by the fresh water and tur-
bidity from rivers. For instance, the menhaden fish-
ery, the most important commercial fishery in the
gulf by volume of catch, is conducted entirely in
estuarine waters of the gulf, according to Gunter
(citing Christmas, Gunter and Whatley, 1960);
catches are made in salinities from 6 to 32 ppt
(compared to 34-36 ppt in the open gulf). Most of
the drums, croakers, sea fronts, flounders, king
whiting, and sheepshead are caught even closer
inshore, or in the bays themselves.
The shellfishes, by far the most valuable part of
gulf coast commercial fisheries, are even more estu-
arine than the finfishes. The principal commercial
species of shrimp (white, pink, and brown) spawn
in the gulf, but most of the progeny that survive to
complete the life cycle are those that find their way
into the estuaries and grow up in the low-salinity
nursery areas (Venkataramiah, Lakshmi, and Gun-
ter, 1974). Shrimp are worth roughly 10 times as
much as all finfishes combined, excluding menhaden.
The second most important crustacean, the blue
crab, also spawns in the gulf and grows tip in the
estuaries; females return to the gulf (or lower ends
of bays) when mature, but most males spend their
entire lives in estuariue waters.
The third most, important shellfishery is that
based on the commercial oyster, which spends its
entire life cycle in estuarine waters. Oyster produc-
tion has been hurt more by pollution than any other
fishery. When a bay is closed or condemned because
of contamination by domestic sewage or industrial
wastes, the oyster is the main species aflected, and
it is oyster fishermen and oyster farmers that are
hurt (not to mention oyster dealers and consumers).
Other commercial molluscs are of relatively minor
value on the gulf coast.
What is the productivity of gulf coast estuarine
waters in pounds of commercial fish and shellfish
per acre? Depending on whether one accepts the
12.4 million acres of estuarine water (including
gulf waters of lowered salinity > calculated by Chap-
man (1973) or the 7.S4 million acres of St. Amaru
(1973), the present commercial production is 117
or 1X5 pounds per acre per year. -Mullet, croaker,
spot, sea trouts and drums could probably stand
up under heavier commercial fishing. Present com-
mercial catches of some species are small compared
to mortalities from natural causes, as pointed out
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180
ESTUARINE POLLUTION CONTROL
by Simmons and Breuer (1962), and by Gunter in
several publications. It seems possible that a com-
mercial fisheries production of 200 pounds per acre
per year could be reached and maintained in the
gulf coast estuarine area.
NATURAL FACTORS LIMITING
GULF COAST FISHERIES
Climatic and Physical Conditions
Temperature has two important effects on gulf
coast fisheries: the high average temperature of the
water hastens sexual maturity and shortens life of
some fishes, and the extreme low temperatures of
the shallow bays during northers cause mass mor-
tality of fish every few years.
Gunter (1950) pointed out that such abundant
fishes as the croaker, spot, spadefish, butterfish and
harvestfish, which are important commercial food
fish in the Chesapeake Bay and Middle Atlantic
states, seldom reach marketable size on the gulf
coast.
The most spectacular effect of temperature is the
killing of millions of fish by extreme cold spells
about once per decade in Texas (Gunter, 1941,
1945, 1952a, 195(5; Simmons, 1957; Breuer, 1962:
Simmons and Breuer, 1962) and in Florida (Storey
and Gudger, 1936; Storey, 1937, and others). The
best documented cold kill, in 1951, was estimated
by Texas Game and Fish Commission biologists to
have killed 60 to 90 million pounds of fish on the
Texas coast. Simmons and Breuer (1962) stated
that "Catastrophic freezes occurring about every 10
years have each destroyed more fish than have been
harvested commercially for the past 50 years." Actu-
ally the bay water does not freeze, but drops quickly
to about 4°C (39°F) and remains there for several
days. Observed mortalities have included very few
animals other than fish. Fish catches return to nor-
mal levels in two or three years.
Salinity extremes also affect some gulf fisheries
adversely at times. The Laguna Madre of Texas
and Mexico is one of the few places in the world
where hypersalinity becomes so extreme as to cause
mass mortality. Before the Intracoastal Waterway
was dredged through the 120-mile length of the
Laguna Madre of Texas, about 1949, this shallow
lagoon, in a region where evaporation is normally
twice as high as precipitation, often developed salini-
ties of over 80 ppt, and sometimes over 100 ppt.
The mass fish kills that were formerly caused by-
extreme hypersalinity have been practically elimi-
nated by the improved circulation via the Intra-
coastal Waterway, according to Simmons (1957)
andHcdgpeth (1967).
Low salinity caused by heavy rains during hurri-
canes sometimes kills fish and crustaceans in the
Laguna Madre, where salinity may drop from 50
ppt to nearly zero on such occasions. In the more
normal estuaries fish, shrimp and blue crabs are not
killed by heavy rains or flooding, but are swept
downbay by floods and escape into saltier waters
by swimming with the current.
Oysters in normal estuaries are often killed by
low salinity in all gulf states. The most spectacular
oyster kills on the gulf coast occur in Mississippi
Sound and the waters of the Louisiana marshland
on the eastern side of the Mississippi River delta.
In bad flood years it is necessary to open the Bonnet
Carr£ spillway in order to prevent flooding New
Orleans. Millions of oysters are killed by fresh water
on these occasions, over an area of many square
miles. Predators and parasites of oysters are also
killed out. Then the oyster reefs are repopulated by
larvae brought in by currents, and the next two or
three years may see unusually large crops of oysters
before the pests become reestablished (Gunter,
1952a, b, 1953, 1967).
Although such local freshwater kills seem at the
time to be disasters, in the long run they are bene-
ficial. The largest and densest populations of oysters
develop in these areas that are frequently cleared
of predators, pests and diseases, and not in the areas
of higher and more stable salinity, because the same
waters of near-oceanic salinity that are physiologi-
cally most favorable to oysters also favor a diversity
of marine organisms, many of which are harmful
to oysters.
For this reason, "salinity intrusion" in estuaries
worries oyster biologists. Other fishery biologists
also worry, fearing that increases in salinity will
make the estuarine nursery areas less suitable for
the survival and growth of juvenile fishes and crus-
taceans (blue crab, shrimp). Gradual increase in
salinity, year by year, occurs when there is rise in
sea level, sinking of land, and erosion of shores,
making bays and passes wider. All of these processes
are going on along the gulf coast, but faster in some
parts than in others. Local svibsidenee of land makes
estuaries larger, deeper and saltier.
In southeastern Louisiana the entire coastal area
is sinking. New sediment;: u«ed to be deposited in
the swamps and marshes and along the shores by
the annual floods of the Mississippi Rive'- Ail dis-
tributaries except Atchafalaya River are uow cut
off by levees, so there are no longer new deposits
of sediments (Morgan, 1973). The inevitable result
of reduced freshwater inflow, increased land subsid-
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FISHERIES
181
ence and erosion, and rising sea level is an increase
of salinity in the waters of the marshland estuaries.
Consequently, marine animals, including predacious
fishes that feed on juvenile fishes, crabs and shrimp,
and the numerous enemies of oysters, penetrate far-
ther and farther into the bays.
There are a few bays on the gulf coast with sandy
shores and bottoms, and clear water. These are less
productive than the typical gulf coast estuary, which
has a mud bottom and highly turbid water rich in
nutrients and organic sediments, either from a river
or from surrounding marshes (Day, Smith, and
Hopkinson, 1973; Odum, Zieman and Heald, 1973).
It is the large area of muddy, low-salinity water
that makes the northern gulf so productive of fish
and shellfish.
The oyster is the only important gulf coast fisher-
ies species that is known to be adversely affected
by high turbidity and sedimentation; it is well
adapted to turbid waters, but oyster beds are some-
times killed when buried in sediments. This happens
naturally when floods deposit thick layers of sedi-
ment or storms shift the bottoms. It can also be
caused by nearby dredging operations.
Gulf coast bays are so shallow (most are less than
10 and some less than 5 feet deep) that they are
well aerated by wave action and seldom have pockets
or layers of water deficient in oxygen. A famous
exception is Mobile Bay. When deoxygenated water
from deeper layers invades the shallows, thousands
of fish, crabs and shrimp swim on the surface and
concentrate in the shallows along the shoreline. This
phenomenon has been known for at least a century
as "the Jubilee" (Loesch, 1960). Apparently the
deoxygenation of the water results from decay of
plant debris occurring naturally on the bottoms, but
organic pollution, if present, could make "jubilees"
more frequent, more extensive, or more intense.
Red Tide (Phytoplankton Blooms)
A mass mortality of fish and shellfish on the
southern part of the west coast of Florida occurs
at intervals of several years, accompanying an area
of discolored water. In recent years this has been
called "red tide," although the water is not always
really red. Since 1947 the gulf red tide has been
known to be caused by a "bloom" of one particular
dinoflagellate, Gymnodinium breve. All of the factors
that must occur together to make this normally
scarce organism explode into a population density
of millions per liter are not yet known. During a red
tide outbreak millions of fish die and many drift
ashore, where they pile up on the beach in windrows
and decay. Lesser red tide outbreaks have also been
reported as rare phenomena on the Texas coast.
Like the Mobile Bay "Jubilee," red tide outbreaks
seem to be strictly natural phenomena that prob-
ably occurred when America was uninhabited. See
Gunter, Williams, Davis and Smith (1948), Wilson
and Ray (1956), Ray and Wilson (1957), Ingle and
Martin (1971), Baldridge (1974), Wilson, Ray and
Aldrich (1974), and Steidinger (1973, 1974).
Diseases of Fish and Shellfish
All animals have parasites and diseases. Fishes,
crustaceans and molluscs are no exceptions, having
the usual diversity of parasitic worms, protozoans,
fungi, bacteria and viruses, plus some little crusta-
cean parasites and parasitic algae. Gulf fishes are
not known to have any disease or parasite that
causes mass mortality or epidemics such as those
that control sea herring in the Atlantic (Sindermann,
1970).
Oysters have many parasites and diseases, in vari-
ous parts of the world. The most important parasite
on the gulf coast is a fungus, or perhaps several
closely related species of fungus, causing a tissue-
destroying disease commonly known as "dermo."
This disease starts to kill oysters in spring as soon
as water temperatures rise above 20°C and continues
to kill them until cool weather lowers water tem-
peratures in autumn (Mackin, 1962). Mortality
is highest in the higher salinities and at the higher
temperatures. Annual mortality from this cause
often exceeds 50 percent. This mortality is in addi-
tion to the more obvious killing by predators such
as the stone crab, the blue crab, the boring snail,
and several species of fish. All of these agents of
oyster mortality are most abundant and most active
in high salinity, which is the reason oysters survive
better in the low salinities. Oystermen therefore
fear "salinity intrusion" and oppose engineering ac-
tivities that may cause increase in salinity.
MANMADE FACTORS LIMITING
COMMERCIAL FISHERIES
Man has introduced new factors that limit com-
mercial fisheries in gulf estuarine areas. These man-
made factors will be discussed under three headings:
engineering activities, pollution, and laws.
Engineering Activities
Most of the types of human alteration of coastal
environment that are here called "engineering activi-
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182
ESTUARINE POLLUTION CONTROL
ties" have been discussed in a report by Cronin,
Gunter and Hopkins (1971). That report also makes
recommendations for the kinds of research needed
on each of the problems caused by these works of
man. Among the engineering activities analyzed in
the 1971 report are: channel dredging, filling and
spoil disposal, damming and diversion of rivers,
levees and spillways, land-cut canals, jetties at
passes between bays and the gulf, hurricane bar-
riers, oceanic disposal of dredged materials and
other wastes, "finger-type" (canal and fill) real
estate developments, and various types of wetland
modification.
To us it seems that the changes caused by engi-
neering activities have possibilities of more serious
damage to commercial fisheries than other effects
of man's activities, because the changes tend to be
permanent and irreversible. Fishery populations
soon recover from overfishing if allowed to, and
polluted waters return to normal when the pollution
is stopped (even long-lasting pesticides and toxic
metals becoming buried in sediments), but when
open bay or marsh is destroyed by a real estate
development that replaces vegetated shallows or
marshes with stagnant, dead-end, vertical-walled
canals, an area of nursery ground is partly taken
out of production for many years (Trent, Pullen
and Moore, 1972).
The gulf coast has the most highly developed
estuarine and offshore oil fields in North America
and perhaps in the world (with some 8 to 10 thou-
sand wells in the gulf and thousands more in bays
and marshes). The engineering activities in coastal
oil field development in Louisiana and Texas involve
the dredging of channels, including canals through
marshlands, to develop fields in the marsh and bay
areas. The damage done (especially to oyster beds)
by activities of this type is probably more important
than oil spillage. Exploitation of oil fields in the
gulf, often many miles offshore, is conducted by
drilling a number of wells from each drilling plat-
form. If oil or gas is found, pipelines must be laid
connecting the producing wells with shore installa-
tions. Shore installations must be built to receive
and process petroleum production and to harbor,
load and unload the vessels used in offshore opera-
tions. All of this necessarily causes some modifica-
tion of the shore and shallow sea environment. Ex-
cepting oystermen, gulf commercial fishermen have
not complained of any losses attributed to oil field
operations other than damage to trawl nets from
pipes, dropped tools, and other obstructions left on
the bottom by the oil men.
Pollution
As a result of the increased utilization of the
coastal zone for domestic residence, recreation and
industrial production, the possibility of pollution of
the environment has increased. The population of
the gulf coastal zone has increased about 2 percent
per year since 1960; at least a million people have
been added during this period.
Increases in domestic wastes necessitate the con-
struction of sewage treatment plants. Raw sewage
released into rivers and eventually into the gulf,
partially treated sewage, detergents, phosphates, ni-
trates, pesticides, petroleum hydrocarbons, and other
compounds are all discharged into estuaries as "mu-
nicipal wastes." Many of these compounds are
directly toxic to commercially important species;
some are toxic in combination with others; some
cause excessive nutrient enrichment resulting in an
abnormal proliferation of certain species, many of
which are considered undesirable by man; and some
have high biochemical oxygen demands (BOD) re-
quiring large amounts of oxygen for their breakdown
and producing oxygen-depleted water masses.
The development of recreational facilities to serve
coastal residents and vacationers presents related
problems. More than 2 million visitors vacation on
the gulf coast of Florida alone. Certain types of
recreational use place a heavy pollution load on a
relatively small area. Marinas, for example, may
result in large amounts of gasoline, oils, lead, phenols
and organic wastes being added to the estuary. Boat
use in Florida has more than doubled since 1960.
Industry has long recognized the value of estuaries
for waste disposal. Among the industrial wastes
which have been introduced into gulf coast estuaries
are heavy metals, plasticizers including PCBs and
phthalates, petroleum hydrocarbons, pesticides (or-
ganochlorines, organophosphates, carbamates and
dioxins), and various other compounds. In most
cases, relatively little is known regarding the toxicity
of these materials to fish and shellfish. Virtually
nothing is known of the sublethal effects of these
compounds on chronically exposed organisms.
Agricultural practices may also result in pollution
of the coastal zone through the addition of fertilizers
and organic wastes. Pesticide usage on agricultural
and livestock producing lands or in the abatement
of insect nuisances in populated areas adjacent to
estuaries has resulted in contamination of estuarine
organisms, including some commercially important
species.
The need for power to supply coastal inhabitants
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FISHERIES
183
has increased. Power plants require large areas of
land and large volumes of water for their operation.
Many commercially important species, especially
their larval and juvenile forms, are trapped and
killed on the intake screens of power plants, in their
passage through the plant itself or in discharge
ponds or canals where heated water (thermal pollu-
tion) and chemicals such as chlorinated algicides
are released (Chesapeake Science, Volume 10, pages
12.5-296 (1969); personal observations). More spe-
cific and detailed information on pollution is pre-
sented in a later section of this paper.
Laws
In general, two kinds of laws limit commercial
fisheries: public health laws intended to safeguard
the health of the consumers of seafood, and conserva-
tion laws intended to prevent over-exploitation of
commercial species.
Public health laws include those providing for
inspection of shellfish, and the waters in which they
grow, by state sanitation officers. If coliform bac-
teria (bacteria similar to those in the human intes-
tine) are found to be too abundant in water or
shellfish, or if inspection of the shoreline shows
possible sources of pollution, a certain estuarine area
or an entire bay may be closed, meaning that no
shellfish can legally be taken in that area. Although
such closures of shellfishing areas are often hard on
local fishermen, in the long run they are beneficial
to the fishing industry. These laws and their en-
forcement not only protect consumers, but help
maintain public confidence in the wholesomeriess of
seafoods.
Conservation laws are more controversial. Often
they are products of political pressures, and of preju-
dices and emotions rather than science. The worst
restrictions on commercial fisheries are those de-
manded by sport fishermen to maintain a monopoly
for themselves. Pressure by sport fishermen has re-
sulted in closing Texas bays to netting for fish.
There is even a movement on foot to outla\v the
sale in Texas and Louisiana of such marine fishes
as spotted trout and red drum because they are
game fishes. As (Juiiter and other fishery biologists
have pointed out, at least some food and game fish
populations are probably underfished at present, and
the numbers of fish killed by natural causes (freezes,
red tides, predators, and old age) may far exceed
those caught by all sport and commercial fishermen
combined.
TRENDS, EFFECTS OF TRENDS,
AND SPECIFIC CASES
OF POLLUTION
In 1959 Gordon Guiiter reported on "pollution
problems along the gulf coast." He mentioned sew-
age pollution, pulp and paper mills, fish processing
plants, chemical plants, sugar refineries, oil refineries,
and so forth, but commented 'T am happy to say
that the gulf coast is probably freer from pollution
than any other area of the ITnitod States coast, at,
present.'' Gunter stated that Galveston Bay was
"the only heavily industrialized area on the coast
of the Gulf of Mexico," but pointed out that 38
percent of the sport fishing in Texas was done in
the Galveston Bay area, that 36.5 percent of the
Texas catch of four common sport fishes was caught
in Galveston Bay and its branches, and that this
area still contained some of the best oyster reefs in
Texas. The conditions in Galveston Bay are nearly
the same today. Approximately half of the bay area
has long been closed to shellfishing because of sewage
pollution, yet the remaining half has produced more
oysters annually during the last decade than in any
period prior to 1960, and there is still excellent sport
fishing in the, bay.
Biglane and Lafleur (1967) revealed the appear-
ance of some gulf coast pollution problems not men-
tioned by Gunter, especially the beginning of fish
kills in Louisiana fresh and coastal waters that were
shown by U.S. Public Health Service scientists to
be caused by insecticides such as endrin. The other
pollution problems they mentioned were attributed
to what we have called engineering activities: levee-
ing of the Mississippi River, change of marshland
drainage patterns by dredged channels, and so forth.
The most obvious effect of pollution is the direct
mortality in what has been termed "fish kills."
According to Environmental Protection Agency
(EPA) statistics, the numbers of reports of fish
kills and the number of fish killed have increased
since the survey was begun in June 1960. The num-
ber of fish kill reports increased from 465 in 1969 to
634 in 1970 and to 860 in 1971. There has also been
a general upward trend in estimated numbers of
fish dying in fish kills, at least through 1971 (when
74 million fish were reported killed).
Every one of the Gulf Coast States has experienced
significant fish kills which have been attributed to
agricultural, industrial or domestic wastes. Since
1965, either municipal wastes (sewage) or industrial
wastes have been reported as the principal cause of
fish kills in the United States for each year. In 1971
the major identifiable cause of fish kills was reported
to be "sewage system wastes" with "pesticides"
-------
184
ESTUARINE POLLUTION CONTROL
second at about one-half that level (US EPA, 1972).
These data do not exactly pinpoint the problem
since municipal sewage contains significant amounts
of petroleum products, metals, pesticides, and other
industrial materials as well as organic wastes.
Most fish were killed in fresh water from 1965 to
1969. However, in 1971 there was a decrease in the
number of dead fish reported from freshwater bodies
and a sharp increase in. the numbers from cstuarine
areas for the first time since these statistics were
lirst compiled (I960). During recent years, a single
kill or relatively few accounted for a considerable
percentage of the total kills for that year. Statistics
for 1971 reveal 29 million fish killed in 12 incidents
in Florida (Escambia Bay) and 16 million in six
incidents in Texas (Galveston Bay).
Three points need to be made here. The first con-
cerns the kinds of fish killed. When kills are caused
by sewage pollution, the first fish killed in estuaries
are likely to be menhaden, which though important
because of their abundance, are cheap fish (worth
four cents a pound in 1973). Second, the numbers of
fish reported killed on the gulf coast by pollution
are less impressive when compared with the 50 to
90 million pounds (perhaps equal to 200 to 360
million fish) killed by a single freeze on the Texas
coast in 1951, or the 500 million fish estimated to
have been killed by a single red tide outbreak off
Florida in 1946-1947 (Gunter, Williams, Davis and
Smith, 1948), not to mention the 1.2 to 1.8 billion
pounds of fish caught annually by commercial fisher-
men and the 400 to 500 million pounds taken by
sport fishermen. Third, fish kills are important not
because of the loss of fish, but because they serve
as warnings that the environment is in danger. If
the condition that caused the kill is only temporary,
other fish will quickly replace the ones killed and
there will be no real loss. If it is persistent, replace-
ment may be prevented, or the replacements may
be less desirable species. Massive fish kills impress
the general public much more than increases in
bacterial counts or metal content of fish and shell-
fish, and are more likely to stimulate action against
degradation of the aquatic environment.
Another demonstration of the effects of pollution
of the environment on commercial fisheries is the
closing of estuarine areas to the taking of shellfish.
In most cases, closure is ordered by the state depart-
ment of health based on bacteriological criteria.
These criteria are based on levels determined by the
state and on levels allowed by the Food and Drug
Administration (FDA1 for interstate shipment.
The largest Texas area permanently closed to
shellfishing is in the Galveston Bay area, nearly
half of which has long been closed. There have been
no significant changes in the acreage permanently
closed in Texas bays since 1970, but some bays have
been closed temporarily after floods, as in the spring
of 1972 (Texas State Department of Health). The
Louisiana Department of Wild Life and Fisheries
(Ferret et al., 1971) reported 139,905 acres closed
to shellfishing, and in 1972 additional areas were
temporarily closed after flooding (NOAA-NMFS
Louisiana Landings, 1974). Varying acreages of
Mississippi bays have been closed in recent years;
Biloxi Bay has apparently been permanently lost
for oystering (Christmas, 1973). The Alabama Con-
servation Department reported almost 74,000 acres
permanently closed to shellfishing, with additional
acreages temporarily closed when floods carried
sewage contamination into other areas (Crance,
1971; May, 1971). During 12 of the 18 years from
1952 to 1970, lower Mobile Bay was closed for
taking of shellfish at least part of the year because
coliform bacteria counts exceeded 70 per 100 ml of
water. Each such closing causes economic loss; the
loss in 1969 was estimated to be $500,000. In 1972,
after floods, Mobile Bay oystering areas remained
closed 217 days (NOAA-NMFS Alabama Landings,
1974). McNulty et al. (1972) reported that on the
Florida gulf coast 170,698 acres of estuarine areas
were closed for shellfishing.
Any general trend that may exist in the closing of
estuarine areas to shellfishing on the gulf coast as a
whole is obscured by the local changes (opening and
closing) from year to year or month to month as
pollution conditions change back and forth. Closures
wen1 especially harmful to the oyster fishery in 1973
because of extensive flooding, but the increased
production in 1974 tended to compensate for this.
Pollution of estuaries, besides causing the closing
of fishing areas, also results in the seizure and con-
demnation of commercial fisheries products when
pollutant residue levels or bacterial counts are above
the tolerances established by the FDA for interstate
shipment. The contamination of estuarine species
by various pollutants has been well documented.
Residues of the DDTs (including DDT, DDD and
DDE), dieldrin, mirex and other organochlorine in-
secticides have been detected in oysters, other bi-
valves, blu.- crabs, shrimp and fishes collected from
estuaries along the gulf coast (Butler, 1973; Petro-
celli et id., 1973, 1975a, 197f>b; Childress, 1968,
197] ). DDT and PCB residue? have been detected
in the tissues of fish, crab;-, shrimp and squid col-
lected fron, offshore waters of the Gulf of Mexico
(Giam et al., 1972).
Butler (1973) in a monitoring study during the
period 1965 to 1972 found that DDT was the most
common pesticide and dieldrin the second most com-
-------
FISHERIES
moil in molluscs. The: incidence of DDT residues
(the percentage of samples in which DDT or prod-
ucts of its decay could be detected) was 63 percent
and that of dieldrin 15 percent. Butler described a
general decline in both the number and magnitude
of DDT residues in oysters over the 7-year period.
The data for the gulf coast samples are as follows:
Frequency (%) of residues
detected tn samples; and
(maximum value in ppb)
.State
DDT
Dieldrin
Date of
survey
Alabama 100% (616) 18% (21) 1968-1969
Texas 73%, (1249) 18% (87) 1965-1972
Florida 62% (5390) 7% (28) 1965-1972
Mississippi 61% (135) 4% (20) 1965-1972
Louisiana no data
Heavy metal residues have also been found in the
tissues of estuarine species (Saha, 1972; Eisler
1973). According to public health officials, relatively
few seizures or condemnations of commercial fishery
products due to pesticide or heavy metals contamina-
tion are made compared with seizures resulting from
elevated bacteriological levels. However, as research
belter defines the sublethal effects of these com-
pounds, human tolerance limits, a.s set by law, may
be lowered thus increasing the possibilities of com-
mercial fishery products exceeding these levels. As-
suming no further input of these compounds into
estuaries, this situation would significantly decrease
the amount and value of marketable products. Any
infmws in the levels of pollutant added t<> estu-
aries in the future would even further complicate
this problem
UNKNOWN EFFECTS
1'ossibly th" most insidious effect of pollution on
the commercial fisheries is one which is the least
understood and is only uow being considered on a
brottd level. This is the effect of pollution on the
ability of organisms to reproduce and for their larvae
and juveniles to develop normally to mature1 adults
fully capable of successful reproduction.
It has i-e-'ii h\ pothesized that high concentrations
<.f DDT in the- ovaries of sea irout are responsible
for ck",'liii
196.", and J.-miian 1967, respectively. Children
(1965, 1966, 1968, 1971) reported DDT incidence
in oysters remaining at about the- same level from
1965 to 1967 with a slight decrease from 1967 to
1968. The incidence of dieldrin residues (the per-
centage of oyster samples in which dieldriri residues
could be detected) increased from 1 percent in 1965
to 23 percent in 1967. The incidence, of endrin resi-
dues increased from .02 percent in 1965 to 1 percent
in 1966 —1967 in the oysters sampled by Childress.
(The oyster is a good test animal for monitoring
pesticides or metals in the estuarine environment
because it filters huge quantities of water and tends
to accumulate materials in its tissues.)
During this study period Breuer (1971, 1972),
reported em the historical and recent abundance of
spotted sea trout (Cynoscion nebulosus) in the lower
Laguna Madre. Sea trout juveniles were abundant
in 1958—1959 but declined in abundance through
the 1971 sampling period. In 1969, only 21 juvenile
sea trout were identified in a total of 21,473 marine
organisms ce>llected. Jn 1971, five juveniles and no
adults were captured using the same sampling tech-
niques. Pesticide residue analysis of juvenile men-
haden, em which sea trout feed, revealed whole body
concentrations of 1.520 ppm of DDT in 1966 and
5.180 ppm in 1967 (Breuer, 1971). Ovaries of adult
sea trout in the Arroyo Colorado area (lower Laguna
Madre) contained DDT residues as high as 7.980
ppm, dieldrin residues to 0.170 ppm and endrin
levels of 0.054 ppm (Childress, 1968). Distributiem
e>f insecticide resieiues (ppm) in these fish were-:
ovaries,
brain
liver
DDT
6.280
0 958
7 560
Dieldnn Endrin
0.028 0 017
From the data it appears that DDT has had an
adverse1 effect em the- reproductive* success of the
le>cal sea trout. It should be explained that the
Arroyo Colorado is a waterway draining part (if the
inte-nselv cultivated farmland and citrus groves in
the- inigated area known as "The Valley" in Texas.
Behaviorally, it has been reported that some
aquatic species are actively attracted or repelled
depending em other interacting parameters by pollut-
ants such a.s copp-'-r and petroleum hydrocarbons
(Kleerekoper. et a!., 1973; Jacobsem and Boylan,
1973!.
Still anothe>r effect which has recently come1 to
light is the interaction among pollutants and be-
tween pollutants and natural stresses. Nimmo (pers.
cornm.) and recent work by Hetrocelli (not vet
published ' h:«.vc .shown that salmi*;/ shock, such ;;••;
occurs ;ii the e.stuar\ in the course of heavy rainfall
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186
POLLUTION CONTROL
or river flooding, combined with exposure to sub-
lethal concentrations of pollutants results in mor-
talities not predictable on the basis of the salinity
change or toxicity of the pollutant alone (Petrocelli
et al., unpublished data; Anderson et al., 19T4;
Roesijadi et al., 1974). In some cases, this effect
can be attributed to changes in the physiological
response of the animals to these stresses. For exam-
ple, shrimp exposed to heavy metals or PCBs and
salinity shocked haw beer, shown to be less efficient
than control;! in the regulation of blood chloride
ion levels to compensate for these change1-'. Over-
street (Hd) described a kill of estuarine fishes,
mainly mullets, in Mississippi, which was apparently
caused by interaction between low salinity and low
temperature, possibly complicated by pesticide con-
tents somewhat higher than in surviving mullets.
Interaction has also been observed in the case of
other physiological factors. For example, crustaceans
during molting are much more susceptible to pollut-
ants than are the same animals during the intornioit
stages (Petrocelli et al., 1974, unpublished data!.
In other studies, sheepshead minnow (Oypnuodon
v(ii'iega,lus} juveniles chronically exposed (03 days')
to sublethal concentration^ of mercury (1.0 ppb)
were observed to have a respiratory rate which was
significantly lower than that oi control fish (Petro-
celli et al., 1974, unpublished data).
The bioU peal effects of petroleum and its prod-
ucts are si ill largely unknown, in spite of all the
literature. The problems are complex because the
hundreds of (rude oils are complex, each containing
hundreds of compounds, and refining adds many
more. Crude and refined oils change upon exposure
to air and water, in different ways under different
conditions Though difficult, the many problems in-
volved in the biological effect- of petroleum products
should be studied by mop1 laboratories. Atlantic
coast oil fields will soon be added to those in the
gulf and Pacific. More important, we will soon have
super tanker ports with possibilitu s for much greater
oii spiiis than ha\ e ever occurred up to now.
The famous Santo Barbara oil loss was estimated
at, 3 million gallons (Holmes, 19f'9). The largest of
the four b'sr oil spills in tlv 'Julf of Mexico iiilil-
x.vas about ,"> million. According to a 1974 repo11 <>t
tlu V.S. Bun au of Land Management, all oil lo^es
of ."iO harri 1- or more in gulf fields during the 10-year
period beginning 19G4 add up to 320.000 barre1--
(l',\ 4 mi.hoii gallons,* out of 2.9 biili(>n barrel, pro-
duced Bui these figures are dwarf( d by the (-ti-
mated 90.000--100.000 tons ('27 to .',0 million gallons^
• " . rud" i.'1 ->i>i''e<' ii'i.i tjii Kn. -I. eh '-< j-> ntral clearing office should be established
to coordinate the whole effort, re insure adherence
to overall goals and to prevent th-" current wasteful
and umiee<>ssariv duplication of v>oi! funded by the
various governmental '.'gencies.
Kurrdi'ig should i>" on a minimum t/f a tno vear
basis sc, that time ami efforts \\ill not be wasted in
unnecessary proposal and report writing or in switch-
ing proj'-cts to obtain cominued funding. Progress
should be reviewed periodir-fllv ',( v vry six months).
iilled !'\" add'liou of new ptngrarns.
-------
1st gulf ,-^pecies are1 prolific
anel have short life cycles—1, 2, ,3 or 4 years from
reproduction to reproduction so that losses from
natural disasters or from heavy fishing pressure are;
s'oon made up.
Unfortunately, the same river water that r-.-duces
salinity anel contributes food also brings in manmade
pollutants, both rnicrobial and chemical. Man fur-
ther endangers the fisheries by ongineerint!; activi-
ties—leveeing, dredging and filling, damming anel
diverting streams, and so forth. Gulf coast fisheries
are especially vulnerable to such manmade changes
because1 most of the catch is made within 12 mile's
of the shore, anel over (.)~> percent of it consists of
species that depend e>n estuarine' nursery areas.
Destruction or poisoning erf nursery areas could
de'stroy most of the gulf coast commercial fisheries.
So far, the'se' fisheries have not been perceptibly
hurt, excepting the' oyster which is confined fo estu-
aries. The damage to the1 oyster fishery has been
mainly from engineering works, from oil contamina-
tion occasionally making oysters in a small area
unsalable' for a few weeks or months, and from
closure1 of bay areas by health authorities because
of sewage1 pollution.
Although gulf commercial fisheries other thai; the
oyster fishcrv have apparently not yet bee-n hurt by
manmaele change's, including pollution, thev are in
danger. There have been warning incidents- pollu-
tion kills of fish in a few are'as. apparent prevention
of reproduction erf sea tremt because of pesticide
concentration in erne aiva— to show \\bat can hao-
pen. [f shores continue to be altered by real estate-
developers, stream flow continues to be interfered
with by levees, dams and diversions, anel man's
wastes anel poisons continue te> increase the gulf
commercial fzsherie's will eventually be K'idiy hurt.
Research is needed te> determine- when the ce>st?> erf
man's activities reach the point where they exceed
the benefits. We do not yet know all erf the environ-
mental ceists, in a quantitative1 way, as we should.
In the meantime, every effort should be made to
aveiid engineering activities anel pointing that wo
know to be harmful.
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188
ESTTARINE POLLUTION CONTROL
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FISHERIES
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ESTUARINE POLLUTION CONTROL
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DREDGING
EFFECTS
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MAN'S IMPACT ON
ESTUARINE SEDIMENTATION
J. R. SCHUBEL
R. H. MEADE
State University of New York
Stony Brook, New York
ABSTRACT
Kstuaries are ephemeral features on a geological time scale being rapidly filled with sediments.
Although most estuarine sedimentation rates are naturally high, man's activities have greatly
accelerated the rates of filling of many estuaries, thus shortening their geological lifetimes. More
importantly, the increased influxes of fine-grained sediments have degraded some estuaries, or
segments of them, to the extent that their useful biological and recreational lifetimes have been cut
drastically shorter than their geological lifetimes.
Much more effort should be directed at reducing the most manageable source of sediment to most
estuaries—soil erosion. This would not only result in an improvement of water "quality," but
would, within a few decades, result in significant reductions in the amounts of dredging required
for channel maintenance. Dredging will, however, continue to be a persistent problem because the
supply of sediments cannot be eliminated.
A new approach to dredging and spoil disposal is required. Regional plans must be developed to
ensure that maintenance channel dredging can be carried out without prolonged delays. The
present standards for characterization of dredged materials do not have a sound scientific basis,
and should be reevaluated. While they were intended to be environmentally conservative, they
may be unduly restrictive.
INTRODUCTION
Estuaries are the major sites for the accumulation
of sediment along our coastline. Their positions at
the mouths of rivers make them the ready recipients
of sediment eroded from the land, and the charac-
teristic circulation patterns produced by the min-
gling of fresh water from the land and salt water
from the sea that takes place in estuaries makes
them effective sediment traps. The rate of sediment
accumulation in estuaries, which is already naturally
high in many situations, has been increased by man's
activities.
The primary purposes of this report are: (1) to
review some of the characteristic estuarine sedimen-
tation processes; (2'j to look at some of the ways
in which man has altered these processes; (3) to
assess the significance of the; effects of these changes
on the estuarine milieu; and (4) to recommend the
types of research needed for significant advances
in our understanding of estuarine sedimentation
processes.
For this discussion, we adopt the definition of an
estuary most commonly used by physical oceano-
graphers—an estuary is a semi-enclosed coastal body
of water freely connected to the ocean within which
scawater is measurably diluted by freshwater runoff
from land.
SEA LEVEL, SEDIMENTATION,
AND THE LIFE EXPECTANCY
OF ESTUARIES
All present day estuaries were formed by the most
recent rise in sea level which began approximately
15,000 to 18,000 years ago. During the last glacial
stage (the Wisconsin) the level of the sea was about
125 m (410 ft) below its present level (Fig. 1) and
most of the continental shelves of the world were
exposed to the atmosphere. With the melting and
retreat of the great ice sheets, sea level rose, rapidly
at first, from about 15,000 years ago until about
9,000 years ago when it reached a position approxi-
mately 20 m (66 ft) below its present level. By
3,000 years ago the level of the sea was within 3 m
(10 ft) of its present position, and since then the
sea has risen even more slowly, averaging less than
1 m per 1,000 years.
The rising sea invaded numerous coastal embay -
ments and produced estuaries in those that received
enough fresh water to measurably dilute the en-
croaching seawater. Many of these coastal basins
were former river valley systems. Examples are
Chesapeake Bay, Delaware Bay, and the estuaries
around the Mississippi Delta. Other basins, formed
by glacial scour, were the fjords such as those found
along the coasts of Alaska arid British Columbia.
193
-------
194
ESTUARINE POLLUTION CONTROL
40
MSl_ 0
50 -
Q- 100 -
LU
Q
THOUSANDS OF YEARS BEFORE PRESENT
35 20 25 20 15 10 5
_j i i i i i i i i i i i i i—i—i—i—i—i—i—1_
50
- 100
-WISCONSIN TRANSGRESSION
LATE WISCONSIN REGRESSION
HOLOCENE TRANSGRESSION
^
MODERN
FIGURE 1.—Fluctuations of mean sea level from present to 40,000 before the present (B.P.). The curve was compiled from pub-
lished and unpublished radiocarbon dates and other geologic evidence. Dotted curve estimated from minimal data. Solid curve
shows approximate mean of dates computed. The dashed curve is slightly modified from Curray (1960, 1961). Probable fluctua-
tions since 5,000 years B.P. are not shown (J. R. Curray, Late Quaternary History, Continental Shelves of the United States in
the Quaternary of the United States, 1965).
Wave action and littoral drift formed bars off the
mouths of some rivers thereby creating embayments
which were later transformed into estuaries. Exam-
ples are Pamlico and Albemarle Sounds. Still other
coastal basins that later became estuaries were
formed by tectonic processes. San Francisco Bay is
an example.
The rapidity of the rise; of sea level was a major
factor in the formation and maintenance of estuaries.
Sedimentation could not keep pace with the rapidly
rising sea that invaded numerous coastal basins.
For the past few thousand years, however, the
relative rate of infilling has been much greater than
during the preceding several thousands of years.
The rate of sea level rise has been slower, and within
the past few hundred years the rate of sediment
input has increased as a result of man's activities.
It is, of course, the relative sea level rise—the rise
relative to the sedimentation rate—that determines
the geological lifetime of an estuary.
All modern estuaries then, are quite young
geologically; certainly less than 15,000 years old.
The relative youthfulness of many estuaries, par-
ticularly of drowned river valley estuaries like
Chesapeake Bay, is indicated by their highly ir-
regular, dendritic shorelines. A.S estuaries mature
there is a progressive rectification or straightening
of their shorelines; headlands are attacked by waves
and current, and re-entrants in the coastline are
filled by drifting sand. Once formed, estuaries are
ephemeral features on a geologic time scale, being
rapidly filled with sediments. Sediments are intro-
duced not only by shore erosion, but also by rivers,
by the wind, by the sea, and by biological activity.
The sources are thus external, internal, and marginal.
Typically, estuaries fill from their heads and their
margins. An estuarine delta generally forms in the
upper reaches of the estuary—near the new river
mouth. The estuarine delta grows progressively
seaward, extending the realm of the river and thereby
expelling the intruding sea from the semi-enclosed
coastal basin. Lateral accretion by marshes may
also play a major role. As a result of these processes,
the estuarine basin is converted back into a river
valley. Finally, the river reaches the sea through a
depositional plain and the transformation is com-
plete.
While depositional rates in estuaries are naturally
high, man's activities both within the estuarine zone
itself, and throughout the drainage basin (sometimes
hundreds of kilometers away) can greatly increase
the sediment yields and the rates of filling, can alter
the natural sedimentation patterns, and can shorten
the geological lifetimes of estuaries—sometimes ap-
preciably. Alore importantly, the indirect effects of
increased inputs of sediments, particularly of fine-
grained sediments, can degrade an estuary, or seg-
ments of it, to the extent that its useful biological
and recreational lifetimes are cut drastically shorter
than its geological lifetime—perhaps several orders
of magnitude shorter.
It has been reported that when John Adams, a
Democrat, was President, he swam in the upper
Potomac at Washington, D.C. Lincoln, a Repub-
-------
DREDGING EFFECTS
195
lican, not only did not swim in the upper Potomac,
but remarked that the stench from it was sometimes
so bad that on warm summer evenings when the
wind was off the Potomac he had to flee the White
House. This indicates either that the quality of the
upper Potomac had been seriously degraded by
man's activities over this period'of about 60 years;
or as a Republican friend of ours, H. H. Carter,
points out, merely that "a Democrat will swim in
anything."
ESTUARINE CIRCULATION
AND SEDIMENTATION PATTERNS
Because of their characteristic circulation proc-
esses, estuaries are effective sediment traps. The
tidal circulation is important in the formation of
channels, tidal flats, and tidal deltas, but it is the
net non-tidal circulation that is of primary impor-
tance in determining the rates and patterns of filling
of most estuaries.
It is in the estuary where the mixing of fresh
water from the land and salt water from the ocean
produces dynamic conditions that lead to the even-
tual discharge of the river water to the ocean. The
mixing may be due primarily to the action of the
river, the \vind, or the tide. There is a sequence of
estuarine circulation types displaying different de-
grees of mixing of the fresh water and the sea water.
The position that an estuary occupies in this se-
quence depends primarily upon the relative magni-
tudes of the riverflow and the tidal flow, and upon
the geometry of the basin that contains the estuary.
Changes in any of these factors may produce changes
in the estuarine circulation pattern and may thereby
alter the resulting sedimentation patterns. One end
member of this sequence is the poorly mixed (highly
stratified) salt-wedge estuary—that so-called Type
A estuary. The other end member is the thoroughly
mixed, sectionally homogeneous estuary—the Type
D estuary. Two intermediate types which have been
described are the partially mixed, Type B, estuary,
and the vertically homogeneous, Type C, estuary.
Estuaries are actually continuously varying in
their characteristics and may shift from type to type
as conditions change. Also, at any given time, dif-
ferent circulation types may be observed within
different segments of an estuary, depending on the
relative magnitudes of the tidal flow and the fresh-
water flow, and upon the local geometry of the basin.
The four types of estuarine circulation patterns are
shown schematically in Fig. 2. In general, an estuary
changes from Type A (Fig. 2A) to Type D (Fig.
2D) as the magnitude of the tidal flow increases
relative to the riverflow and/or as the width of the
basin increases relative to the depth.
The Salt-Wedge
(Type A) Estuary
The Type A estuary, Fig. 2A. is a river-dominated
estuary. It is also called a salt-wedge estuary because
there is little mixing between the seawater and the
fresh water, and the encroaching seawater is present
as a wedge underlying the less dense, fresher river
water. Salt-wedge estuaries occur where the ratio
of width to depth is relatively small and the ratio
of riverflow to tidal flow is relatively large. At
locations upstream from the tip of the salt-wedge,
the flow is downstream at all depths. Seaward of the
tip of the wedge, the flow throughout the upper
layer is still downstream at all times because of the
dominance of the river over the tide. In the lower
layer, the instantaneous flow may be upstream at
all times, or it may reverse with the tide, but the net
flow is upstream.
Fine suspended particles that are brought into the
estuary by the river and settle into the lower layer
are brought back upstream to the tip of the wedge
by the slow net landward flow of the lower layer
and accumulate in the vicinity of the tip of the
wedge. This fluvial sediment may also be supple-
mented by fine particles from other sources. Heavier
particles transported along the riverbed accumulate
upstream of the wedge. The region surrounding the
tip of the wedge, then, is a zone of rapid shoaling.
The position of the tip of the salt-wedge is deter-
mined primarily by the freshwater discharge and the
channel depth.
The Southwest Pass of the Mississippi River is a
classic example of a salt-wedge estuary. The average
flow through Southwest Pass is more than 5,100
m3/sec (180,000 ft3/sec), and peak flows may ex-
ceed 8,500 nvVsec (300,000 fts/sec). The 'river
completely dominates the circulation. The tidal
range in the Gulf of Mexico is only about 36 cm
(1.3 ft). The tip of the wedge migrates more than
235 km (126 n. miles) in response to changes in the
discharge of the Mississippi. During periods of
minimum flow, the tip may be about 40 km (22 n.
miles) above New Orleans—nearly 235 km (126 n.
miles) above the mouth of Southwest Pass. During
periods of moderate flow, the tip of the wedge is
located near the river's mouth, and the shoaling
problem is so serious in this region that around-the-
clock dredging is required to keep the navigation
channel open.
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196
ESTUARINE POLLUTION CONTROL
A.
FIGURE 2.—Four distinct examples in the sequence of estuarine types. A. Type A estuary. B. Looking seaward in Type B
estuary in N. Hemisphere. C. Looking seaward in Type C estuary in N. Hemisphere. D. Looking seaward in Type D estuary in
N. Hemisphere.
The Partially Mixed
(Type B) Estuary
If the tidal flow is increased relative to the river-
flow so that the tide is sufficiently strong to prevent
the river from dominating the circulation, the added
turbulence provides the mechanism for erasing the
salt-wedge. This occurs when the volume rate of
flow up the estuary on a flood tide is on the order
of 10 times the volume rate of inflow of fresh water
from the river. There is both advection and tur-
bulent mixing across the freshwater-saltwater inter-
face. The sharp interface which separated the fresh
water of the upper layer from the sea water of the
lower layer in the salt-wedge estuary is replaced by
a region of more gradual change in salinity. Such
an estuary is called a partially mixed, Type B,
estuary. The difference in salinity between top and
bottom remains nearly the same over much of the
length of the estuary. The Coriolis force—an ap-
parent deflecting force caused by the earth's rota-
tion—produces a slight lateral salinity gradient
across the estuary. The boundary between the
seaward-flowing upper and landward-flowing lower
layers is slightly tilted. In the Northern Hemisphere,
the upper layer is deeper and the flow slightly
stronger to the right of an observer facing seaward.
The lower layer is nearer the surface and its flow
is slightly stronger to the left of the seaward-facing
observer.
Fine suspended particles that settle into the lower
layer are carried upstream by its net landward flow,
leading to an accumulation of sediment on the
bottom between the upstream and downstream limits
of salt intrusion. Because of the mixing which is
more intense than in a salt-wedge estuary, there is
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DBEDOING EFFECTS
197
generally an accumulation of fine suspended sedi-
ment in the landward reaches of the estuarine cir-
culation regime. Such features, called "turbidity
maxima," have been reported in the upper reaches
of a large number of partially mixed estuaries
throughout the world. These turbid zones charac-
teristically begin in the estuary where a vertical
gradient of salinity first appears and commonly
extends downstream for 20—40 km (10-20 n. miles).
Within a turbidity maximum the concentrations of
suspended sediment and the turbidities are greater
than either farther upstream in the source river or
farther seaward in the estuary. Their formation has
been attributed to the flocculation of the fluvial
sediment, to the deflocculation of fluvial sediment,
and to hydrodynamic processes. We believe that
turbidity maxima are produced and maintained by
physical processes—specifically the periodic resus-
pension of bottom sediments by tidal scour, and the
estuarine circulation pattern—and that the impor-
tance ascribed to the role of flocculation in estuarine
sedimentation is not supported by field evidence.
The most rapid shoaling in partially mixed estu-
aries normally is between the flood and ebb positions
of the limit of sea salt intrusion. Rapid shoaling may
also occur where the upstream flow of the lower
layer is interrupted by entering tributaries, by
abrupt changes in cross-sectional area, or by mean-
dering or bifurcation of the channel. The Chesapeake
Bay is a good example of a partially mixed estuary.
The Vertically Homogeneous
(Type C) Estuary
If the role of the tide, relative to the river, is
increased over that in the partially mixed estuary,
the tidal mixing may be sufficiently intense to com-
pletely eradicate the vertical salinity gradient and
produce a vertically homogeneous water column. The
longitudinal salinity gradient still remains with the
salinity increasing seaward. And, because of the
Coriolis force, the lateral gradient in salinity also
remains with the higher salinity water to the left of
an observer facing seaward in the Northern Hemi-
sphere. The boundary between the lower salinity
water flowing seaward and the higher salinity water
flowing up the estuary becomes more nearly vertical,
and may intersect the water surface. In the Northern
Hemisphere then, the net flow and sediment trans-
port are generally upstream on the left side of the
estuary facing seaward and downstream on the right
side. Shoaling is generally most rapid near the up-
stream limit of sea salt, in regions of large cross-
sectional area, adjacent to islands, and in channel
bifurcations where the flow is interrupted. The wider
reaches of the Delaware and Raritan (New Jersey)
Bays are examples of vertically homogeneous es-
tuaries.
The Sectionally Homogeneous
(Type D) Estuary
If the tidal flow is increased even more so that it
is very large relative to the riverflow, it may almost
completely overwhelm the effect of the river. The
tidal mixing may be so intense that not only is the
vertical salinity gradient eradicated, but so also
is the lateral gradient, producing a sectionally
homogeneous estuary. The movement of water is
essentially symmetrical about the main axis of the
estuary with a slow net seaward flow at all depths.
Truly sectionally homogeneous estuaries may not
exist in nature. In estuaries that are approximately
sectionally homogeneous, the most rapid sedimenta-
tion occurs in areas where the slow net seaward flow
is interrupted by tributaries or obstacles. The
Piscataqua estuary in New Hampshire appears to be
nearly sectionally homogeneous, but observations in
estuaries of this type are limited.
As pointed out previously, the position that an
estuary occupies in this sequence of estuarine types
depends primarily upon the relative magnitudes of
the riverflow and the tidal flow, and upon the
geometry of the basin. Relatively subtle changes in
any of these factors may produce changes in the
estuarine circulation pattern and thereby alter the
resulting sedimentation patterns. In general, an
estuary's sediment trapping efficiency is increased
as the riverflow increases relative to the tidal flow,
or as the depth increases. Most of the fluvial sedi-
ment is generally introduced into an estuary when
the riverflow is high, when its trapping efficiency is
greatest. When the riverflow subsides and the relative
importance of the tidal flow increases, the estuary
shifts in its circulation pattern toward one of greater
mixing. During these more prolonged periods of low
to moderate riverflow the sediment is redistributed.
ALTERATION OF PREVAILING
SEDIMENTARY PROCESSES
Sources
Although sediment in estuaries comes from many
sources—including the erosion of the margins of the
estuarine basins, and the beaches and sea floor
outside the estuary mouths—the sources most af-
fected by the hand of man are the rivers that carry
sediment from upland areas into the estuaries. Our
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198
ESTUARINB POLLUTION CONTROL
discussion will focus mainly on the- sediment loads
of rivers, which are increased by such activities as
farming, mining, and urbanization; and which are
decreased by reservoirs and other protective works.
MAN'S ACTIVITIES
THAT INCREASE
RIVER SEDIMENT LOADS
Ever since the first European settlers landed, man
has affected the amount of sediment in streams
draining North America. The influence of man on
sedimentation is especially well documented in the
Chesapeake Bay region, where clearing of forests
and wasteful farming practices (especially those
used in raising tobacco) contributed enormous loads
of sediment to the rivers. Clear streams became
muddy and once relatively deep harbors at the
heads of a number of the tributaries were filled with
sediment. The Potomac River, whose waters were
already somewhat turbid but which were still suit-
able for municipal use in 1853, had become so
muddy by 1905 that the city of Washington had to
install its first filtration plant. A comparison of the
1792 and 1947 shorelines of the upper Potomac
(Fig. 3) shows that large areas of the Potomac near
Washington have been filled with sediments stripped
from farmland farther upstream. The Lincoln and
Jefferson Memorials now stand on what was de-
scribed in 1711 as a harbor suitable for great
merchant vessels. Even today, an average of about
2 million m3 (2.6 million yds3) of sediment is
deposited every year near the head of tide in the
Potomac; not all of this sedinvnt is the result of
agriculture, as we shall see. There are other former
seaport towns on the western shores of Chesapeake
Bay where decaying docking facilities are now
separated from navigable water by several miles of
sediment-filled lowland.
Streams that drain modern day farmlands in
many of the mid-Atlantic stales carry about 10
times as much sediment as streams that drain
equivalent areas of forest land. And this relation is
by no means unique. In the Coasi al Plain of northern
Mississippi, sediment yields from cultivated lands
are 10 to 100 times the yields from equivalent
areas of forested lands. In two other areas where
studies have been made—the Tobacco River Valley
of Michigan and the Willamette Valley of Oregon-
streams draining farmland carry two to four times
as much sediment as streams draining equal areas
of forested land.
Mining is another activity that has increased the
sediment loads of rivers that flaw into some estu-
WASHINGTON f CAPITOL
MONUMENT
LAND AREA
1792
FILLED
1792-1947
REMOVED
1792-1947
FIGURE 3.—Accumulation of sediment at Washington, D.C.,
near the head of tide in the Potomac and Anacostia Rivers,
between 1792-1947.
aries. San Francisco Bay, for example, contains
nearly a billion cubic meters of sediment washed
from the Sierra Nevada during the 30-odd years
of intensive hydraulic mining for gold. Even after
the hydraulic processing was stopped in 1884, the
mining debris continued to choke the valleys of the
Sacramento River and some of its tributaries for
many decades. Gradually, over the years, the debris
has been moved downriver to be deposited more
permanently in the marshes and shallower areas
around San Francisco Bay. The mining debris that
was released in only three decades is more than the
total sediment from all other sources (including
farmland) that the Sacramento River has carried
in the twelve-and-a-half decades since 1850. It has
been shown that this sediment had an important
effect on the bay; the tidal prism was decreased,
and the flushing regime significantly changed.
Urbanization is the most recent of man's activities
to contribute large amounts of sediment to streams.
Sediment loads derived from land being cleared or
filled for the building of houses, roads, and other
facilities are best documented in the area between
Washington, B.C. and Baltimore, Md. During
periods when housing developments, shopping cen-
ters, and highways are being built, the soil is dis-
turbed and left exposed (o wind and rain. The con-
centration of sediment in storm runoff from con-
struction sites is a 100 to 1,000 times what it would
be if the soil had been left in its natural vegetated
state. Even though the soil is left exposed to ero-
sion of this intensity for only a short time—a few
years at most—the amount of land cleared for
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DREDGING EFFECTS
199
new housing and ancillary uses in the Washington-
Baltimore area has been so great in recent years
that the contribution of sediment is significantly
large. Harold Guy of the U.S. Geological Survey
has estimated that the Potomac River receives
about a million tons of sediment per year from
streams that drain the metropolitan Washington-
area. This is about the same amount of sediment
that the Potomac River brings into the Washington
area from all its other upland sources.
Another of man's activities that increases the
sedimentation rates of estuaries is the disposal of
dissolved phosphorus, nitrogen, and other plant
nutrients into rivers and estuaries. Municipal sewage
effluents, including effluents that have received
secondary treatment—the highest degree of conven-
tional treatment—contain high concentrations of
nutrients. In some areas, agricultural runoff from
fertilized croplands and animal feedlots also con-
tributes nutrients to river waters and estuaries.
These nutrients promote the growth of diatoms and
other microscopic plants (phytoplankton) both in
the rivers and in the estuaries that the rivers flow
into. The mineral structures formed by many of
these organisms persist after the organisms die and
become part of the sediment loads of the rivers and
the sedimentary deposits of the estuaries. The Army
Corps of Engineers estimates, for example, that the
diatom frustules produced in the Delaware River
and Delaware Ba}^ contribute about the same amount
of sediment (a million-and-a-half tons per year) to
the Delaware estuary as all other upland river
sources. The effects of nutrient loading from munici-
pal wastes on primary productivity are readily
observable in the Potomac estuary, in Baltimore
Harbor and the Back River estuary (Maryland), in
Raritan Bay, in the Arthur Kill estuary, in the
Hudson estuary, in the Delaware estuary, in Sari
Francisco Bay, and in many other estuaries around
the country. Stimulation of plant growth by nu-
trient-enriched runoff from agricultural areas is
apparent in the upper Chesapeake Bay, the estuary
of the Susquehanna River.
MAN'S ACTIVITIES
THAT DECREASE
RIVER SEDIMENT LOADS
Reservoirs probably cause the most significant
interruptions in the natural movement of sediment
to estuaries by rivers. Reservoirs are built on rivers
for a number of purposes: for hydroelectric power,
for flood control, for water supply, and for recrea-
tion. Regardless of their purpose, reservoirs share
in common the ability to trap sediment. Even small
reservoirs can trap significant proportions of river
sediment. For example, a reservoir that can hold
only one percent of the annual inflow of river water
is capable of trapping nearly half the river's total
sediment load. A reservoir whose capacity is 10
percent of the annual river water inflow can trap
about 85 percent of the incoming sediment. Although
a river will tend to erode its own bed downstream
of a reservoir to partly compensate for the sediment
it has lost, the net effect of the reservoir is to
decrease the overall amount of sediment carried by
the river. In the larger river basins of Georgia and
the Carolinas, the sediment loads delivered to the
estuaries are now something like one-third of what
they were about 1910, mainly because of the large
number of reservoirs that have been built since then
for hydroelectric power and, to a lesser extent, for
flood control.
On some rivers, settling basins and reservoirs have
been built specifically as sediment traps to improve
the quality of water farther downstream. In 1951,
three desilting basins were constructed on the
Schuylkill River of Pennsylvania to remove the
excessive sediment that resulted from anthracite
coal mining in the upper river basin. The basins are
dredged every few years, and the dredged material
is placed far enough from the river to be out of
reach of floods. As a result of these basins, the
sediment load carried by the Schuylkill into the
Delaware estuary has been reduced from nearly a
million tons per year to about 200,000 tons per year.
NET EFFECT
OF MAN'S ACTIVITIES
ON SOURCES OF SEDIMENT
The net effect of man's activities has no doubt
been an increase in the sediment supplied to most of
the estuaries of the United States, but we cannot
say by how much. Although reservoirs and other
controls have reduced the sediment in rivers in
recent years, they have only partly offset the in-
fluences that caused the increases in the first place.
Added to this is the fact that sediment takes
decades to move through a river system. Much of
the sediments released by past mistakes—such as by
poor mining practices and by poor soil conservation
practices associated with agriculture—are still in
the river valleys in transit storage between their
sources and the estuaries. Elven if the active supply
of sediment to rivers were completely checked today,
many decades would pass before the sediment loads
would drop to their natural, pre-colonial, levels.
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200
ESTUARINE POLLUTION CONTROL
CONTROL or RIVER
SEDIMENT INPUT
The ultimate method of controlling the sediment
that rivers contribute to estuaries is to control
erosion at the source. The possibility of complete
control, however, is remote. Erosion is basically a
natural phenomenon. All land, whether in its natural
state or altered by man's activities, yields a certain
amount of sediment. Because the natural processes
of erosion are less subject to control than are man's
influences on these processes, perhaps the best that
one can hope for is to keep erosion down to its
natural level. But even this is probably a vain hope.
In spite of the marked reduction that conserva-
tion measures have caused in soil erosion since they
began to be applied in earnest over 30 years ago,
cultivated farmland in the eastern United States,
for example, continues to yield sediment at about
10 times the rate of equivalent areas of forested
land. In places where former croplands and grazing
lands have been replanted in forests and grasses,
sediment yields have been considerably reduced.
Although it is true that as long as men cultivate
land, there seems to be little hope of reducing
sediment yields to their natural rates—rates typical
of heavily vegetated lands—much more effort should
be directed at reducing sediment yields through ap-
propriate soil conservation practices. If these con-
trols are enforced not only for agriculture, but also
for strip mining, urbanization, and highway con-
struction, significant reductions in sediment inputs
to estuaries will result. These reductions will, within
a period of decades, be manifested in reductions in
the dredging activity required to maintain many
shipping channels; and may result in improvement
in water quality of the estuarine zone, particularly
if nutrient inputs are decreased.
ROUTES AND RATES
OF TRANSPORT
Once sediment reaches an estuary, it may move
directly to a site where it will remain permanently,
but it is more likely to be deposited in a series of
temporary storage areas or "parking lots" before
coming to its final resting place. Although we have
some idea of the kinds of places where sediment is
most likely to eventually accumulate in estuaries,
we are generally unable to predict, the detailed route
that sediment will follow between the point where
it enters the estuary and the place where it finally
comes to rest. Furthermore, we know little about
how often sediment moves—whether it moves a
short distance every day, or moves mainly during
short but severe events such as storms and floods.
We suspect that infrequent severe events are more
important in delivering sediment to the estuary in
the first place, but that the slower day-to-day
processes are more important in redistributing sedi-
ment from one part of an estuary to another to
determine the final depositional patterns. In upper
San Francisco Bay, for example, the sediment
brought in by the Sacramento River during the
rainy winter months is initially deposited in broad
shallow areas of the estuary. During the dry summer
months the daily breezes that blow across the bay
stir up the shallow waters and resuspend the sedi-
ments blanketing the shoal areas. The tidal currents
transport this material to deeper areas, mostly
farther up the bay. The deeper areas, in and near
Mare Island Strait, are the location of the most
intensive dredging of navigation channels in San
Francisco Bay. About two million cubic meters, or
about a third of all the sediment dredged in the
entire San Francisco Bay system, are removed every
year to maintain adequate channels into and within
the Mare Island Naval Shipyard.
If we have only a limited knowledge of the routes
of transport within the estuary, we know even less
about the rates of transport. We have some measure-
ments of the rates at which sediment is supplied to
the estuary from selected sources, mostly rivers.
And, we have some knowledge of the rate at which
some of the sediment accumulates in specific parts
of estuaries, particularly in the dredged navigation
channels. But we have only a limited picture of the
rates of input from other sources and the rates of
accumulation at other less obvious places, and a
particularly limited picture of the rates at which
a given particle of sediment might be expected to
move from one part of the estuary to another on
its way to a permanent resting place.
Patterns of Deposition
The pattern of deposition of sediment in an estuary
is determined mainly by the non-tidal circulation
patterns of the water. As pointed out previously, an
estuary's net circulation pattern is determined
primarily by the relative magnitudes of the river
and tidal flows, and by the geometry of the estuarine
basin. The circulation pattern can be altered, some-
times drastically, by changes in any of these factors.
TRAINING WORKS
Training works such as jetties and dikes are built
for the expressed purpose of changing the pattern
of flow and deposition in estuaries: specifically, to
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DREDGING EFFECTS
201
discourage the deposition of sediment where it is not
wanted, or to facilitate its deposition in other places.
The deposition of sediment is discouraged by chan-
neling flows to increase their velocity and scouring
potential. Deposition is encouraged by providing
quiescent areas whore suspended particles can settle
to the bottom.
Although in theonr training works should be an
efficient means of controlling sediment, in practice
their results are often difficult to predict. Works
constructed in the early years of this century along
the main shipping channel in Liverpool Bay in
England, for example, were successful in increasing
the velocities and the depths in the channel. How-
ever, they caused an unexpectedly rapid increase in
sedimentation in the areas of the bay outside the
channel as well as in the tributary estuary of the
Mersey River.
DREDGING
Since problems associated with dredging are dis-
cussed at length in several other papers in this
volume, our comments will be limited. Dredging of
navigation channels is the most pervasive of man's
activities in estuaries that affect the circulation of
water, and consequently, the pattern of deposition
of sediment. In many estuaries, dredging seriously
disrupts the natural equilibrium that formerly
existed between river inflow, tidal exchange, sedi-
ment supply, and the configuration of the estuary
floor. The response to dredging is frequently to
"heal" the disruption by filling the dredged channel
with sediment.
If left to itself, the healing might proceed in the
following way. Suppose we have an estuary where
the sediment inflow and the bottom geometry are
in some kind of steady-state balance with respect to
each other. This might be a large estuary, such as
Delaware Bay, thai is slowly and steadily being
filled with sediment, mainly in its upper reaches,
or it may be a narrow estuary, such as the Savannah
River between Georgia and South Carolina, that
flows in a river-size channel through sediment-filled
lowlands to the sea. When a deep channel is dredged
in such an estuary, it allows salt water to penetrate
farther inland than formerly and it shifts the nodal
point of the upstream flowing seawater farther up
the estuary. This nodal point becomes the locus of
most rapid sedimentation and remains so until the
channel at that point is filled with sediment. When
that part of the channel is filled and the salt water
can no longer penetrate that far inland, the nodal
point is progressively shifted seaward and another
part of the channel is filled. This process continues
until the entire navigation channel is healed-—
provided that enough sediment and time are avail-
able. If the navigation channel is dredged repeatedly,
as are most channels whore the supply of sediment is
heavy, the sediment continues to accumulate at or
near the first nodal point which continues to be
the location of maximum dredging effort in the
estuary. The maintenance of navigation channels in
many estuaries, therefore, is a battle between man's
efforts to disrupt a pre-existing state of equilibrium,
and the estuary's tendency to restore that equi-
librium.
A major problem in dredging is the disposal of
the dredged material (spoil). In many cases, spoil is
dumped in places where sediment of that texture
would not have accumulated naturally, or at least
not nearly as rapidly in the natural course of events
as in spoiling. This applies to disposal sites both
inside and outside of estuaries.
Spoil is commonly dumped inside the estuary,
sometimes directly alongside the channel. The spoil
may remain where it is dumped, especially if it is
dumped in deep spots out of reach of strong currents.
Often, however, dredge spoil returns to the channel.
In recent years, according to estimates made by the
U.S. Army Corps of Engineers, about half the
sediment dredged from the navigation channels in
Charleston Harbor and San Francisco Bay is mate-
rial that has already been dredged at least once
before and has made its way back into the channels
from the place \\here it was dumped.
In some estuaries, spoil is dumped on fringing land
areas. A principal advantage is that these areas can
be diked to prevent the return of the spoil to the
estuary. The main disadvantage is that the marginal
areas are often salt marshes that are valued for
their role in the protection and production of fish
and other forms of estuarine life. Dumping spoil on
these areas usually destroys their original plant and
animal communities.
Spoil is also taken by barge or hopper dredge and
dumped in the ocean outside estuaries. In 1968, for
example, about 50 million tons of dredged spoil was
dumped in ocean waters off the coast of the United
States. In many ocean areas, such as off New York
city where some 7 million tons of spoil are dumped
every year, the spoil is a markedly different type of
sediment from the natural bottom material and it is
introduced at a rate many times greater than the
natural rate of local sediment input to the ocean.
This is perhaps man's greatest alteration of the
pattern of deposition—taking material that was
destined by nature to be deposited in estuaries and
dumping it at sea.
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202
ESTUARINE POLLUTION CONTROL
Modification of Prevailing
Sedimentation Processes
By Engineering Projects:
A Mistake and A "Success"
CHARLESTON HARBOR
Charleston Harbor, one of the finest natural
harbors on the Atlantic seaboard, has served the
needs of the region since the town was settled in
1670. It is an interesting example of an estuary
whose circulation and sedimentation were markedly
altered by changing the freshwater input to the
estuary. The Charleston Harbor estuary receives
freshwater inflow from the Ashley, Cooper, and
Wando Rivers. The mouth of the estuary is restricted,
and entrance from the Atlantic Ocean is gained
through a single, jettied-chanuel. Prior to 1942,
the freshwater input was very small, averaging less
than 20 nrVsec (700 ft3/sec); and the harbor was
somewhere between a vertically homogeneous and
sectionally homogeneous estuary. Fine-grained sedi-
ment was moved slowly through the estuary to the
ocean, and little dredging was required. Mainte-
nance dredging to keep the mam channel at a depth
of 9 m was only about 00,000 m.1 yr t SO,000 yds3/ > r)
at a cost of about $ll,600/yr.
In late 1941, a hydroelectric dam was completed
which diverted most of the flow of the nearby
Santee River, the largest river on the south Atlantic
seaboard, into the upper Cooper River which flows
into Charleston Harbor. The average freshwater
input to the harbor rose from less than 20 m3/sec
(700 ft3/sec) to more than 400 m3/see (14,000
fts/sec). The inflow of fluvial sediment was in-
creased by about a factor of four. More importantly,
the marked increase in the freshwater discharge
shifted the circulation pattern in the harbor from
a well-mixed estuary to a two-iaycred circulation
pattern characteristic of a partially-mixed (Type B)
estuary. Fine sedimentary particles which would
previously have been carried completely through
the estuary to the ocean were no'v entrapped in the
estuary by the net upstream flow of the lower layer
and accumulated in the inner harbor—in the upper
reaches of the non-tidal estuarine circulation regime.
Shoaling became a serious problem. Dredging re-
quired to maintain the inner harbor channel jumped
to an average of 1.8 million raVyr (2.3 million
yds3/yr) at an average cost of about $380,000/yr
during the 9 year period from 1944 to 1952. More
recently, dredging has averaged about 7.5 million
m3/yr (10 million yds'/yr).
Nearly half of the currently dredged material
represents older dredged spoil that has returned to
the channel. Another 10 percent or so of the new
spoil is due to the deepening of the main navigation
channel from 9.1 to 10.7 m (30 to 35 ft) between
1941 and 1943. The major factor in the increased
shoaling rate- was the change in estuarine circulation
produced by the diversion of water from the Santee
River into the harbor. This was conclusively demon-
strated by hydraulic model studies.
The shoaling problem has become so difficult and
expensive to control that plans are well underway
for rediversion of the Santee back to its original
channel.
DELAWARE BAY
Delaware Bay has also served maritime commerce
since colonial times, providing access between the
sea and such cities as Philadelphia and Trenton. In
recent years some fairly successful measures have
been taken to control sediment, both in the inflowing
rivers and in the bay itself. The desilting works in
the Schuylkill River need no further discussion here
except to point out that thejr have; resulted in a
fivefold decrease in the sediment brought by the
Schuylkill to the upper estuary at Philadelphia.
Within the Delaware estuary, the Corps of Engi-
neers has been able t o decrease the amount of dredge
spoil that has returned to the navigation channels.
Before 19r>4. when spoil was dumped overboard in
the Delaware estuary Jo to 20 million m3 (20 to
2(5 million yds'j of sediment were dredged in an
average year, and the navigation channel could not
always be maintained at its specified depth. Begin-
ning in 1954, all dredge spoil was placed in diked
areas to prevent its return to the channels. Since
then, only about f> million m3 (S million yds3) of
sediment are dredged every year, and the navigation
channels .ire consistently deeper. Although this is
one of the more successful instances of coping with
estuarine sedimentation, it is only a temporary
expedient in the long run. Peripheral lands for spoil
disposal are becoming scarcer and more costly
because of competing demands such as development
or conservation, and the end of available land for
spoil disposal around the fringes of the Delaware
estuary is already in sight
The Effects of Sediments
on the Biota
and on the Aesthetics
of the Estuarine Environment
Clearly, man has affected the input of sediments
to estuaries by land-use practices throughout their
drainage basins, by the construction of darns and
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DREDGING EFFECTS
203
reservoirs on tributary rivers, by diversion of rivers,
and by engineering projects to control shore erosion
of the margins of estuaries. He has also affected the
distribution patterns of sediments within estuaries,
both in the water column (suspended sediments)
and OTI the bottom (deposited sediments), by
changing the estuarine circulation patterns either
through alteration of the freshwater inputs, or
through modification of their geometry by dredging
or by othir engineering project.-!. Man's impact on
depositional patterns has already been described
briefly in the previous scctioi, fr, addition (o the
obvious effects of shoalings on basin geometry and
therefore on circulation, and on the geological life-
times of estuaries, changes of the rate of sedimenta-
tion and of the character of the sedimentary material
can have significant effects on organisms, particu-
larly the animals that live on the bottom. Fine-
grained sediments may also affect the chemical
character of the interstitial water and, when resus-
pended by waves and currents, that of the overlying
waters.
EFFECTS ON THE BIOTA
Dredging and the disposal of dredged materials
have generated a great deal of concern, discussion,
and speculation about the impacts of such activities
on the quality of the estuarine environment. During
active dredging and spoiling there are increases in
ihe concentrations of suspended sediment. Sub-
stantial increases—increases of more than a 100
mg/1—are generally local, restricted to an area
within a few hundred meters of the activity, and
any biological or aesthetic effects of these increased
turbidities are not persistent.
Dredging can. of co'arse, alter the estuarine circula-
tion pattern and, in doing so, also change both the
genera! sediment distribution patterns and the con-
centrations of suspended sediment. Changes in these
factors can persist aft.-r dredging and spoiling have
been completed.
Increases in tin concentrations of suspended sedi-
ment above some threshold level that result from
am activity can have Hgt.ificant environmental
effects- on aesthetic, on water quality, and on the
biota. The available literature indicates, however.
that direct efftct.-- -;f suspended sediment on most
es'narin; nrg-mi-ms of the higher trophic, level?
occur c-i.ly at relHUvely high concentrations, con-
centjations greater than 500 rng/1. and generally
greater than 1,000 mg/1. Hucli concentrations are
JT-U' iii r/iost, estii'irie-. ey-n during dredgm? :md
spoi'';ig activities < '-cepi. a>. 01 vs_r\ near, tiie noiitce.
Even in the immediate vicinity of dredging activity,
the increased suspended sediment concentrations
may not be lethal to important organisms of the
higher trophic levels. Studies of caged fish and
crustaceans placed within 8 to 15 meters of active
dredges and overboard spoil discharges failed to
produce any evidence of increased mortality or
damage to gill epithelium compared to control
organisms.
It has also been reported that there was no
increase in the mortality of oysters adjacent to
dredging operations in the intercoastal waterway
near Charleston, S.C. The same investigators also
found that oysters could survive even when sus-
pended directly in the turbid discharge, and that
the organisms died only when they were actually
buried. Other investigations indicated that oysters
decrease their pumping rates when subjected to
relatively high concentrations of suspended sedi-
ment. It has been reported that a concentration of
suspended silt of only 100 mg/1 reduces the pumping
rate of adult oyster?, by about 50 percent. If the
pumping rate were reduced below some critical
threshold for an extended period, the oyster would
obviously die from starvation. It is unlikely that this
would happen as a result of dredging activity.
Furthermore, concentrations greater than 100 mg/1
occur naturally over many productive oyster bars
whenever bottom sediments are rcsuspended by
normal tidal currents. These periodic increases of
suspended sediment do not appear to seriously affect
growth rates.
Sublethal effects of chronic exposure to moderate
excess concentrations of suspended sediment—con-
centrations above those that would occur naturally—
have not been convincingly documented for any
estuarine species. Such effects will be difficult to
establish unequivocally. One would anticipate that
sensitivity to suspended sediment \\ould be a func-
tion not only of species, but of life stage, and of
other environmental stresses.
Increases in the concentration of suspended sedi-
ment that are large enough to markedly change the
visibility of the waters of segments of an estuary can
produce shifts in the fish population. Since game
fish feed by sight, some minimum visibility is re-
quired for successful feeding. If visibility falls below
this threshold, fish such as carp which feed in a
vacuum-cleaner fashion are favored. This probably
occurs only when concentrations of fine suspended
sediment exceed several hundreds of mg/1. Visibility
is a function not only of the concentration of total
suspended solids, but also of their size distribution
and composition.
Che disposal of dredged materials generally results
in the initial destruction of many, perhaps most, of
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204
ESTUARINE POLLUTION CONTROL
the bottom dwelling organisms (benthos) at the
disposal site through burial arid smothering. It has
been documented in a number of estuaries, however,
that the spoil is recolonized relatively rapidly by
organisms from surrounding areas except when the
spoil differs markedly in texture from the host
sediments. Studies of overboard disposal sites in
the upper and lower Chesapeake Bay showed that
within one-and-one-half years the population density
and species diversity of the spoil areas could noi be
distinguished from those of surrounding areas. In
the upper Chesapeake Bay recovery of the channel--
the dredged area—was not complete, but in the
lower bay complete recovery of both the dredged
and spoil areas was documented. Where marked
textural changes result from the dredging or spoiling
activity, recolonizatiori may be limited. The dredged
canals of Boca Ciega Bay, Ma., are examples.
If dredging or spoiling produce substantial changes
in the depth distribution of an estuary, or segments
of it, significant changes may occur in habitat space
and therefore in the distribution of organisms. Areas
of the bottom can be removed from the euphotic
zone by dredging, and areas can be built-up by
spoiling from a relatively deep position into the
surface layer where they are subjected to stirring by
currents and waves. Clearly such alterations are not
necessary consequences of dredging and spoiling.
The magnitude of the impact of dredging and
spoiling is also a function of the time of year they
are done. These activities should be scheduled when
there will be the least probable impact on the most
"important" indigenous species. Generally, for any
given species the early life history stages are more
sensitive to environmental stresses than later stages.
Studies indicate that substantial dredging and
spoiling projects can be carried out in estuaries
without any gross biological effects or any persistent
aesthetic degradation. Any chronic biological effects
that might arise either from exposure of organisms
to spoil and associated contaminants for long periods.
or from exposure to relatively subtle, but persistent.
changes of the physico-chemico milieu have not-
been documented. Much of the research that has
been done and is still being done to determine the
effects of dredging and spoil disposal is ill conceived
and will not provide answers to the pertinent
questions.
EFFECTS ON WATER QUALITY
AND AESTHETICS
Fine-grained suspended sediment CPU affect the
distribution of dissolved oxygen in estuarine waters
both directly and indirectly. The oxygen demand of
organic-rich sediments may produce a sag in the
oxygen distribution. It has been reported that in
the Arthur Kill, for example, when dredged spoil
was resuspended oxygen levels were reduced from
16 to 83 percent below their average levels. Other
investigators reported that when surface sediments
from Wassaw Sound, Ga., were suspended in the
estuarine water, they were capable of removing
"533 times their own volume of oxygen from the
water." No such effect was observed in the upper
Chesapeake Bay, and studies of Louisiana marshes
did not demonstrate any significant oxygen deple-
tion as a result of dredging activities. Since the con-
centration of suspended sediment affects the trans-
parency of water, increases in suspended sediment
levels decrease the depth of the euphotic zone and
therefore the production of oxygen by phyloplankton.
Increased suspended sediment concentrations may
also affect the production of oxygen by rooted
aquatic plants. Areas of the bottom formerly within
the euphotic zone can be removed from it as a result
of man's activities. Prior to about 1920 much of the
bottom of the upper Potomac outside of the channel
was covered with a dense growth of rooted plants.
During the 1920's this vegetation almost completely
disappeared and lower oxygen levels were reported
in this area. The effects of the disappearance of these
plants on the distribution of dissolved oxygen were
confounded by the effects of other significant en-
vironmental changes on oxygen levels.
Fine sedimentary particles can act as both a
source and a sink for nutrients and other constitu-
ents. Nutrients may be sorbecl onto fine-grained
particles, or desorbed from thorn depending upon a
variety of physico-chemico conditions. These include
salinity, pH. temperature, the chemical composition
of the particles, and the concentrations of nutrients
in the water. The mechanisms that control these
exchange processes are poorly understood, and
should be investigated.
It is well known that fine-grained particles con-
centrate a variety of pollutants, including: petroleum
byproducts, heavy metals, pesticides, and some
radionuclides. In the water column the bulk of each
of these contaminants is usually associated with
line suspended particles, and therefore the distribu-
tion, transportation and accumulation of these sub-
stances are determined primarily by the suspended
sediment dispersal -systems. Filter-feeding, organisms
which ingest these particles and associated cor-
taminants agglomerate the smaller particles into
larger composite particles in their feces and pseudo-
feces thereby providing the contaminants in a in j;e
concentrated form to deposit fs-cders. Laboratory
experiments have demonstrated the ability of oysters
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DREDGING EFFECTS
205
to concentrate DDT in their pseudo-feces. Increases
in the concentration of DDT and other pesticides in
detritus particles of fine-grained bottom sediment of
estuaries of up to 100,000 times those in the over-
lying waters have been reported. These residues can
sometimes be transferred to detritus feeding or-
ganisms. Increases in the concentration of con-
taminants at each trophic level are well documented
for radioactive isotopes and some pesticides. This
phenomenon has been referred to as "biological
magnification."
Fine sediments can also serve as a temporary sink
for radioactive contaminants. It has been shown, for
example, that 65Zn may be held by fine-grained
sediments for months with a continual low level
release to the interstitial and overlying waters.
The effects of fine-grained particles and their
associated contaminants on the composition of both
the interstitial and overlying waters, and on the
biota are poorly understood. This is an area that
should receive considerable attention. From the
standpoint of dredging, it is particularly important.
Appropriate standards for permissible levels of
contaminants in spoil should be based, not on the
total concentration of each contaminant, but on the
concentration that is available for biological uptake—
the concentration of the reactive fraction. While
standards based on totals are safe they place undue
restrictions on the disposal of dredged materials. It
is becoming clear that fine-grained particles play a
significant role in determining the quality of the
estuarine environment, and the composition of its
biota.
Increases in the levels of suspended particulate
matter can also have a significant aesthetic effect.
Above some threshold level, suspended matter is
aesthetically displeasing and inhibits recreational
use. This level is a function not only of the total
concentration, but also of the size distribution and
the composition of the suspended material. A con-
centration of 100 mg/1 of fine quartz sand does not
have the same effect on water color and transparency
as does the same concentration of organic-rich silt
and clay. Individuals also have different aesthetic
thresholds.
SOME RECOMMENDATIONS
FOR FURTHER STUDY
Some of the types of studios we feel must be done
if we are to understand how estuaries operate
sedimentologically; if we are to be able to predict
the consequences of manmade alterations of the
prevailing sedimentary processes; and if we are to
manage estuaries for the greatest use of man, are
described below.
Sources of Sediment
to Estuaries
One of our principal needs in understanding the
sources of sediment brought to estuaries is for more
complete data on the sediment loads carried by
rivers—the principal source of sediments to most
estuaries. In less than half of the estuaries of the
country do we have any kind of regular measurement
of the input of river sediment. Furthermore, the
records we do have are mostly too short. Only a few
river sediment stations have been in operation long
enough to have documented the extreme events that
are so important in the introduction of sediment:
events such as the hurricane flood of August 1955
when the Delaware River carried more sediment past
Trenton in two days than in all five years combined
in the mid-1960's drought; or the three days in
December 1964 when the Eel River in northern
California transported more sediment than in the
preceding eight years; or the week following Tropical
Storm Agnes in June 1972 when the Susquehanna
discharged 20-25 times as much sediment as during
the previous year. Events of this magnitude occur
only rarely—a few times a century at most—but
their importance to estuarine sedimentation is so
great that programs should be designed to record
their effects when and where they do occur.
Daily sampling stations should be established on
the lower reaches of all major rivers—upstream
from the landward limit of measurable sea salt
intrusion—to measure the inputs to estuaries of
water, sediment, nutrients, and other substances.
These stations should be permanently maintained
to catch the large events, and permit an assessment
of their relative importance. In addition, a funding
mechanism should be developed to support research
of the effects of events on the estuarine environment.
We also need to further our understanding of
sources of estuarine sediments other than rivers. In
a recent study of the sources of shoaling material in
the navigation channels of the Delaware estuary, for
example, the U.S. Army Corps of Engineers esti-
mated that only one-fourth of the shoaling material
could be accounted for by present day river sources.
The remaining three-fourths was attributed to
erosion of the bed and banks of the estuary, diatoms
produced in the estuary in response to an excess
supply of nutrionts, and other sources (some of
which could not be identified). It has been suggested
that shore erosion is the principal source of sediment
to the middle and lower reaches of the Chesapeake
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206
ESTUARINE POLLUTION CONTROL
Bay estuary. Those sources deserve more of our
attention so that we can identify them more ac-
curately, assess the rates at which they add sediment
to the estuaries, and find out to what degree they
are subject to manipulation and control by man.
Routes and Rates
of Sediment Transport
Tracers offer a promising approach to studying
the routes and rates of sediment movement. Tracers
such as fluorescent particles can be added to the
sediment, and the sediment can be sampled re-
peatedly to determine the routes and rates of sedi-
ment movement; or one can make opportunistic use
of distinctive contaminants, such as radioactive
isotopes or heavy metals, that are dumped into
estuaries either intentionally or inadvertently. These
compounds sometimes can be used as labels to
follow sediments from known sources to sites of
deposition. Releases from nuclear power plants
should be investigated as possible tracers. An at-
tempt should be made to assess the impact of man
on the prevailing sedimentary processes. Such an
assessment would have to come primarily from an
examination of the sedimentary record.
Patterns of
Sediment Accumulation
In the past we have relied mainly on dredging
records as a measure of sediment accumulation, but
they tell us little about how sediments accumulate
in the large areas of estuaries that lie outside the
dredged channels. For some estuaries, modern day
navigation charts have been compared with older
ones (some dating back to the mid-1800's) to
estimate the accumulation of sediment. Because the
charts are already available, a systematic comparison
of old and recent survey sheets could be made for
most estuaries of the country at relatively little
expense. Some newer techniques can also be ap-
plied—particularly those techniques that use the
decay rate of naturally radioactive material to
measure the age of sediment and how long ago or
how rapidly it may have accumulated. An effort
should be made to refine those radiometric dating
techniques that are particularly applicable to estu-
arine deposits, and to apply the techniques to a
variety of estuarinc systems. The two methods that
have the greatest promise are Pb210 which has a
useful range of 10 to 100 years and C14 which can
be used to date events that occurred in the past
1,000 to 10,000 years.
Another difficult aspect of the sediment budget of
most estuaries is the question: on a net basis, does
more sediment move out of the estuary into the sea
than moves into the estuary from the sea? We know
that sediment escapes from estuaries on outgoing
tides, and we know that sediment is moved into
estuaries from the sea floor on incoming tides; but
we do not know enough about the quantity or kind
of sediment that moves either way to be able to
say whether, on balance, more moves out than in.
Here again, well-designed tracer studies might be
useful.
An estuary's sedimentary deposits contain the
history of that environment, and it is only through
the examination of this sedimentary record that one
can assess the impact of man on the distributions
of both naturally occurring substances and of man-
made pollutants, such as PBCs (polychlorinated
biphenyls) and pesticides. Naturally occurring sub-
stances include not only innocuous sedimentary
particles, but also some pollutants; pollutants such
as heavy metals which are present in the earth's
crust and are carried into the estuarine environment
both in solution and adsorbed to fine suspended
particles b\ rivers and streams. Heavy metals are,
of course, also introduced into the environment as
a result of man's activities.
The sedimentary record also contains the most
reliable information of the frequency of natural
catastrophic, events such as floods, droughts, and
hurricanes that have occurred during the past several
thousand years. The importance of episodes in the
development of estuaries has not been well docu-
mented because of the infrequency of such events
and the difficulty of sampling during most storms
and floods.
Model Studies
Physical and mathematical models can provide
valuable insight into a variety of sedimentary proc-
esses. They are not, however, a panacea for all
estuarine sedimentation problems, and are only as
good as the prototype data and theoretical assump-
tions on which they are based. Perhaps the greatest
need is for more attention to be directed at the
formulation of conceptual models of estuarine sedi-
mentation. Conceptual models should, in any case,
precede the construction of mathematical or physical
models.
Characterization of
Fine-Grained Sediments
Appropriate field arid laboratory studies should
be conducted to characterize the chemical and
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DREDGING EFFECTS
207
mineralogic nature, and the reactivity of the fine-
grained, carbon-rich particles. It is clear that fine-
grained particles can play a major role in determin-
ing the quality of coastal waters, and the distribu-
tion of organisms. These studies should also include
investigations that would lead to the establishment
of meaningful diagnostic standards for the disposal
of dredged materials. While the present standards
used by the EPA to characterize dredged materials
were intended to be environmentally conservative
they may be unduU restrictive with respeet to the
designated parameters, while1 they ignore a larg<
number of important contaminants such as PCBs,
pesticides, and others. In any event, they are clearly
not based on sound scientific evidence. Standards
for dredged materials should not be based on the
total concentrations of contaminants, but rather
they should reflect the total masses of contaminants
that are available for biological uptake. These
masses are the concentrations of the reactive1 frac-
tions of these contaminants—the fractions available
for biological uptake—times the total mass of
dredged material. Even with such standards, deci-
sions on dredging and spoil disposal should be based
on the physical, chemical, biological, and geological
characteristics of the particular estuary. The uniform
application of Federal standards has little merit
other than simplicity of enforcement.
We know far too little about the effects of
sediment-borne contaminants on estuarine life. We
need an extensive series of laboratory experiments
to test the effects of a variety of contaminants on
different organisms. It is particularly important that
these experiments simulate field conditions; too
many of the experimental results we already have
cannot be extrapolated beyond the laboratory. Only
after such a series of experiments can we establish
diagnostic standards and criteria for such things as
dredged materials. Increased emphasis should be
directed at studies to determine the chronic effects
of exposure to moderate excess concentrations of a
variety of contaminants.
The new Dredged Materials Research Program
(DMRP) of the U.S. Army Corps of Engineers is
an important step in the right direction. The
DMRP should provide a great deal of valuable in-
formation for the more effective mangement of
estuarine dredging and spoil disposal.
Alternatives to Present Practices
Even if we succeed in reducing sediment inputs
to estuaries through enforcement of strict soil con-
servation measures, dredging will continue to be a
persistent estuarine activity. Not only are estuaries
naturally areas of relatively rapid sedimentation, but
much of the material dredged from navigation
channels is material previously introduced, and re-
distributed by prevailing estuarine circulation proc-
esses. Further, the increasing use of deeper draft
vessels, arid the increasing demand for pleasure boat
marinas and facilities will require additional dredging.
Estuary-wide dredging and spoil disposal plans
should be developed to ensure that maintenance
channel dredging can be carried out without undue
delays. Such pians should include the designation of
a variety of types of sites (overboard, diked, et
cetera) for disposal of different types of spoil.
Certain kinds of spoil may have a greater environ-
mental impact if disposed of in aerobic (oxygenated)
diked areas, than if disposed of by conventional
overboard methods within oxygen-deficient areas of
an estuary. If regional plans are not developed
promptly, the activities of a number of major ports
will be seriously affected and will result in serious
economic perturbations. These dredging and spoil
disposal plans should be significantly flexible to
provide a mechanism for decision making on requests
for other types of dredging permits. The suggestion
that a number of our major ports are "poorly
located" is to some extent correct, but the suggestion
that they should be moved is naive at best. Major
ports could not be moved without serious economic
upheaval, and the lead time to implement any such
proposals would have to be decades. The growth of
some ports located near the heads of estuaries should
perhaps be controlled.
We should also direct more attention to more
productive means of disposing of spoil. An example
is the process developed by Professor Donald
Rhoads of Yale University to make construction
bricks from estuarine mud. Or we might consider
taking railroad cars that haul coal to seaports and
filling them on the return trip with dredge spoil
that can be used to fill or reclaim lands that have
been strip mined. Formation or nourishment of
islands for recreational use is another possibility.
Surely there must be other more ingenious ways of
disposing of dredged material than dumping in
estuaries or transporting it out to sea.
SOME CLOSING OBSERVATIONS
The great value of the estuarine zone is in the
multiplicity of vises it serves, but herein also lies its
vulnerability. Estuaries can support certain levels
of shipping and transportation without a loss of
commercial and recreational fish landings. Estuaries
can tolerate some dredging and disposal activities
without persistent damage to the biota or aesthetic
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208
ESTUARINE POLLUTION CONTROL
degradation. Estuaries also have a capacity to
tolerate some human, industrial, and municipal
wastes; and to assimilate some waste heat without
suffering persistent and significant ecological dam-
age. And, the biological resources of estuaries can
be harvested at certain levels without seriously
affecting future yields. Estuaries can serve all of
these uses and still remain aesthetically pleasing
environments for man's recreation—for his re-
creation. But an estuary's capacities to support
these varied activities are finite. The ability of an
estuary to tolerate each "environmental insult"
before suffering significant ecological or aesthetic
damage not only varies from estuary to estuary but
varies in different parts of a given estuary as well.
And, within any segment of an estuary it varies
temporally. Uniform, invariant regulations and stan-
dards for the disposal of wastes, whether they are
heat, nutrients, or dredged spoil, are environmentally
naive. The only justification for their enactment is
that it simplifies enforcement. A uniform speed limit
of 25 mph is as irrational as one of 100 mph is
irresponsible. Uniform estuarine regulations are
wasteful of valuable natural resources—resources
that should be used, and used responsibly. The
philosophy of those crusaders who espouse cessation
as the solution to all environmental problems is not
viable. People live. They eat, they defecate, they
procreate, and yes, they also need to recreate. This
is not to imply that we should not insist on good
waste treatment, on carefully supervised methods
of dredging and spoil disposal, and on controlled
mining of bottom and subbottom mineral resources.
We should. We should insist on more.
Estuaries should be zoned. To date, formal zona-
tion of the estuarine environment has been restricted
primarily to that associated with military activities.
Man zones his terrestrial environment into residential
and industrial areas, and he sets aside portions of it
for parks and forests for recreation. He identifies
other segments of it for the disposal of his waste
products. He does not make it an official policy to
spread his garbage and trash uniformly over the
landscape. He neither demands nor expects all parts
of his terrestrial environment to be of equal quality.
Should he expect to be able to swim and harvest
seafood in every part of every estuary? Segments of
some estuaries should be identifieo. as spoil disposal
areas, other segments as the receiving waters for
municipal and industrial wastes, others as sinks for
the heated effluents from power plants, others as
spawning and nursery areas, others for military
activities, and others as fishing and recreational
areas; still others should be preserved, or at least
conserved in a wild state. These segments are not
all mutually exclusive; there would be considerable
overlap. And the spatial boundaries of the various
zones should be defined as a function of time.
Because the primary reasons for the management
of estuaries are to protect their biological resources
and to conserve their aesthetic and recreational
values, certain activities should be restricted more
severely in some areas than in others and also during
those periods when organisms are most vulnerable.
During these vulnerable periods—generally the egg
and larval stages—temperature standards should
perhaps be more stringent, and dredging and spoil
disposals should perhaps be restricted or prohibited
in the important spawning and nursery zones. The
zonation of estuaries would be much more difficult
than zoning man's terrestrial environment, and some
of these suggestions may not be applicable to small
estuaries. The establishment and enforcement of an
estuarine zoning system would require more than
simple policing. It would require careful and intel-
ligent planning and management. But planning and
management by whom?
The establishment of a zoning system is contingent
upon the assignment of priorities to the various uses.
These decisions require not only scientific inputs but
social and economic inputs as well. Decisions as to
which activities are "most important" and what
water quality standards are "good" or "acceptable"
are largely value judgments—important to whom?
. . . good or acceptable for what purpose? Natural
scientists have no peculiar talents for making value
judgments. Scientists can incontestably determine
neither what uses of an estuary are most important
nor even which are most desirable. In terms of gross
monetary return, the most important uses of the
estuarine zone are, according to the "National
Estuarine Pollution Study," for military activities,
for shipping, and for industry. But the monetary
values of commercial and recreational fisheries are
also very high although they are more difficult to
estimate. And, if indeed, communication with nature
is one of man's ultimate sources of happiness as
Dubos and others have suggested, then the true
worth of the recreational value of estuaries cannot
be measured in dollars and cents.
Through science, we can learn to understand
estuaries and even to control them in part, but
scientists cannot unequivocally and decisively deter-
mine the ways in which we should control them.
These decisions should be made by the citizens who
are affected—by all of them.
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DREDGING EFFECTS
209
REFERENCES
Barnes, R. S. K. and J. Green, 1972. The Estuarine Environ-
ment. Applied Science Pub. Ltd., London.
Folger, David W., 1972. Characteristics of Estuarine Sedi-
ments of the United States. U.S. Geological Survey Profes-
sional Paper 742.
Ippen, Arthur T., ed,, 1966. Estuary and Coastline Hydro-
dynamics. McGraw Hill, New York.
Lauff, George H., ed., 1967. Kstuaries. American Association
for the Advancement of Science, Pub. 83. Washington D.C.
Nelson, Bruce W., ed., 1972. Environmental Framework of
Coastal Plain Estuaries. Geological Society of America
Memoir, 133.
Schubel, J. R., ed., 1971. The Estuarine Environment:
Estuaries and Estuarine Sedimentation. American Geo-
logical Institute, Washington, D.C. Short Course Lecture
Notes.
ACKNOWLEDGEMENTS
We thank M. Nichols, D. Hubbell, J. Conomos, and C.
Zabawa for their suggestions. Contribution 116 of the Marine
Science Research Center of the State University of New York.
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SIGNIFICANCE OF CHEMICAL
CONTAMINANTS IN DREDGED
SEDIMENT ON ESTUARINE
WATER QUALITY
G. FRED LEE
The University of Texas at Dallas
Richardson, Texas
ABSTRACT
During the past several years, there has been a major change in dredged material disposal in some
estuarine waters in the U.S. This change is largely the result of finding that many of the sediments
of rivers and harbors contain potentially significant concentrations of chemical contaminants.
Some water pollution control regulatory agencies have adopted dredged material disposal criteria
which have caused more expensive methods of disposal.
A review of the information available today on the relationship between the presence of chemical
contaminants in dredged sediments and water quality shows no technical justification for the
general adoption of alternate methods of disposal at this time. Further, it is shown that some of
the alternate methods of disposal may be more ecologically damaging than those previously used.
The U.S. Army Corps of Engineers initiated in 1973 the 5-year, $30 million Dredged Material
Research Program, designed to provide a technical base of information for the determination of
the most ecologically sound, technically, and economically feasible methods of disposal. This
program shows great promise in providing needed information.
It is recommended that the overly restrictive dredged material disposal criteria advocated by
some environmental activist groups not be adopted. The results of the Army Corps of Engineers
Dredged Material Research Program and other studies should be used for establishing criteria.
INTRODUCTION
Mam' American waterways have a significantly
recurring problem of accumulating sediments which
eventually interfere with navigation. It is of econom-
ic and social interest to Americans to maintain the
navigable waterways at a depth sufficient to allow
the water transport of goods. Generally, the question
is not one of whether or not the U.S. waterways
should be dredged but is one of what method of
dredging and dredged material disposal is in the
best overall interest of society.
The process of removing settled solids from one
location and depositing them in another has an
environmental impact on both locations. The po-
tential impact includes turbidity (cloudy wateri
stirred up at the dredging and dredged material
disposal sites mechanical damage to the aquatic
organisms due to pumping for hydraulic dredging
operations, burial of organisms at disposal sites, as
well as toxicity to organisms arising from chemical
contamiuaiits in the sediments. It is the latter that
causes sediments 1o be classified as polluted.
In the riiid to late 1960's, increasing amounts of
information were gathered which showed that the
sediments in many estuarine environments contained
amounts of chemical contaminants which could
potentially lower water quality. By the early seven-
ties, many Americans were caught up in the en-
vironmental quality movement. During this period,
at the mere discovery of a chemical contaminant in
the environment, activists would advocate large
expenditures of funds for corrective action. In that
spirit, the Federal water pollution regulatory agen-
cies developed criteria which changed the method of
disposal of dredged sediments for some areas of the
country.
The new methods of disposal were predicated on
the fact that the sediments contained amounts of
chemical contaminants, which caused them to be
classified as polluted. The alternate methods of
disposal generally required a much greater expendi-
ture of funds for the dredging operation. In some
areas, the lack of a suitable alternate method of
disposal has caused the dredging of the waterway to
be stopped or greatly curtailed. As a result, the
cargo vessels using the waterway had to either
lighten their loads or seek an alternate port.
The situation that exists today in San Francisco
Bay is a good example of this problem. The cost of
213
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212
ESTUARINE POLLUTION CONTROL
dredging and dredged material disposal in the bay
region has doubled during the past several years,
largely as a result of environmental considerations.
One would expect some problems associated with the
presence of chemical contaminants in the sediments
of the bay which, when dredged and disposed of in
bay waters, have a significantly'ad verse effect on
water quality. However, upon examination of the
situation in the bay region, one finds that no one,
including the water pollution control regulatory
agencies and the environmental activist groups, has
yet attributed any problems to the presence of
chemical contaminants in sediments, which have a
deleterious effect on water quality as a result of
dredging and dredged material disposal activities.
Individuals knowledgeable in the behavior of
chemical pollutants in natural waters examined the
federal criteria which forced alternate methods of
disposal; they raised serious questions about the
validity of these criteria. As a result, the U.S. Army
Corps of Engineers, which is one of the major dredg-
ers of waterways in the U.S., initiated a program
to determine which methods of dredging and dredged
material disposal are in the nation's best interests.
Their headquarters for this project is at the Water-
ways Experiment Station (WES) in Vicksburg,
Miss. In addition, a number of Corps of Engineers
districts have initiated regional research programs
designed to evaluate the potential problems of dredg-
ing and dredged material disposal. This report dis-
cusses the progress that has been made in the con-
trol of chemical pollutants in waterways to be
dredged.
This report is not intended to be a discussion of all
of the various problems associated with dredging
and dredeed material disposal. It instead focuses
exclusively on one of the most significant problems
of the past few years in the area of estuarine water
quality. This problem requires congressional atten-
tion in order to develop a more meaningful approach
to the protection of water quality in U.S. estuaries
with dredging and dredged material disposal activ-
ities. It should be emphasized that other aspects of
dredging and dredged material disposal should also
receive congressional attention. These problems
include the development of a more effective land
erosion control program to reduce the need for dredg-
ing, the selection of a few harbors and waterways
as principal ports for deep draft vessels, the more
effective control of chemical and biological contam-
inants arising from domestic, industrial, and agri-
cultural activities, and the development of more
effective means for allocation of the nation's estu-
arine and marine resources. Many of these topics
are covered in other authors' contributions to the
U.S. EPA overall report to Congress on estuarine
water quality. They are beyond the scope of this
paper.
This report does not attempt to provide detailed
documentation of each point raised. Instead, it con-
sists of a synthesis of the author's views, which are
based on his having been actively involved as a
teacher, researcher and advisor to governmental
agencies and industry on the environmental impact
of dredging and dredged material disposal. The U.S.
Army Corps of Engineers Dredged Material Re-
search Program (DMRP) includes comprehensive
literature reviews prepared by various contractors,
which provide documentation of the various points
covered in this report. Anyone interested in addi-
tional discussion and documentation should contact
the author and/or the Corps of Engineers Dredged
Material Research Program at the Waterways Ex-
periment Station, Vicksburg, Miss.
Two Corps reports are especially pertinent as
backup information to the discussion presented in
this report. The first is by Boyd et al. (1972), and
presents a review of the overall problems associated
with dredging and dredged material disposal. The
second report, by Lee and Plumb (1974), presents
a detailed review of the literature on the potential
significance of chemical contaminants in sediments
as influenced by dredging and disposal activities.
HISTORY OF THE PROBLEM
Prior to the environmental movement, dredged
material was generally disposed of in the most
economic manner possible, usually transportation to
and disposal in deeper waters. By the late 1960's,
and early ]970's, environmental activist groups and
some federal and state pollution control agencies
were advocating on-land disposal. Large amounts of
funds have been expended for land disposal areas.
During the past three years, there have been sev-
eral attempts on the part of federal and state water
pollution control regulatory agencies to develop
dredged material disposal criteria. These criteria
were based on a limited scope study conducted in
the Great Lakes, and were unfortunately made
applicable to estuarine and marine systems a? well.
In retrospect, it appears that such criteria wcr11 not
suitable for the Groat Lakes, much less other waters
throughout the country. As a result of the use of
these criteria, sediments in many parts of the coun-
try were classified us polluted when significant doubt
exists as to whether this was the case.
NATURE OF THE PROBLEM
The rapid changes in dredging and dredging mater-
ial disposal methods during the past few years have
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DREDGING EFFECTS
213
probably created as many problems as solutions.
In some areas, dredging has stopped. In other areas,
escalating costs are forcing private dredgers out of
business. Those who continue operating must ab-
sorb the increased costs. Yet, some of the more ex-
pensive alternate methods of disposal are prob-
ably more ecologically harmful than the previous
methods.
It is difficult to estimate at this time the total
magnitude of the additional cost of alternate meth-
ods. However, in a survey of the various Corps of
Engineers districts, it was found that environmental
quality factors raised the cost of dredging by 10 to
20 percent. For some Corps of Engineers districts,
the increase represented 50 to 60 percent additional
cost.
It is impossible to estimate the total cost for
alternate methods of dredged material disposal in
estuarine waters. However, it is reasonable to expect
that several tens of millions of dollars are being spent
each year for alternate methods of disposal because
of arbitrarily adopted criteria which cause dredged
sediments to be classified as polluted. Yet, there is
no evidence that the relatively economical sediment
disposal methods used in the past had significant
adverse effect on water quality.
Many areas are not finding the alternate methods
of disposal, such as on-land disposal, feasible, and
as a result must barge the dredged material further
out into the open ocean. For example, the New York
District of the Corps of Engineers estimates that
they are spending about 1.2 million dollars per
year out of a total dredging cost of 5 million dollars
for additional transport of dredged material to open
water. The New York District Corps of Engineers
points out that these figures do not include the in-
creased cost of goods such as oil, because partly
loaded or shallow draft vessels must be used.
The New York District also reports that several
marinas and small volume dredging companies have
had to go out of business because they cannot afford
the increased costs of transporting the material to
the open ocean. Also, because of environmental con-
cerns, dredging has ceased in some east coast harbors,
such as Baltimore. Although the total increase in
cost is unknown, alternate disposal methods place
a substantial burden on the public without any ap-
parent benefit in terms of improved environmental
quality.
PROBLEMS WITH
ON-LAND .DISPOSAL
In many areas, on-land disposal with complete
containment of the water associated with the sedi-
ments is not possible; so near shore diked area dis-
posal was adopted. Generally, on-land and in-water
diked disposal areas have overflows that enter near-
by watercourses. Thus, this disposal approach may
be more harmful to aquatic ecosystems than the
disposal of dredged sediments in deeper waters.
Those knowledgeable about the behavior of pol-
lutants in natural waters have known for some time
that the primary area of concern for chemical con-
taminants in natural water systems is fine particles.
Coarse particles readily settle to the bottom. The
fine particles often contain the greatest concentra-
tion of chemical contaminants and, because of their
slower settling rates, have greater opportunity for
interactions with aquatic organisms.
Some of the on-land or dike disposal areas near-
shore have been operated in such a way as to allow
only a relatively short period of time for the settling
of finer particles before returning the excess water
to the nearby watercourse. This means that if there
is any adverse effect from dredged material, it would
occur to the maximum possible extent with on-land
or contained disposal. By contrast, any adverse
effects of chemical contaminants associated with
dredged sediments would generally be expected to
be minimized in open water disposal because, in
general, open waters allow much greater mixing of
the contaminants with the surrounding waters. This
mixing would tend to rapidly dilute the chemical
contaminants below critical threshold concentrations
for the organisms present in the water column. More-
over, on-land disposal would bring contaminant
concentrations into contact with the most sensitive
forms of aquatic organisms, since nearshore waters
serve as the nursery grounds for the juvenile forms of
many aquatic species. Thus, it is possible that
in some areas the more expensive on-land disposal
methods in use during the early 1970's, have done
more ecological damage to the water bodies than
have the traditional deep water disposal methods.
In addition, on-land disposal may also lead to con-
tamination of terrestrial ecosystems as well as nearby
watercourses. However, at this time, little is known
about the uptake of chemical contaminants by ter-
restrial plants grown on polluted dredged sediments.
It is clear that, as normally practiced today, many
of the alternate, more expensive ways of dredged
material disposal may not be less ecologically damag-
ing. Frequently, those who advocate alternate meth-
ods based on the presence of chemical contaminants,
justify the increased expenditure by citing the lack
of knowledge of the environmental impact of aquatic
disposal. They assert that the conservative approach
should be used in those situations where there are
questions about the impact on aquatic ecosystems.
This argument has some validity where the concern
is over the introduction of a chemical contaminant
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214
ESTUARINE POLLUTION CONTROL
into the environment. It is not technically valid,
however, for dredging and dredged material disposal
since the contaminants are already present in the
environment and most importantly, since the alter-
nate methods of dredged material disposal could
produce significant environmental quality problems.
DREDGED MATERIAL
DISPOSAL CRITERIA
In 1972, two developments of major potential
significance to the disposal of dredged materials
occurred. The first was the passage of the 1972
Amendments to the Federal Water Pollution Con-
trol Act. This act required the U.S. Environmental
Protection Agency (EPA) to propose water quality
criteria by October 1973. The other important event
was the 1972 release of the National Academies of
Science and Engineering (NAS-NAE) Water Qual-
ity Criteria (NAS-NAE, 1972). These criteria repre-
sent several years of work on the part of scientists
and engineers throughout the U.S. in assessing the
significance of various physical, chemical, and
biological contaminants to potential uses of fresh and
marine waters. The two events are closely related in
that the criteria proposed by EPA in October 1973,
were essentially based on the July 1972 NAS-NAE
water quality criteria. Both documents are potenti-
ally crucial to dredging because they suggest that
agencies which regulate water quality standards
significantly reduce the permissible concentrations
of chemical contaminants.
The most crucial change stemmed from the dis-
covery that pollutants could be chronically toxic.
Previous water quality standards throughout Amer-
ica had been based on acute lethal toxicity (i.e., the
relatively high levels of chemicals that cause the
death of organisms within a few days of continuous
exposure). However, researchers found that con-
tinuous lifelong exposure of aquatic organisms to
relatively low levels of chemical contaminants would
result in impaired growth and/or reproduction. The
NAS-NAE concluded that, in order to provide the
ultimate protection to aquatic life, water quality
criteria must also be based on chronic toxicity levels.
The full impact of the NAS-NAE water quality
criteria is yet to be manifested. The main problem is
that although the National Academies released the
criteria in 1972, it took two and one half years for
EPA and the Government Printing Office to print
them.
The importance of the new NAS-NAE criteria is
that they will eventually become water pollution
control standards because they are essentially being
adopted by EPA as a basis for their October, 1973
Proposed Water Quality Criteria. It is likely that
attempts will be made to use these standards to
govern dredging and dredged material disposal. For
example, EPA Region IX has recently proposed
revised dredged material disposal criteria for which
they use as a justification the EPA October 1973
Proposed Water Quality Criteria. However, this
presents a problem in that the criteria developed by
the NAS-NAE and promulgated by EPA are applica-
ble to forms of chemicals in a relatively simple chemi-
cal state. In natural waters, chemical contaminants
exist in a wide variety of forms, many of which are
much less toxic than those simpler forms frequently
used to test aquatic toxicity. For instance, the chemi-
cals associated with the solids in sediments being
dredged would generally be in the least toxic form.
Therefore, any attempts to apply the EPA proposed
criteria to dredging would likely be highly over-re-
strictive in assessing the potential toxicity of chemi-
cal contaminants associated with sediments.
In developing dredged material disposal criteria,
emphasis must be given to the role that dredging
and dredged material disposal plays in affecting the
significance of chemical contaminants on water
quality in a particular region. The problem is not
one of determining whether or not the sediments are
contaminated. The sediments of the majority of
the U.S. harbors and waterways are contaminated
by chemicals of municipal, industrial, and agricul-
tural origin. These contaminants do have an adverse
effect on water quality in many U.S. estuaries. The
basic question, however, is what is the impact of
dredging and dredged material disposal in altering
the significant adverse effects of these chemical
contaminants on water quality in the region.
CURRENT RESEARCH
By the early 1970's, the funds supporting research
in the development of water quality criteria had
been greatly curtailed in an attempt to cut back on
federal spending. Currently, little work is being
conducted on the development of new criteria for
the hundreds of new compounds that are being pro-
duced each year, much less the thousands of com-
pounds that have been produced and are being in-
troduced into the environment today. It appears
that, unless a major change takes place in the ap-
proach to funding in the water quality criteria de-
velopment area, it will be difficult to develop mean-
ingful criteria which can be used to properly evaluate
the full significance of chemical contaminants asso-
ciated with sediments in rivers and harbors.
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DREDGING EFFECTS
215
With respect to dredged material disposal prob-
lems as they affect estuarine pollution, perhaps the
most significant event of the past three years was the
funding of the $30 million, 5-year research program
being conducted by the U.S. Army Corps of Engi-
neers, Vicksburg Waterways Experiment Station.
In many parts of the country, typical costs of dredg-
ing have increased from 30 to 40 cents per cubic
yard to 50-60 cents per cubic yard. In some cases,
because of environmental considerations, the costs
of dredging and dredged material disposal approach
$10 per cubic yard. The U.S. Army Corps of Engi-
neers' current annual budget for dredging and
dredged material disposal is approximately
$200,000,000 a year. While the dollar magnitude of
the 5-year research program is substantial, it should
be noted that if this program results in savings of
one to two cents per cubic yard, it will pay for itself
during its lifetime.
The Corps of Engineers Dredged Material Re-
search Program (DMRP), while originally moti-
vated primarily by a lack of knowledge on environ-
mental impact of dredging and dredged material
disposal, is providing information on constructive
use of dredged materials, such as in the development
of wildlife habitat. Most importantly, from the point
of view of this discussion, this research project will
provide valuable information that can be used to
develop meaningful dredging and dredged material
disposal criteria. These will enable those responsible
for environmental resource management to evaluate
the potential environmental impact of chemical
contaminants in sediments which are scheduled to
be dredged. From these studies, criteria will be de-
veloped which will be transformed into standards
for dredging and dredged material disposal.
CURRENT SITUATION
At present, although dredged material disposal
criteria are supposed to be uniform across the U.S.,
there is considerable confusion in the estuarine
dredging field concerning the criteria which deter-
mine whether a givs-.n sediment contains sufficient
concentrations of chemical contaminants to warrant
alternate methods of disposal. A situation exists
whereby each El'.V region is able to promulgate its
own criteria irrespective of EPA's efforts (o estab-
lish uniform criteria. To develop their criteria, the
regional EPA districts often resort to the bulk
analysis approach rather than attempt to assess
what part of the chemical contaminants may ad-
versely affect wati-r quality or aquatic life as a re-
sult of being made available by dredging or dredged
material disposal.
It is apparent that one of two things must take
place in order to eliminate the dredged material
disposal criteria chaos that exists today. Either the
EPA regions must utilize the criteria established
by EPA national headquarters, or Congress must
appropriate sufficient funds to strengthen the tech-
nical competence of the regional staffs so that these
staffs could develop meaningful criteria '"or '.heir
particular regions. Fn,"{uemiy, the individual' re-
sponsible for making decisions of this type have
limited knowledge of the environmental chemical
behavior of pollutants in natural water systems.
These individuals usually play it safe by taking the
conservative approach and assuming that everything
is polluted. Thus, they cause the public to spend
large amounts of money for alternate methods of
disposal. Since dredging is largely funded by tax
dollars, such an approach leads to increased govern-
ment spending and accelerated inflation. In the
opinion of many, the adoption of arbitrary bulk
chemical criteria which have no relationship to
potential effects on water quality may do much
greater harm to the financial and ecological resources
of a particular area than the utilization of the avail-
able information to determine whether a particular
chemical contaminant present in sediments is likely
to have an adverse effect on water quality.
Another significant problem with water pollution
control agencies adopting arbitrary dredged material
disposal criteria is that this will eventually further
erode the public's confidence in the ability of the
agency to act on its behalf. Many individuals al-
ready question whether the approaches being used
by water pollution regulatory agencies are in the
overall best interest of the public There is an urgent
need for these agencies to gain credibility in the
environmental quality control area.
The first attempt to establish criteria relative to
the pollutional tendencies of a given concentration
of chemical contaminants in sediments utilized what,
is termed "bulk criteria." Bulk criteria arc based on
an examination of the total content of the sediments
for a particular element or compound. Use of these
criteria generally assumes that all the forms of
that element are equally toxic. Those familiar with
aquatic toxirity know that this is certainly not the
case. There is no relationship between the hulk com-
position of sediments and the water pollution tend-
cies of the chemical contaminants present in the
sediments.
In an effort to eliminate the problems associated
with bulk criteria, EPA and the Corps of Engineers
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216
ESTUARINE POLLUTION CONTROL
developed the elutriate test. This test exposes the
sediment sample to a known volume of water and
then allows the chemical contaminants to be leached
from the sediments. The elutriate test is primarily
designed to examine potential problems due to the
release of chemical contaminants from sediments
during the dredging and dredged material disposal
process. The primary problem with the elutriate test
i? that it has not yet been properly evaluated for the
svide variety of sediments that occur in various-
••stuaries and waters throughout the country. This
leads to confusion over the interpretation of the
test results. The Corps of Engineers DMRP is de-
voting considerable effort to finding a remedy for this
situation. It is likely that within a year or so the
elutriate test will become a standard tool to evaluate
the potential deleterious effects of chemical con-
taminants such as copper, DDT, et cetera, on the
water near dredging and dredged material disposal
sites.
In addition to developing the elutriate test, the
Corps of Engineers DMRP is funding studies which
are designed to evaluate the potential deleterious
effect that will occur on benthic organisms at the
dredged material disposal site. It is likely that
a standardized bioassay procedure will be developed
as part of this research program. Within a few years,
water pollution control regulatory agencies will
likely have the tools necessary to evaluate, prior to
dredging, whether the chemical contaminants pres-
ent in the sediments will have an adverse effect on
water quality at the dredging and dredged material
disposal sites.
It is in the best interests of the public, overall,
to adopt interim dredged material disposal criteria
which prevent the deposition of dredged materials in
ecologically sensitive areas, such as significant fiih
spawning areas and shellfish beds. The interim cri-
teria should be based on all available information
on the significance of chemical contaminants present
in dredged sediments to aquatic ecosystems. If al-
ternate methods of dredged material disposal are
advocated because of these criteria, a careful review
should be conducted to ensure that the alternate
methods do, in fact, minimize environmental im-
pact of the chemical contaminants in sediments in
both terrestrial and aquatic ecosystems. These in-
terim criteria should be modified according lo in-
formation developed as a result of the Corps of
Engineers Dredged Material Ees^arcb Program
and other studies.
RECOMMENDATIONS
The following recommendations are proposed to
serve as the basis for developing the technical in-
formation needed to evaluate the environmental
impact of dredging and dredged material disposal
in estuarine waters of the U.S.
1. The U.S. Army Corps of Engineers Dredged
Material Research Program, devoted to evaluating
the environmental impact of dredging and dredged
material disposal (including the evaluation of various
beneficial uses of dredged material) should be con-
tinued, at least at the currently programmed funding
level, for the duration of the program.
2, The overly restrictive position based on bulk
chemical criteria advocated by some environmental
activist groups and water pollution control regula-
tory agencies at the local, state, and federal level,
should not be adopted.
3. The current fragmented approach toward estab-
lishing dredged material disposal criteria and stand-
ards at the various regions of the EPA should be
eliminated and national criteria should be adopted.
The national criteria should provide a basis for eval-
uating the potential significance of chemical con-
taminants present in dredged sediments. In applying
these criteria, consideration should be given to local
factors which would influence the significance of
chemical contaminants at a particular dredging
and/ or dredged material disposal site. These criteria
should be developed jointly by individuals repre-
senting the EPA, Army Corps of Engineers, and
others knowledgeable about the environmental
impact of dredging and dredged material disposal.
REFERENCES
Boyd, M. R , R, T. Saucier, J. W. Kelley, R. L. Montgomery,
R. D. Brown, 1). B. Mathis and C. J. Guice. Disposal of
Dredge Spoil. Problem Identification and Assessment and
Research Program Development. U.S. Army Corps of
Engineers Waterways Experiment Station, Vicksburg,
Miss., Technical Report H-72-8, (1972).
Lee (i. F. and H. B. P'miili. Literature Review on Research
~tudy for ^ue De\oloi>tnent of Dredged .Material Disposal
,'niens. T">'. Vrmy Corp- \>i Fnjrineer-; Waterways Experi-
ment Station Yir.ksburg., Miss., Contract No. DACW-
:>,' >-7-i- C-Oi 124, :,197^.
ni.ionnl Academy of '•Vit-nre:-, National Academy of Engi-
neering, Water Qualiu Cri;eri:t 1972. U.S. Government
Piinling Olhci, Washington, D.C.
-------
LIMITING FACTORS THAT
CONTROL DREDGING ACTIVITIES
IN THE ESTUARINE ZONE
JAMES H. CARPENTER
University of Miami
Miami, Florida
ABSTRACT
The current level of dredging activity for navigation channels (250,000,000 cubic yards annually)
is producing substantial effects in the United States estuaries. These effects derive from 1) physical
changes at the dredge site and release of substances from the sediment during the dredging; and
2) physical changes at the disposal area—filling of deeper areas and smothering of bottom dwelling
organisms—and release of substances to the waters of the disposal area. The recent increased use
of diked disposal areas, along the shorelines at increased costs, does not eliminate all of the
environmental effects. Since soil erosion throughout the watershed is the primary source of the
sediments, the obvious management strategy is control at the source. In addition to the recognized
desirability of soil conservation, erosion control should be identified as essential to prevent
continuing damages to estuaries.
INTRODUCTION
Navigation and cargo transport are valuable uses
of estuaries that must he considered in formulating
strategies and policies for management of U.S.
estuaries. The optimization of policies to meet mul-
tiple-use objectives for estuaries presents intriguing
and perplexing challenges with unavoidable inter-
twining of scientific and political considerations.
Policy development that does no! adequately con-
sider botii kinds of considerations may lead to (he
extremes of thoughtless waste of natural resources or
to excessive preservation. Examples of both extremes
can lx found in th-- United States today.
Creation and maintenance of navigation channels
in ihe United Sbvtes is a substantial activity of the
Federal government through projects carried out
by the U.S Arrny C 'orps of Engineers. The scope of
recent activities and associated partially understood
environmental effects have been reviewed by the
Army Corps of Kngineers1, The level of dredging
aot'vity has h-,v approximately 2oO,000.000 cubic
;,ards anmmlly in recent vc'irs for jusi maintenance,
and the magnitude has IK! to questioning of the
acceptability of th" various environment':)] effects.
The rather hinh I'-v.-l o!" activi' \ has d. veloped as
thi1 resuii of i\\o '.afferent processes. Increased land
utilization for Mfa'icuitural, industrial, and domestic
purposes in tin- •-.aiersheds that feed the estuaries
has led t" ittr-i-,isii:j; amount1- •;!' soil introduction.
t"..,va; ••-nt!v !••.. .iiitf expanded nor1 have bf n
<_k-ve* )\Hi(K increasing use o' J< epi-r draft
cargo vessels. In some cases the construction of dams
to produce reservoirs has reduced the flow of soil
to the estuaries but the reservoirs are rapidly ac-
cumulating sediment. Past and present failure to
control erosion has led to a continued filling of the
estuaries. In many cases, fine-grained sediment has
been introduced to the point where resuspension by
wind, waves and tidal currents leads to rapid transfer
into the quieter waters of deep channels and rapid
filling of navigation works.
Failure to develop effective policies will impact the
economies and natural resources of many coastal
states. As shown in Table 1. nearly every coastal
state had maintenance and new projects proposed
for FY 72. Many of the proposed work programs
were not carried out, either for a lack of funding
priority or because of questions concerning environ-
mental effects and whether or not the optimal ap-
proach had been proposed. The economic con-
sequences of the projects are not related to proposed
yardage of dredging by a constant proportionality.
For example, Maryland's project of 0.4 million cu yd,
(a small part of the national program,), was not
carried out in FY 72 and the Baltimore Evening Sun
recently headlined, "Port Dredging Delay Costs City
$30 Million."2 This article describes the economic
impacts of the continued delay in mainten nice
dredging with 42-foot authorized channel.-* having
shoaled to 30 feet and at some points to 27 feet.
Similar substantial economic impacts are occurring
in other regions, notably San Francisco. Mobile,
(r.'ilveslor i1 i the (ire-u It-dees. ' .Miri'ii^d stale-
mates will have increasing impact s on the citizens
affected and the adversary postures of national and
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218
ESTUARINK POLLUTION CONTROL
Table I.— Dredging proposed for Fiscal Year 1972
i i
State 1 Maintenance 1 New Projects
New Hampshire
New York
Pennsylvanial
Delaware f-
New Jersey J
North Carolina
South Carolina.
Fionda
Alabama,.
Mississippi!
Louisiana J
Washington
-1 1.7
J million cu yd
1 2.4
1
; 1.8
0.4
2.C
- . -H 8.0
6.9
__j 1.7
1 2.8
16.5
I 74.4
J 28.7
4.9
0.4
j 0.1
1
4
million cu yd
zoo-
5.4
8 6 Z I8°-
Q
_!
- j| 160-
0.1 1
if)
0.1 ^ 140-
_l
~ O
Q 120-
IOO-
3.2
21
1/.6 Fl O m
^ ^ ro to cvi
64 65 66 67 68 69 70 71 72 73 74
FISCAL YEAR
1 — Recent federal dredging activities in volume and
Data supplied by U.S. Army Engineer Waterways
lent Station.
RVED AND POTENTIAL EFFECTS
REDGING AND DISPOSAL
Data source1, reference 1.
;-,tafe agencies will have to he modified toward
collaboration to develop multiobjective policies that
balance economic and conservation considerations.
The national dredging effort during the past dec-
ade is shown in Figure 1 in terms of yardage and dol-
lars. The decrease following FY (Hi \\as the result of
a twofold decrease in new projects and the increases
since FY 09 are primarily associated with main-
tenance dredging. The rapid rise in costs since FY 72
appears to be due to change* in disposal practices to
meet \ resumed environmental requirements. It
should be noted that in some localities increased
costs have been much greater than average increases
shown iu Figure 1 and the nitior a! effort cost sta-
tistics are ballasted by the high volume-low co=t
operations in Mississippi. Local project co^ts have
gone a,- high a» 10 times the ua'icnal a\vraa,e or up
to S;"i per cu vj. In some ca^es >•• h-rc costs lu°ve
increased d;aM'"tally, ibe proj.jr>K '.aviot be justified
on the basis of a cost-benefit unaUsis and the pro-
jects have not been undertaken. The national trend,
-4v:>\-,i: 'M Figure 1. appears to be substantial and the
I'oi'owhu' vV'n>'on ,u:<- ;'•'- Tr LUti,' •• " V' eonsiu-
L-ratio'i? .hil a.t- lea ling to !-'ie moreuKing uo.-.ts and
delavs.
The effects of channel construction and main-
tenance occur at the construction location and at
the disposal location. Considering iirst the con-
struction activities, the effects may be categorized as
follows.
Direct Effects of Dredging
The excavation of channel includes the removal
of the living organisms and the loss of a fraction of
the total local population of bonthic (.bottom-dwell-
ing) organisms. Harvestable species, such as oysters,
clams, shrimps, and so forth, may be involved as
well as species that are eaten by bottom grazing
fishes. The presence of a particular species is strongly
related to the physical character of the bottom,
particularly with respect t'i crain size, degree of
compaction, or iirmness and oigumc content. When
a channel is cut, the newh exposed material is
usually fin,icr th;m the previous surface and repopu-
lation is li.nitcd t>/ those i-pecie.-, that find the new
conditions amenable. While chsuin] coir-iruction
reduces the area available to some species, channels
in the nation'i'estuares occupy on1'.- a smail fraction
of the total area. The effects on th'- J-x.'il populations
.".e of CjUcsM'niHb'i ,iuamR-iU'-'c : :i;v i'arv * v.ui the,
Josses appe."- t:, ;>. • 'utv-ugii- .* by :•/. <;--,Julness or
the channels.
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DREDGING EFFECTS
Indirect Effects of Dredging
Tilt- bottom materials of estuaries are composed
primarily of quartz (sands), aluminosilicates (clay)
and calcium carbonate (skeletal fragments). These
materials are predominantly inert. However, organic
materials are also present and many elements (in-
cluding transition or heavy metals) are present in
lesser abundance in association with the surfaces of
the bulk material and the organics. The organic-
materials may come from plant and animal life on
the watershed, plant and animal life in the estuary,
and discharges from domestic and industrial activi-
ties. As the estuarine sediments are being deposited,
much of the organic material is metabolized by
microorganisms that flourish at the sediment sur-
face. However, not all of the organic material is
metabolized and some becomes buried as additional
materials accumulate at the sediment surface.
Metabolism occurs within the sediment and, at
some variable depth below the sediment surface, the
supply of oxygen is inadequate to support the meta-
bolic rate and the metabolism is dominated by
anaerobic or oxygen-fret1 processes. The predomi-
nant anaerobic process is the use of sulfate ions to
support the oxidation of organic materials with the
result that hydrogen sulfide is produced and mineral
sulfides may be formed in the sediments, and hydro-
gen sultide (rotten egg or swamp gas) accumulates in
the waters within the sediment.
As the metabolism proceeds, nitrogen and phos-
phorus compounds (plant nutrients) are released to
the waters within the sediment. Some metals, par-
ticularly manganese and iron, are solubilized from
the minerals and appear in sediment waters in
concentrations greater than that of the overlying
waters. The net result of these processes is that
many sediments that are considered for dredging
have relatively high concentrations of biologically
and chemically active substances. For example,
hvdrogen sulfide reacts rapidly with dissolved
oxygen and contributes substantially to the so-called
chemical oxygen demand of tho sediments as well as
acting as a direct toxicant.
Tin- presence of growth promoting (nutrients!
and growth inhibiting compounds (toxicants) leads
to questions concerning the effects of release of
these substances during the disturbances associated
with dredging. It is pertinent to note that molecular
diffusion naturally transports these substances to
the, overlying water and the dredging disturbance is
primarily a local, intense acceleration of the trans-
port process. Mosl of the dredged material is trans-
ported to the disposal site and effects of nutrients
and toxicants are usually more important at the
disposal site.
While it should be trivially obvious that environ-
mental effects are quantitative in character, for
example, the release of one pound of an active
substance per day may have discernible effects in a
particular estuarine location and almost imper-
ceptible effects in another estuarine location, efforts
continue to classify sediments and dredging activities
on the basis of the composition of the materials
involved. Inspection shows that a guideline or stand-
ard that would protect all estuarine locations from
environmental effects would be unnecessarily re-
strictive and lead to a waste of public monies.
The point to be made is that release of active
chemical compounds is a potential limiting factor
on the acceptability of any particular dredging oper-
ation, but the substantialness of the limitation can
only be determined for each particular location and
specific activity.
A second kind of indirect effect that persists after
the channel construction has been completed derives
from changes in the currents and circulation caused
by the presence of the channel. The intrusion
of sea water into an estuary depends OH the fresh-
water flow rates, the strength of tidal mixing and the
depth of the estuary. A new channel has the potential
for increasing the intrusion and therefore the salti-
ness along the length of the estuary. Many activities
and requirements of estuarine organisms are related
to the salinity of their environment. Some lishes
spawn in fresh water and other? spawn in salt water
but require brackish or low-salinity waters during
their maturation into adults. Increases in salinity
have the potential for reducing the amount of habitat
available to these species Success of some estuarine
organisms, notably the oyster, reflects the intolerance
of some predators, the oyster drill, to low salinities
and increasing salinities potentially extend the range
of the predators into the estuary. Once again, the
potential of these effects can be recognized but only
evaluated in the context of a specific location \vith
its particular biota and physical characteristic.
Turning next to the effects of open water disposal,
they may be categorized as follows.
Filling of Deeper Areas-
Open Water Disposal
The deep regions of estuaries may play a unique
role in supporting fish by providing havens during
the winter cold season, as hss been observed for
striped bass and croakers in northern Cheasapeake
Bay. The deeper water is saltier but warmer than
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220
ESTUARINE POLLUTION CONTROL
the surface waters in the winter and the existence
of the deep water refuges may be critical in avoid-
ing "cold kill" of these fishes or migration of the
fishes to the ocean. The significance of this considera-
tion varies from estuary to estuary and no generali-
zations are possible. While the,values of naturally
occurring deep regions have been identified, there
does not seem to have been justification for deliber-
ately over-deepening stretches of navigation channels
but this approach might be considered to mitigate
the loss of the natural areas, if the water quality in
the navigation channels is suitable.
Smothering of Bottom-Dwelling
Organisms and Repopulation
Open water disposal of dredged material may re-
sult in covering rather large areas with the spoil.
Discharged materials have been observed as deposits
in areas manyfold larger than the nominal disposal
site.3'4 The potential for this effect is substantial
since the annual volume of dredging could cover
268 square miles to a depth of 1 foot. The degree of
dispersal depends on the nature of the spoil, the
strength of the currents at any particular disposal
site, and on the kind of dredging operations since
hopper dredging produces less opportunity for disper-
sal than hydraulic dredging.
If the dredged material is similar to the existing
material at the disposal site, the effects of smother-
ing may be transient and repopulation to replace the
killed organisms could occur. This may be the case
frequently for new work, but maintenance dredging
commonh' involves fine-grained material that ac-
cumulates preferentially in the dredged channels.
Transfer of fine-grained materials to locations with
existing firmer, coarse-grained sediments may be
expected to produce long-term population changes
as reported in reference 3, and, even though some
species reappear in large numbers, the community
structure will be changed. Such changes in the bot-
tom of a habitat may be a major limitation on spoil
disposal in estuaries.
Smothering may be a particularly severe limita-
tion in areas of high water clarity, since benthic
grasses may be an important part of the community
and repopulation of denuded areas will be slow.
Even in the warm waters of Florida, the return of
seagrasses to damaged areas has been observed to
require many years. Similarly, corals regenerate
slowly and losses are not readily replaced.
Modification of Currents
and Flushing Rates
At locations where the dredged material is not
widely dispersed, filling to substantial depths will
occur and such environments have obviously weak
currents. The reduction in cross-sectional area
through which the water can flow may reduce the
total flow and, thus, the flushing or renewal of the
waters in the estuary. Since the salinity distribution
in an estuary depends on rates of river water input
and the circulation, the reduction in depths may
have an additional effect in terms of changes in the
salinity distribution. The potential for these effects
is rather easily identified, but there do not seem to
be examples where it has been quantitatively signifi-
cant.
Release of Sediment
Constituents to the Water
As noted above, sediments contain biologically
active substances, both nutrient and toxic materials.
The possible release of these substances during open
water disposal and following deposition of the dis-
charged materials has led to questioning the ac-
ceptability of such operations and is a major source
of current arguments.
The Environmental Protection Agency ha.s put
forth "criteria for determining acceptability of
dredged spoil disposal to the Nation's waters" (refer-
ence 1, page 32). Criteria (h) reads, "...when con-
centrations, in sediments, of one or more of the
following pollution parameters exceed the limits
expressed below, the sediment will be considered
polluted in all cases and, therefore, unacceptable for
open water disposal."
SEDIMENTS IN FKKSH AND MARINE WATERS
Cone. % (Dry Wt.)
Volatile solids 6.0
Chemical oxygen demand 5.0
Total Kjeldahl nitrogen 0.10
Oil-grease 0.15
Mercury 0.001
Lead 0.005
Zinc (). 005
Some of the deficiencies associated with numerical
concentration limits may be seen from consideration
of the zinc "criterion." The average abundance of
zinc in rocks and soils on the surface of the earth is
0.01 percent5 and most naturally occurring materials
would fail to meet the criterion but it is difficult to
consider them polluted. The sediments being dis-
-------
DREDGING EFFECTS
charged to the Chesapeake Bay in the Susquehanna
River flow average 0.05 percent zinc6 and nearly all
of the sediment in Chesapeake Bay -would not meet
the criterion. However, there is no evidence that
these concentrations impair the environment of the
aquatic organisms in Chesapeake Bay.
There appear to be two major deficiencies in the
concentration criteria. The first is that the quantity
involved in any particular activity is not considered;
i.e., disposal of 100 tons of sediment with 0.0f> percent
zinc could potentially result in the release of 0.0.1
tons or 100 pounds of zinc 1o an estuary and. simi-
larly, with numerical criterion of 0.005 percent zinc,
the release could be 10 pounds. Whether or not the
resulting environmental perturbation in either case
would be significant depends on the particular estu-
ary and the rate of the release. Each particular op-
eration should be considered in terms of the time
and spatial intensity of the perturbation and whether
or not appropriate water quality criteria will be
exceeded in a sufficient area for a sufficient time to
produce an unacceptable effect on the aquatic pop-
ulations in the estuary.
For sediments, the gross or total composition does
not seem to be the appropriate aspect for considera-
tion and this is a serious deficiency in the existing
criteria. Using zinc as an example, the pertinent
information is the availability of the zinc to the
biological systems, both during the disposal opera-
tions and after the dredged material has been depos-
ited, i.e., both short and long-term release. Much of
the sediment zinc may be immobile and, thus, in-
nocuous. An approach to evaluating the short term
release is the elutriate test described under the ETA
Ocean Dumping Final Regulations and Criteria
227.61 (C)7 in which the materisl proposed for dis-
posal is shaken with water from the disposal site
and the resulting solution is anah z,ed for released
substances. At present, there is no accepted way of
evaluating the potential long-terns release or effects
on bottom-dwelling organisms. A possible procedure
would be the examination of the characteristics of
the material at the proposed dredge site by analysis
of the pore or interstitial waters of the sediment and
the bottom-dwelling, deposit feeding organisms. If
substances are being released to the overlying waters,
the pore waters will be greatly enriched and an
estimate of the rate of release can be found from the
contrast between the concentrations in the pore
waters and the overlying waters. If substances are
entering the biological food chains through deposit
feeding organisms, the significance of this process
could be judged from the amounts appearing in such
organisms.
The purpose of drawing attention to the inad-
equacy of numerical concentration limits for dredged
materials (that are analogous to effluent standards)
is that such an approach will frequently either not
properly protect environmental values or unneces-
sarily restrict some useful activity. Just as a re-
sponsible physician will not make a diagnosis or
prescribe treatment without studying the individual
patient, limitations on estuarine dredging due to
release of materials to the water can only be devel-
oped on the particulars of each individual proposed
activity. Environmental requirements of estuarine
organisms can be established in a straightforward
way and be broadly applied as water quality criteria.
but (he meeting of those requirements cannot be
mandated by adoption of arbitrary input concentra-
tion limits, despite administrative enthusiasm for
simple, universal regulations.
Creation of Land Along
Shorelines and Islands
In view of the above effects of open water disposal,
confined or diked disposal areas have been increas-
ingly used. Frequently, the shallow areas along the
estuary shorelines have been used. Such use causes a
permanent loss of valuable estuarine environment
and, in some cases, has produced land that has only
limited usefulness for long periods of time. Current
research directed by the Army Corps of Engineers
is aimed at developing techniques and engineering
practices to improve the quality of the land in the
diked disposal areas. However, in view of the limited
area of estuaries in the United States, conversion of
present estuarine water bodies to fast land is not an
attractive long-term strategy.
One limitation on the use of shoreline diked dis-
posal is the necessity of retaining sufficient width to
permit the discharge of storm runoff without ex-
cessive upstream flooding. The Potomac estuary
below Washington, D.C., is a good example in that
past diking produced useful land for Washington
National Airport, Blue Plains Treatment Plant, and
so forth, but further diking would likely produce an
unacceptable reduction in the capacity to discharge
flood waters. Changes in the width of an estuary also
will have effects on the circulation, flushing, and
salinity distribution to change the character of the
estuary.
In addition to the ready generalization that de-
struction of shallow water and marshland habitats
on a large scale and continuous basis is a waste of
our limited resources, few property owners view
with favor the construction of a diked spoil disposal
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222
ESTUARINE POLLUTION CONTROL
facility adjacent to their lands and the states are
reluctant to enter into condemnation proceedings.
This is a practical limitation that is limiting dredg-
ing in estuaries and will also he a serious limitation
to upland or dry land disposal.
The use of diked disposal areas has been proposed
for materials that have been classified as polluted.
As noted above, such classification may not be an
accurate evaluation of the environmental hazards
associated with 1he materials, but, in addition, it is
not clear that diked disposal solves the problem.
The process of dredging unavoidably involves the
mixing of the sediment with large quantities of
water. If biologically active materials are released to
the water, the discharge of the water from the diked
area into shallow waters with little dilution capacity
would be expected to display greater environmental
effects than would have occurred with open water
disposal. M any estuaries have sediments with high
concentrations of iron sulfides that are stable in the
absence of oxvgeu. With diked disposal, the percola-
tion of oxygenated waters through the material may
produce the familiar acid mine drainage water? that
result from the production of sulfuric acid upon
oxidation of iron sulfides. Evaluation of the signifi-
cance associated with these potential effects requires
quantitative considerations; i.e., what fraction of
the habitat is modified, for how long, to what degree
from water quality criteria.
SHORT-TERM AND LONG-TERM
POSSIBILITIES
The current research program directed by the
Arm,y Corps of Engineers should provide improved,
factual information upon which assessment of new
short-term options can be based. Whore open water
disposal is not suitable (habitat modification through
physical effects may be expected to be a more severe
restraint than pollutional effects'"1, diked disposal
with adequate engineering practices may be a viable
option. Reduction in environmental damage due to
runoff and leaching from the disposal sites may lead
to increased costs and more complex disposal tech-
nology. The acceptability of such operations should
be increased as techniques for making the disposal
areas useful as land for human activities or wildlife
habitat are developed. The optimal procedures will
have to be developed for each estuary with due
regard to its socio-economic setting.
However, these approaches- to ameliorating dam-
age^ to estuaries from dredging will be increasingly
costly as the cheaoer uprions are exhausted. Thi«
trend is clearly shown in the pattern illustrated by
Figure 1. As appropriate open water estuarine sites
and adjacent shoreline areas are fully utilized, Upland
and deep ocean disposal become the only alternatives
and costs can be expected to increase by tenfold or
more. As costs move to tens of dollars per cubic
yard, the alternate of vigorous action to attack the
root of the problem becomes more attractive. Failure
to regulate human activity has led to well-docu-
mented increases in the rates of soil erosion8. Prob-
lems in the national dredging program arc inversely
related to successes in the national soil conservation
program. It has long been the view of this writer
that sedimentation at increased rates poses the most
serious threat to the nation's estuaries and the dredg-
ing problems simply highlight the continuing damage
being done through failure to control erosion.
Substantial progress has been made in the re-
search, development, and application of procedures
to reduc^ erosion. Many examples of successful use
of such knowledge could be cited; however, more
obvious are the failures to use such knowledge. Poor
agricultural practices, slipshod road construction,
and aggravated stream erosion due to storm water
from paved areas are easily observed. The federal
program of advice arid information dissemination
to the state's, counties and individuals has been
sound, but action is primarily at the county and
individual level. At present there are only local in-
centives and the pollutional aspects of the soil erosion
in one county harminia: the estuarine, resources,
including navigation, of an adjacent county have
received little attention. With increasing costs and
greater recognition of damages due to upstream
negligent or improper practices, the need for action
should be a matter for federal concern and activity
by the appropriate agencies.
REFERENCES
1. Boyd, M. B., R. T. Saucier, J. W. Koeley, R. L. Montgo-
mery. R. D. Brown, I). B. Mathis and C. J. Guice,
"Disposal of Dredge Spoil—Problem Identification and
Assessment and Research Program Development," Tech.
Report H-72-8, U.S. Army Engineer Waterways Experi-
ment Station, Vicksburg, Miss., 1972
2. The Erening Sun, December 12, 1974, Baltimore, Md.
3. Cronin, L. E., "Gross Physical and Biological Effect? of
Overboard Disposal in Upper Chesapeake Bay, NRI
Special Reporl, No. 3, (U S. Department of Interior,
Washington, D.C., 1970).
4 Saila, S. B.. S D. Pratt and T. T. Polgan, Providence
Harbor Improvement Spoil Disposal bite Evaluation
Study. Phase II, (University of Rhode Island, Kingston,
R. I., 1971).
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DREDGING EFFECTS
223
5. Kankania, K. and Th. G. Sahama, Geochemistry, (The
University of Chicago Press, Chicago, 1950).
6. Carpenter, J. H., W. L. Bradford and V. Gant, "Processes
Affecting the Composition of Estuarine Waters (HCOs,
Fe, Mn, Zn, Cu, Ni, Cr, Co and Cd)," Recent Advances
in Estuarine Research, (Academic Press, Spring, 1975).
7. Environmental Protection Agency, "Ocean Dumping Final
Regulations and Criteria," Federal Register, Washing-
ton, D.C., October 15, 1973.
8. Brown, C. B., "Effects of Soil Conservation," Applied
Sedimentation, Ed. by P. D. Trask, John Wiley, New
York, 1950.
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-------
ENVIRONMENTAL ASPECTS OF DREDGING
IN THE GULF COAST ZONE
WITH SOME ATTENTION
PAID TO SHELL DREDGING
WILLIAM H. ESPEY, JR.
Espey, Huston & Associates, Inc.
Austin, Texas
ABSTRACT
The coastal zone is a rich national asset closely tied to pur economy. Man's activity in the coastal
zone has caused this rich national asset to be placed in jeopardy. "The National Estuarine Study"
(1970) estimated that approximately 85 percent of the estuaries located on the guif coast have
been modified because of man's activities.
Shell dredging activities in the gulf coast region indicate a slight downward trend and are expected
to decline as a whole in the future. The reasons for the reduction in shell dredging activity reflect
both alternative raw materials and environmental concern. However, the overall USCE dredging
activities as well as private dredging are expected to increase in the near future. Insufficient data
are available on the extent of dredging and filling in the gulf coast, where it is a major environmental
problem. Many of the environmental aspects of dredging are not well understood.
The federal permit system that deals with dredging activities in the coastal zone needs to be
centralized and streamlined to expedite the efficient processing of permits. Environmental criteria
used in evaluating USCE dredging permit applications should be clarified and quantified to the
extent possible.
INTRODUCTION
The coastal zone constitutes one of our most
valuable and vulnerable natural resources, an asset
closely related to our national economy. As the
economic value of the coastal zone rises and popula-
tion pressure increases, the conflict between com-
peting uses of the coastal zone becomes a complex
problem. Today, we have almost six times as many
people in the United States as we had a century
ago. Since all of these people, in some fashion, call
upon and derive some benefit from the coastal zone,
the "nation has been forced to recognize that what
it had in surplus, it now has in jeopardy" (Singer,
1969). Even seemingly unrelated uses of a coastal
zone can have dire consequences; a solution to one
irritating problem may engender far more pressing
problems. For example, pesticides that help citrus
growers in South Texas could result in fish kills in
the Laguna Madre. While supertankers transport
oil economically to all parts of the world, a massive
oil spill can result in severe environmental damage.
Modifications of estuaries through dredging opera-
tions, filling for real estate development, discharge
of wastes from a city, fertilizer and pesticides in
runoff from nearby land, are capable of disfiguring
and destroying the coastal zone.
These estuarine systems are generally more fertile
and productive of plant and animal life than either
land or sea, due in part to the dynamics of the tidal
cycle, which mixes incoming fresh water, with its
nutrient burden from the land, with the mineral-
rich water from the sea. Thus is formed a kind of
rich broth fed by both the land and sea, resulting
in a cradle of marine life. The estuary provides a
sheltered environment for organisms which forms
an abundant food supply for higher members of the
food chain. Some estuaries are the spawning grounds
and nurseries for man}r commercially important
species. The United States Fish & Wildlife Service
(Cain, 1968) estimated that approximately 90 per-
cent of the total harvest of sea food taken by Ameri-
can fishermen comes from the continental shelf, and
approximately two-thirds of the species involved
depend in one way or another on estuaries.
In addition, estuaries serve other beneficial needs,
such as important nesting and wintering habitat
for migratory waterfowl, as well as resting and feed-
ing places during migration. Estuaries also provide
many forms of recreation to people who boat, camp,
explore, picnic, nature walk, or merely enjoy the
natural beauty of the coastal environs. Nowhere
else do nature arid urban conglomeration occur in
such close proximity. Approximately 30 percent of
225
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226
ESTUARINE POLLUTION CONTROL
the total population of the United States is located
within a 50-mile coastal belt, while this area repre-
sents only about 8 percent of the total United States.
The U.S. Department of Commerce (1970) made
an intensive study of the economic activity of the
U.S. continental shelf for calendar year 1964. Eight
major economic activities were identified: mining
and petroleum; marine engineering; recreation;
health and welfare; transportation; food and agri-
culture; defense and space; and research and de-
velopment. The level of economic activity was
estimated at $21.4 billion, a total that included
operating expenses, investments, and income. A
little more than half the money was spent for trans-
portation activities; nearly $4 billion was spent for
recreational activities; and about $330 million was
the dockside value of the U.S. Fishery catch from
the continental shelf area. The harvest of shellfish
constituted the largest single portion of the U.S.
Fishery catch value, about 38 percent. If the invest-
ment for harvesting and processing the entire U.S.
Fishery catch for 1964 were included, then the total
economic activity in fisheries increased to $1.4 bil-
lion, a very respectable industry (Singer, 1969).
A significant segment of the United States coastal
zone is the gulf coast, from the Mexican border on
the west to the tip of Florida on the east. This
1,500 miles of coastline constitutes the border of
five states where they meet the Gulf of Mexico.
The economic importance of this region is reflected
in the commercial fishery production. In 1973, gulf
coast landings represented 30 percent of the esti-
mated $907 million in U.S. commercial fisheries
landings. The value of commercial fisheries along
the gulf coast has steadily increased in terms of both
total poundage and dollar value (Table 1) as com-
pared to other coastal areas of the U.S.
Approximately S5 percent of the gulf coast, as
compared to like percentage of the Atlantic and 15
percent of the Pacific coast, is composed of estuaries
(Singer, 1969). Gunter (19(57) estimates that the
total area, of gulf coast estuaries ranges from approxi-
mately 17.000 to 20,000 squar^ miles, or five to six
times the size of Chesapeake Bay and its tributaries.
The principal bays of the Gulf of Mexico are shown
in Figure 1. "The National Estuarine Inventory,
Handbook of Descriptors" ^Wastler and de Guer-
rero, 1968) lists 39 primary estuarine systems in
the Estuarine Register Areas and 175 secondary-
tertiary systems along 3,070 miles of the shoreline.
Multiple utilization of gulf coast estuaries has
resulted in significant modification and loss of valu-
able marsh and open water areas. "The National
Estuary Study" (1970) determined the areas of
gulf coast estuaries that had been modified by man's
Table 1.—U.S. commercial fisheries landings Gulf Coast Region compared to
other major coastal regions." (From U.S. Dept. Comm. 1970; 1973)
Percent
Rank..
Percent ..
Rank
1940
] 1
1950 1960 1970
1972
1973
Total Poundage
6%
6th
11%
3rd
12%
3rd
15%
3rd
26%
2nd
35% 34%
1st 1st
Total Value
24%
1st
27%
1st
32%
1st
33%
1st
30%
1st
i Chesapeake
South Atlantic
Gulf
Alaska
New England & Middle Atlantic
Washington & Oregon
California
Great Lakes & Mississippi River
Hawaii
activities. Approximately 15 percent had been
slightly, 51 percent moderately, and 34 percent
severely modified by man's activities (see Figure 2).
Unfortunately, many people do not realize the pro-
found influence on the ecology of an estuary which
can result from modifications in the watercourse.
Oftentimes, even when they do understand the con-
sequences, the short-term gain, rather than the
overall or long-term effects, may be the overriding
consideration for making such modifications.
DREDGING ACTIVITIES
One area of significant activity which results in
modification of the coastal zone and its estuarine
regions is dredging. Whether to provide channels
for navigation or materials for construction, dredg-
ing operations can represent a substantial alteration
to natural coastal environments. Moreover, the in-
tensity of dredging activities in the coastal zone is
anticipated to increase as a result of pressures such
as exploration, drilling, and transportation in re-
sponse to the energy crisis; the need for develop-
ment of superports; increased demand for housing
and commercial sites; and demands for additional
coastal recreational facilities.
Dredging is the process by which sediments or
other materials are removed from the bottom of
streams, lakes, and coastal waters, transported by
ship, barge, or pipeline, and/or discharged to land
and/or open water. The common purposes of dredg-
ing are to maintain, improve, or create new navigable
waterways, or to provide construction materials
such as sand, gravel, or buried shell. In the majority
of dredging operations, the solids are hydraulically
transported from the bottom of the waterway to a
dredge and then to a disposal site. This mixture of
suspended solids and water is called dredge soil. It
-------
DREDGING EFFECTS
96 9[i 92 90 88 86 8^ 82 80 78
227
32
22
20 -
18 -
20
IS
82
80
78
FIGUBE 1.—Major bays of the gulf coast of the United States.
1. LACUNA MADRE
2. BAFFIN BAY
3. CORPUS CHRISTI BAY
4. COPANO BAY
5. SAN ANTONIO BAY
6. MATAGORDA BAY
7. GALVESTON BAY
8. SABINE LAKE
9. CALCASIEU LAKE
10. VERMILLION LAKE
11. ATCHAFALAYA BAY
12. TERREBONNE BAY
13. BAHATERIA BAY
14. LAKE PONTCHARTRAIN
15. MISSISSIPPI SOUND
16. MOBILE BAY
17. PENSACOLA BAY
18. CHOCTAWHATCHEE BAY
19. APALACHEE BAY
20. WACCASASSA BAY
21. TAMPA BAY
22. CHARLOTTE BAY
23. FLORIDA BAY
is typically about 5 to 20 percent solids by weight
and 98 percent water by volume. The suspended
solids vary in size from rather large rocks, bricks
and debris (e.g. cans, tires, and steel cable) to ex-
tremely small particles of clay. When given the
opportunity, the larger material quickly settles out
of the water, but the smaller and lighter particles
settle very slowly and dewater poorly. To protect
the quality of the waterway, largo volumes of spoil
must be transported and then stored for some time
in a disposal site before the water can be returned
to the waterway. Transport and storage of spoil is
expensive and difficult when the disposal site is of
insufficient size or near capacity. Moreover, in urban
areas adequate disposal sites are becoming increas-
ingly difficult to acquire.
Types of Dredges
In general, dredging in the coastal zone is accom-
plished by "floating dredges" which can be classified
as hydraulic or mechanical. Hydraulic dredges in-
clude suction pipeline dredges, with a suction or
cutterhead for digging in hard material, and the
self-propelled hopper dredge. Mechanical types in-
clude dipper and bucket dredges. Hydraulic channel
dredging and shell dredging make use of essentially
the same equipment although there are differences
in operations. Channel dredges construct or main-
tain navigation channels. In this operation, recent
alluvium and water are pumped from the bottom of
the channel and the spoil is discharged by pipeline
usually some distance away from the channel. Shell
-------
228
ESTUARINE POLLUTION CONTROL
GULF OF MEXICO ESTUARINE ZONE
CAPE ROMANO TO MEXICAN BORDER
FIGURE 2.—-Extent of effects of man's activities on gulf coast estuaries (from "National Estuary Study," 1970).
dredges generally operate outside of channels in the
open estuary. Dredged material is screened and
washed to remove the shell. The discharge, com-
posed mostly of original bottom material is returned
overboard in the immediate vicinity of the dredge.
Required Dredging Permits
The basic permit that is required for dredging
activities in the coastal zone is under Section 10 of
the River and Harbors Act of 1899, which is admin-
istered by the United States Corps of Engineers
(USCE). This permit is required when any dredging
or filling is done in navigable waters of the United
States or in areas which may affect navigable waters.
New Federal guidelines (Federal Register, April 3,
1974) require that the environmental aspects of
these dredging permits be considered. In addition,
the Environmental Protection Agency requires per-
mits under Section 404 of the Federal Water Pollu-
tion Control Act Amendments of 1972 for the dis-
charge of dredged or filled material. In each of the
federal permits, review and approval is required
from various state agencies. Also, along the gulf
coast, each state requires permits for dredging in
the coastal zone. As a result of the 404 dredging
permit system, considerable questions have arisen
with regards to its relationship with the existing
Section 10 permit system. These questions concern
jurisdiction as well as specific engineering and en-
vironmental requirements. The present Section 10
permit system, because of other federal agency re-
view in many cases, results in considerable time and
money being expended by the applicant because of
the time delay and lack of coordination.
Shell Dredging
Buried shell is an important natural resource found
in the coastal zone. Industrial demand for this almost
pure source of calcium carbonate is significant and
several major industries depend upon it. Private
companies annually dredge about $30 million worth
of unprocessed clam and oyster shells from gulf
coast estuaries and the resource makes a substantial
contribution to the economy of many coastal areas.
-------
DREDGING EFFECTS
229
Table 2.—Shell production In cubic yards by State (1965-74)
1965 j
1966 - - .
1967 1
1968
1969 - J
1970
1971
1972
1973
1974
Florida
(Jan. 1-Dec. 31)
1,675,557
1,796,561
1,492,102
1,102,052
1,949,668
1,480,472
1,539,299
1,611,403
1,046,988
325,806*
Alabama
(Oct. 1-Sept. 30)
1,972,499
1,842,737
1,766,611
1,867,794
N/A
N/A
1,685,445
1,543,217
1,275,603
1,608,997
Mississippi
208,222
187,028
206,333
228,183
119,662
165,144
135,008
281,129
339,513
98,033
Louisiana
(Jan. 1-Dec. 31)
N/A
8,681,177
9,500 285
10,921,101
10,097,148
10,283,276
10,901,371
11,708,035
'.1,996,579
N/A
Texas
(Sept. 1-Aug. 31)
N/A
11,702,553
12,512,977
10,033,221
9,108,682
9,097,316
8,198,153
7,791,577
7,444,232
7,027,909
Total
N/A
24,210,056
25,478,308
24,152,351
22,975,160"
22,726,208"
22,459,276
22 935,361
22,102,915
N/A
* Five months only.
"* Estimated 1,700,000 for Alabama.
Florida—William Witfield, Florida Department of Natural Resources, Division of Marine Resources and Jack Dull, Fiscal Office, pers comm, Nov. 1974
Alabama—Mr. Swingle, Alabama Department of Conservation and Natural Resources, Marine Resources Division; Revenue Department, pers comm, Nov 1974; May, 1971
Mississippi—Mr. Quinn, Mississippi Marine Conservation Commission, pers comm Nov. 1974.
Louisiana—Joseph Cuadrado, Louisiana Wildlife and Fish; Revenue Department, pers comm, Nov 1974
Texas—Chester Harris, Texas Parks and Wildlife Department; Revenue Division, pers comm, Nov. 1974
In addition, royalty from shell dredging contributes
about $3 million each year to conservation activities
in the gulf states (May, 1971). Shells from this
source are extensively used for cultch (attachment
material for new oysters) on public oyster beds in
many states and the practice has greatly increased
oyster production.
Along the gulf coast shell dredging is a major in-
dustry. Most of the shell is used for manufacture of
cement, masonry blocks, road materials, poultry
feed, and in some cases for the creation or establish-
ment of oyster beds. Summarized in Table 2 are
shell production figures for each of the gulf coast
states as determined from published records and by
personal communications with various state agen-
cies. The total production for the gulf coast for the
period 1966 through 1973 shows a slight downward
trend. In Mississippi shell production has recently
been stopped. In Texas (along with Louisiana, the
major producer) shell production has been declining.
In Texas, production has shifted from the Galveston
Bay area to Matagorda and San Antonio Bays (see
Figure 3). The change from the Galveston Bay
system to Matagorda Bay is a result of changes in
Texas Parks and Wildlife dredging policies coupled
with significant reductions in the shell reserve in
Galveston Bay.
Extent of USCE
Dredging Activities
The majority of dredging activities in the coastal
zone is accomplished by the U.S. Corps of Engineers
in the development and maintenance of navigable
waters. Within this authority, the USCE is responsi-
ble for the dredging of a large volume of material
in the gulf coast each year. Boyd, et al. (1972)
present a compilation of data on the magnitude of
dredging operations. It is important to note that
this data does not reflect dredging activities of other
agencies or private industry under the permit pro-
gram administered by the USCE. The majority of
the dredging operations in connection with USCE
projects are done by pipeline and hopper dredgers.
The USCE is responsible for dredging and maintain-
L A.
TEXAS
MATAGORDA BAY(
LAVACA BAY
NUECESBAY
Corpu
SAB ME LAKE
GALVESTON AND
TRINITY BAYS
SAN ANTONIO BAY
RPUS CHRIST/ BAY
Gulf of Mexico
FIGURE 3.—Percentage of shell production in the State of
Texas for major bays by year (from Eifler, 1968 and Texas
Parks & Wildlife, Revenue Division, 1974).
Year
Sabine San
Lake , Qalwiton Matagorda Antonio Lavaca Nwcet
1965-66
66-67
67-68
68-69
69-70
70-71
71-72
72-73
73-74
1.4
2.1
0.1
0.2
0.9
0.6
0
0
0
62.8
62.2
41.7
4.9
0.9
0
0
0
0
0
0
0
0
11.2
24.8
33.8
41.3
62.8
23.7
24.5
42.8
80.5
81.5
69.1
59.9
51.0
34.0
1.6
1.8
5.8
6.1
0.2
0
0
0
0
11.0
9.4
9.6
8.4
5.4
5.6
6.4
7.8
3.3
-------
230
ESTUARINE POLLUTION CONTROL
ing approximately 4,000 miles of navigation channels
on the gulf coast. Gulf coast dredging represents
historically 48 percent of all USCE dredging activi-
ties. Total dredge spoil generated in maintenance
dredging annually averages 143.0 million cubic yards.
Average quantities of spoil for each Corps of Engi-
neers District in the gulf coast is shown by disposal
type in Table 3.
The USCE (Boyd, et al., 1972) estimated that
approximately 177.6 million cubic yards of spoil
material would be dredged in 1972 in the gulf coast
zone, of which 55.2 million cubic yards would be
new work. Of these activities 61 percent of the
dredging was proposed in the New Orleans District,
26 percent in the Galveston District, 11 percent in
the Mobile District and 2 percent in the Jackson-
ville District.
ENVIRONMENTAL ASPECTS
A variety of studies (Masch and Espey, 1967;
Chapman, 1968; May, 1973; Cronin et al., 1970;
U.S. Army Corps of Engineers, 1974) describe the
environmental aspects of shell dredging, channeliza-
tion, arid spoil disposal. Unfortunately, the impact
of these operations on the gulf coast ecosystem is
incompletely known. However, enough is known
about the ecology of estuarine systems to evaluate,
in general, the major ecological consequences in-
volved. Figure 4 is a generalized flow chart which
diagrams the manner in which ecology is affected
by dredging. Three main categories resulting in four
principal pathways are involved. This is a simplifi-
cation of the complex interactions which actually
occur. However, some of the other more obscure
interactions form pathways which may or may not
occur in a particular system, or are poorly under-
stood. Attention given them would only serve to
confuse the basic cause and effect relationships.
The following subsection will deal with the pri-
mary effects of dredging separately.
TABLE 3.—Average Quantity of Spoil Material (million cubic
yards) Dredged in the Gulf Coast, by Disposal Method and
District*
Undiffer-
etitiated1'
Confined
Open Water
Upland
Galveston
18.2
8.7
21.0
None
New
Orleans
None
20.3
40.5
None
Mobile
13.6
2 5
13.7
0.4
Jackson-
ville
None
0.2
2.5
1.4
* From Boyd, et al. (1972)
t Disposal Method Not Defined
PIGUHK 4.—Environmental aspects of dredging.
Physiography
All dredging operations involve the physical modi-
fication of the environment by removal of bottom
material and its disposal. Such actions result in the
loss of habitat for benthic organisms, including
oysters and a multitude of other creatures of signifi-
cant value in the food chain. The extent of the area
in the gulf coastal zone which has been impacted by
dredging is difficult or impossible to determine.
Table 4 is a compilation of data from the various
segments of the Cooperative Gulf of Mexico Estu-
arine Inventory and Study for the Gulf States, and
Chapman (1968). Historically, Cain (1967), Chap-
man (1968), and the "National Estuarine Study"
(1970), have all estimated the amount of estuarine
habitat and acreage modified. The inconsistencies in
the acreage values listed from one report to another
are based primarily on the use of differing criteria
in defining the limits of estuarine areas, period of
record, and incomplete data. The latest total estu-
arine acreage value is 13,898,978 acres taken from
Table 4. The NES C1970) lists 655,900 acres of im-
portant habitat that had been lost to dredging and
filling for the period 1950 to 1969.
Due to siltation, dredged areas usually require
periodic maintenance dredging which disturbs any
recolonization by benthic organisms which may have
occurred. In many channels, however, the substrate
stabilizes enough to allow the establishment of a
benthic community.
It is important to note that some estuarine areas
are more valuable than others. Thus a simple acreage
figure of dredged areas may not tell the entire story.
Areas of submerged aquatic vegetation (turtle grass,
widgeon grass), emergent marsh grass areas (salt-
-------
DREDGING EFFECTS
231
Table 4.—Alteration of estuarine areas In the Gulf Coast Zone (acres)
i McNulty, Lindall, and Sykes, 1972
" Christmas, 1973
5 Oiener, R. A., 1974.
* Estimate of total length and area of channels and canals in Louisiana.
Total
Alteration
Filled causeways
Housing industry and other -- -_ _ ,- ___
Flondai
(West Coast)
3,003,213
921 688
2,081,525
1,135
3,977
18,409
26 676
l,500f
Alabama*
431,967
34,614
397,353
17
76
2,059
144
3,420
Mississippi3
500,380
66,933
433,447
9,000f
_
_
_
300f
! Crance, 1971
< Ferret, et al , 1971.
6 Chapman, 1968.
** All filled areas combined
t Approximate.
Louisiana4
7,289,568
3,910,644
3,378,924
Texas5
2,673,830
1,141,400
1,532,430
25,369
1,246
47,792
40,000
l.OOOf
(4,572.6*)
_
(42,104*)
—
—
78,500«
990
20,260«
marsh, cordgrass), mangrove swamps, and shell
reefs all rank higher in ecological value and sensitiv-
ity than do soft open bay bottoms. Estuarine areas
are centers of production for many commercially or
recreationally important species and for the orga-
nisms on which they depend for food. Measures
must be taken to perpetually protect such areas
from destruction. Indeed, a worthwhile endeavor is
the creation of new habitat, e.g., marshland areas,
when possible. The feasibility of such procedures is
discussed by Woodhouse (1972).
Another area of concern is the loss of habitat
through sedimentation. The dredging processes sus-
pend part (1 percent according to Mackin, 1962)
of the dredged material into the water column. The
resulting suspension forms a plume of turbid water
at the surface and turbidity currents along the bot-
tom. Masch and Espey (1967) noted that, while
shell dredging does not introduce sediments into the
bay water, the dredging does resuspend materials
already present on the bay bottom. The suspended
sediment load in the vicinity of even a single dredge
is at least an order of magnitude greater than the
suspended load produced by currents, strong wind
and wave action, ship and barge traffic, and ship
swells in Galveston Bay, Tex. The levels of nitrates
and phosphates in the immediate vicinity of the
dredge were f>0 to 1,000 times greater than the
ambient levels; however, no detectable effects on
photosynthesis of plankton were noted (Cronin,
1970).
Masch and Espey (1967), O'Neal and Sceva
(1971), and May (1973) have all delineated density
flows of sediment along the bay bottom associated
with dredging operations. These turbidity currents
seem to be principally affected by tidal currents,
bottom sediments, topography and dredge discharge
characteristics. The hydrodynamics of these currents
are not well xmderstood; however, they can cover
broad areas of bay bottom before flocculating out,
thus substantially reducing benthic populations by
smothering them. Studies of the effect of shell dredg-
ing on live oyster populations have shown these
turbidity currents are capable of covering and smoth-
ering live reefs. The U.S. Army Corps of Engineers
(1974) in San Antonio Bay, Tex., showed that al-
though noktonic organisms easily escaped turbidity
flows, sessile benthic populations were adversely
affected. While deposition of spoil on bay bottoms
and in dredge cuts substantially reduces benthic
populations over time periods ranging from several
months to several years, these populations, if un-
disturbed, slowly recover.
Circulation
CURRENT PATTERN AND
SPEED ALTERATION
Within this category are the effects of density
currents and topographic changes which modify
both the current pattern and speed. Many of the
migratory species (e.g., white and brown shrimp,
crabs, various fish) utilizing the estuaries are de-
pendent on salinity for their navigation. The stable
long-term density gradients (in salinity) set up by
-------
232
ESTUARINE POLLUTION CONTROL
a dredged canal could possibly redirect the migratory
route of species and potentially negatively impact
the standing crop of those organisms.
Topographic changes associated with dredging
can affect current velocities. Such changes can alter
the distribution of current-dependent plankton orga-
nisms. Where current velocity is significantly re-
duced, established pathways for the distribution of
planktonic organisms may be blocked. Also, in-
creased sedimentation associated with velocity
alterations may smother benthic populations and
reduce the suitability of the substrate for such
populations. Kutkuhn (1966) notes that, because
of new circulation and water quality regimes, the
creation of "fish passes" may increase the ecological
carrying capacity of an area.
Water Quality
Water quality parameters fall into two categories,
physical and chemical. Factors such as turbidity,
light penetration, and temperature are important
physical parameters, while salinity, nutrient loading,
dissolved oxygen, and toxic substances are chemical
parameters.
PHYSICAL PARAMETERS
Increased turbidity is one of the more noticeable
short-term effects of dredging. This was discussed
in the physiography section, where it was pointed
out that while nekton and plankton can escape from
turbidity plumes, benthic organisms are negatively
impacted by the settling out of the suspended solids.
Reduced light penetration (euphotic zone) due to
turbidity plumes is documented by Sherk (1971).
Odum and Wilson (1962) state that "the turbid
mixtures of organic and inorganic matter both inter-
fere with photosynthesis and stimulate it by in-
directly raising inorganic nutrient levels." Depend-
ing on location, dredge spoil may or may not contain
nutrients. It is important to note that estuarine
productivity is primarily dependent upon organic
and inorganic nutrient loading from the rivers and
marshes emptying into them rather than upon local
photosynthesis. Thus turbidity does not impact
estuarine production to the extent that it would in
a system having phytoplankton as the primary
base of the food web. In addition, these effects are
transient, being in evidence only during the actual
operation of the dredge. Over longer periods of time,
some increase in turbidity may occur in the vicinity
of spoil banks. This is possible because the decreased
depth of water over these areas may facilitate stir-
ring of soft bottom materials by current and wave
action.
Temperature changes as a result of dredging op-
erations are probably relatively unimportant to the
estuarine ecosystem when compared to those in
other physicochemical parameters. Most gulf coast
estuaries are shallow bodies of water which are not
thermally stratified. Deep dredged channels repre-
sent an area where stratification can occur. The
ability of a deep water mass to resist venr rapid
temperature changes associated with winter storms
known as "northers" occasionally prevents fish kills,
which sometimes occur in the shallow bays of Texas
(Counter, 1941; Gunter and Hildebrand, 1951), by
providing a thermally stable haven for fish.
CHEMICAL PARAMETERS
Salinity is a critical chemical parameter poten-
tially affected by dredging activities. The distribu-
tion of many species within an estuary is closely
tied to the salinity pattern. In the case of many
species (e.g., blue crab, brown and white shrimp),
the distribution of various stages in the life cycle is
tied to different salinity levels. In some instances
the intrusion of more saline water due to channeliza-
tion may not be extremely detrimental; however,
in general, increasing salinity intrusion reduces the
necessary low and mid-range salinity areas required
for the development of juveniles of many estuarine
species. Salinity wedges moving up and down chan-
nels depending on freshwater inflow prevent the
establishment of a stable benthal community.
The salinity pattern of an estuary can be impacted
by deep channels through the formation of density
gradients. Such gradients are long-term phenomena
which provide a series of decreasing isohalines as
the distance from the channel increases. Migratory
routes of animals such as shrimp might well be inter-
fered with by these density gradients.
Due to sorption and ionic processes bay sediments
represent effective traps for a wide variety of poten-
tially hazardous industrial and natural chemicals.
Dredging and spoil deposition may release many
such substances (e.g., herbicides, pesticides and
heavy metals) into the aquatic ecosystem. Lee and
Plum (1974) describe an elutriate test designed by
the USCE and the EPA to detect the release of
chemical contaminants in dredged materials into
the water column.
Deeper channels often display anoxic conditions
due to benthal oxygen demand. Dredging in recrea-
tional developments with dead end canals with
depths of over five to six feet often produces stagnant
conditions because of poor water circulation, low
-------
DREDGING EFFECTS
233
light penetration and high nutrient loading. Such
conditions often foster plankton blooms which ulti-
mately raise biological oxygen demands and some-
times produce fish kills.
CONCLUSIONS
The following is a summary of major conclusions.
1. Eighty-five percent of the Gulf of Mexico estu-
aries between Cape Romano, Fla. and Brownsville,
Tex., has been moderately or severely modified by
man's activities.
2. The energy crisis and the resulting increased oil
exploration, production, and transportation activi-
ties further threaten the environment of the coastal
zone.
3. Important estuarine habitats have been de-
stroyed by dredging and/or filling.
4. Approximately 48 percent of U.S. Corps of
Engineers dredging activities occur along the gulf
coast.
5. Insufficient data is available on the extent of
dredging and filling operations in the gulf coast for
both the Corps of Engineers and private industries.
6. Shell dredging production data indicates a slight
reduction in the gulf coast zone for the period
1966-1973.
7. Texas shell production for the period 1966-1974
indicates an approximate 40 percent reduction.
8. The direct overboard disposal of washwater
from shell dredging operations is a major environ-
mental problem.
9. Additional information is required on the release
of chemicals from bottom sediments as a result of
dredging activities.
10. Environmentally acceptable spoil areas should
be identified in major estuarine areas.
11. Additional information is also needed on the
movement and fate of sediments suspended by
dredging activities.
12. Salinity is a critical chemical parameter poten-
tially affected by dredging activities. However, in-
sufficient information is available on the effect of
channel dredging and spoil deposition on salinity
modifications.
13. The Dredged Material Research Program of
the USCE should provide additional information on
the environmental aspects of dredging in the coastal
zone.
14. Clarification of environmental criteria used in
the evaluation of USCE dredging permits is needed.
In. Streamlining and centralization of the federal
permit, system is required for dredging activities in
the coastal zone.
REFERENCES
Boyd, M. B., R. T. Saucier, J. W. Keeley, R. L. Montgomery,
R. D. Brown, D. B. Mathis, and C. J. Guice. 1972. Disposal
of dredge spoil problem identification and assessment and
research program development. Technical Report H-72-8,
U.S. Army Engineer Waterways Experiment Station,
Vicksburg, Miss.
Breuer, Joseph P. 1962. An ecological survey of the lower
Laguna Madre of Texas, 1953-1959. University of Texas.
Pub. Inst. Mar. Sci. 8:153-183.
Cain, S. A. 1967. Statement before the Subcommittee on
Fisheries and Wildlife Conservation of the Committee on
Merchant Marine and Fisheries House of Representatives
90th Congress. March 6, 8, 9, 1967. Serial No. 90-3.
p. 28-76.
Chapman Charles R. 1968. Channelization and spoiling on
gulf coast and south Atlantic estuaries. In Proceedings of
the Marsh and Estuary Management Svmposium. Baton
Rouge, 1967. p. 93-106. LSU, Baton Rouge, La.
Christmas, J. Y. 1973. Cooperative Gulf of Mexico estuarine
inventory and study, Mississippi, Phase I: area description.
Gulf Coast Research Laboratory, Ocean Springs, Miss.
Crance, J. H. 1971. Description of Alabama estuarine areas—
Cooperative Gulf of Mexico estuarine inventory. Alabama
Marine Resources Bulletin No. 6. Alabama Marine Re-
sources Laboratory. Dauphin Island, Ala.
Cronin, L. E. 1970. Gross physical and biological effects of
overboard spoil disposal in upper Chesapeake Bay, Sum-
mary, Conclusions, and Recommendations. Special Report
No. 3, Natural Resources Institute, University of Maryland.
, Gordon Gunter, and S. H. Hopkins. 1969. Effects of
dredging activities on coastal ecology. Interim Report to
the Office of the Chief of Engineers, Corps of Engineers,
U.S. Army.
Diener, R. A. MS. 1974. Cooperative Gulf of Mexico estuarine
inventory and study, Texas: area description. U.S. Dept.
of Commerce. NOAA Technical Report. NMFS CIRC,
xxiv+265 ms. p. (in press)
Eifler, G. K, Jr. 1968. Industrial carbonates of the Texas
Gulf Coastal Plain. In Proceedings, Fourth Forum on
Geology of Industrial Minerals, L. F. Brown, Jr. (ed)
Bureau of Pjco-Geology, University of Texas. Austin, Tex.
pp 45-56.
Gunter, Gordon. 1941. Death of fishes due to cold on the
Texas coast. Ecology. 22(3) :203-208.
. 1967. Some relationships of estuaries to the fisheries
of the Gulf of Mexico. In Estuaries edited by George H.
Lauff, America Association for the Advancement of Science,
621-638.
, and H. H. Hildebrand. 1951. Destruction of fishes
and other organisms on the South Texas coast by cold
wave of January 28-February 3, 1951. Ecology, 32(4):
731-736.
Kutkuhn, J. H. 1966. The role of estuaries in the development
and perpetuation of commercial shrimp resources. American
Fisheries Society Special Pub. # 3, p 16-36.
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234
ESTUABINE POLLUTION CONTROL
Lee, G. F., and R. H. Plumb. 1974. Literature review on
research study for the development of dredged material
disposal criteria. Contract Report No. D-74-1, U.S. Army
Engineer Waterways Experiment Station, Vicksburg, Miss.
Mackin, J. G. 1961. Canal dredging and silting in Louisiana
bays. Publ. Inst. Mar. Sci. (Tx.) 7:202-314.
Masch, Frank D. and W. H. Espey, Jr. 1969. Shell dredging—
A factor in sedimentation in Galveston Bay. Center for
Research in Water Resources, University of Texas.
May, Edwin B. 1971. A survey of oyster and oyster shell
resources of Alabama. Alabama Marine Resources Bulletin
No. 4, Alabama Marine Resources Laboratory, Dauphin
Island, Ala.
. 1973. Environmental effects of hydraulic dredging in
estuaries. Alabama Marine Resources Laboratory—Pre-
pared for National Marine Fisheries Service, April 1973.
COM-73-11271 NTIS.
McNulty, J. K., W. N. Lindall, Jr., and J. E. Sykes. 1972.
Cooperative Gulf of Mexico estuarine inventory and study,
Florida: Phase I, area description. NOAA Technical Report
NMFS CIRC-368, Seattle, Wash.
Odum, H. T., and R. F. Wilson. 1902. Further studies on
reaeration and metabolism of Texas bays, 1958-1960.
University of Texas, Pub. Inst. of Mar. Sci." 8:23-55.
O'Neal, Gary, and Jack Sceva. 1971. The effects of dredging
on water quality in the northwest. EPA Region 10, Seattle,
Wash.
Ferret, W. S., B. B. Barrett, W. R. Latapie, J. F. Pollard,
W. R. Mock, G. B. Adkins, W. J. Gairdry, and C. J. White.
1971. Cooperative Gulf of Mexico estuarine inventory and
study, Louisiana: Phase I, area description. Louisiana
Wildlife and Fisheries Commission, New Orleans, La.
Sherk, J. A., Jr. 1971. The effects of suspended and deposited
sediments on estuarine organisms, literature summary and
research needs. Natural Resources Institute of the Univer-
sity of Maryland, Chesapeake Biological Laboratory,
Solomons. Maryland, Contribution No. 443.
Simmons, E!. G. 1957. An ecological survey of the Laguria
Madre, Texas. University of Texas. Publ. Inst. Mar. Sci.
4(2):156-200.
Singer, F. S. 1969. Federal interest in estuarine zone builds.
Environmental Science and Technology, Vol. 3, No. 2.
pp 124-131.
Wastler, T. A., and L. C. de Guerrero. 1968. National
estuarine inventory, handbook of descriptors. U.S. Depart-
ment of the Interior, FWPCA, Washington, D.C.
U.S. Army, Corps of Engineers. 1974. Shell Dredging in San
Antonio Bay, Texas. U.S. Army Engineer District, Galves-
ton, Tex.
U.S. Department of Commerce, NOAA National Marine
Fisheries Service. Current Fishery Statistics #5600,
Fisheries of the United States, 1970. March 1971.
. Current Fisheries Statistics #6124, Texas Landings,
Annual Summary 1972. December 1973.
U.S. Department of the Interior, U.S. Fish and Wildlife
Service. 1970. National Estuary Study, 1970. Volume 1-8,
USGPO Washington, D.C.
Woodhouse. 1972. Marsh building with dredge spoil in North
Carolina. North Carolina State University, Agricultural
Experimental Station Bulletin 445.
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NUTRIENTS
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NUTRIENT LOADING IN
THE NATION'S ESTUARIES
MICHAEL A. CHAMP
The American University
Washington, D.C.
ABSTRACT
An evaluation is made of the current status of nutrient loading in the nation's estuaries. Special
consideration is given to sources and transport of nutrients and their impact on estuarine ecosys-
tems. Critical problems and trends in nutrient loading are reviewed at the national level and for
six major estuaries: Cook Inlet, Columbia River Estuary, San Francisco Bay, Galveston Bay,
Pamlico Sound and Chesapeake Bay.
INTRODUCTION
Estuaries and their transition zones comprise
27,000,000 acres in the United States (Congress,
1970) and are annually responsible for more than
65 percent of America's fish and shellfish harvest
(Smith, Massmann and Swartz, 1966). An estuary
is a unique zone in coastal environments in which
fresh water from rivers mixes with salt water from
the ocean. It is a complex interacting system in
delicate balance among the physical, chemical, and
biological forces present at any particular time.
An estuary is a nutrient storehouse; marshes and
wetlands are constantly flushed of decomposing
plant material by tides. These nutrients are trans-
ported into the estuary and support a substantial
production of biomass. A Georgia salt marsh for
example contains enough nutrient reserve to permit
optimum ecosystem functioning for ,100 years with-
out renewal (Clark, 1974). The enriched soils of
estuaries are often several feet thick and are held
together by extensive plant root systems. This
natural ageless phenomenon can continue as long
as the system is not modified by the impact of
human activities. "The National Estuary Study"
(1970) reports that all of the nation's estuaries have
been modified: 23 percent severely, 50 percent
moderately and 27 percent slightly. One of the major
impacts has been increased nutrient loading.
Nitrogen, phosphorus and organic carbon are the
major components of nutrient loading; their transi-
tion is cyclic, resulting in effects which are cumula-
lative and compounded (Woodwell, 1970). A major
result of nutrient, overenrichment is eutrophication
which is the normal environmental aging process.
Eutrophication is the buildup of rapidly cycled
organic carbon. Early signs are excessive growth by
phytoplankton or vascular plants, and a reduction in
species diversity. Nutrient loading is a relative state
in which low and high levels produce undesirable
conditions: high levels stimulate eutrophication while
low levels limit productivity. The optimum nutrient
load is a mid level in which the estuarine system
reaches stability in both productivity and diversity.
The optimum nutrient loading will vary with each
estuary due to the natural accumulative capacity of
each system. In all cases, the limiting nutrient
controls the total potential development.
The health of an ecosystem is directly proportional
to the species diversity of that system over an ex-
tended period of time. A healthy system exhibits
many species of phytoplankton, each of which has a
particular dominance period followed by its return
to background levels, with other species blooming
at their selected times when environmental condi-
tions dictate. This natural cycle permits many dif-
ferent algal species to coexist and compete against
one another while the entire system remains in
careful balance. Under natural conditions, these
blooms will occur regularly, each with an associated
assemblage of zooplankton, invertebrates and fish
larvae within the estuary. Many species prey on
selected plankton forms and have evolved mecha-
nisms of timing stages of embryonic development to
follow specific plankton blooms. It is this type of
mechanism that characterizes a healthy aquatic
ecosystem and permits it to function with a high
rate of productivity year after year. Excessive
nutrient loading supports the bloom of one or more
species which are particularly favored and/or toler-
ant of the added nutrients. Those species which
succeed under these conditions are usually not pre-
ferred components of food webs, and total fisheries
productions are reduced. The result is an unbalanced
system, low in species diversity due simply to the
selective fertilization of undesirable phytoplankton.
237
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238
ESTUARINE POLLUTION CONTROL
NUTRIENT SOURCES AND TRANSPORT
Municipal Sewage and
Industrial Waste Discharges
The major contributors of nutrient sources are
municipal sewage and industrial waste discharges,
urban runoff, agricultural and' forestry practices. In
the coastal zone, most nutrients are terrigenous and
are transported toward the ocean with river flow.
In some estuarine zones, it is even possible for
nutrients to be tiansported up river by floodtide
(Ketchum, 1969). Therefore, an area of an estuary
cannot be considered immune to a nutrient source
located below it.
The flushing of nutrients from an estuary is a
function of the volume and flow rate of the water
source in addition to the physical topography of the
water basin. If the freshwater source is of great
magnitude, as in the case of the Columbia River in
Washington, the residence time of water mass may
be very short, meaning that nutrients do not have
enough time to exert their effects upon the system.
If, on the other hand, the freshwater flow rate is
slow (Pamlico River Estuary), the flushing action
is reduced and the system is unable to rapidly export
nutrients, therefore allowing them lime to exert more
influence on the system. For this reason, estuaries
differ greatly in their tolerances of nutrient loading.
Thousands of municipalities dump sewage treated
to various degrees into inland waterways flowing
towards the sea. A great number of inland coastal
cities were founded on rivers for a variety of reasons,
but among; them was the availability of municipal
and industrial waste disposal into the waterways.
This practice has continued today. Even though the
cities have grown to tremendous sizes, these rivers
are expected to transport greatly expanded volumes
of waste downstream to be rendered innocuous by-
natural processes, even though the average annual
riverflows remain approximately the same. Munici-
pal sewage has its origins in plant and animal wastes;
therefore, it is an enriched mixture of nitrogen,
phosphorus and carbon compounds which provide
the essentials necessary for plant growth. This
growth (primary production) is consumed in turn
by microorganisms, protozoa, rotifers, zooplankton,
crustaceans and so on up the food chain, stimulating
species diversity and stability in the system. Pollu-
tion of the stream by sewage treatment effluents and
runoff from fertilized lawns has caused the State of
Florida to place restrictions on recreational activi-
ties there, after seeing the harmful effects exemplified
by a number of fish kills between 1970 and 1973.
Unregulated construction in urban areas increases
the amount of sediment and nutrient transport into
estuaries by freshwater runoff from the land. Simple
construction like paving significantly increases the
sediment loading. Dredging activities, bridge-build-
ing and resort land developments tend to resuspend
the sediments containing nutrients, organic particles,
trace elements, and toxic substances in estuaries.
Public Law 92-500 requires that point source dis-
chargers (industries, municipal treatment plants,
feedlots, and other discrete sources) must obtain
permits requiring that such discharges meet all
applicable requirements relating to effluent limita-
tions as regulated by the Environmental Protection
Agency. This effort to regulate what enters the
nation's waters represents an attempt on the part of
the government to not only limit nutrient input but
also the thousands of other chemicals discharged
daily with little if any treatment. States which
desire to administer the national permit program
may submit complete program descriptions to the
Administrator for approval with the stipulation
that all individual permits are subject to EPA
review, and annually the states must submit reports
to EPA that inventory all point sources of pollution
and assess existing and anticipated water quality.
This National Pollution Discharge Elimination Sys-
tem (NPDES) provides EPA with the authority to
enforce the effluent limitations and allows private
citizens or groups to levy judicial process against
any polluter in violation of an effluent limitation or
administrative order.
Industrial and commercial wastes provide a further
nutrient source to estuaries. Industry has been ac-
credited with contributing over 60 percent of all
U.S. water pollution (Nobile and Deedy, 1972). The
principal industrial offenders are by category: paper,
organic chemicals, petroleum and steel. Much of the
conventional technology used in municipal waste
water treatment is used also to treat industrial
wastes. Existing data suggest that about half the
total volume of waste water treated by municipal
plants is of industrial origin. The current trend
appears to be toward more joint use of treatment
plants by industry and municipalities. It is also
difficult to generalize on treatment of industrial
waste waters because the sources are highly diverse.
Industrial waste waters generally are less amenable
to conventional waste treatment because they con-
tain substances such as trace metals and chemical
compounds that resist biological degradation. Also,
to reduce discharges, industry has increased its
reuse of water, partly to reduce the costs of pollution
abatement and stay within federal regulations per-
taining to discharges. Today, industry probably
reuses an average of three gallons of water for every
new gallon it takes in.
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NUTRIENTS
239
Table 1.—INDUSTRIAL SOURCES OF NUTRIENT LOADING
Industries
Minerals
Petroleum
Agricultural
Pulp and Paper
Major wastes
DISSOLVED
Metals
Alkalies
Gases
(organic)
Gases
(inorganic)
Modified from Nobile and Oeedy (1972).
Most industrial discharges contain high oxygen-
demand wastes or toxic materials; however, a large
portion of industrial discharges contain some form
of available nutrients. Most contain some form of
carbon (inorganic or organic). Then there are special
industries which produce some form of nitrogen or
phosphorus either as an intermediate byproduct or
a waste product (i.e., fertilizer manufacturing or
phosphate mining, cattle feed lot operations). In
farming operations, the fertilizer is applied to in-
crease production and a portion leaches out and is
carried away in runoff. The major industries and
their major wastes are given in Table 1.
Another important industrial waste as a source of
nutrients is the food processing industry. Most of
these discharges are processing wastes and are dis-
charged into rivers from the canneries. However,
commercial fishery industries have a unique waste
that is discharged directly into the estuary; for
instance: one third of a salmon's weight is con-
sidered to be waste and Alaska salmon canneries
annually dump more than 100 million pounds of
this waste into estuaries. Some of this fish is used
as mink food but the vast majority is dumped into
coastal waters. The decomposing fish waste con-
tributes to the nutrient loading and greatly in-
fluences species diversity and can increase selected
species populations. In Alamitos Bay, Calif., very
polluted bottom areas are found which are sur-
rounded by a thick sediment of fish scales containing
unnatural populations of red annelid worms (Capi-
tella capilata) in concentrations as high as 6,000 per
square meter. In 1963 it was reported that several
Texas harbors were receiving shrimp and crab
wastes, raising the phosphorus concentration from
0.049 mg/L to 0.143 mg/L (Odum, et. al., 1974).
Such dumping not only represents an additional
nutrient source but it enters in such forms as
protein and fat at irregular intervals. The abundance
of nutrients favors organisms which expend less
metabolic energy and gives advantage to forms
which can use organic breakdown products at the
early stages of their decomposition cycle. For
instance, species capable of utilizing ammonia as a
nitrogen source are usually tolerant to high levels
and survive better than those organisms requiring it
oxidized to nitrate.
Pulp and paper mills have long been known for
their pollution effects in rivers. The waste produced
by their processes exerts an immediate oxygen
demand upon the water their effluent enters. This
is caused by the chemical demand for oxygen made
by the S02 which depletes the dissolved oxygen
present in the water. Studies of the York River, Va.,
indicate that sulfate wastes inhibit oysters from
efficiently metabolizing carbohydrates. The volume
of water filtered by the oysters was also reduced but
increased as they were removed from the waste
water. (Odum, et. al., 1974)
Urban Runoff
Vitale and Sprey (1974) have reported that
between 40 and 80 percent of the total annual
BOD and COD entering receiving waters from a
city is caused by sources other than the treatment
plant. They also report that 94 to 99 percent of the
total BOD and COD load from a single storm event
is contributed by sewer overflows, storm sewers,
runoff and bypasses, and that the periodic loads
from storm events exert a demand which is 40 to
200 times greater than that of the normal dry
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240
ESTUARINE POLLUTION CONTROL
weather effluent from the sewage treatment plant.
In their study they found that the storm water
annual contribution of nutrients (nitrogen and
phosphorus) appears to be generally less than 10
percent; however, storm water nutrients dominate
all other sources during a storm event.
ESTUARINE NUTRIENT CYCLES
A better understanding of the cycling of nutrients
in estuaries would greatly contribute to man's
ability to increase the yield of coastal fisheries.
Already estuaries are considered among the most
productive aquatic areas in the world and their
importance continues to grow with the world's
growing populations.
Estuarine ecosystems differ from freshwater and
marine ecosystems by their relatively high concen-
trations of nutrients. These nutrients enter the
estuary from river nutrient loading and the decay
of marsh vegetation and are trapped by physical,
chemical and biological processes. The large quanti-
ties of nutrients trapped in the estuary promote a
high rate of plant production. This plant biomass
is very important because the animals in an estuary
are directly or indirectly dependent upon plant
material as an energy source. Plant tissues are com-
posed of the following principal elements in descend-
ing order by weight: oxygen, carbon, hydrogen,
potassium, sodium, calcium, sulfur, chlorine, phos-
phorus, and magnesium. Certain necessary trace
elements include silicon, iron, manganese, and zinc.
Much current literature indicates that in coastal
waterways, nitrogen and phosphorus compounds
have been reported to be the limiting factors for
plant growth.
Nitrogenous Compounds
Nitrogen represents the fourth most abundant
element by weight present in plant tissues and one
of the two generally considered to be limiting in
aquatic production. Clark (1974) reports that in
coastal waters the amount of available nitrate is
generally believed to be the nutrient factor that
controls the abundance of plants. Municipal sewage
disposal into rivers and estuaries is the major con-
tributor of nitrogen compounds in the estuarine
systems. Nitrogen naturally occurs in these forms:
ammonium ion-NH4+, ammonia-NHs, nitrite-N02~,
the nitrate ion-NOs™, molecular riitrogen-N2, and
complex organic nitrogen complexes. A simplified
estuarine nitrogen cycle is given in Figure 1, which
has been modified from Odum, 1971.
In the atmosphere, most of the nitrogen present
is in the form of N2 with lesser amounts of ammonia,
and oxides of nitrogen derived from the combustion
of fossil fuels. Atmospheric ammonia originates
from a number of sources including air pollution,
photochemical reactions of the stratosphere, and the
decay of plant and animal byproducts. Rainfall
acts to rinse the air, bringing this vast array of
nitrogeneous products into aquatic systems. Only
a few algal and bacterial species are able to utilize'
molecular nitrogen (N2) for their nitrogen require-
ments. Ammonia is oxidized into nitrites (NO2~)
by nitrifying bacteria, which is further converted
to nitrate (NO3~) using the reaction as an energy
source and making the product more available to
plants. Most plants use ammonia, nitrate, or nitrite
in the production of proteins and nitrogeneous
nucleic acid components. This is an important inter-
conversion of inorganic nitrogen to organic nitrogen.
Animals, being unable to make this interconversion,
are entirely dependent on plants. In decomposition,
biological processes convert organic nitrogen to
ammonia, nitrite, and nitrate for recycling. The
refractory organic forms are resistant to decomposi-
tion and may remain for years in the system
(Williams, 1971).
Photosynthesis assimilates inorganic and organic
nutrients, most of which are present in excessive
amounts. However, nitrogen naturally occurs in
micromolar concentrations which can be completely
assimilated from the water mass by phytoplankton
of a given area. The major unnatural sources of
nitrogen in an estuary are: municipal and industrial
wastes, fertilizers from agricultural and forestry
practices, and urban runoff. In estuaries where
nitrogen is limiting, these wastes accelerate eutro-
phication. EPA criteria (1973) recommended pre-
vention of any nutrient discharge causing enrich-
ment leading to any major change in the natural
levels of flora. However, there are no EPA standards
regarding nutrient loading for "maximum acceptable
concentrations" of nitrogen and its compounds
(Proposed Criteria for Water Quality, EPA, 1973).
Phosphorus Compounds
Nitrogen and phosphorus represent the two
elements generally found to be limiting in natural
systems; however, nitrogen is generally considered
to be the more important of the two. Ryther and
Dunstan (1971) suggest that since phosphate is
normally present in concentrations twice that of
nitrogen in the coastal marine environment, nitrogen
must be the critical limiting factor. The "maximum
acceptable concentration" for phosphorus is placed
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NUTRIENTS
241
Agricultural &
forestry runoff
Fecal material
Municipal sewage
Organic N
Plants & Animals
protein
synthesis
bacteria &
fungi of decay
N fixing algae
Atmospheric N
electrification &
photochemical fixation
loss to sediments
(refractory N)
Agricultural &
forestry runoff
Fecal material
Municipal eewage
FIUURK 1.—The estuarine nitrogen cycle (modified from Odum, 1971).
as 100 mg/L with no "minimum risk threshold"
value given (EPA, 1973).
Phosphorus exists in a great number of forms, the
most prevalent of which is the phosphate group PO/i.
A simplified estuarine phosphate cycle is given in
Figure 2, which has been modified from Odum, 1971.
The slightly soluble inorganic phosphorus of the
earth's crust is an unlimited reservoir which slowly
leaches into aquatic systems through the weathering
of rock. These soluble orthophosphates are quickly
assirnilated by plants and transformed into par-
ticulate organic phosphorus. Dissolved inorganic
phosphorus compounds are released into solution by
excretion or decomposition and are transformed into
particulate organic phosphorus, or through degrada-
tion are converted back to inorganic orthophos-
phates. As in nitrogeneous forms, some of the organic
products result in refractory compounds, unavail-
able for biological use; and become part of the
sediments.
Afanmade detergents contain phosphates similar
to those prodviced by living organisms. If phosphates
in detergents are replaced by nitriloacetic acid
(NTA), a nitrogen compound as is, the current
trend in industry, the net effect could be the ac-
celeration of eutrophication (Ryther and Dunstan,
1971). These authors also estimate that So-.lO
percent of the total land-derived phosphate comes
from detergents. The amount of nutrient exchange
between sediments and the water column is depen-
dent on the exposed surface area between the two
media and not on the amount of nutrient material
present. Low oxygen concentrations cause the
release of phosphorus from the sediment. Several
studies have found that under natural conditions an
equilibrium is established between the phosphate
concentration of the sediment and the water (Lee
and Plumb, 1974). However, if these sediment
nutrient reservoirs are covered by silt, or sand, no
such interchange can take place. One study showed
no phosphorus was released 0.54 cm below the
surface of the bottom (Lee and Plumb, 1974).
Unlike many pollutants, phosphorus appears
harmless by itself, but in combination with nitrogen,
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242
ESTUARINE POLLUTION CONTROL
Organic Phosphates
Plants & Animals
Terrestrial runoff
Animal feces
Detergents
Municipal sewage
Industrial wastes
invertebrates
Estuatine Sediments
Refractory Phosphate
FIGURE 2.—The estuarine phosphorus cycle (modified from Odum, 1971).
it can change the whole biota (Redfield, et. al.,
1963). Samples of water enriched with phosphate
alone show no greater growth than control samples,
while nitrogen-enriched cultures have shown tenfold
growth in several cases (Ryther and Dunstan, 1971).
Carbon Compounds
The sources for most inorganic and organic carbon
compounds in estuaries are terrestrial runoff, munici-
pal and industrial discharges into rivers, and photo-
synthetic carbon fixation. A simplified carbon cycle
for estuaries is given in Figure 3, which has been
modified from Wangersky, 1972. Inorganic carbon
is converted into organic carbon by photosynthesis.
Organic carbon can be separated into particulate
organic carbon (POC) and dissolved organic carbon
(DOC) fractions by bacterial decomposition. Either
of these can be associated with the sediments, the
POC by settling, the DOC by adsorbing onto larger
aggregations and settling to the bottom. Organic
carbon is important as a nutrient because of the
interconversion to inorganic carbon.
Since algal tissue contains between 35 and 50
percent organic carbon by weight, it merits classifica-
tion as a major nutrient. In many cases, organic
carbon may be directly correlated with nitrate
distribution in a body of water. Carbon fixation
rates are often stimulated by the addition of nitrogen
or phosphate compounds as in the case of eutrophica-
tion. Organic carbon does represent an area of
concern, but many authors believe that the reservoir
of inorganic carbon compounds is in such excess
that the rapidly cycling organic carbon is usually
not a limiting factor under natural conditions.
Mineral and Trace Elements
In the late 1800's Dittmar studied 77 sea water
samples and found chlorine, sodium, magnesium,
boron, potassium, calcium, sulfur, sulfate, carbonate,
bicarbonate and strontium represent from 99.7-99.9
percent of the total dissolved material. (Corcoran
and Alexander, 1964.) The 0.2 percent remaining
included the principal plant nutrients: nitrogen,
phosphorus, and silicon, in addition to iron, copper,
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NUTRIENTS
243
aggregate formation & adsorptt
1— *• t
Refractory Carbon[
FIGURE 3.—The estuarine carbon cycle (modified from Wangersky, 1972).
jbalt, and manganese. Iron, because of its role in
emoglobin, catalases, and cytochromes is an es-
?ntial element in life processes. Iron in the form
f ferric hydroxide (rust) has been postulated by
lolberg (1952 and 1934) to have a scavenger role
i the accumulation of trace elements, allowing
hytoplankton to concentrate them along with their
ormal uptake of iron. Copper, another essential
lenient, is found in hemoglobin, cytochromes, and
emocjanins, as well as being necessary in the
tabilization of the chloroplast. It aids in oyster and
arnacle attachment, formation of octopus melanin,
nd the hardening of exoskeletons and egg encase-
lents. However, its toxicity at high concentrations
5 evidenced by its use in antifouling paints.
The trace elements exist in all three phases: water,
edimcnt. and the biota. Using zinc as an example,
n the \\ ater column it can be in an ionic state or a
omplexed form with many other molecules. While
, part of the estuaiine sediment, it can be dissolved
in interstitial water, ionically bound to charged clay
and organic surfaces, entrapped within iron and
manganese precipitates in addition to lattice and
organic complexes. In the biotic phase, zinc is as-
sociated with an organism: bound to mucous mem-
branes, enzymes, contained in cellular protoplasm
or within the digestive system. This permits bio-
logical cycling as it passes up the food chain from
the plankton through the carnivorous fish, and
possibly returning to the sediments.
The concentrations of trace elements present in
the estuary prevent them from being limiting factors
for photosynthesis. Dittmar's hypothesis includes
a general statement thai the concentrations of
these elements vary little in relation to each other
in sea water. Trace elements can be toxic at con-
centrations above background levels (Doudoroff and
Katz, 1961). EPA has sot up a table listing "maxi-
mum acceptable concentrations" (Clark, 1974;
EPA, 1973) for various substances; see Table 2.
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244
ESTUARINE POLLUTION CONTROL
Table 2.—Maximum acceptable concentrations for indicated substances. U.S.
Environmental Protection Agency, 1973
Beaufort Sea
Substance
Aluminum - - .. - - -. .. - _
Arsenic , . , -
Copper. ,
Fluorides _ _ _
Iron _-...- - -_ . j
Lead
Manganese ._ ,
Nickel ]
Concentrations (mg /I)
1.5
0.05
0.05
N.A. adequate data
not available
1.5
0.3
0.05
0.1
0.001
0.1
0.0001
The values represent the "maximum allowable concentrations" of toxic substances
as established by EPA following a National Academy of Sciences Review in 1973.
NUTRIENT LOADING IN
SIX MAJOR U.S. ESTUARIES
Cook Inlet, Alaska
Cook Inlet (see Figure 4) in the south central
area of the state, exhibits a 30-foot tidal range, a
rapid flow rate, and a large natural suspended
sediment load. The estuary has an estimated 400-
500 miles of tidal shoreline (1 percent of Alaska).
In Cook Inlet there are four major sources of
nutrient loading: (1) municipal sewage discharges,
(2) fish processing waste discharges, (3) salmon
spawning wastes, and (4) turbid outwash—outflow
from glaciers. Anchorage borders the inlet and dis-
charges the sewage of nearly one-half of the state's
population. The depth and flow rate of the estuary
greatly reduces the impact of this nutrient load.
However, with the discovery of oil, the Anchorage
area will experience tremendous population growth.
In 1963, oil was discovered at Middle Ground Shoal
in Cook Inlet; in less than two years oil production
exceeded 1,000 barrels per day per well ("National
Estuary Study," 1970). Along the shores of Cook
Inlet numerous fishing villages (Seldovia, Anchor
Point and Homer) base their economies on chinook,
pink and red salmon, king crabs and shrimp. It
is a common practice for canneries to dispose of 20
percent by weight of salmon back into the inlet,
producing unnaturally high nitrogen concentrations
in small areas. Murphy et. al. (1972) concluded that
there is some pollution near the Chester Creek and
Cairn Point Outfalls, but as a whole, Cook Inlet
is not polluted due to the high degree of turbulence,
flow rate, and sediment transport. They further
suggest that 200 million gallons per day of untreated
domestic waste could be pumped into the inlet
without causing an undesirable situation.
Bering Sea
V...,-^....^
Amchitka Island
Pact f ic Ocean
FIGURE 4.—Cook Inlet and Alaska (from "National Estuary
Study," 1970).
In Alaska many fishing villages are located on
small finger bays. The villagers utilize individual
cesspools and septic tanks for sewage disposal,
which seep nutrients into the coastal waterways
(Department of Health and Welfare, 1967). In
many small villages waste materials are stored
frozen during the colder months and dumped onto
intertidal beaches to be washed away. These
practices of waste disposal permit contaminants to
enter the ground waters, infecting wells and becom-
ing a hazard to public health.
Brickell and Goering (1970), investigating the
concentration of nitrogen in a pink salmon spawning
stream (Sashin Creek, and its associated estuary,
Little Port Walter on Baranot Island in southeastern
Alaska), found that dissolved organic nitrogen
ranged from 0.006 mg/L to 0.018 mg/L following
spawning, indicating a tremendous nutrient loading
from the decay of adult fish.
In the future, the anticipated population growth
in Alaska will overload the current estuarine waste
disposal methods and greatly impact these waters.
Continued nutrient loading through human waste,
commercial fisheries' waste, and industrial dis-
charges will alter the natural equilibrium of these
estuaries, especially duiing the warmer months.
Columbia River Estuary
The Columbia River Estuary has a high velocity
flow rate. It is ranked seventh in total length (1,324
miles) and second in flow volume (behind the
Mississippi) of any river in the United States. The
yearly mean discharge has been calculated to be
170,000 cubic feet per second, with a watershed of
-------
NUTRIENTS
245
259,000 square miles. The elevation of the river
drops from 2,650 feet to sea level, generating an
enormous velocity and producing a large effluent
plume into the Pacific (see Figure 5).
The Columbia River has significant impact on the
adjacent Pacific coastal zone. During 1966 and 1967
the annual chemical input to the Pacific was esti-
mated to be 108 moles of phosphate, 2.6 X 109 moles
of nitrate, and 2.2 X 1011 moles of total carbon
dioxide (Pruter and Alverson, 1972). Due to the
high velocity and short retention time within the
estuary, these levels of nutrients do not have enough
time to produce adverse conditions. It has been
reported that: "With the exception of slime growths
(Sphaerotilus natans) in the lower river, the biologi-
cal populations of the river are diverse and balanced,
the opposite of eutrophic conditions. Although
nitrate and phosphorus levels exceed desirable
levels (particularly during high runoff periods),
there are none of the usual symptoms of excess
productivity such as noticeable variations in dis-
solved oxygen saturation. There are no trends to
suggest increasing eutrophication" (EPA; National
Water Quality Inventory, 1974). The slime growths
mentioned were found to be associated with pulp
and paper mill wastes and became a problem to the
fishermen by fouling their nets and also to those
using the river for recreation. By the summer of
1972, practically all of the slime growth had been
eliminated following a program of more extensive
effluent treatment by the paper plants. The recom-
mendation made was that all pulp and paper mills
should at least have mechanically cleaned primary
Table 3.—Columbia River: Distribution of point waste discharges by source
(1972-73)
R M 1018
summer ,
etlluant !
at ume >
Waste source
Municipalities.-
(Portland)
Pulp and paper
Chemicals -
Aluminum reduction. . .
Washington public power
AEC Hanford Works
Food processing _ J
Other
Total
Flow
*m.g./d.
113.6
(71.1)
395.1
85.3
91.3
1,710.0
289 5
47.2
36.0
2,768.0
BOD
Ib./day
145,132
(66 962)
606 211
7,418
4 300
4 033
1,634
768 728
Phosphorus
Ib./day
5,800
(3 102)
993
107
493
1
39
75
7,508
Nitrates
Ib./day
16,372
(9 340)
706
463
415
8
95
18 059
FIGURE 5.—The Columbia River showing summer effluent
plume and dam locations (modified from EPA, National Water
Quality Inventory, 1974).
* Million gallons per day.
Modified from National Water Quality Inventory; 1974.
waste treatment facilities to reduce the release of
paper fibers into the river.
Nutrient enrichment can be divided into con-
trollable point discharges and generally uncontro-
lable non-point discharges coming from the normal
land runoff. The point discharges come from a
variety of sources on the river including municipal
dumping, pulp and paper mills, food processing
plants, grain washing plants, and so forth. Each
of these makes contributions to the Columbia
through industrial discharges. A point waste dis-
charge for the Columbia River is given in Table 3.
These point discharges are generally minor in their
influence on the water but twice they have been
involved in pollution problems in the lower river.
Fortunately, the volume and velocity of the Colum-
bia River have been great enough to maintain a
quality that rarely drops below the very high stan-
dards set by the States of Oregon and Washington.
While the quality of water in the Columbia remains
generally high, some of her tributaries experience
nutrient levels higher than state standards.
Sufficient amounts of all nutrients are present to
support a diverse and abundant biota. During most
of the year, nitrates are present in concentrations far
greater than the 0.3 mg/L limit set for the usual
formation of algae blooms (EPA; National Water
Quality Inventory, 1974). In fall and winter nitrate
median concentrations range from 0.3 to greater
than 0.4 mg/L from McNary Dam (RM330) to
the mouth; in spring, the median exceed 0.3 mg/L
from Longview (RM6S) to the mouth. Concentra-
tions at McNary Dam exceed 0.8 mg/L in 15
percent of the readings; however, the effect is very
slight. During the summer months when conditions
are optimum for algal growth, nitrate concentrations
fall well below the 0.3 mg/L value.
Phosphorus concentrations show a similar annual
trend. From McNary Dam to the mouth, during
-------
246
ESTUARINE POLLUTION CONTROL
the fall and winter, the median phosphorus value
exceeds the O.On mg/L value set as the limit. During
the warmer summer months, the median value is
consistently below the limit value except in the
lower 60 miles. It appears that total phosphorus
concentrations can be correlated .to river flow. Low
flow years experience lower values (1967-1969),
while higher flows (1970-1972) produce higher
median concentrations. Fortunately, the Columbia
River's nutrient levels are sufficient, with the vast
majority of nitrates and phosphates coming from
natural non-point sources. Phosphorus comes from
soil-bound materials and is runoff dependent. "In
1972, 6 percent of the annual loading of the Columbia
occurred from point sources discharging directly into
the Columbia, 65 percent was carried to the Colum-
bia by its major tributaries, and 29 percent was
accounted for by other mechanisms—among them
minor tributaries, direct runoff, and sedimentation"
(EPA, National Water Quality Inventory, 1974).
Therefore, the Columbia River receives vast
amounts of nitrogen and phosphorus principally
from land runoff, but natural conditions have not
permitted eutrophic conditions to occur. Point
sources contribute large amounts of nutrients but
the rate and volume of river flow is enough to dis-
perse these substances during the algal growth
season. It appears that some of the tributaries are
experiencing increased eutrophication. The Columbia
River has been sampled for 82 years and now has
89 monitoring stations along its length, which should
enable recognition of potential problems.
San Francisco Bay
San Francisco Bay represents the oceanic outlet
for the Sacramento River, San Joaquin River, and
many lesser rivers that drain the Central Valley of
California into the Delta (see Figure 6). Its history
is unusual; in about 1850 the bay complex was
estimated to be 700 square miles but by 1960
extensive diking and filling had reduced the area by
38 percent to 435 square miles. In addition, the bay
area boasts a population in excess of five million,
which discharges industrial and municipal wastes
into the rivers and bay. This population represents
a fourfold increase over census figures of 1930.
In 1969, municipal and industrial wastewater
discharges were estimated at approximately 600
million gallons per day and this figure is forecast
to increase to over 2,100 million gallons per day by
the year 2020 (Kaiser Engineers, 1969). These
figures do not include industrial use of water for
cooling purposes. Natural runoff has increased due
to increased urban development.
FIGURE 6.—San Francisco Bay (from Kaiser Engineers,
Final Report to State of California, 1969).
In San Francisco Bay, nutrient overenrichment
is the major problem. The rivers entering the bay
are rich in nitrogen, phosphorus and carbon from
point sources (municipal and industrial) and non-
point sources (natural and agricultural) from the
California Central Valley. Low velocity riverflows
produce a residence time for the northern reach of
San Francisco Bay estimated at 100 days according
to the California State Water Resources Control
Board in 1971. This time period permits extensive
nutrient cycling and high rates of carbon assimila-
tion. "Recent studies have indicated that nitrogen
and phosphorus concentrations were from 10 to
100 times greater in the Delta than those reported
for substantial growths of algae" (Kaiser Engineers,
1969). Reported concentrations of total nitrogen
ranged from 0.2 to 2.5 mg/L with the higher values
found at the San Joaquin River near Stockton, an
agricultural area. An unusual feature of the bay
is that nitrogen and phosphorus are at too high
levels for them to be limiting eutrophic conditions.
A California State Water Resources Control Board
Report (Kaiser Engineers, 1969) states that in the
Suivun Bay (see Figure 6) during periods of maxi-
mum phytoplankton concentration, no more than
17 percent of available nitrogen was being utilized.
-------
NUTRIENTS
247
The report further states that the possibility that
phosphorus could be the limiting nutrient is even
less credible. Data from 1961-1964 computes that
municipal and industrial sources contribute 53 tons
per day of total nitrogen and 42 tons per day of total
phosphates (Pearson, Storrs and Selleck, 1909).
Phytoplankton blooms occur frequently. In gen-
eral, algal populations found in the bay are 1/10
to 1/100 of those found in the delta region; however,
densities of greater than 4 million cells per liter
have been observed below Dumbarton Bridge.
Blooms occur almost every summer. Typical summer
plankton counts in the delta area range from 3
million cells per liter in the Sacramento River to
greater than 30 million cells per liter in the San
Joaquin River which normally exhibits much higher
values than the other inflowing rivers (Kaiser
Engineers, 1969). Therefore, nutrient enrichment
and eutrophication are a major water quality prob-
lem for the bay-delta system. The increasing volume
of wastes expected in the future, coupled with the
reduced freshwater flow caused by the development
of the Central Valley Project and the State Water
project influenced Kaiser Engineers (1969) to
project: "Within the proceeding context, it is
believed that the bay-delta system has no assimila-
tive capacity for wastes above the quantities now
being discharged. Kutrophication of the system,
particularly in the delta and south bay, is well
advanced. Increasing: waste loads and the decreasing
availability of flushing water from the Sacramento
and San Joaquin Rivers will inevitably accelerate
the eutrophication of the system."
In the Final Report for the California State Water
Resources Control Board, comparison was made
between San Francisco Bay and Lake Erie. The
Report states many differences between the two
bodies of water: size, salinity, Erie's 920 day
residence time vs. the bay's 100 day period, et
cetera . . . but the mean soluble phosphate content
is 10 times that of Lake Erie's and the bay's average
nitrate concentration is usually three times higher
than Erie. Furthermore, the median coliform bacte-
ria content of Sari Francisco Bay. which is an indi-
cator of the presence of domestic waste*, is fro in 5
to 250 limes that which is reported for Lake Erie.
Galveston Bay, Texas
The Galveston Bay Estuary is made up of about
1,022,000 acres including 383,400 acres of water,
230,000 acres of rice farms and cattle ranges, and
190,000 acres of urban and industrial areas; see
Figure 7 (''National Estuary Study," 1970).
The estuary exchanges water with the Gulf of
Gulf of Mexico
sf Say
7.—Galveston Bay, Tex. (from EPA Proceedings in
the Matter of Pollution of the Navigable Waters of Galveston
Bay and its Tributaries, 1971).
Mexico in three places: Bolivar Pass, San Luis Pass
and Rollover Pass. In 1914 the Houston ship channel
was constructed, making Houston a major seaport
with entry from the Gulf of Mexico, The major
direct effect has been oil pollution from ship traffic
and from the development of petrochemical in-
dustries along the Houston ship channel. The in-
direct effect has been the tremendous urban develop-
ment and other industrial growth in the entire area.
These have produced major chemical and biological
changes in Galveston Bay.
Under the Texas Water Quality Act of 1967,
permits are issued to municipalities and industries
regulating disposal into Texas estuaries. By 1971,
the Environmental Protection Agency had granted
141 municipal and domestic sewage permits and 136
industrial permits. The total permitted discharge
of waste effluent to Galveston Bay and tributaries
was 779 million gallons per day: 583,000 pounds
suspended solids; 270,000 pounds BOD, and 1,0.37,000
pounds COD. The 136 industrial waste discharges
were allowed to add 563 million gallons per day in
total effluent, most of which enters into the Houston
ship channel. The remaining 215 million gallons
represented effluent from the 141 municipal and
domestic waste sources. These sources contribute
high levels of coliform bacteria which have closed
many of the shellfish areas within Galveston Bay.
Of the 277 permits mentioned above, the waste
treatment needs and status of 1S9 of them were not
listed, and an additional 40 provided either in-
-------
248
ESTUARINE POLLUTION CONTROL
adequate or no treatment at all. Only 22 were listed
as being in compliance with permit requirements
(EPA Galveston Bay Conference, 1971).
Major nutrient alterations have occurred fre-
quently in the recent history of Galveston Bay.
Wallisville Dam, located on the Trinity River four
miles above its entrance into the bay. will eliminate
"20,000 acres of brackish ponds, sloughs, marshes,
and bottomland, nearly all of which biologists of
fSit, V.S. -Fish and Wildlife service regard as prime
•Jirimo and finfish nursery grounds with an annual
productive capacity of not less than $300 an aery
and probably more" (Carter, 1970). This marshland
loss will substantially alter the nutrient input of
Trinity Bay which is part of the Galveston Bay
complex. The nutrients contributed by the Trinity
River support the tidal marshes, the estuary and
Galveston Bay. The 0.5 feet tidal fluctuation con-
tributes additional nutrients from the tidal marshes
to the estuaiy. McCullough and Champ (1973)
reported that 255 miles or half of the entire length
of the Trinity River was impacted by municipal
and industrial waste discharges from the Fort Worth-
Dallas area before organic carbon concentrations
returned to background levels. Also, the authors
calculated that the Trinity River exports an esti-
mated 3.52 X 10" metric tons/year of total organic
carbon, into Trinity Bay, utilizing data from the
1972-1973 study period.
Several other human activities have a potential
for increasing the impact of nutrient loading in
Galveston Bay:
1. Silting in at the new bridge at San Luis Pass,
a process that is increasing the water mass retention
time.
2. Increased dredging activities that include
$2,807,000 in 1970 in the polluted Houston ship
channel, which was necessary for navigation.
3. Escalation in recreational construction of bay
homes and bay front properties by diking marshes
and dredging activities. "In sum, Galveston Bay is
providing a classic case history of an estuary that
can be rescued from its troubles only by determined
and imaginative effort—the solutions to the bay's
problems seem to lie in large scale research, ambi-
tious programs of pollution control plus tough en-
forcement and a close watch on the outfalls"
(Carter, 1970).
Pamlico Sound
The Pamlico Sound and adjacent Alhermarle and
Currituck Sounds represent a drowned North
Carolina coastal plain separated from the Atlantic
Ocean by the Outer Banks (see Figure 8).
Virginia
Chowi
rnluck Sound
FIGURE 8.—Pamlico Sound (from "National Estuary Study,"
1970.)
This entire complex makes up the second largest
estuarine area in the eastern United States with
Chesapeake Bay being first (Schoenbaum, 1972).
Currituck Sound
Albemarle Sound
Pamlico Sound
TOTAL
Chesapeake Bay
102,400 acres
302,000 acres
1,088,000 acres
1,492,000 acres
2,816,000 acres
Exceeded only by Alaska and Louisiana, North
Carolina contains an estimated 2,200,000 acres of
estuarine area (Rice, 1968). Shallow water charac-
terizes these estuaries with a maximum depth of
7 feet in Currituck Sound and 20 feet in Pamlico
Sound, but lessens to a few inches in many of the
numerous shoal areas. In Washington, N.C., the
Tar River becomes the Pamlico River flowing east
to the Pamlico Sound (see Figure 8). An important
feature is the slow riverflovv allowing longer residence
time and consequently a much slower flushing rate.
Lunar tides are negligible due to the Outer Banks,
and the extreme shallo\vness allows wind mixing of
the water producing turbid conditions during most
times. (Copeland and Hobbie, 1972),
Copeland and Hobbie (1972) have reported that
-------
NUTRIENTS
249
nitrogen appears to be the nutrient limiting eutro-
phication in the Pamlico River Estuary. The soils
of this region are unusually high in natural phos-
phorus, allowing large amounts to leach into the
waterways. Natural deposits are high enough to
make mining (for use in fertilizers) profitable by
the Texas Gulf Sulphur Company (TGSCo) which
contributes quantities into the Tar River. This
additional phosphorus enters the water column and
becomes part of the sediment, particularly near the
TGSCo effluent pipes. Under conditions of low
oxygen, significant amounts of this phosphorus arc
released from the sediment to the overlying water
mass. Copeland and Hobbie (1972) have reported
that:
When the total unfiltered phosphorus data were sum-
marized for the upper, middle and lower river, it became
obvious that there had been a general increase in the
concentration of phosphorus in the upper river over
three years of sampling (67—69). In spite of the scatter
of values and seasonal changes, there was a tripling in
the phosphorus concentration in the upper river . . . the
middle river was greatly affected by the concentration
of phosphorus entering from Texas (lulf Sulfur . . . the
lower section . . . also seems to be strongly affected by
Texas Gulf Sulfur's activities . . . while it is difficult to
say whether or not the amount of phosphorus reaching
Pamlico Sound is increasing, most of the time only low
leveln reach the Sound.
Yeritsch (unpublished data; NAS, 1969) has
postulated 2.8 ng of phosphate per liter as the ap-
proximate upper limit for unpolluted coastal waters.
Thi* value is exceeded most of the time in the,
Pamlieo area but euirophic conditions do not exist
because 'it appears that nitrogen is limiting in this
estuary and that the polluting effects of 1hc Texas
Gulf Sulphur phosphate are slight at this time."
(Copoland and Hobbie, 1972). Other required
micronutrient s appear to be abundant. Experiments
were conducted adding phosphorus id tlv water but
increased photosynthesis did not occur. Added
nitrogen produced significant increases in carbon
assimilation.
In summary, phosphorus by itself is relatively
harmless in the Pamlico Estuary area but if nitro-
genous compound^ become1 available to the system.
excessive eutroohi'-ation could occur.
Chesapeake Bay
The Che-apef.'v<- Bay represents the largest estu-
arine area in the eastern United States (2,816,000
acres), having major freshwater flow from the
Siisuuehaona Rivor Potomac River Rappahannock
:liV"[. arid tre .) ir •••- R,>ver iu$ r>> r welter'' shore
v">:atioua! Lstuiiry Study," 1970); .see Hgure 9.
The Potomac River itselt drains 14,670 square
Washington
Potomac R.
Rxjppahi
Richmond,
James R.'
Delaware
.Chesapeake Bay
Atlantic
Ocean
FIGURE 9.—Chesapeake Bay (from "National Estuary Study,"
1970).
miles and extends 100 miles southeast from Washing-
ton, D.C., to the bay (Jaworski et al., 1971). Major
cities contributing to the bay or her tributaries
include Baltimore, Md., (pop. 905,759), Washington,
D.C., (750,510), Richmond, Va., (249,430) and
Norfolk, Va., (307,951), These urban areas con-
tribute to the nutrient load through municipal and
industrial wastes, land silt runoff, and wastes con-
tributed by the estimated 110 million tons of cargo
annually shipped through the bay ('''National Kstu-
a.ry Study," 1970). The Susquehanua River con-
tributes 600,000 tons of U rrigeneous silt to the
Chesapeake each year, but this volume .seems
insignificant to the estimated 2.5 million tons origi-
nating in the smaller Potomac Basin, Nearly half
of the economically important oyster beds located
in the upper bay have been destroyed or moved lower
in the bay due to this massive sedimentation. Cities
and suburban areas ;;re presently adding uncontrolled
quantities of silt into Chesapeake Bay ("National
Estuary Study," 1970;.
Regarding nutrient enrichment in Chesapeake
Bay, there are two considerations: ()) the predomi-
nant iiifh'o', » .»;' ih.v. pc'T'Cinal wati'"sheds on the
nufrifijt balann of the bay—-the Susqu-haiuia, the-
Potomac, and the James; and (2) the seasonal
-------
250
ESTUARINE POLLUTION CONTROL
nature of nutrient enrichment, whereby ihe majority
of nutrients transported are via nontidal discharges
(Guide and Villa, 1972). There is a relationship
between river discharge and nutrient loadings,
especially X02 and X03 as nitrogen. High NO?
and XOs as nitrogen loadings are indicative of land
runoff as contrasted to TKX as nitrogen loadings
which are attributable mainly tj treatment plant
discharges. Conversely, total phosphorus as POj is
more difficult to characterize since it tends 1o
absorb to particles and sediments. During low fiov\
phosphorus is retained in hot to n deposits in the
stream channel and is unavailable due to sedimenta-
tion. The greatest impact of those nutrient loadings
occurs during periods of low flow (and high tempera-
ture) during which high retention times result in
algal blooms. Guide and Villa (19721 have by
regression extrapolation over a 15-month study
period (Xov. 1969-May 1970) calculated the primary
source of nutrients entering Chesapeake Bay as
follows:
LOADINGS (Las, DAY) AS %
Tributary
Watershed
Susquehanna River _
Potomac River
James River
Rappahannock
River
Pamunkey River
Mattaponi Rivtr
Chickahominy
River
Clark, Guide, and Pheiffer (,1974) have developed
the following conclusions regarding the nutrient
loading in the Susquehanna River:
1 Runoff from agricultural land (42 percent of the
study area) accourted for 75-85 percent of the ion-
point, source phosphorus contribution, 60-70 percent
of the TKN contribution, and more than 90 percent
of the nitrate nitrogen contribution from all nonpoint
sources
2. Runoif from forested land (53 percent of the study
area) accounted for 10-15 percent ot the /ion-point
source phosphorus load, 25-30 percent of the TKX
load, and aboat 5 percent of the nitrate nitrogen
load from all non-point source?.
?:. Phosphorus is e'j'.i^iderably n'Oie manageable ilian
r'i'Tc;ien in the lowei Siicqi eh.iiina River Basin
during ail flow conditions.
4. In order to protect the biological integrity of the
upper Chesapeake Bay, a sueable reduction (70-90
j.rtivent'' in the exiting point -ouree contribution of
l-\\( -jj'hoii.s j'.ii.-i be n-!>l> •«!
',. : [>., t • >('"VenC--^ ' ! 'll '.'S'fl '•"" t -1 :.! ;)' lrlt S"'UVes
i^ .jia'-'tions.ble U'.ies- a1'tnt- >n is °i"Fr io<*ar;l>
leducing the exi.-lmg luad ironi agricultural runoff.
T
P04
as
PO,,
49
33
12
<>
2
1
Pi
54
27
13
2
2
1
TKN
as N
60
'22
10
2
]
NO,
+
NO3
as N
66
25
6
1
1
<1
NH3
as N
71
15
11
1
1
<1
TOG
51
27
12
3
4
2
Guide and Villa (1972) have also reported the
existence of a direct relationship between total and
inorganic phosphorus concentrations as PCn and
river discharge. They found that higher than normal
flow resulted in total and inorganic phosphorus
surges from the upper Susquehanna River Basin.
Jaworski et al., (1971) report that 32.5 million
gallons per day of waste water is discharged from
municipal treatment facilities which serve the
Washington area. Schubel (1972Ni adds that this
present sewage discharge contains more than six
metric tons of phosphorus and 10 metric lortn of
nitrogen per day with these values expected to
double in the next 30 years. During periods of low
river flow (75 m3/sec.) these inputs drastically alter
the nutrient load of the Potomac, increasing the con-
centration of phosphorus; by about 180 iug/liter
(Carpenter, et. al., 1969). Total nitrogen in the
river varies seasonally but generally appears highest
from January to March. Total phosphorus reaches
its highest values during the late fall and early
winter. Agricultural drainage and sewage in the
Potomac produce adverse phosphate conditions
above Washington, D.C. Measurements made in
1965-1966 showed that nitrate concentrations in
the river above, Washington were 100-lnO pig at./
liter during periods of high river flow, and phosphate
concentrations were 5 Mg at./liter (Carpenter, et. al.,
1969). This loading in summer and fall produces
large algal populations of blue-green algae Micro-
cystis aeruginosa which are present from the metro-
politan area as far downstream as Man land Point
(40 river mile;-). Comparison of chlorophyll a con-
centrations for 1965-1966 to 1969-1970 for Smith's
Point (River Mile. 0) and Indian Head (River Mile
75 from the mouth of Chesapeake Bav) indicate
that algal populations have not only increased in
density in later years but have become more per-
sistent over the annual c>cle ulaworski, et. al.,
1971).
Organic carbon studies in (he Patuxent River,
Md., have found that the concentrations of dis-
solved organic carbon (DOC) were higher than
particulate organic carbon nn*ry only at low and high salinities.
E^oth DOC 'ird POC concentnrdons decreased dr>'rn
river ac:'ijg buJii _•: :•,' "utror.iJiic -"o;:diKon-; vhi'-h arc
;u<. ^1, ;i nil-' v ','i'i u'.r'i1:: (:. I OIMPIH. R'.v.'-,
Patuxent River and Black River) In the mam
-------
NUTRIENTS
251
body of the upper bay nutrient levels and phyto-
plankton production are high, but the grazing rate
is also high, thereby preventing an undesirable
buildup of algae. Nu+rient levels are probably near
the upper limit for healthy conditions in the bay.
The discharge of improperly treated sewage and
municipal wastes constitutes the most serious im-
mediate threat to the Chesapeake Bay estuarine
system (Schubel, 1972).
CRITICAL PROBLEMS AND
RECOMMENDATIONS
Current U.S. Trends
in Nutrient Loading
The current trend in expansion, development and
population growth of coastal cities will greatly
accelerate man's impact on the Nation's estuaries.
Nutrient loading is increasing in general with some
harmful results. The 1974 National Water Quality
Inventory stated that the "chemical and physical
measurements taken in 22 waterways show that the
pollutants receiving the most widespread controls
^including bacteria and oxygen demand) greatly
improved in the last five years." It continued to
report that "nitrogen and phosphorus, the nutrients
most frequently associated \\ith eutrophication,
showed worsening trends." The overall effect of
these opposite trends is not completely understood;
however, if the present increased use of chlorine as
a disinfectant is considered, lower bacteria counts
and BOD levels could be explained even though
nutrient loading has increased. Phosphorus levels
were high enough to exceed suggested levels in tip
to 57 percent of the roaches studied. In addition,
l'S2 percent of the reaches showed increased levels
of phosphorus from 1968-1972 over the previous
five years , . . with nitrogen exceeding reference,
levels in one quarter of the reaches measured, and
increased in up to 76 percent of (he reaches." Table 4
presents the percent uf ihe reaches exceeding refer-
ence levels and the percent change from 1963
to 1972.
The National Water Quality Inventory (1974)
represents a landmark work in the study of the
United States continental waterways because it was
a cooperative effort by the states in association with
the Environmental Protection Agency. The report
studied the 10 longest rivers in the country; the
10 rivers with the highest strearnflow volume; and
the rivers or harbors where the 10 largest urban
areas are located.
In 1972, the National Pollution Discharge Elimi-
nation S.ystem (NPDES) Act was passed requiring
Table 4.—Major waterways: Reference level violations! 1963-72
Parameter
Suspended solids- _-
Turbidity
Ammonia
Nitrate (as N) -
Nitrite plus nitrate .
Total Phosphorus
Total Phosphate.
Dissolved Phosphate
Chlorides-
Sulfates .
Reference level
and source
H 80 mg/l aquatic life
H 50 JU aquatic lite
0.89 mg/l aquatic life
0.9 mg/l nutrient
_ 0.9 mg/l nutrient
- 0.1 mg/l nutrient
0.3 mg/l nutrient
-i 0.3 mg/l nutrient
-j 250 mg/l water supply
250 mg/l water supply
Percent of reaches
exceeding reference levels
1963-72 [ 6S-72Tchange
I
26
28
16
12
18
34
30
11
12 >
12
14
28]
6
24
26 I
57
41
22
«'l
-12
0
-10
412
4-8
+23
+ 11
+ 11
0
Modified from National Water Quality Inventory; 1974.
permits for discharging from a point source into the
nation's waters. These permits specify the amounts
of pollutants that each discharge point is allowed.
By March 1974, about 41,000 permit applications
had already come in with an expected 34,000 still
to be filed.
Municipal sewage contributes large amounts of
nutrients to the river or estuary depending upon the
treatment it receives. Primary treatment removes
the particulate matter from the raw sewage thereby
removing 20-35 percent of the biological oxygen
demand (BOD). Tertiary waste treatment, using
the effluent from the secondary process, involves
nutrient removal (nitrogen and phosphorus) and
can reduce BOD effluent concentrations significantly
below secondary treatment. Table 5 lists the number
of municipal discharges by treatment level and In-
state.
Agricultural sources are more difficult to study.
Most farms are not considered to be point sources
and are not required to have permits, but large
feedlots. iish hatcheries, and return flows from
irrigated fields must have permits. Most, operations
of this type an1 found in the west and midwest with
about 6,500 permit applications expected under the
National Pollution Discharge Elimination System
(NTDES).
Increased nutrient loading represents a potential
hazard to the nation's estuaries which may have a
profound effect on a type of American way of life.
Many communities bordering the estuaries depend
upon the estuarine ecosystem for their economic and
cultural livelihood. In tidewater Virginia, for exam-
ple, fishing and oystering have been community
pursuits for well over a century and they could
easily be eliminated, impacting economic and social
structures. Socially, the estuaries annually provide
recreation for millions in the form of swimming,
boating and fishing. In North Carolina, the annual
-------
252
ESTUARINE POLLUTION CONTROL
Table 5.—Municipal discharges by state (From EPA National Water Quality Inventory, 1974)
State
Number of mumcipalfacil'ties by treatment level
by population served
Adequate Inadequate | Unclassified j Tertiary
secondary i secondary i secondary*
10,000 to [Greater than
100,000 1 100,000
Alabama
Alaska
Arizona
Arkansas.
California
Colorado
Connecticut
Delaware
District of Columbia i
Ftouda
George
Hawaii
Idaho.
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine.
Maryland.
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire.
New Jersey
New Mexico.
New York
North Carolina
North Dakota
Ohio
Oklahom
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas.
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyomin
Guam
Puerto Rico.
Virgin Islands.
Total
' Data insufficient to classify further.
marine sport fishing value was estimated at 9 million
dollars in I960, with marine commercial fisheries
valued at 3.6 million dollars. Estuarine dependent
oceanic fish were valued at 2.5 million with water-
fowl hunting valued at 0.2 million dollars. Therefore,
the annual primary economic value of fish and
wildlife resources of the North Carolina estuarine
areas were in excess of $15 million in 1960 (National
Estuarine Study, 1970). In 1966 in Chesapeake Bay
$30 million dollars worth of fish and shellfish were
harvested, half of this oysters. The 20 million pounds
of oyster meat harvested in 1966 dosen't compare
well with the 177 million pounds harvested in 1880
Oyster harvesting could evidently be prohibiiec
-------
NUTRIENTS
in some areas if pollution and eutrophication are
allowed to continue. Swimming has been banned in
some rivers, for instance in the Potomac River,
where up to o million gallons of untreated raw
sewage per day are currently being discharged due
to treatment plant overloads.
Nutrient loading in some estuaries has accelerated
eutrophication, altering the biota and reducing
species diversity. The species considered to have
economic value generally do not thrive in eutrophic
conditions. Perhaps the most significant alteration;-
in the biology of eutrophic e,>tuaries \\ould be the
reduction in embnonic and juvenile survival rates
and the reduction of alternative food webs. Oysters.
clams, lobsters crabs and manr species of fish
have been placed in stressing environments. The
resulting biota is composed of large populations of
polychcate worms, trash fish, and echinodcrms. In
tropical waters, sewage dumping accelerates algae
production which drastically alters the production
of coral reefs. On the west coast, sewage disposal
stimulates large populations of sea urchins, which
over-graze the giant kelp beds, eliminating nursery
areas for larval and juvenile forms, habitats for fish,
sea otters, and numerous invertebrate.v These altera-
tions are at the interacting ecosystem level and
cause, irreversible damage.
With world food production today at a premium,
the 4.06 billion pounds of U.S. estuarine commercial
fish and shell fish (1967) are a very important source of
protein. Several investigators have reviewed the
potential for controlled cultural eutrophication as
a new source for man's food (Sawyer, 1070). The
philosophy is that added nutrients increase phyto-
plankton biomass, which could he channeled into
food chains specifically for the production of com-
mercially important fish or shellfish (aquaculture).
This could serve a twofold purpose: first, it could
use treated sewage as a nutrient source, and secondly,
it could produce a vast industry if developed The
statistics compiled for 1969 by the National .Marine
Fisheries Service of the National Oceanic and
Atmospheric Administration indicate that the Gulf
of Mexico Fisheries contributed $152 million, or
about 30 percent of the total U.S. fisheries produc-
tion (SnlS.o million). In 1970 the gulf shrimp
fisheries alone were estimated to be worth $108
million.
A smooth system doesn't exist whereby federal
agencies administer to state agencies, which control
local operations, with one federal group as the lead
organization responsible for coordination of estu-
arine programs. Instead, a free lance theory of
operation exists which can break down interagency
cooperation. Federal "maximum acceptable permis-
sible concentrations''' exist in many cases but these
need to be evaluated as standards for water quality
and as methodology incorporating both accuracy and
simplicity. EPA and other governmental groups are
on the right track in coordinating activities and
defining critical values, national zones and areas
of study. However, a total cooperative program will
be required to reverse the national trend. An
integrated systems approach will enable a better
qualification and quantification of estuarine dy-
namics, eliminating problems associated with inter-
preting individual parameters. For enforcement
policy to be effective, it must be uniform, and those
at fault must be given an economic incentive- for
corrective action. If fines are not enough, sfiffer
measures must be taken to develop cooperation.
A nationwide monitoring system using standard-
ized methodology is needed which could be state
and federal!v supported and staffed. This allows for
progressive trends to be realized and would be
beneficial in discovering problem areas. Phosphates,
largely coming from households, represent an easy
source for action but certainly that is not enough.
Nitrogenous compounds, generally considered 1o be
the limiting nutrient in coastal areas, need to be
strictly monitored. Xew technology in municipal
sewage treatment has increased the efficiency of
phosphate removal: however, there must be a
greater effort to investigate the impact of specific,
nutrients on specific estuaries. Fertilizers could be
made less deleterious simply by increasing the
efficiency of their uptake.
Nutrient loading in the nation's estuaries exists
as a problem between good management (coopera-
tive policy and decision) and enforcement of
regulations.
RECOMMENDATIONS
1. Formation of a Xational Esiuannc Co(/rdinatit>y
Board. The Board would consist of representatives
from the various state and federal agencies. The
Board would be responsible for approving manage-
ment programs and directing the enforcement of
policies and enactments. The Board uould be
responsible for reviewing every estuarine proposed
project prior to submission to Congress for funding,
similar to the Board of Engineers for River and
Harbors for civil works projects. The Board would
be responsible for coordinating estuarine monitoring
surveys and evaluating national trends. The Board
could be housed in the Office of Coastal Zone
Management of NOAA.
2. Development of a national policy on coastal land
use with regard to construction of recreational homes
-------
ESTUAHINE POLLUTION CONTROL
and beach houses, et cetera, modeled after the
Currituck County Plan in Xorth Carolina. This
plan concentrates housing and populations in small
areas which enables better sewage treatment and
reduces the human impact on the system.
3. Formation of a Xationiride Estuarine Man itorinq
System in which the many regional programs would
be coordinated and manned by federal and state
authorities using standardized techniques. The data
could be stored in KPA 8TORKT System with a
system of quality control instigated.
4. Designation of natural undisturbed estuarine
areas as biospheres to be preserved and protected for
research and long term studies
."). Seasonal and long term studies evaluating the
impact of the addition of specific nutrients to
specific estuarine ecosystems to determine the limit-
ing nutrient.
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waste disposal in the Gateway Borough. Published by I he
Branch of Environmental Health. Juneau.
Brickell, 1). C. and J J. Goering. 19VO. Chemical effects of
salmon decomposition on aquatic ecosystem^. In Inter-
national Symposium on Water Pollution Control in Cold
Climates. Edited by R. S. Murphy and I). Nyguist. U.S.
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California State Water Resources Control Board. 1971. A
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Carpenter, J. II., \). W Pritchard, and R. C. Whaley. 1009
Observation* of ouU'ophieation and lutrient cycle* ii\ some
coastal plain estuaries. In Eutrophication: cause*, conse-
quences and correctives. National Academy of Sciences,
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Carter, L. J. 1970. Galveston Bay: te-t case of an estuary in
crisis. Science, Vol. 107, No. 3921. pp. 1102-1108.
Clark, John. 1974. Coastal eco*ystcms: ecological considoia-
tions for management of the coa*tt,l /one. The Conserva-
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Clark, Leo J., D. K. Donnellj, and Ortcrio \"illa, Jr. 1973.
Nutrient enrichment and control requirements in the Tapper
Chesapeake Bay. EPA-903/9-7?>-002-a.
Claik, L. J., Victor Guide, and T. H. Pfeifler. 1974. Nutrient
transport and accountability in tr e Lower Susquehanna
River Basin. US-KPA-903'9-74-014. Technical Report 60.
Copeland, B. J. and J. E. Robbie. 1972. Phosphorus and
eutrophieation in the Pamlico River Estuary, N.C. Water
Resources Institute of the Univ of N.C Report No. 65.
Couoran, K. F and J. E. Alexander. 1904. The distribution
of ceitain trace element* in tropical sea water and their
biological significance. Bull, of Manne Science of the Gulf
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sewage outfalK California Mar. Res. Comm., CalCOFI
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Goldberg, Edward D. 1952. Iron assimilation by marine
diatoms. Biological Bulletin. Vol. 102, No. 3. pp.'243-248.
Goldberg. Edward D. 1951. Marine geochemistry L Chemical
scavengers of the sea. Journal of Geology, Vol. 62, No.
3. 1954. pp 249-265
Guide, Victor, and Orterio Villa, Jr. 1972. Chesapeake Bay
nutrient, input .study Technical Report 47. US-EPA
Region III.
Hill, J. M. 1973. Distribution and diurnal cycle of dissolved
and participate oiganic carbon in the Patuxent River, Aid.
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Report 45. Environmental Protection Agency.
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Ketchum, B. H. 1909. Eutrophieation of estuaries. In Eutro-
phicalioiv causes, consequences, and correctives. 1971.
National Academy of Sciences. Washington, D.C. pp
197-209.
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research study for the development of dredged material
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Murphy, U. S , R. F Carsou, D. Nyquist, and R. Brit oh.
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A case study of Cook Inlet, Alaska. Institute of Water
Resources, University of Alaska. Publication No. IWR 26.
Nobile, Philip, and John Deedy. (Editors.) 1972. The com-
plete ecology fact book Doubleday and Co , Inc., Garden
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-------
NUTRIENTS
255
Pruter, A. T., and D. L. Alver^on (ed.) 1972. The Columbia
River estuary arid adjacent ocean waters. U. of Seattle press.
Redfield, A. C., B. H. Ketchum, and F. A. Richards. 1963.
The influence of organisms on the composition of seawater.
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Schubel, J. IL 1972. The physical and chemical conditions of
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Fish. Soc. Spec. Publ No. 3. pp. vii-viii.
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Water Planning and Standards. Washington, D.C. EPA-
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Tex
ACKNOWLEDGEMENTS
Sincere appreciation is extended to William J. Rue, Jr.,
without whose valuable assistance this manuscript could not
have been compiled. A. R. Armstrong, Roland F. Smith, and
Paul R. Becker are to be thanked for their critical review.
Rosie Yaligra's efforts in editing and typing the final manu-
script are also greatly appreciated.
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-------
EFFECTS AND CONTROL
OF NUTRIENTS IN
ESTUARINE ECOSYSTEMS
JOHN E. HOBBIE
B. J. COPELAND
North Carolina State University
Raleigh, North Carolina
ABSTRACT
Almost all nutrients entering estuaries come via streams, with smaller amounts from precipitation
and the ocean. Oversupplies of nutrients are transported to estuaries from land-use activities,
sewage disposal, industry, agricultural wastes, urban runoff and mining. Increased nutrients cause
algal blooms, which lead to more subtle estuarine ecological problems.
Many processes affect nutrient concentrations during transportation and after they reach the
estuary. Absorption, dilution, coagulation, and sedimentation decrease nutrient concentrations
in estuarine waters. Since an equilibrium is established between water and sediment, nutrients
are also released to (he water from sediment storages. Biological activities influence nutrient
cycling and concentration.
Several control mechanisms are discussed. The potentially most successful and least harmful means
of controlling null lent inputs to estuaries is to control them at their source. After nutrients reach
estuaries, there is little possibility for effective reduction in nutrient concentrations.
Suggestions for research to develop new and more effective means to control nutrient inputs to
estuaries are made These include denitrificalion, land-use practices, natural filters, treatment
innovations, and new ways to assess ecosystem response. Finally, management mechanisms are
.suggested to influence nutrient inputs and to minimize effects.
INTRODUCTION
The Problem
In all aquatic systems, nutrients are important
raw materials supporting a basic biological activity,
prirnan- production. Estuaries, being open-ended
and subject to tidal flushing, are highly dependent
upon a continuous import of nutrients to maintain
their productivity. Under circumstances of an over-
supply of nutrients, however, the normal rate of
primary productivity is altered and changes in
structure and function of the ecosystem result.
The most obvious symptom, of increased nutrient
input is the often-cited bloom of certain types of
algae. This is usually manifested by the, rapid
growth of the few species capable of rapid utilization
of the incoming nutrients. The result is the com-
petitive exclusion of many species present under
more normal conditions. When these imbalances in
the primary producers occur, entire food chains
may also be altered and the secondary production
prized by man may decrease.
Algal blooms may also lead to more subtle
changes in the ecosystem. Decomposition of the
dying and sinking bloom organisms results in low
oxygen conditions, especially in areas of slow
flushing, which lead to fish kills and destruction of
benthic populations. Some algae prominent in
blooms (e.g., some blue green algae) are little
utilized by consumer organisms; these may also clog
gills of animals. Shading occurs in bloom conditions
and the photosynthetic activity of bottom plants
is affected (e.g., several instances have been reported
of grass flats being replaced by phytoplankton in
cases of high nutrient input).
Estuarine waters are a mixture' of sea and fresh
water. As seawater contains large amounts of a
mixture of salts, most of the salts necessary for
plant growth, such as potassium and sodium, will
be plentiful. Also, there will be no lack of the trace
elements, such as molybdenum or cobalt, thai often
limit photosynthesis in oligotrophic lakes (Goldman,
1972). Two nutrients that are low in concentration
in both sea and fresh water, nitrogen and phosphorus,
have been shown to control productivity in estu-
aries. Consequently, we will consider only phos-
phorus and nitrogen in the following pages.
Objectives
1) To identify the sources and characteristics of
nutrients entering the estuaries of the U.S.;
257
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ESTTJARINE POLLUTION CONTROL
2) To characterize the transport mechanisms for
nutrients entering estuaries;
3) To summarize the impact and fate of nutrients
in the estuarine ecosystem, both physical and
biological;
4) To identify control mechanisms and evaluate
them in terms of estuarine management; and
5) To recommend future programs of control and
management.
SOURCES OF NUTRIENTS
Estuaries receive nutrients in both dissolved and
particulate forms. Almost all of these nutrients enter
the estuary in streams and rivers; a small amount
also comes from precipitation and from the ocean.
These relative proportions will be different in dif-
ferent reaches of an estuary so that at the mouth,
for instance, most of the nutrients may have come
from seawater (a large volume offsets the small
concentrations). In this dependence on outside
sources of nutrients, estuaries resemble lakes and
rivers. All these systems contrast with forests or
crop lands where some nutrients are constantly
supplied from breakdown of the parent rocks and
from the soils.
In forests and grasslands undisturbed by man,
the soils and vegetation combine to conserve the
nutrients in the watershed and allow only small
amounts to leave in the streams. One example of
this comes from a New Hampshire forest where more
nitrogen and phosphorous entered the watershed in
the rainfall than left by streams (Table 1, Table 2).
Hobbie and Likens (1973) mentioned that while
only 21 g P/ha loft the watershed, some 1900 g P/ha
were contained in the annual leaf-fall alone.
(from Deevey 1972, Table 2)
Average all undisturbed
Weighted av. cone watersheds 1963/1969
1963/1969 (kgha-iyr1)
; Input
Ca;+ j 0.21 2.6
Mg!+ J 0.06 0.7
Na+ _| 0.12 1.5
K+.- : Q.09 1.1
CI-._ - -- 0 42 5.2
Sof J 3 1 38.3
NHr ' 0.22 2.7
NO*" 1 1.31 16.3
SiOj. - -, <0.l ! *"
AI3+ — **
HCOj- 0 **
Output
11.8
2.9
6.9
1.7
4.9
48.6
0.4
8.7
35.1
1.8
14.6
Table 2.—Input of phosphorus in precipitation and output in streams from
watersheds 2 (deforested) and 6 from 1 June 1968 to May 31,1969(in g P ha iyr~').
The output is given as the sum of the total dissolved phosphorus (TOP) plus fine
particulate phosphorus (FPP) and as large particulate phosphorus (LPP) which
is the sum of the phosphorus in inorganic particles plus that in organic parti-
cles > 1 mm (from Hobbie and Likens, 1973, Table 3)
W-6
Input
Output
TDP + FPP__
LPP..
Net gam or loss.
* Sample data from Likens et al. (1971).
** Not measured but very small.
* Estimated on the basis of precipitation analyses during 1971-1972, when the
weighted concentration was 8 ug P liter*1.
When the forests are cut, then the nutrient loss
increases. For phosphorus, this loss doubled for the
dissolved P in Hubbard Brook but increased fifteen-
fold for the P in particulate matter (Table 2). The
nitrogen also increased drastically (36-fold) in
Hubbard Brook after the forest was cut (Borman
et al. 1974), mostly as dissolved nitrate. It is true
of soils in general thai, phosphorus is strongly
attached to soil particles and is lost from soils
mainly by erosion of the particles themselves. In
contrast, nitrate nitrogen is soluble in the soil water
and is lost by percolation.
Much of the nutrients entering the freshwater
streams and rivers of the U.S. come from sewage
and agricultural wastes. The nutrients in sewage
arise from human wastes, detergents, street runoff,
and industrial wastes. There are a number of
detailed studies of the amounts contributed by
each source; an idea of the magnitude of the prob-
lem may be gained from the summary of Vollen-
weider (1968) for average conditions in central
Europe (Table 3) and from Jaworski, Lear and
Villa (1972) for the Potomac estuary (Table 4).
The actual concentrations of nutrients in a given
river will vary according to such factors as volume
of flow, number of cities, amount of forest, and type
of agriculture. High concentrations of nutrients are
added by point sources, such as domestic sewage
and industrial wastes (domestic sewage contains 1
to 4 g P/person/day and 5 to 15 g N (Vollemveider,
1968)). The concentrations of nutrients from non-
point sources, such as farms and forests, is low but
the total amount added will often equal or exceed
that from point sources (Table1 3). Thus, Vollen-
weider states that a lightly fertilized pine forest may
receive 2 kg P/ha and 26 kg N/ha each year while
heavily fertilized farmland may receive 37 kg P and
340 kg N. Between 10 and 25 percent of the nitrogen
and 1 and 5 percent of the phosphorus will enter
the streams from this fertilized land.
-------
NrTRIENTS
259
Table 3-Amounts of nitrogen and phosphorus (kg/ha/yr) in runoff from an
average area (from Vollenweider 1968). The range for farmlands and meadows
and grassland reflects differing amounts of fertilizer reaching the streams
Sources
kg/ha/yr
Sewage
Human wastes—
Detergents..
Street runoff
Industrial wastes..
6.6
Agricultural and Forest Runoff
Arable land
Meadows and grasslands
Forests
Total.
2
4
8
16
0.7
0.7
8.0
3- 5 8
3-13.3
1.0
6-20.1
6-28.1
0.8
0.4
0 1
0.1
1.4
0.1-0.5
0.1-0.5
0.1
0.3-1.1
1 7-2.5
Table 4.—Summary of nutrient sources, upper and middle reaches of the
Potomac estuary (from Jaworski et al. 1972, Table 3)
Low-flow conditions !
(Potomac River discharge all
Washington, D.C. = 33.98]
Carbon
Nitrogen
Phosphorus
Median-flow conditions
(Potomac River discharge at
Washington, D.C. = 184.06
Carbon
Nitrogen
Phosphorus
* Of the 72,600 kg day'1, 27,200 kg day-' are discharged as inorganic carbon.
** The potential COi obtainable from the atmosphere was determined by using only
0.1% of the transfer rate of 0.8 mg cm-2 min~l as indicated by Riley and Skirrow (1965).
*** Based on a nitrogen fixation rate of five Ib acre"1 yr1 as reported by Hutchmson
(1957).
Seawatcr is also a source of nutrients in estuaries.
It is usually considered that the reverse is true, and
little thought is given to input from the ocean. As
will be discussed later, however, a number of
processes in estuaries will concentrate nutrients from
water so even the nutrient-poor ocean water may
lose some P and N to estuaries. In one estuary in
Scotland, the Ythan, 70 percent of the P and 30
percent of the X that flow into the estuary were
marine in origin (Leach, 1971) but the distribution
of the P and N retained was not measured.
TRANSPORT OF NUTRIENTS
After the nutrients enter streams and rivers, some
fraction may be changed by various processes before
they finally reach the estuary. One process is the
absorption by plants and bacteria; another is the
absorption by sediments. The total quantity ab-
sorbed is difficult to quantify and it is also possible
that some of the absorbed material eventually
reaches the estuary (e g., by washout during excep-
tionally high discharge). In the Upper Potomac
Basin "(Jaworski, Villa and Hetling, 1969), 38
percent of the phosphorus entering the surface
waters is retained in the channel. The high nutrients
in the water and the rich sediments will cause a
dramatic increase in the aquatic plants (Fig. 1).
Another factor causing loss of nutrients in streams
is adsorption onto participate matter. Jaworski
et al., (1972) states that more than 20 percent of the
reduction of phosphates measured during peak
flows could be attributed to adsorption followed by
sedimentation of the particulate.
Nitrogen in land runoff enters the rivers and
streams mostly as nitrates; however, the nitrogen
from wastewater enters mostly as ammonia. This
nitrogen is taken up by algae and other plants, is
deposited on the bottom (as organic nitrogen after
death of algae and plants), and is oxidized to nitrite
and nitrate by nitrifying bacteria. In the Potomac
200-
^ 180-
O
_l
= 160-
I
5 140-
o
Q 120-
100-
o DOLLARS
x CUBIC YARDS
-450
m
o
o
ro
r400
o
350 U)
-300 S
O
-250 g
64 65 66 67 68 69 70 71 72 73 74
FISCAL YEAR
FIGURE 1.—Phosphorus, nitrogen, and organic carbon in the
upper Potomac River from 1913-1970. The top line gives
plant nuisances (from Jaworski, Lear, and Villa, 1972,
Fig. 7).
-------
260
ESTUAHINE POLLUTION CONTROL
FLOW 79 29 l
TEMP=27 5' C
NO---NO, (OBSERVtD)
SALINITY INTRUSION
KILOMETERS BELOW CHAIN BRIDGE
FIGURE 2.—The average and predicted concentrations of ammonia and nitrite plus nitrate in the Potomac River on August
17-22, 1968. The brackish water begins at about 50 km (from Jaworski et al., 1072, Fig. 12).
River the nitrification is the dominant reaction and
most of the nitrogen is changed to nitrate (Fig. 2).
In some rivers that traverse coastal plains, such
as the Chowan River in Virginia and North Carolina,
the flood plain of the river is often flooded and the
swampy ground resembles a giant sponge. Tremen-
dous amounts of water flow in and out of those
swamp soils as the water level in the river rises and
falls due to flow and wind effects. The change in
water level in the soils is easily measured 1 km from
the river. The effect of this exchange of water on
the concentration of nutrients is unknown but soils
and peats do act as ion exchange columns and
there are undoubtedly many changes occurring.
PROCESSES AFFECTING
NUTRIENT CONCENTRATION
IN ESTUARIES
A number of distinct processes change the con-
centrations of nutrients in estuaries. Most of these
are acting simultaneously in most cases, but some-
times one process predominates. Thus, although the
processes are described below in isolation, we do not
mean to imply that only one process is occurring.
Physical and Chemical Processes
DILUTION
The circulation of estuaries causes a continual
inflow of seawater and continual mixing with fresh
water. If this were the predominant mechanism
changing the concentration of the nutrients, then
their concentrations would decrease in direct propor-
tion to the increase in salt concentration. (The
assumption that the ocean water has a lower con-
centration of nutrients than the fresh water is
almost always valid.)
One estuary where dilution is important is
Charlotte Harbor, on the west coast of Florida.
Here, water from the Peace River, one of three
rivers emptying into the estuary, contains 0.6 mg
P/liter. This phosphate comes from phosphate
mines and so there are no accompanying high
amounts of nitrogen. Therefore, there are no algal
blooms and the phosphate remains in the water
(Alberts et al., 1970). As seen in Figure 3, the
decrease in P concentration closely follows the ideal
dilution curve indicating that neither biological nor
chemical processes are important.
ADSORPTION AND COMPLEXING
Some of the nutrients entering estuaries are at-
tached to particulate materials in the rivers. This is
particularly true for phosphate and, to a lesser
extent, ammonium. Most of the research has been
carried out on phosphate.
When phosphorus is added to stirred suspensions
of estuarine sediment, half of the phosphorus is
adsorbed to the particulate matter within 15 seconds
or so (Pomeroy, Smith and Grant, 1965). Much of
the particulate matter is clay and silt and the
adsorption properties of clay arc well known.
Evidence exists that some of this phosphorus may
-------
NUTRIENTS
261
o.«oo-
o.soo -
O.400 -
(X O.900
g
o.
o.too -
0.100-
DEC. 1969
o.«oo-
0.300-
0.400
0.9 OO
0100
o.too-
MARCH 1970
it
to
24
28
II
I*
CO
24
20 32
FIGURE 3.—Phosphorus concentrations and salinity in Charlotte Harbor, Fla. An ideal dilution curve is given as a solid line
while actual measurements are plotted as dots (from Alberts et al, 1970).
be released or displaced by competing ions, such as
chloride or sulfate, when the particulate matter
reaches brackish water (Upchurch, Edzwald and
O'Melia, 1974).
There also appears to be a good correlation
between the amount of phosphorus and the amount
of extractable (with oxalate) iron in estuarine
sediments; this leads to the hypothesis that phos-
phorus can also be bound to particulate matter as
a part of a phosphorus-iron-solids complex (Up-
church et al., 1974).
COAGULATION AND SEDIMENTATION
When the nutrient-rich river water reaches the
upper parts of the estuary, the current slows as
the river broadens. As a result, there is a rapid
sedimentation of particulate matter and also of the
phosphorus complex mentioned above. This sedi-
ment is very phosphorus rich (Fig. 4, the sediments
above the 7 mile sample).
Some of the particulate matter is colloidal (i.e.,
small particles with a large surface area per unit
mass). Typically, these colloidal particles are clays
with an electrical charge. In fresh waters, the par-
ticles are kept from aggregating by repulsive forces,
but when the particles move into brackish water
the ions affect the particles and floes are formed.
The size and settling velocity of these floes may be
several orders of magnitude larger than those of the
individual particles (see Edzwald, Upchurch and
1.60
1.20
-0.80
0.00,
4 8 12 16 20 24 28 32
Nautical Miles Downstream from Station I
36
FIGUBE 4.—The amount of phosphorus extracted from
sediments by acid treatment (available phosphorus) as a
function of distance downstream from the freshwater end of
the Pamlico River Estuary (from Upchurch et al., 1974,
Fig. 2).
-------
262
ESTUAKINE POLLUTION CONTROL
O'Melia (1974) for a detailed description). In the,
Pamlico Estuary (Fig. 4), the decrease in P in Hie
downstream sediments is possibly caused by coagula-
tion and release of some of the phosphorus when the
salinity of the water increased.
Although coagulation undoubtedly occurs in estu-
aries, it is a process that is easy to demonstrate in
the laboratory and difficult to study in the field. In
natural waters, organic colloids are present in addi-
tion to the clay colloids as well as some mixtures of
the two. In addition, the adsorption sites on the
clays in nature, may be filled \\ith a variety of ions
both organic and inorganic. Thus, Button (1969)
found that natural particulate material did not
absorb small molecular weight organic compounds.
Finally, other processes may be acting that obscure
the coagulation effects. In the study shown in
Figure 4, for example, large populations of clams
are present in the upper parts of the river that may
be just as effective in removii g the particulate
matter from suspension as the coagulation process.
No matter what the exact mechanism may be, the.
amount of nutrients deposited in the sediments of
an estuary is high. For example, in upper Chesa-
peake Bay, Carpenter, Prichard and VVhaley (1969)
measured a loss of some 45 ug-at of nitrate nitrogen/
liter (610 ug NOs-N) during the late spring and
summer or 4,50 mg-at/m2 at the mean water depth
of 10 m. They calculated that the annual sedimenta-
tion rate of 1 mm per year would add 500 mg-at/m2
of nitrogen to the sediments. Thus, the loss of
nitrogen was accounted for by the sedimentation
(the authors regard the close agreement as fortui-
tous, however, as the sedimentation rate cannot be
determined very precisely).
EQUILIBRIUM BETWEEN
SEDIMENTS AND WATER
Not only do particulate matter and estuarine
sediments remove phosphorus from solution, but
they also release phosphorus back to the water.
Thus, Pomeroy et al., (1965) showed that surface
sediments acted as a giant buffer or reservoir for
phosphates (Table 5). When the phosphorus in the
water was less than about 0.9 ug-at/liter (28 ug
P/liter), then phosphorus was released from the
sediments to the water. Higher concentrations were
absorbed by the sediments. Thus, these particular
sediments were in equilibrium with water containing
0.7 to 0.9 ug-at P/liter.
This equilibrium level is somewhat higher than
other values for fresh water but this will depend
upon the type of sediments, previous history. pH,
et cetera. It should be noted that recent studies bv
Table 5.—Influence of suspended sediments on estuarine water of varying
phosphate content. Final phosphate values are mean ± one standard error of
the mean. Phosphate in ,urtioles liter, 5 March 1964 (from Pomeroy et al. 1965,
Table 1)
Initial P0f~ Final F0t>- P0i3~ in sediment
of water of
0 j 0 72
vater (wg PCV ,g
dry sediment)
-4- n rw i
0.5 ] 0 73 -4- n m . n
1.0 0 9C
2.5 ] 0 8S
4 3. ._. i 0.87
8.4_ .._ ._ 1.61
± 0 07 +0
± 0 05 +7
± 0.002 +11
± 0.22 +30
I
0
4
6
6
0
9
Lean (1973) and others show that the exchange of
phosphorus between the soluble and particulate
forms is really quite complex. Low-molecular
weight phosphorus compounds and colloidal phos-
phorus may be involved as well as the particulate
and dissolved inorganic fractions.
While it is likely that many of the same reactions
and processes are occurring with nitrogen com-
pounds, these interactions of nitrogen and sediment
have never been investigated in detail. One reason
for this is the great difficulty in techniques; there is,
for example, no radioisotope of nitrogen and Use of
the stable isotope 15N requires elaborate instru-
mentation and a mass spectrometer. Another reason
is that phosphorus is much more1 important in the
eutrophicatioti of fresh waters and much of the
research has centered on lakes.
THE ESTUA.IUNE NUTRIEIST TRAP
There is always some upstream movement of
seawater or diluted scawater in estuaries; otherwise
there could be no salty water in the upstream areas.
In certain estuaries with a high freshwater runoff,
a shear zone is maintained for long periods with
frc'sh water or low salinity water on top moving
downstream and more saline water on the bottom
moving upstream. If nutrients are moving vertically
from the top to the bottom layers, by sinking or
migration of the organisms, then the bottom waters
will be enriched with nutrients that otherwise would
be lost from the estuary. Also, the bottom waters
will be enriched because of decomposition of organic
particulate matter in the surface sediments. The
theory of this nutrient trap is given in detail by
Redfield, Ketchum and Richards (1963").
A good example of this countercirculatioii comes
from the Gulf of Venezuela (Fig. 5). The seawater,
containing about O.o ug-at P/liter, moves into the
shallow waters of the gulf. As it does so, it accumu-
lates phosphorus (up to 1.0 ug-at P/liter). An
-------
NUTRIENTS
263
o
20
40
60
0
20
40
60
PHOSPHORUS
OXYGEN
FICJURK 5.—The distribution of total phosphorus and oxygen
in a section along the axis of the Gulf of Venezuela (the depth
is in meters). From Redfield et al., 1963, Fig. 11
example of this type of circulation producing a
sediment trap comes from upper Chesapeake Bay
(Schubel, 1968). Sediments were kept in suspension
in this part of the bay by tidal currents that mix
the water column twice each tidal cycle and also
transport the turbid matter upstream in the bottom
waters.
Although the nutrient trap certainly exists in
estuaries, its importance for the annual nutrient
budget has not yet been proven. Thus, in Long
Island Sound, Riley and Conover (1956) and Harris
(1959) measured accumulations of phosphorus and
nitrogen in the summer but also found comparable
losses during the winter. In estuaries at Sapelo
Island, Ga., Pomeroy et al., (1972) found no nutrient
trap operating.
Biological Processes
BlODEPOSITION
A number of biological processes are also removing
particulate matter and its associated nutrients from
solution. This block-position may even be more im-
portant than the physical-chemical processes already
discussed. Van Straatan and Kuenen (1958) found
that dense populations of molluscs filtered clay
from the water and produced pellets and flakes
which then behaved like sand grains. Organic
detritus also trapped clay particles and the resulting
floes settled faster than those formed by coagula-
tion. In a more quantitative study, Lund (1957)
calculated that oysters filtered and deposited eight
times the volume of sediment deposited by gravity
alone. In fact, the deposited material was enough to
completely cover the oysters in 36 days.
From tables given in Chestnut (1974), the bio-
deposition rate of the oyster is around 1.5 g dry
wt/individual/week. If the amount of suspended
solids is 5 mg/liter, this represents a minimum of
300 liters of water filtered per week. Jorgenson
(1952) gives a rate of 10 to 15 liters per day per
animal which would be a slower rate than the 300
liter value. Certainly, a tremendous amount of
water is processed by an oyster bed; when this
oyster filtering is added to the activity of other
filter feeders, it is enough filtering activity to process
the whole of the volume of an estuary in a matter
of days or a few weeks.
The large rooted plants of estuaries also act as
traps for the sediments, both by catching fine sedi-
ments (Van Straatan and Kuenen, 1958) and by
providing protection (e.g., mangroves) so that the
sedimentation rate is increased in the calm water.
Various invertebrates and even diatom algae also
secrete mucus or slimes that trap sediments.
The net result is that estuaries in general and
marshes in particular act as giant filters to remove
participate materials from the w ater. The vegetation
of the marshes also stabilizes the sediment arid thus
reduces the turbidity (Odum, 1970). The importance
of these processes is illustrated by the rapid siltation
that took place in many harbors in southeastern
England when the marshes were first diked and
filled (Gosslink, Odum, and Pope, 1974). In the U.S.,
Port Tobacco on the Potomac is now landlocked
but received large sailing vessels during colonial
times (D. Flemer, personal communication).
UPTAKE BY ORGANISMS
There are four main types of photosynthetie
organisms in estuaries, rooted plants, attached
algae, phytoplankton algae and sediment algae. The
most obvious plants are the marsh grasses and rushes
(e.g., Spartina and Juncus}. These plants take up
nutrients only from the sediments (Broome, 1973)
so are not in active competition with other primary
producers for nutrients. As noted, their presence
creates conditions favoring sedimentation and bio-
deposition (e.g., the mussels in salt marshes). These
plants also tie up a tremendous quantity of nutrients.
For example, the annual production of organic
matter in a Georgia Spartina marsh is 1600 g/m2
(Cooper, 1974). Assuming that 44 percent of this is
C and a C:N:P ratio of 125:2:0.3 for Spartina
(Thayer, 1974) gives 11.3 g N and 1.7 g P/m2. Even
more is tied up in roots and rhizomes.
In some areas, submerged eelgrass (Zostera) is an
important primary producer. Williams (1973) esti-
mates that eelgrass may supply as much as 64
percent of the total production of phytoplankton,
-------
264
ESTUARINE POLLUTION CONTROL
Spartina, and eelgrass in the shallow estuaries near
Beaufort, N.C. This may be 350 g C/m2/yr and
other plants in the eelgrass beds (Hdodule and
Ectocarpus) may produce another 300 g C.
Attached algae are not important generally in
estuaries because the soft substratum and the tidal
flooding of the marshes do not offer a suitable
habitat. Permanently submerged plants, on the
other hand, accumulate a thick layer of attached
algae (reds and browns) as they grow. Measure-
ments of the primary productivity of these algae
show a photosynthesis rate equal to that of the
Zostera (P. Penhale, personal communication).
Microscopic algae also live in the upper layers of
the mud. When these are extensive mud flats, such
as in the Georgia salt marshes, the primary produc-
tion may be as high as 420 g C/m2/yr (see summary
by Cooper, 1974).
Phytoplankton algae are not abundant in many
estuaries (Table (>) because of rapid flushing and
high turbidity. Yet, they may be the most important
food for zooplankton and invertebrate larvae (Odum,
1970). In very large estuaries, such as Chesapeake
Bay, there is adequate time for the algae to develop
and primary production may reach several hundred
g C/m2/yr '(Flemer, 1970). '
The well-known efficiency of algae in taking up
nutrients from even very nutrient-poor waters, means
that they will be an agent for removing nutrients
from the water of the estuary. This can come from
death and sinking to the sediments, from the filtering
action of benthic worms and molluscs, from being
eaten and carried away by migrating fish, or from
washout from the estuary when strong tides are
present.
Green plants are not the only organisms removing
nutrients as bacteria are also important. The only
quantification of this comes from the work of Thayer
(1974) who pointed out that the Spartina has low
amounts of N and P relative to the C (see ratio
above) while bacteria need a C:N:P ratio of
200:10:1 for their growth. Thus, bacteria decompos-
ing the Spartina must get the additional N and P
they need from the surrounding water. Thayer
Table 6.—Organic carbon production (g C mv year) In salt marshes and adjacent
estuaries at Sapelo Island, Ga., and near Beaufort, N.C. (from Cooper, 1974;
Williams, 1973)
Submerged plants
Attached micro algae
Mud algae.
Phytoplankton
Georgia salt
marsh
700
420
Beaufort shallow
estuary
256
650
350
66
(1974) also showed that the bacteria out-competed
the algae for these nutrients and suggested that the
bacterial immobilization of nutrients might be a
major cause of the extremely low levels of nutrients
found near Beaufort, N.C.
NUTRIENT CYCLING
Once nutrients reach the estuary and either are
transported to the sediments or are taken up by the
biota, they can cycle through various compartments
before being locked into the sediments or flushed
out of the estuary. For example, Spartina is tall
near the creek banks where fresh sediments are
continually deposited but short farther from the
creek. Broome (1973) traced this effect to deficien-
cies of N in the sediments away from the creeks.
Once the nutrients are taken up into the plant, part
is used for growth, part is excreted or otherwise
lost from the plants, and part is eventually released
during decomposition. Some of the complex of
reactions occurring in a Zostera bed are given in
Figure 6 where 166 mg P/m2/day arc absorbed
from the sediments and 62 mg P excreted into the
water.
SEAWATER
(25pg P/hter)
SEAWATER
<25>ig P/liter)
t
1
5.41
8.61
LEAVES
-1.48— -
68.71
8.6!
6.89
1.39
-•—7.22-
LEAVES
\- 18.80— -
-•—0.66-1
ROOTS a
RHIZOMES
-1.31 —
87.50
1.39
"• — 0 66-
ROOTS
1 a RHIZOMES
[-16.64 — •-
8.20
0.74
INTERSTITIAL'
WATER
(25jug P/liter)
104.14
0.74
(
1
INTERSTITIAL*
WATER
2000>ig P/liter)
FIGURE 6.—Calculated daily phosphorus flux through 1 g dry
wt. of eelgrass. Left: uniform dissolved reactive phosphorus
concentration in water. Right: phosphate gradient similar to
the natural environment. Units are ug P/g plant-day (from
McRoy et al., 1972, Fig. 7).
-------
XuTRlENTS
265
WATER
PARTICULATE 14,000
PHOSPHATE 19,000
DISSOLVED ORGANIC 6,000
39,000
PARTICULATE 5,410 \] MAninillC IX
PHOSPHATE 70 „„;>=- MODIOLUS r^
— ™°"4~~ POPULATION " K
~^> I BOD1 25,000 \Z/
s SHELL 11,000 ]
PSEUDOFECES4700 / LIOUOR 1,200 ' l^
^xt • . 37.2o° r^
MORTALITY 21
GAMETES 11
DISSOLVED ORGANIC 23
PHOSPHATE 260
FECES 460
liteSlJSSj^^ , -^ -i? M\Jp y-;:*;:; > $--?;&"S5S|^^^-sCJ
Table 7.—Some contributions to the net increase or decrease of inorganc
nitrogen that occurred within the Pamlico River Estuary
Increase
(metric tons N day
FIGLRI-; /.— Diagram of phosphorus flow through the mussel
population. Values for the water and the mussel population
are ug P/rn2 day. The flux rates of phosphorus in food and
pseudofeces are calculated values necessary to balance the
other, measured flux rates.
Algae and bacteria also excrete phosphorus
(Kuenzler, 1971). The phosphorus budget for a salt
marsh mussel (Kuenzler, 1961) illustrates that the
large amount of P cycling through the animals is
about equal to the quantities moving into the plants
(Fig. 7).
Nitrogen also cycles in the estuary. The general
pattern is for nitrate to enter the estuary (see Fig. 2)
and be rapidly removed from solution. Ammonia is
continually being formed (by decomposition proc-
esses and XO.s reduction) and taken up so its con-
centration does not change very much. Organic
nitrogen excretion and decomposition products are
also continually cycled through the sediments and
water. In the Pamlico River Kstuary, for example,
Harrison (1974) found that urea was recycled every
1.4 da\s in th^ summer and every 200 days during
the winter His budget for X in this estuary (Table
7) indicates that during a winter month the X
assimilated during photosynthesis was balanced by
the X (mostly XO-]) left in the estuary as the water
flowed through (here, this is given as a net increase
of 6.91 tons,!. The budget is badly out of balance
during the summer, however, and it is likely that
ammonia recycling in the 'water column and coming
from the sediment made up the discrepancy of
227..1 tons/day. Similar recycling in the upper
waters was measured by Carpenter et al., (1969) in
Chesapeake Bay. Thus, the observed photosynthesis
rate would result in a recycling of XT and P every 1
to 4 days. Because of the large number of zoo-
plankton present, they thought that the algae were
being controlled by grazing.
It is reasonable that marshes are nutrient sinks
as they usually accumulate organic matter which, in
turn, contains nutrients. The actual evidence for
this is divided, however. Byron (personal commu-
February 1972 net increase of 6.91
metric tons N (day~')a
1. Sediment release—0.52
2. Rainfall —0.11
0.63
August 1972. net increase of 0.10
metric tons N (day"')"
1. Sediment release—3.43
2. Rainfall —0.71
4.14
Decrease
(metric tons N day~!)
1. N assimilation—6.68
6.68
1. N assimilation—231.65
231.65
" Calculated from inputs minus output.
nicatlon) found a 40 percent reduction in nitrogen
leaving a salt marsh compared with the amount
entering on the flood. In contrast, Heinle et al.,
(1974) found that the net annual flow of X, P and
C was from the marsh to the estuary while the
chlorophyll pattern was the reverse. Marshall (1970)
reported that marshes treated with sewage retained
large quantities of X and P.
Finally, nitrogen may be lost from the estuaries,
and particularly from the marshes, by denitrifica-
tion. This is an anaerobic bacterial process that
requires NOs and energy in the form of organic
molecules. Both denitrification, and the opposite
process, nitrogen fixation, are occurring in estuaries
but their importance, judging from only a little
data, is likely small.
Estuarine Responses to
Nutrient Additions
In a review of the literature 021 estuaries that
receive sewage wastes, Weiss and Wilkcs (1974)
concluded that hydrographic conditions, particularly
the rate of flushing, was the most important factor
determining the response of the ecosystem. An
estuary with rapid flushing can handle tremendous
amounts of added nutrients as long as they are
quickly transported away and quickly diluted with
low nutrient ocean water.
MORICHES BAY AND
GREAT SOUTH BAY, LONG ISLAND, X. Y.
The first example, from Ryther (1954) and Ryther
and Dunstan (1971), describes two connected em-
bayments, Moriches Bay and Great South Bay.
Duck farms around Moriches Bay formerly fed
-------
266
ESTUARINE POLLUTION CONTUOL
. 2 t
c E
,
Ptiyttp^nkton t
Inorginic photphorut
. 6n»t South til
a
7 =
II 30 15 14 ;
Station number
.). Morchni fly
ock tor
FIGURE 8.—The distribution of phytoplankton and inorganic
phosphorus in Great South Buy, Moriches Bay, and Shin-
necock Bay, Long Island, in the summer of 1952. Station
numbers on the map (above) correspond to station numbers
on the abscissa of the figure (right) (from Ryther and Dunstan,
1971, Fig. 1).
wastes into the bay. These nutrients reached Great
South Bay which has a retention time of one month.
This bay formerly had good stocks of fish and
shellfish but the fishery began 1o decline in the
earl}' 1940's as the duck population increased. At the
peak of the algal blooms, their numbers declined
on either side of the Moriches Buy peak (Fig. 8).
Laboratory and field tests showed that the algae
were actually limited by the low nitrogen which
was used up almost as soon as it entered the estuary.
The damage to the oysters came from a shift of
phytoplankton from a mixed group of species
dominated by diatoms to two small forms, Xanno-
chloris and Stichococcus. Although oysters will eat
these forms, these algae are nutritionally inadequate.
Another factor adversely affecting the oysters was
the large production of Serpulid worms which were
able to overrun the oyster beds and competitively
exclude the oysters.
PAMLICO RIVER ESTUARY, N. C.
A second example conies from the Pamlico River
Estuary in North Carolina (Hobbie, 1974). The
cities on the Tar River, the main influence, are
relatively small but a great deal of nutrients enter
the Tar from agricultural runoff, presumably from
heavily fertilized tobacco, potato, corn, and soy-
bean fields. The total phosphorus entering the
estuary ranges from 2.4 to (i.3 ug-at P/liter (74 to
195 ug P/iiter) while the reactive P ranges from
0.4 to 4.1 ug-at 1'/liter (12.4 to 127 ug P/liter).
There is always adequate phosphorus? in the estuary
and also enough ammonia. There are tremendous
blooms of dinonagellates (esp. Peri/linium tri-
quctruin] in the middle reaches of the estuary
(Fig. 9) in the winter months (January until
April) whose occurrence is apparently triggered by
the winter influx of nitrate nitrogen into the estuary
(Fig. 10). It should be noted that any chlorophyll
concentration above 1-5 is an algal bloom.
CHLOROPHYLL A (UG/UTER)
ASONDJ I-MAMJJA
FIGIRI: 9.—Chorophyll a (ug/liter) in the Pamlico River
Estuary for 1970-7]. Distance i-< in km from Washington,
N.C. (from Hobbie, 1974, Fig. f>5).
NITRATE (UG-AT/LITEFO
FIGURE 10.—Nitrate (ug-at N'liter) in the Pamlico River
Estuary for 1970-71 (from Hobbie, 1974, Fig. 38).
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XlTTIUENTS
267
The ecological effect of these blooms is slight so
far. The estuary still harbors a commercial blue
crab and shrimp industry and the benthic biota is
diverse. The one well-documented result of the rich
conditions is that areas of low oxygen bottom water
do develop now and then during calm periods of the
summer. These only last for a few weeks but do kill
all the bottom fauna in the central part of the
estuary each year (Tenore, 1072). Another minor
effect is the apparent increase in filamentous algae.
In ^urnmary, this eMuary has reached a high level
ol production but the .species arc unchanged. The
only effect is an indirect one b\- way of the sediment
and their increased oxygen uptake during periods
of low flow and calm condition-..
CONCLUDING STATEMENT
In these1 two examples it may be seen that the
flushing of the estuan plays a central role in
allowing the effects of high levels of added nutrients
to be expressed In both cases, the nutrient levels
were greatly above the levels that would have
ruined am lake. I'Yom these1 findings, and from the
experiments that successfully added se'\\age to salt
marshes with little detrimental effect^ we conclude
that estuaries can handle large quantities of nu-
trients. They do this by removing mo^ of the
nutrients to the sediments (by .sedimentation,
coagulation, biodeposition, et cvtera) where1 they
serve to enrich salt marshes. In adelition, three
characteristics of estuaries (rapid flushing, elilutioii
with low nutrient seawatcr, nnd (juite a lot of tur-
bidity i help unvenf dense algal blooms from de-
veloping.
When the1 capacity of estuaries to handle nutrients
is exceeded, algal blooms can result that seriously
degrade- the wate'r qu'ilitv. .Moriches H;jy bus been
mention* el and Hack lliver, a tributary of Chesa-
peake Hay thai receiver Baltirne>re's selvage, is
another example (Carpenter. I'ritchardand Whalev.
llMi','.. Where conditions are -uitable, rooted plants
iiia1' also reach nuisance amounts as \\a^ seen for
the water chestnut in (lie i'Jl'O's and the water
milfoil in J!)."j\ V'tl- ii, Chesapeake Hay i Jaworski
et 'd., 1072)
As noted, nutrients by themselves can adversely
affert e>tuai!es by supporting ;ilg;d bloom< and the
eien..-. iietiutii.n th'i' em accompany e'uti'opbicatiem.
l'i "h'l;/,-, '"*! ipore importance' .ire the < rganie matter,
heavy metals, and pesticides that often enter estu-
aries along with the nutrient*.
CONTROL MECHANISMS
Control at the Source
The potentially me>st successful and least harmful
means of cemtre>l of nutrient inputs to estuaries is
to control the nutrients at the:ir sources. Obviously,
semie semrces e>f nutrients are more easily identified
than others. Technology is available to institute
control mechanisms for nu>st point sources, but in
some cases the costs are1 beyemd social desires. In
case's of non-point sources of nutrient pollution the1
technology for control has not beceme feasible. In
these1 situations, effective nutrient control is pos-
sible through change-s in land use, cultural practices,
environme'iital manipulations, ecememiics, and other
management schemes.
SEWAGE TREATMENT
Since nitrogen and phosphorus concentrations in
domestic sewage1 are; rather high, sewage effluent
constitutes an important source1 of nutrient materials
(Table 3). Recent developments in technology,
however, have made it ecexnornically possible to
control the- nutrient emissions from sewage treat-
ment plants. In most instances, however, these
technologies have' not been utilized and large nu-
trient inputs are1 still e>ccurring via selvage treatment
plants.
Through the1 utilization of treatment technole>gy
and the1 enforcement of regulations, nutrient inputs
from sewage1 treatment facilities can be controlled.
Indiscriminate, blanket regulatienis, however, can be1
unnecessarily expensive1 when cemple'te1 control is not
needed. Thus, nutrient, control at the sewage1 plant
shemlel be eleme on a case by case basis anel be
dictated by the1 location of the1 treatment facilities
anel the nature1 of receiving waters. For example1,
ve'ry high elegrees ejf treatment and stringent regula-
tions may be necessary in very sensitive1 and eleli-
cate'h balanced, protected systems. In contrast, less
stringent treatment regulations are required in large1,
open, rapidly-flusheel systems or in areas .such as
marshes wlwre1 theTe are already storages of organic
matte r anel nutrients.
FERTILIZATION AND AGRICULTURAL PRACTICES
About erne-third to one-half e>f the food and fiber
proeluction in the1 U.S. is attributed to the use of
fertilize1^ in agricultural practices. Thus, the ap-
plication eif fertilizer to farmland is a necessity if
we are to maintain the level of food production at
present levels. Studies have shown, however, that
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268
ESTUARINE POLLUTION CONTROL
10 to 25 percent of the nitrogen fertilizer applied to
cultivated crops leaves the field in drainage water.
Thus, crop fertilization is a source of nutrients
capable of flowing into estuaries. Heavy applications
of fertilizers are applied to cultivated crop? par-
ticularly in the coastal plains of the Gulf of Mexico
and southeastern Atlantic areas.
Since the rate of food and fiber production in the
U.S. must be maintained, application of less fertilizer
is not likely in the near future. Possibilities of control
at this source of nutrient inputs lie in the areas of
agricultural practices and technological break-
throughs. One possibility is the utilization of cover
crops during the non-cropping seasons to help hold
the fertilizer in the soil layers. Other possibilities
include timing and rates of fertilizer applications,
repeated small applications and development of new
crops. Of high potential for control of nutrient
transport is the control of \vater drainage from
fields by catchment basins, with re-percolation back
into the fields between plowings. The very remit
development of chemicals to control nitrifying
bacteria, to prevent conversion of ammonia to
nitrate, offers great hope for reducing nitrogen loss
from fields. These chemicals help maintain the
nitrogen in the form of ammonia (which has much
greater potential for remaining in the soil than
nitrate), and therefore allow reduced application
rates of nitrogen fertilizer.
Animal production techniques are changing from
small producers with several types of animals on
pastures to intense production of one species in
feedlots. Confinement has allowed increased and
more economical production, but has also resulted
in point sources of nutrient materials to surface
waters. Although, because of convenience and
economics, these materials are disposed of in liquid
systems, land disposal is considered to be another
feasible method of terminal disposal. In either situa-
tion, however, there is the potential for nutrient
percolation to ground water and surface water
runoff.
It is unlikely that conventional sewage treatment
facilities will be utilized for animal waste systems
within the near future. Therefore, the most likely
means of immediate control of this nutrient source
is in disposal practices. Some feasible alternatives
include deep well injection, controlled land applica-
tion, or recycling through newly-devised feed prepa-
ration systems. This area of activity, however,
probably presents one of the more serious disposal
problems facing present day technology.
Where large metropolitan are.is are adjacent to
coastal waters the practice of the suburban dweller
"keeping up with the neighbors" and over-fertilizing
his lawn presents a real nutrient input problem.
With very little means of disposing of suburban
runoff, the ultimate fate of that water is usually
the adjacent surface waters. The main control
mechanism available at the present time is to cycle
these materials through municipal treatment plants.
INDUSTRIAL WASTE TREATMENT
Industrial wastes 7'epresent another large source'
of nutrients to surface waters and constitute another
area where treatment- technology is available for
control. Advanced industrial waste treatment tech-
nology has been developed for the control of nu-
trient materials in most industrial wastes. The
problem has been in instituting complete and proper
waste control facilities in existing industrial com-
plexes.
The runoff of nutrient materials from the surface
areas of industrial complexes presents a separate
problem in the control of nutrient sources. Mecha-
nisms need to be developed for channeling this
runoff through treatment or filtering systems to
reduce nutrient inputs and drainages
RUNOFF
One of the sources hardest to control is the runoff
of materials from watersheds. This represents a very
diffuse and highly variable source of nutrient mate-
rials but is, nevertheless, extremely important. The
main possibilities of controlling nutrients from runoff
involve watershed management.
Erosion control can prevent a large source of
nutrients entering surface waters from watersheds.
Carefully controlled forestry practices, reforestation,
protection of uncovered a;'eas, road maintenance,
controlled drainage, vegetated filter strips, and
contour plowing are management techniques cur-
rently available for erosion control.
Large areas of urbanized watersheds represent a
tremendous source of nutrients and other materials.
Catchment basins and storm drainage mechanisms
are the best possibilities for control here.
GROUND WATER
(>round water as a source of nutrients lor estu-
aries is not very well understood. Urainag*- of
nutrient materials from septic tanks into ground
water has been documented in several situations,
particularly on the Harrier Islands along iLf V S.
seashore. Shallow ground v, ater teudt, to pc.i'.'ouvte
toward the inside of Barrier Island shores, thus,
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NUTRIENTS
269
leaking into estuaries and sounds. The best means
of control under these situations is the central
collection of waste waters and channeling through
waste treatment facilities on a regional basis.
A problem that must be dealt with is the physical
manipulations that allow alterations in ground water
drainage patterns. For example, dredging deep
channels in estuarine systems may enable ground-
water percolation to bring in a new source of
materials from outside the estuarine system. Con-
siderable research must be conducted on this prob-
lem before the impact is understood or control
legislation can be enacted.
Control of Transport Mechanisms
Control of nutrient inputs through manipulation
of transport processes offers scant possibilities. There
are some subtle changes that may be enacted in
various physical processes. By and large, however,
these may have little beneficial effect on the receiving
system downstream because detrimental side effects
may be greater than any benefit from nutrient
control (e.g., reduction of vital freshwater inputs).
STREAM FLOW
Once nutrient materials reach the streams flowing
into estuaries, institutional controls offer little
benefit. Considerable evidence exists concerning
decrease in nutrient concentrations downstream
from sources due to deposition, biological cycling,
and so forth, but additional control of nutrient
inflows is not now technologically feasible.
Utilization of reservoirs on streams may offer some
control benefits. Selective release of downstream
water through reservoir dam structures can be vised
to regulate nutrient concentrations downstream.
CHANNELIZATION
The increase in channelization of natural streams
in recent years for the purposes of increased drainage
and agricultural activities has changed normal
stream flow mechanisms. Creating faster flowing
streams has minimized the natural loss of nutrients
as water meanders downstream. Channelization
also allows the \vator to move downstream rapidly,
thus avoiding the natural cleansing action by swamp
soils around those streams whew water normally
percolates (see Transport of Nutrients).
Controlled transport of nutrients can be main-
tained if channelization procedures are closely
regulated. For example, construction of low dikes
or diversions to assure normal percolation can be
beneficial. Considerable research needs to be done
on this phenomenon before control mechanisms can
be a significant factor on nutrient inputs into coastal
systems.
DENITRIFICATION
Denitrification offers the best possibilities for the
control of nitrogen during transport. Considerable
reduction of nitrogen can be achieved if conditions
are properly maintained over a time period. Holding
drainage water from agricultural lands, for example,
could be maintained so that favorable conditions
could exist for denitrification (considerable research
is underway in this area and still more needs to be
done). The use of small reservoirs and low level
dikes in some stream situations could be utilized in
denitrification. Sewage holding ponds have long
been utilized to achieve reductions in nitrogen con-
centrations in effluents. This technique has also
been used for some industrial waste.
Within the Estuary
Control mechanisms for nutrient reduction within
estuarine systems probably offer the least possi-
bilities of effective reduction in nutrient concentra-
tions. The worst problems include detrimental side
effects, high costs, and interference with normal
cycling procedures within the ecosystems. A few
innovations, however, are worth looking into on a
pilot study basis.
SELECTIVE HARVESTING
Since certain organisms (e.g., species of algae
during blooms) take up large amounts of nutrients,
selective harvesting of these species serves as a
means of removing the nutrients from the system.
This technique, however, offers little hope for
effectively removing nutrient materials from estu-
arine waters since the cost and engineering of such
harvesting systems would be large. Natural means
of doing this have been tried in several cases by
culturing species of algae-utilizing fish, Manatee
harvesting underwater grasses in Florida, culturing
species of clams and oysters, and so forth. Estuaries
are large dynamic systems, making this kind of
control mechanism very difficult. Physical means,
such as filtering algae and clipping higher plants,
are expensive and ineffective.
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270
ESTUARINE POLLUTION CONTROL
DIVERSIONS
Creating canals to divert nutrient-laden water
around estuarine systems is an unlikely means of
control because of obvious side effects. There are
several examples in the U.S. coastal area where
large regional sewage interceptors are diverting large
amounts of waste waters around estuaries for off-
shore disposal. These are expensive and, in some
cases, deprive estuaries of the much-needed fresh-
water input and its flushing action.
ZONING
Estuaries in each state might be zoned so that
some receive added nutrient input while others are
protected. This means of control, however, assumes
that decisions can be made concerning which estu-
aries receive added nutrients and which do not.
Considerable research will be required before zoning
can become a viable option.
IMPOUNDING
Construction of impoundments at the heads of
estuaries offer some possibility for selective control
of nutrient inputs into the large estuarine expanse.
Impoundments offer the advantage of trapping
water, allowing time for denitrification and deposi-
tion of phosphorus materials into the sediments,
and selected withdrawal of water from the im-
pounded area. This type of control, however, has
serious side effects in that the normal flushing
activity of freshwater inputs would be altered,
possibly leading to severe changes in the estuarine
system.
REGENERATION OF MARSHES
Marshes adjacent to estuaries art} known to select
nutrient materials from estuarine waters flushing
over the marsh areas. The marsh system, with its
grasses, algae and accumulated organic muds, acts
as a filtering system to reduce nutrient content of
the surrounding water. This, indeed, is one of the
more beneficial roles of marshes as part of the
estuarine system (i.e., maintaining the balance of
nutrients and organic materials in estuarine waters).
The technology for regeneration of marshes has
been worked out. Thus, it is possible to plant marsh
grasses and generate new marsh area around estu-
arine shores. This may serve as an important means
of controlling nutrients in estuarine waters and of
creating desirable nursery habitat as well.
RECOMMENDED FUTURE PROGRAMS
Research Needs
DENITHIFICATION
Since nitrogen seems to be a major nutrient factor
in estuarine ecosystems and it is difficult to control
at point sources, denitrification offers many op-
portunities for the reduction of nitrogen compounds
entering estuarine systems. The biological and
physical aspects of denitrification processes arc
fairly well understood, but the conditions of natural
systems necessary to control the processes are less
well known. Utilization of sewage holding ponds has
offered significant promise in aiding the denitrifica-
tion process. These techniques have been expanded
to include the waste from animal feed lots and
industrial sources. The diffuse and harder-to-identify
sources of nitrogen from agricultural practices, run-
off, and ground water are places where denitrifica-
tion processes offer considerable promise for imposing
controls.
Experiments and pilot studies need to be con-
ducted to determine natural conditions whereby
denitrification can be initiated. For example, we
need to know the length of time water running off
and through cultivated fields needs to be impounded
before denitrification is significant. Some work is
being conducted now in North Carolina, Oregon and
California on drainage water from fertilized fields.
NITRIFICATION
Since ammonia nitrogen has greater potential than
nitrate for binding with soils and remaining on the
fields, prevention of its conversion to nitrate (nitrifi-
cation) could provide considerable promise for
control of nitrogen loss. Chemical procedures to
reduce nitrification, capable of widespread and
effective use in agriculture, have been recently
developed. Still unknown, however, are application
procedures, timing of application, rates of applica-
tion, economic returns, environmental impact of
the added chemicals and cultural acceptance. If
this process can be developed and utilized there can
be tremendous reductions in nitrogen losses from
fields through both prevention of nitrate formation
and from reduction in fertilizer amounts needed to
maintain productivity.
FORESTRY TECHNIQUES
Recent work has verified that nutrient materials
in water running off deforested areas is higher than
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NUTRIENTS
271
water coming from similar forested areas. It is not
known, however, how much vegetation needs to
remain on the forest floor to hold the nutrient
materials against runoff nor is it known what
mechanisms are at work in adding the nutrients to
runoff water. For example, decaying tree stumps
on the forest land could aid in percolation of water
into the soil, thus averting nutrient escapement
from the forest lands. Well-vegetated filter strips
adjacent to surface streams might help control the
loss of nutrients from the watershed. These kinds of
research activities could lead to considerable reduc-
tion in the amount of nutrient materials washing
from the large expanses of forested areas, particularly
in the southeastern section of the U.S.
FARMING ACTIVITIES
More research is needed to determine the optimum
rates and timing of fertilizer applications to various
crops. Although it is well understood that the use
of fertilizer is necessary to maintain the production
of food and fiber at the present level in the United
States, it is possible that additional research could
reveal means of preventing fertilizer loss from these
crops. The use of certain types of cover crops during
the non-cropping season might benefit the control
of nutrient escapement. Controls of water tables,
drainage procedures and harvesting activities need
to be investigated,
The treatment and disposal of waste from animal
feed lot activities need to be researched. It is
already known that lagoons and oxidation ponds are
very helpful in the reduction of nutrient concentra-
tions and effluents, but the land disposal of these
wastes still raises problems and the necessity for
additional treatment is not known. Considerable
interest has been recently generated for the recycling
of wastes from feed lots back into the feed cycle
and utilization of valuable nutrients as growth
additives.
Research needs to be conducted on the ways and
means whereby large areas of forested land are
converted to agricultural lands by drainage and soil
conditioning. Very little is known about optimizing
the drainage patterns, density of drainage ditches,
and vegetation belts around fields to reduce nutrient
loss.
NATURAL FILTERS
The use of natural filters for decreasing nutrient
loading in estuarine systems offers some possibilities,
but research is needed before these can become a
practical reality. Although regeneration of marshes
is presently feasible, the positioning and physical
arrangements of such systems need to bo investi-
gated before much practical judgement can be made.
Utilization of attached algae and rooted plants in
incoming streams and peripheries of estuaries for
taking up nutrients might be a possibility if the
biology and harvesting problems can be worked out.
If harvesting techniques for algae could be developed,
the use of certain species could be feasible for the
removal of large amounts of nutrients from estuarine
waters.
TREATMENT INNOVATIONS
Although technology for the removal of nutrient
materials from sewage and industrial waste has been
developed, the costs and hardware needed for this
treatment level are often prohibitive. Thus, addi-
tional research needs to be conducted to find ways
to reduce these costs and to provide means whereby
siting benefits can be used.
New treatment technology needs to be developed
for handling animal waste and drainage from
agricultural areas. Deep well injection and land dis-
posal of these wastes are presently being utilized
without complete knowledge of the fate and changes
in nutrient components of the waste.
Disposal of domestic and industrial waste into
deep ocean waters is a popular remedy. Before this
becomes more widespread and waste water criteria
established, we need to know niore about what
kind of treatment is needed and the fate of these
materials in the near ocean waters. Further, various
innovations concerning the type of disposal conduits
and outlets need to be investigated and realistic
distances from shore for disposal need to be known.
ECOSYSTEM RESPONSE
In spite of the recent emphasis on the fate of
nutrients in estuarine waters, we still lack con-
siderable knowledge about the response of whole
ecosystems to nutrient additions. We can predict
certain algal blooms under certain conditions of
nutrient inputs, but we fall dismally short of predict-
ing the response of food chains and other ecosystem
components to nutrient inputs. Can we, for example,
under certain conditions of additional nutrient in-
puts expect larger fish yields in estuarine systems?
Since nutrient input controls make little sense
unless the impact on the estuarine ecosystem is
known to be detrimental, we need to develop better
knowledge and predictability of these inputs on
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272
ESTUARINE POLLUTION CONTROL
various kinds of estuarine systems. More work
needs to be done in the development of ecosystem.
modeling as it relates to nutrient flows and the use
of microcosms for testing various practical theories.
Management Mechanisms
POINT SOURCES
Although it is the aim of the Environmental
Protection Agency to eventually control inputs at
all point sources, it is necessary to initiate a manage-
ment scheme to make this a reality. These manage-
ment mechanisms may include the selection and
mixing of different kinds of materials, particularly
regulating nutrients into other selected inputs. For
example, in certain instances auxilliary input of
nutrient materials may be beneficial in establishing
additional opportunities for selected harvesting, food
production or ecosystem planning.
Some benefit may be obtained in regard to point
sources of nutrient materials by the physical place-
ment of the input mechanisms. For example, con-
trolled point source release of nutrient materials in
estuarine channels or into marsh systems may be a
viable management technique.
RUNOFF
Management means to control the nutrient inputs
from runoff involves a complicated and well devised
management plan. A factor complicating manage-
ment of watersheds for controlled runoff is the fact
that most watersheds are owned by private citizens
outside the jurisdiction of the water manager.
Nutrients from runoff are largely attached to or
incorporated in particulate materials. Various mecha-
nisms are available to control the removal of par-
ticulato matter, but programs of implementation and
regulation need to be developed. For example, silt
screens could be used in construction activities to
capture particulate runoff and prevent it from en-
tering surface waters.
Transport of sediments from the surrounding
watershed to streams entering estuaries offers great
potential for control. The sediment transport could
be minimized by management techniques involving
improved road maintenance practices, stabilization
of uncovered land areas, and drainage of excess
water through filter strips.
Development of vegetated filter strips adjacent
to streams and estuarine shores would minimize the
transport of nutrient materials into the surface
waters. Changes in forestry and agricultural prac-
tices by private land owners can be a means of
controlling runoff and possibly improving the eco-
nomic return for the land owner.
ESTUARINE MODIFICATIONS
In the management of estuaries, it may become
desirable to modify inputs and components to
maximize utilization of materials and productivity.
If these action programs are to be instituted they
should be identified as an example of a class of
action and studied before and after the change so
that we can obtain guidelines for future operations
of this type. For example, the diversion of nutrient-
laden input water over and through large, natural
filtering systems in estuaries may be a viable pos-
sibility in estuarine management.
Recently the use of systems analysis and simula-
tions have been effective in assessing management
needs. Although it is necessary for the system as a
whole to be managed to avoid detrimental side
effects and to maximize system yield, simulations of
component parts may be a powerful tool for achiev-
ing the goal. In managing estuaries in regard to the
desirability of modifications, it is important that
the scientific approach be combined with economic
analyses to achieve some management optimization.
LAND USE PLANNING
By examining the environmental characteristics
of an area, land use planning can be delineated and
used as a guide for locating various use categories.
Most urban areas have adopted zoning ordinances
and have developed procedures for exerting some
control over their patterns of development, but
outside the confines of these municipalities little
has been done in terms of developing realistic plan-
ning. To make land use planning a reality in coastal
systems, one must be able to combine and optimize
the environmental needs with the economic needs.
Since the technology exists for controlling nutrient
inputs at point sources, management of point source
inputs is a matter of economics and enforcement.
But, the non-point sources present a more difficult
problem. Land use planning offers the greatest
potential for controlling these non-point sources.
Drawbacks include lack of knowledge in instituting
a planned program and development of public trust.
ESTUARIES AS ECOSYSTEMS
Any plans for the successful development, manage-
ment and regulation of estuaries of the LTnited
States must be consistent with the ecological and
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NUTRIENTS
273
economic principles by which such systems operate,
with and without man. Unlike normal land problems,
estuaries are moving, dynamic systems influenced by
inputs from every direction. For example, many
maps from regional planning programs show their
boundaries lying across bays and estuaries as if
they were a piece of real estate. This is unworkable
because any planning and management done on one
side of the bay may be negated if something contrary
is done on the other side of the bay. Any new legisla-
tion enabling planning and management schemes
must allow authority over units of circulation if the
management is to be scientifically sound. Until
estuarine systems are recognized and planned as
whole ecosystems, any management mechanisms
brought to boar will be doomed to failure.
REFERENCES
Alberts, J., 11. Harris*, H. Mattraw. and A. Hanke. 1970.
Studies on the geochemistry and hydrography of the
Charlotte Harbor Estuary, Florida. Progress Report No.
2. Mote Marine Laboratory, Sarasota and Placida, Fla.
Hermann, F. II., (i. E. Likens, T. G. Siccama, R. H. Pierce,
and J. S. Katon. 197-4. The export of nutrients and recovery
of stable conditions following deforentration at Hubbard
Brook. Ecol. Monogr. 44:255-277.
Broome, S. W. 1973 An investigation of propagation and the
mineral nutrition of Spartino. altermjlora. Unpublished
Ph I). Thesis, Dept. of Soil Science.-, North Carolina State-
University.
Button, D. K. 1969. Effect of clay on the availability of dilute
organic nutrients to steady-state heterolrophic populations.
Limnol. Oceanogr. 14:95-100.
Carpenter, J. H., D. W. Pritchard, and K. C. Whaley. 1969.
Observations on the eutrophicatiori and nutrient, cycles in
some coastal plain estuaries, p 210—221. In Anonymous
'ed), Kutroplnoation: Causes, Consequences, and Correc-
tives. National Academy of Sciences, Washington, D.C.
Chestnut, A. F. 197-1. Oyster reefs, p 171-203. In H T. Odum,
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-------
ESTUARINE WASTEWATER MANAGEMENT:
DESIGN CONCEPTS
AND CONSIDERATIONS
ERMAN A. PEARSON, S.D.
University of California
Berkeley, California
ABSTRACT
The design of estuarine wastewater management systems should consider the co*t and etl'ectiveness
of specific pollutant removal (treatment), and the cost and efficacy of wastewater transport to and
dispersion in areas of high dilution capacity, and of minimal ecological significance A representa-
tive example cost analyses for a city of one million persons (wastewater flow of ~4. I in' -'see )
indicates that the incremental cost oi upgrading treatment from secondary to advanced (tertiary)
level is adequate to build and operate a land interceptor-transport system about 124 kilometers
(-—77 miles) in length. Similarly, for a coastal city (Pacific Coa^t conditions) the same incremental
cost for upgrading treatment would build and operate (break-even basis) a deep water outfall-
diifuser system about 28.0 kilometers ( ~17.2 miles) in length. If long-term piotection of e.^tuarine
resources is to be achieved, all technical and economically feasible steps should be taken to trans-
port adequately treated wastewaters out of estuarine system*, to the open roaot in well engineered
transport and high-dilution capacity outfall dispersion systems.
INTRODUCTION
Increasing concern about environmental quality
coupled with limited factual information about waste
discharge effects and a general ignorance of conven-
tional wastewater treatment systems, contribute to
increasing confusion in the development of estuarine
and coastal wastewater management systems. Al-
though this paper is concerned with estuarine waste-
water management systems, it will be pointed out
that one cannot rationally separate the estuarine
problem from the broader question of coastal waste-
water management. Unfortunately, all too often
these two problems are treated separately, even by
some evolving regulatory policies. If this continues,
it will result in substantial if not gross damage to
our estuarine resources.
There appears to be a general belief among the
public, conservationists, and even some scientists
and regulatory agencies that all waste/water treat-
ment systems accomplish the same or simitar ob-
jectives. \Vaste\\ater treatment is conceived os
uniformly good, depending only upon the level or
cost of treatment (i.e.. the higher the cost the
better) ; theiefore, the higher the level of iicatmont
for a given discharge location, the better the results.
Unfortunateh, generalizations of this type may lead
to wastewater system designs that are inappropriate
for the pnrtioubr situation both teclmicalh and
economically. In «ome cases, such systems eouid
produce drastic effects on the local ecosystem.
The estuaries and coastal regions of the United
States are the ultimate recipients of the major
portion of conservative (non-decayable) pollutants
discharged to inland lakes and rivers directly con-
nected to the sea. In addition, a substantial addi-
tional load of both conservative and non-conserva-
tive pollutants is discharged directly to the estuaries
from municipalities and industries located on the
immediate estuarine periphery. Obviously, con-
servative pollutants as well as some of the non-
conservative (decay-able) pollutants will reach the
coastal area in a relatively short time. Considering
the estuary's location in the wastewater recipient-
transport structure, in the interest of long-term
protection of the estuarine system, it would appear
prudent to reduce the locally generated waste load
as much as is economically feasible by either waste-
water treatment or removal from the estuarine
system.
Un fortunately, the subject of estuarine and coastal
wastewatcr disposal has riot received as much atten-
tion as that of inland disposal practices. Con-
sequently, the advajitages and disadvantages of
traditional inland wastevater treatment and disposal
applied to the; estuarine-'marine systems have not
been elucidated clearly. (Jt the total effort expended
on estuarine problems, most, has been devoted to
studyina The pmMc;il-h->draalie 'exchange u^-p^et- <:)'
the problt m, rather than the biological and chemical
effects on the local ecosystem.
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276
ESTUARINE POLLUTION CONTROL
THE PROBLEM-
WHAT AND WHERE
TO DISCHARGE?
The nature of the estuarinc wastewater manage-
ment problem depends upon the regulatory agency
position, the characteristics of \vaste\vater dis-
charges, and of the estuary itself, and the particular
beneficial uses that are to be protected. Regulatory
requirements always affect wastewater management;
however, in the estuarine system these may play a
special role in eliminating treatment-disposal options
that may have both economic and ecological bene-
fits. For example, if the minimum degree of waste-
water treatment required, regardless of location of
the discharge, is secondary treatment (such as cur-
rent federal policy), then the option of using the
incremental cost between primary and secondary
treatment to transport the waste water to the open
coast for submarine outfall-diffuser discharge (fol-
lowing primary treatment) is not available.
Problem Types
The types of estuarine pollution problems en-
countered range from those found in inland lakes and
rivers to those that may be associated with near-
shore, shallow, coastal waters. The geometry and
characteristics of the estuarine system and the
wastewater discharge will determine the type of
pollution problem. In estuarine systems as else-
where, the effects of pollutants can be highly vari-
able; nonetheless, they can be lumped into several
general categories that describe roughly the general
spectrum of problems and effects.
MlCROBIAL/TuBLIC HEALTH
One of the oldest parameters of wastewater
pollutants is the coliform group of bacteria. These
organisms are used as presumptive indicators of
the presence of pathogens. Concentration levels of
coliform organisms (MPN/100 ml—most probable
number of coliform bacteria) are established to
protect the waters for water contact sports, shellfish
growing and harvesting, aesthetic enjoyment, and so
forth.
ORGANIC ENRICHMENT/OXYGEN DEPLETION
The classic oxygen demand parameter of waste-
waters is its biochemical oxygon demand (BOD),
the removal of which has been the principal ob-
jective of secondary treatment processes. The addi-
tion of organic matter or BOD exceeding the natural
capability of respiration, synthesis, and reaeration
processes (assimilative capacity) of the receiving
waters may result in substantial depletion of the
dissolved oxygen content of the water. Such deple-
tion may adversely affect its suitability for main-
taining a balanced biota, sport or game fish having
some of the highest dissolved oxygen requirements.
SUSPENDED SOLIDS/WATER CLARITY
The second major municipal wastewater con-
stituent that is removed in substantial degree (65—90
percent) by primary and secondary wastewater
treatment processes is that of suspended solids.
However, in most estuarine systems the amount of
suspended solids contributed by wastewater dis-
charges is a very small fraction (<1.0 percent) of
the total suspended solids contributed by river in-
flow, surface runoff and re.suspension of bottom
sediments. Similar, but somewhat less extreme
relationships exist for the organic (volatile) fraction
of the suspended solids.
ACUTE TOXICITY/BIOTIC STRESS
A relatively new "lumper" parameter of the
acutely toxic substances (toxic metals, organics,
ammonia, et cetera) present in wastewaters, the fish
bioassay for determination of the median tolerance
limit (TL5u) is being used to an increasing degree in
assessing potential toxic stresses from wastewater
discharges. One of the major concerns about adverse
stresses on the biota of estuarine systems is that of
acute toxicity and increasingly stringent require-
ments are being imposed both on the concentration
in the wastewater discharges and in the receiving
waters.1'2-3
FLOATABLES/AESTHETIC EVJOYMENT
The amount of particulates of identifiable waste-
water origin and slick forming material-; foil mid
grease) constitute one of the most significant char-
acteristics of public waste water discharges foi which
there is no ;>deqtia,tc quantitative method for assess-
ment. Moru-thelesi-', in terms of poti'nli.f adverse
and obvious effects on the receiving watt r.s. these
materials must be given increasing attention,
Fortunately, the oil and grease fraction of ihe float-
ab]cs can be quant if ated crudelv. and corvtrol '< vels
established to minimm the phy-ac.u appearance »i
surface films or slicks.
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NUTRIENTS
277
NUTRIENTS/EXCESSIVE ENRICHMENT
Quantitation and control of the discharge of the
various nutrient forms, nitrogen, phosphorus and
others, is possible in those estuarine situations where
adequate information is available to show that
specific nutrient species are in fact, controlling the
level of phytoplankton in the receiving waters. Un-
fortunately, adequate information is rarely available
to show clearly that a particular nutrient (or several
nutrient species) is actually responsible for the
existence of excessive plankton concentrations or
excessive pulses (blooms) in the concentration of
particular algal species. Generally, practical control
of the discharge of particular nutrients is based upon
the presumption that it will help to keep the con-
centration of plankton in the receiving waters within
acceptable limits.
EXOTIC POLLUTANTS/SPECIAL EFFECTS
On occasion, exotic or special pollutants may give
rise to unusual problems which fall in a separate
category. An example might be that of identifiable
chlorinated hydrocarbon compounds in public waste-
water systems.4 Such problems may require special
methods for their solution ranging from extensive
source control efforts5 to the application of special
treatment systems.
Treatment/Discharge
Location Considerations
INSTITUTIONAL/ REGIONAL
Most estuaries have a substantial number of
discrete public (municipal) and private (industrial)
waste\\ater management organizations located
around their periphery. The number and type of
these organizations depends upon the historical de-
velopment of the area as well as upon local waste-
water regulatory policies and practices. For example,
in the San Francisco Bay area there are currently
(1974) over 100 different political or administrative
institutions, each involved with its own particular
wastewater management problem. It should be
obvious that the development of a coordinated or
regional wastewater management program will
require a tremendous effort to satisfy the legitimate
technical, economic and political interests of each
organization. Nonetheless, the development of a
coordinated arid appropriate regional wastewater
management plan is essential for the prime reason
of economy, to say nothing of ancillary benefits, not
the least of \\hich is adequate protection of the local
ecosystem.
How MUCH TREATMENT AND WHY?
The critical problem in estuarine waste manage-
ment after resolution of the political-institutional
problem, is what level of wastewater treatment is
required and where should the treated effluent be
discharged? Historically, the general trend in waste-
water management has been to invest heavily in
treatment processes—frequently as much as can be
financed, and to pay little attention to the location
and type of dispersal system. This general and
significant neglect has been and still is being abetted
by those who believe that the diluting or assimilating
characteristics of the receiving water should not be
considered in the design process. Regardless of one's
philosophy on this question, the hard facts are that
the treated effluent must be discharged to and
diluted with the receiving water. The faster that
this dilution can be accomplished, or the greater
the immediate dilution of the effluent with the
receiving water the lower the concentration of
pollutants in the receiving water environment. Con-
sequently, for any level of pollutants in the treated
effluent, the greater the dilution the lower the con-
centration, and the effect on the local ecosystem is
reduced proportionately.
In the past, the choice of the level of wastewater
treatment has been somewhat arbitrarily made be-
tween the minimal, or primary (mechanical removal
of suspended and settleable solids) and secondary
(biological) treatment. However, with the advent
of PL 62-500 and EPA's definition of the minimum
acceptable wastewater treatment regardless of loca-
tion as secondary,6 the apparent treatment choices
will be between secondary and advanced waste treat-
ment (tertiary). Thus the fundamental question re-
mains, is it preferable to provide advanced waste
treatment and discharge the highly treated effluent
directly to the estuary with little or no concern for
the discharge location or initial dilution; or, is it
preferable to employ a lesser degree of treatment
(i.e., secondary which is cheaper with lower levels
of pollutant removal), and transport the effluent to
a distant area, such as the open coast, where high
dilutions (at least 100 to 1) are available. The latter,
equal-cost alternative, would use the incremental
cost between advanced and secondary treatment to
transport the effluent seaward, preferably to the
open coast, where greater volumes of diluting water
are available.
Unfortunately, an attitude appears to be develop-
ing in favor of continuously increasing the degree
(and cost) of wastewater treatment with least con-
sideration to the location of the ultimate discharge,
the degree of initial and subsequent dilution of the
waste water, or to the decay rate of the pollutants
-------
278
ESTUAKINE POLLUTION CONTROL
in the receiving water. This trend appears to be
supported by many of the nonsuiting engineers and
scientists involved with the design of wastewater
management systems. If the foregoing concept be-
comes accepted and practiced \\idely, it will discour-
age any economic or ecologic incentive to use the
incremental cost between various levels of treatment
to transport the lesser treated effluent to a disposal
site with maximum diluting capabilities and the
least adverse effect, on the local ecology.
If one is concerned about pollutant concentrations
in the environment and their effects, one must give
serious consideration to determining waste discharge
locations where the residual pollutant concentration
will have minimal ecological (including human) im-
pact. To accomplish this, it should be obvious that
quantitative information must h( available on pol-
lutant mass emission rates and concentrations, on
the efficacy of pollutant removal processes, and on
the physical, chemical, and biological characteristics
of alternative disposal sites. The practical facts are
that such information is not generally available to
permit rational assessment of alternative treatment
and dilution combinations. However, this lack of
such information in no way justifies the absence of
rational qualitative assessment of the consequences
arid quantitative assessment, of the costs of the
various alternatives.
DILUTION REALITIES
The available dilution of wastcwaters within an
estuary depends upon the size of the estuary, the
amount of advective (river) inflow, tidal exchange,
the quantity of wastewater, and the discharge loca-
tion. For most estuaries located in urbanized areas,
the available dilution ranges from approximately
the ratio of river inflow to wastewater flow at the
head end of the estuary, to a maximum of from -30-.30
to 1 for a well designed diffuser discharge at the
seaward end of the estuary. Obviously, these num-
bers will vary depending upon runoff, river flow,
tidal exchange, and waste flow. However, in general,
the available dilution for wastewaters discharged
within theestuarine systems is markedly less than is
often implied. For example, if all estimated 1,990
municipal and industrial wastewaters generated
around the periphery of San Francisco Bay were
collected and discharged to the central bay in front
of the Golden Gate, the average dilution of the
wastewaters would be in the order of only 30 to
40:1. And, it must be noted that San Francisco Bay
is a large estuary with appreciable river inflow and
tidal exchange.
In contrast, wastewater disposal systems located
along open coasts (such as the California coast adja-
cent to San Francisco Bay) can be designed to
achieve immediate dilutions of the wastewater with
ocean water in the order of 150:1 or more for waste
flows up to at least l.f) X 106 m3/day (~400 mgd).
While these dilutions may appear to be on the
favorable side, it is difficult, to envision any likely
disposal area along the major U.S. coastlines where
well-designed submarine outfalls could not achieve
average initial dilutions of 100:1 or more.
It is helpful to put the effect of treatment or
pollutant removal in ternvs of equivalent dilution;
that is, the reduction of pollutant concentrations
in the effluent stream. Conventional secondary treat-
ment plants affect, as an average, about 90 percent
of the pollutants for which they are designed (essen-
tially BOD and suspended solids). Thus, about 10
percent remains as residual pollutant concentration
in the effluent. Such treatment efficiency is equiva-
lent to a dilution of ~10:1, if the diluting water
has negligible concentrations of that pollutant. Simi-
larly, advanced waste treatment processes may
achieve at best an average removal of about 98 per-
cent, leaving about 2 percent of the original pollutant
in the effluent. This is equivalent, on a pollutant
concentration basis, of an average dilution of only
,50, assuming of course that the dilution water is
essentially free of the pollutant.
The foregoing examples do not consider the effi-
ciency of disinfection processes for bacterial removal.
Disinfection efficiency is a combined function of
disinfectant dosage and contact time and to be effec-
tive must achieve levels equal to or greater than,
99.99 percent removal which is equivalent to a
physical dilution of about 10,000:1 with bacteria
free water. Obviously, the latter physical dilution is
not a likely possibility.
Example of Alternative Analysis
To illustrate most effectively some of the log-
ical treatment/transport-discharge alternatives that
should be considered in designing cstuarine waste
management systems, a simplified example will be
considered. Figure 1 shows a typical estuary con-
nected to the open coast with a major city located
at its head. The city has several obvious choices
with respect to the disposal of its wastewater. One
choice, designated as discharge location A, would
entail a high degree of treatment—say advanced
waste treatment (average of 98 percent pollutant
removal)—to meet discharge or effluent require-
ments. A second alternative, designated as discharge
location B, would entail modified secondary treat-
ment with an average pollutant removal of about
-------
NUTRIENTS
279
OPEN
COAST
\
z
3
4
5
DISCHARGE LOCATION
INITIAL WASTE DILUTION, SQ
(WIN. RIVER FLOW)
POLLUTANT CONCENTRATION NEAR SOURCE
(AT DIFFUSER) (NO TREATMENT)
TREATMENT (ASSUME) PERCENT
REMOVAL OF POLLUTANT
POLLUTANT CONCENTRATION NEAR
SOURCE IN RECEIVING WATER
A
10
Co
10
98
Co
500
B
30
~ C°
30
90
.. Co
300
c
150
~Co
150
85
C0
1000
FIGI in: 1.—Idealized estuarme-coastal disposal alternatives
90 percent. The third alternative' discharge, location
C, would have the current EPA. minimum secondary
treatment with an average of 85 percent removal of
pollutants. Alternatives B and C obviously entail
significant transport and submarine outfall disper-
sion systems compared to that required at discharge
location A. To make these alternatives economically
competitive, the incremental cost between the levels
of treatment required at the B and C locations and
that required at location A will finance construction
and operation of the interceptor sewer and sub-
marine oul rail difl'user system on a break-even basis.
The basic, questions to be answered are:
1. What are the average lesidual pollutant con-
centra! ions in the receiving waters right at the dis-
charge location? Presumably, from an envhonmental
point of view, the system producing the lowest pol-
lutant concentration in the leceiving waters would
be the preferred solution.
2. On an equal cost basis, how long an interceptor
sewer and submarine outfall can be built for dis-
charge locations B and C with the incremental
savings in treatment costs ($A > $B > 1C)?
3. What, advantages may be associated with each
alternative?
POLLUTANT CONCENTRATIONS
To answer the first question outlined above, a
simple tabular computation analysis is presented in
Figure 1. While the dilution values reported in Fig-
ure ] are hypothetical, nonetheless, the values are
typical of those found in real estuaries. Obviously,
these values must bo estimated for each particular
estuary. The crux of the analysis is to illustrate the
need to compare the trade-off in costs and conse-
quences of pollutant, removal •with transport and
disposal in areas of high dilution potential -with
the goal of achieving reduced levels of pollutant
concentrations and effects in the estuary.
Line 2 in the table shows the average physical
dilution of the wastewater with the receiving water
at each of the three discharge locations. At location
-------
280
ESTUARINE POLLUTION CONTROL
A, a dilution, So, of 10:1 assumed, that is, the ratio
of the river flow Q and wastewater flow, Qw (Qr/Qw)
is about 10:1. At point A the only dilution available
for the wastewater is the advective river flow: there
is no dilution at the head end of the estuary due to
tidal exchange. At location B, line 2, the average
dilution. So, is assumed to be about 30:1, a typical
value encountered in estuaries. At location C, the
average initial dilution. So, is assumed to be 150:1
which is an easily attainable value with a well de-
signed outfall-dispersion system in open coastal
waters.
Line 3 in the table reports 1he pollutant concen-
trations in the mixed wastewater-receiving water
right at the discharge location. The pollutant con-
centration is simply the reciprocal of the dilution;
that is Co710 at A* Co/30 at B, and Co/150 at C,
where Co is the pollutant concentration in the un-
treated waste water. This computation assumes that
the pollutant concentration in the diluting water
is negligible.
Line 4~ introduces the effect of the different treat-
ment levels in reducing the pollutant concentration
in the discharged waste and correspondingly in the
receiving water. As mentioned previous!}", it is as-
sumed that the highest level of treatment is provided
at location A with an average pollutant removal
efficiency of 98 percent. A lower degree of treatment
with an average pollutant removal of 90 percent is
provided for location B. At location C a still lower
level of treatment is provided; however, this is as-
sumed to be equivalent to the "EPA defined second-
ary treatment," the currently specified minimum
level of acceptable treatment, providing an average,
of 85 percent removal of pollutants.
Line 5, the crux of the table, shows the calculated
concentration of pollutants in the receiving water
resulting from the combined effect of pollutant re-
moval by treatment and the dilution of the treated
effluent with the receiving water. The pollutant
concentration at location A of Co/500 is the result
of the product of the physical dilution, So, of 10:1
and the equivalent dilution of 50: I due to the pol-
lutant removal (9S percent) by treatment (2 percent
remaining), which gives Co/10 X 1 750 = Co/500.
The values of Co/300 at B and Co/1000 at location
C are found in the same way.
It should be noted that alternate C, the coastal
outfall discharge, produces a pollutant concentra-
tion at the din'user equal to one-half (Co/1000 vs
Co/500,) that produced by alternate A, advanced
wastewater treatment with discharge at the head of
the estuary. Thus, discharge at point C should be
the preferred solution to minimi/A' ecological effects.
The reported concentrations relate to all pollutants
that arc removed by treatment at the percentages
cited for each level of treatment, namely, 98, 90,
and S5 percent respectively.
Two questions logically might be asked concern-
ing the efficacy of the several alternatives.
1. Which alternative is preferred relative to possi-
ble effects of pollutants that are either unknown or
are removed to a lesser degree than the pollutant
removals stated for each process?
2. Although alternate C apparently produces the
lowest pollul ant concentration, it also has the highest,
pollutant mass emission rate to the environment.
If the pollutants are concentrated or magnified in
the biota, will not alternate C be the poorest solution
rather than the preferred solution?
Both of the foregoing questions need serious con-
sideration. With respect to question 1, and consider-
ing our imperfect knowledge about pollutants and
their effects, one should be concerned about both
possibilities. Inspection of the table in Figure 1
reveals that in both cases, alternate C is the pre-
ferred solution, because the total apparent dilution
is less dependent on the "equivalent treatment dilu-
tion" and depends in major degree on the physical
dilution to produce the lowest pollutant concentra-
tions. For example, if all treatment processes failed
or suffered serious loss in removal efficiency, such
as has been known to happen, alternate C would
produce a pollutant concentration in the receiving
water of Co/150 compared to Co/10 for alternate
A—more than a order of magnitude lower pollutant
concentration which is not insignificant in terms of
possible effects on the local ecosystem. Moreover, in
an era of labor strikes and chemical shortages, the
possibility of major impact on process performance
from this standpoint alone must be considered.
With reference to question 2, it must be remem-
bered that pollutant effects are a function of both
the pollutant mass omission rate (i.e., kgms/day),
and pollutant concentration for a given exposure or
contact time. However, the direct effect of pollutants
on any aspect of the environment is primarily con-
centration dependent for a given exposure time.
This is true for both conservative and non-conserva-
tive pollutants, including those materials that may
bo concentrated (magnified) in the biota. The rate
.it \\ hich any effect is demo'i^-tnilcd by any transport
mechanism kiuAsn to the \\ri1fT is concentration
dependent: that is. i he hiiy.ior the pollutant concen-
tration the more rapid its accumulation or effect on
the biological system. Consequently, any wastewater
management svstoni that produces the lowest pol-
lutant concentration in the environment at the dis-
charge point will have the least effect on the local
ecosvbtem
-------
NUTRIENTS
281
No mention has been made of the effect of pollut-
ant decay rates on the preferred discharge location.
For pollutants such as BOD where a significant
decay rate exists, it should be obvious that for the
•''within the- estuary" discharge locations (A and B).
oxygen demand will be exerted and in some cases
may impose significant oxygen depression in at least
part of the estuary. Thus, some of the estuary's pol-
lution assimilative capacity \\ill be utilized. How-
ever, U>i the discharge locution on (he open coast, C,
the oxygen demand imposed with an initial dilution
oi' 1.10: 1 is general'\ non-detectable in terms of the
dissolved oxygen level of the coastal \\-iter.
Several other significant advantages are associated
with coastal wastewater discharge, alternative C.
1'irst, by removing the locally generated \\astewater
load from the estuary, one preserves the capacity of
the estuary to handle ihe ever increasing quantity
of pollutants generated upstream in the drainage
basins tributary to the estuary. These pollutants
are included in the incoming river flow and there
are no economically feasible methods for their re-
moval once the*' reach the head of the estuary.
Second, it is likely that the coastal region will have
an area available for wastewater discharge that \\ill
be less important and sensitive from the standpoint
of the local ecosystem than the estuarine region.
Third, some nutrients such as nitrogen may need
to he removed from the \\aste\\ater discharge to
control excessive enrichment of the estuary. Coastal
waters are generally deficient in nutrients, nitrogen
in particular, --o there would be no reason for their
removal. In fact, the nitrogen sources mav be valu-
able for the1 controlled enrichment of coastal waters.
This is a practical example of a pollutant in one
situation which might become u valuable resourct
at another location.
TREATMENT/TEA VSPORT- —
DISPOSAL TRADE-OFFS
To answer question 2, hov, large a transput/dis-
posal system can be constructed and operated for
Ihe incr'-meMtrd co-i between the alternative plans,
it is necesspr\ tn deal '-pecirically with UK cost func-
lions I'm treatiin r.t, interceptor and nutf/tH -ov.ir
construction, 'i .should be o'>viou-, tha' the iti'tre-
Tut/I'll co'-, sa»pi)i:v bet\\ef"-; tu' K v el;-, • >f 1 r»!Uini>rn,
f;r>n be '-nnsideii'd 'is availi.bli f'»i waslc\\i'ter trans-
port (ii»'er<:"plor se\vei I and .submarine outfall,'dif-
fuf-er r oustiuetioi; and operation. Thus, we can
compar.' "in s\^nisi \\ith a >>i<. level of ireatnicnt
altd :'!-\ !\l '(;•" X', I'll i. :\!l>">'< l.'ilu.'o'' CIS/-' '•, !i(-
,soi rcc •' \\.\-ie '_( ;u'ra'K!]!, ; . ,. '
280
4SO
490
9!0
125
280
280
430
!40 '
140
100
1UO
175
265
>• Costs' a) mciudfc disposal of .vaste residuals.
b) Treatment capital costs based upon 20 year 'ife, i = 5%.
-------
ESTUARIXE POLLUTION CONTROL
pressed in dollars per million gallons ($/mg) and
include all costs: capital (based upon 20 year life
and o percent interest), operation, and maintenance.
TRANSPORT
The cost of the transport system, principally that
of the interceptor sewer depends primarily upon the
surface ami subsurface condition* along the pipeline
route, 1'umpiiig, if required to o\ ercome the friction
loss for tlv pipeline system, ('institutes a small
fraction ( < lO-lo percent i ol the total cost for a
system of reasonable size (10 To 200 mgd). Table 2
presents estimated 1073 California construction costs
for dry-trench construction of ii terceptor sewers of
suitable size to handle the three example flow rates
considered.
OUTFALL
The costs of submarine outfall diffuser systems
vary considerably because of differences in construc-
tion (surf, et cetera) and bottom conditions. Also,
the cost of the inshore-surf section is high where the
outfall must, be buried for protection of the pipe.
The average cost of outfalls depends upon the length
of the onfall and fraction of inshore to offshore
lengths. For outfalls in excess of one mile in length
and for construction to terminal depths of 2.~> to GO
motois, Table 3 presents the best estimate of 197;!
construction costs based upon actual costs of outfalls
constructed along the Pacific coast during the past
20 years. Kssentialb, all of the^e outfalls have been
designed to provide average dilutions of the waste
watei with the coastal wati rs of at least 100:1.
Actual porfonnauee of the* built systems generally
results in average dilutions higher than the design
objective.
BREAK-EVEN
INTERCEPTOR-OUTFALL LENGTH
[f one considers the incremental fieatment cost
between advanced waste treatment, alternate B (see
Table 1} ami secondarv treatment, assuming that
to no the minimum treatment I'-v >1 allowed, one
can compute the length ol interceptor or outfali that
can be buili for this incremental annual cost. Table
4 present.1- a >ummary computation ot these pipeline
lengths based upon the cost data cited in Table's 1,
:_' ind !'.. Tin "-able -ii »• - t-io rompm d interceptor
ai.u outi.ti! !• "e'l^-. ! liai ca • '>•• ,i!,;i; i«>r tjj(. in;jT(>-
niontal treatment costs ijetweei advanced \\asii-
Table 2.—Estimated 1973 unit construction costs*—interceptor sewers
Design flow
Se day ' inches , centimeters j $/'foot $/meter
10
36 i
96 i
25.4
91.5
245
18.00 I 60
63.00 , 206
205.00 j 672
1 3,780
10 i 37,800
100 1 378,000
* Dry trench Construction.
EPA Index = 200.
Table 3.—Estimated 1973 unit construction costs*—submarine outfalls
! .
Design flow j Sewer size i Construction cost
mgd
ms,day
Inches 'Centimeters $/Foot
$/Meter
1
10
100
3,780 ,
37,800 i
378,000
5
24
76
15
61
194
100
425 1
830
330
1,395
2,720
* California construction practice.
EPA Index = 200.
water treatment, alternate B, for throe wastewatcr
flow rates, 1 mgd, and 100 mgd.
It is of particular intermi<';i.; th'M t ri ,itn\ent
ai.d di^Miar»e ;•! location A
The data presented in Table 4 indicate that waste-
-------
Table 4.—Lengthi of interceptor sewer or submarine outfall that can be constructed for incremental cost between secondary treatment ard advanced waste treatment,
alternate b-f-
Flow
mgd
i
10
100—
incremental unit cost Total annual
secondary to AWT Ait b ! incremental cost Equivalent interceptor length*
sec vs AWT Alt b.
$ mg ' $ 'm' $ i Unit cost
! ! $;Mile-yr
j 1
490 0.13 179 000 5 230
195 0.053 712 000 , 18 200
125 0 033 4 560, COO ' 59,400
Miles Km
34.2 55
39.1 i 63
76.7 ' 124
Equivalent o
Unit cost
30,800
131,000
256 000 ;
mail length**
Miles
5
5
)7
i Km.
8 ' 9
4 8
S ?8
t See Table 1 for process description
"* Based upon useful life of 50 vrs, i — 5%, friction losses (pumping) and O&M not mc[.
** Based upon useful life of 40 yrs, i ~ 5%, Friction losses (pumping) and O&M not incl.
waters can be transported great distances on either
land or in the sea for the cost of upgrading the level
of wastewater treatment. Certainly, there is ade-
quate evidence to indicate that in planning an esfu-
arinc wastewater management .system, a reasonable
extensive investigation of alternative disposal sites,
both within the estuary and on the open coast, is
warranted before derisions are reached to provide
very high degrees of wastewater treatment with dis-
posal to the local environment. It should he noted
that (hi1 preceding analyst is based upon a compari-
son of secondary and advanced \\aste\vater treat-
ment Where legulations do not require secondary
treatment as a minimum, a similar comparison can be
made for the iiK'reniental cost between primary and
secondary treatment. Surprisingly, the incremental
cost between primary and secondary treatment is of
similar magnitude as that between secondary and
advanced treatment used in the example computa-
tion; hence, similar transport distances would be
obtained.
Ancillary Considerations
Several additional aspects of the open coast dis-
posal alternative should be mentioned. First, it has
shown that it is economically possible to transport
about 100 mgd of waste-waters over 70 miles at the
same cost as upgrading treatment from secondary
to advanced Cor from primary to secondary Treat-
ment^. From an environmental or ecological point
of view, it would appear highly logical to expect
that, within a distance; of that magnitude from the
waste-water sourer, one could find a wa.stewafer dis-
charge location with high dilution capabilities and
of lower ecological significance than discharge at or
near the IK,id of an estuarme system.
Vet a valid argument can be made against coastal
waste disposal. In the long term we cannot afford
to waste the freshwater sewage to Hie sea; it should
be reclaimed. In many places, such as California,
this may well be true. If wastewaters are ever to be
reclaimed for beneficial reuse, including public water
supply, more pollutants must be disposed of than
at present. Moreover, the major pollutant to be re-
moved to permit continued reuse is salt. Where is a
better sink for salt and other non-reclaimables, after
suitable terminal treatment, than the sea? Nowhere
in the writer's judgement—at least for those cities
located in the coastal zone.
Moreover, in the short term, one of the major
adjuncts for wastewater reclamation is the existence
of a marine outfall not only to handle the treated
non-reclaimable substances compatible with the sea,
but to provide an effective, economic alternate1 dis-
posal system for the waste-water when it is not pos-
sible to reclaim it all (i.e., seasonal and demand
variations, failsafe provisions, and so forth).
CONCLUSIONS
Rational analysis of estuarine wastewater manage-
ment requires: (I) consideration of the efrJea'-y of
several levels of treatment with respect to pollutant
removals and costs; (21 the consequence's and costs
of transporting adequateh treated wastewaters to
disposal sites with high diluting capabilities and or
low levels of significance in the local ''cosystem;
(3) and the effects of the resulting pollutant concen-
trations in the receiving water environment. The
absence of adequate data on pollutants, their re-
moval or effects, or on the characteristics oi the local
ecosystem, should in no way preclude the straight-
forward comparison of alternate treatment 'trans-
port/disposal systems on an economic and pollutant
concentration basis such as presented herein.
Adequate conceptual design of wastcwafer man-
agement systems requires consideration of the incre-
mental costs between several possible levels of
wastewater treatment for assessment of the trans-
-------
284
ESTCABINK POLLUTION CONTROL
port distances that the wastewater can be conveyed
to a disposal site with high diluting capacity and/or
a lesser level of significance in the local ecosystem.
An example computation shows that for a 100 mgd
(378,000 in3/day) plant the incremental cost be-
tween secondary (including filtration) and advanced
waste treatment, an interceptor sewer 38 miles
(61 km) long and a coastal submarine outfall ~{)
miles (~14 km) in length can be constructed at
1973 California prices.
As has been, shown, in many situations the coastal
outfall alternative not only provides the lowest
waste concentrations, but also may well be the most
economic. Moreover, the coastal alternative is highly
superior to the high treatment-estuary disposal alter-
native for unknown pollutants or pollutants only
partially removed by the conventional treatment
processes (i.e., some toxic substances).
In general, a number of specific advantages can
be claimed for open-coast, treatment-disposal alter-
natives as compared to higher treatment level and
disposal within the estuary. These can be summa-
rized as follows:
1. Produces the lowest concentrations of pollutants
in the receiving waters for conventional levels of
treatment.
2. Discharge location likely can be in area of
lesser significance in the local ecosystem.
3. Reduces pollutant stresses on the estuarine eco-
system resulting from locally gererated wastewater,
thereby allowing capacity for the inevitable increas-
ing pollutant stress associated with incoming river
flow and drainage basin pollutant contributions.
4. Because of the high terminal dilutions, greater
protection is provided for the local ecosystem from:
a) Unknown pollutants or those not removed
by treatment.
b) Treatment process malfunction or failure
(strikes, et cetera).
fi. Provides maximum economy and flexibility to
deal with:
a) Identification and control of new pollutants.
b) Major improvements in treatment tech-
nology.
c) Future development of engineered waste-
\vater reclamation.
In short, if long-term protection of our estuarine
resources is to be provided, all technical and eco-
nomically feasible steps should be taken wherever
possible to transport adequately treated wastes out
of the estuarine system to the open coast in well
engineered, high dilution capacity outfall dispersion
systems.
RECOMMENDATIONS
The federal government in cooperation with the
states should sponsor large scale field investigations
of all significant estuaries and adjacent coastal
waters. The focus of these studies should be twofold:
1. Development of quantitative descriptions of
the estuarine ecosystems to permit realistic assess-
ment of the characteristics of the flora and fauna,
its general condition or "health" and the general
level of sensitivity and biological significance of the
various portions of the estuary and adjacent coastal
waters.
2. To identify, insofar as possible, the significant
effects of pollutants on the estuarine ecosystem—at
least to the degree of categorizing what appears to
be the critical pollutant problems and parameters
associated therewith.
REFERENCES
1. Pearson, E. A., P. N. Storrs, and R. E. Selleck. 1970. Final
Report, A Comprehensive Study of San Francisco Bay.
Vol. 8, Univ. of California Sanitary Engineering Research
Laboratory Report No. 07-5. Berkeley.
2 Kaiser Engineers Consortium. 1969. Final Report, San
Francisco Bay Delta Water Quality Management Pro-
gram. California Water Resources Control Board,
Sacramento, Calif.
3. State Water Resources Control Board. 1972. Water Quality
Control Plan, Ocean Waters of California, Sacramento,
Calif.
4 Burnett, Robin. 1971. DDT Residues: Distribution of Con-
centrations in Emerita analoga (Stimpson) along Coastal
California Science: (174):606-008.
5. Parkhurst, J. D. 1971. The Control of Pesticide Emissions
from Municipal Discharges, Report at hearing before
State Water Resources Control Board, Lo« Angeles,
Calif.
(i. U.S. Environmental Protection Agency. 1973. Office of
Water Programs Operations. Washington, D.C.
-------
POLLUTION PROBLEMS IN
THE ESTUARIES OF ALASKA
DONALD W. HOOD
JOHN J. GOERING
University of Alaska
Fairbanks, Alaska
ABSTRACT
The Alaskan marine coastal systems are classified into 13 categories which represent nearly all
systems found in the 48 contiguous states with the exception of tropical .systems and those heavily
stressed by petrochemical and other complex industrial pollutants. Alaska is the only state that
has ice-stressed coastal systems. It also has 54 percent of the United States coastline and 53 percent
of its tidal shoreline.
The scope of Alaskan coastal pollution problems at present, and in the future are examined. Minor
problems associated with wastes from municipalities and activities of the petroleum,
, timber, pulp
c - .vasres irom municipalities ana activities 01 tne petroleum, runner, pulp
and paper, and the fishing industries are presently evident. Increased petroleum production and
the associated transport of oil products through Alaskan coastal systems poses a future large
scale pollution risk
An evaluation of previous Alaskan coastal pollution abatement programs and trends is given.
Because Alaska has such unique coastal systems it is concluded that any future coastal pollution
control program will succeed only if based on sound environmental data rather than on adaptations
of standards uniformly administered throughout the 48 contiguous states. Emphasized through the
paper is the need for better environmental understanding of Alaska's coastal systems upon which
decisions can be wisely made that will protect them, and at the same time utilize them for waste
disposal and extraction of the resources needed to benefit man.
INTRODUCTION
Alaska, with its total population of about 3.50,000
people is very sparsely populated. Centered around
Anchorage is a population of 1.10,000 which consti-
tutes by far the largest population center; Fairbanks
is second with about 40,000. and Juneau third with
about 20,000. The remaining population is composed
of small villages and towns, mostly located on the
coast. Most of the villages are native and still adhere
to native customs and practices.
Most Alaskans live on the state's coast, a coast
that extends from the rain forest of southeast Alaska
to the arctic tundra (Fig. 1). The gradation from
temperate to arctic, which encompasses a very broad
geographical range in latitude and longitude, in-
cludes all types of coastal systems found in the con-
tiguous 48 states with the exception of tropical sys-
tems and those stressed by petrochemical and other
complex industrial pollutants. Alaska is the only
state that has ice-stressed coastal systems. There
are four types: glacial fiords, turbid out wash fiords,
sea ice systems and ice-stressed coasts. The first
two types occur in southeast and southcentral
Alaska and the last tv>o types are arctic (Fig. 1 and
Tables 1 and 2).
The small population of Alaska, although concen-
trated on the coast, has had a very limited influence
on the natural systems of the 76,100 km of Alaskan
tidal shoreline. But, Alaska is presently experiencing
rapid economic growth primarily from development
of the natural resources (e.g., petroleum, timber
and fish) near its coast and certain coastal systems
are therefore already stressed by man's activities.
Classification of Alaskan Marine
Coastal Systems
Alaska's coastal systems are very diverse (Fig. 1,
Tables 1 and 2) because its coastline extends over
a very broad geographical range. The general coast-
line of Alaska is ] 0,080 km long (McRoy and
Goering, 1974), 54 percent of the total (19,924 km)
coastline of the United States (Pederson, 1965).
The tidal shoreline, which includes islands, inlets,
and all shoreline to the head of tidewater, is much
longer and reflects the intricacy of coastal Alaska.
This distance is estimated to be 76,100 km in Alaska
and 142,610 km in the United States. Alaska, then
has 53 percent of the total United States tidal
shoreline. The tidal shoreline is greatest in southeast
Alaska (63 percent), where the coast is a maze of
fiords, islands, bays, and rocks, and is minimal in
285
-------
286
ESTUARINE POLLUTION CONTROL
172° 156° 140°
66°
66'
58'
58°
50°
172° 156° I40e
FIGURE 1.—Map of Alaska. Numerals refer to regions described in Table 2.
the arctic ('2 percent), existing as a series of lagoons
and barrier beaches (Table 2).
Because the four ice-stressed systems are unique
to Alaska their characteristics will be briefly de-
scribed.
GLACIAL AND TURBID FIORDS
The major indentations of the southeast Alaskan
coastline are fiord-type estuaries. Glacial and turbid
outwash fiord refers to inlets which owe their dis-
tinctive physiography to the action of glacial ice on
mountainous coastal regions. These inlets are usually
narrow, straight, have deep water and receive their
major freshwater runoff from active glacial sources.
Those fiords with active glaciers in the intertidal
zone are referred to as glacial fiords. In these, most
of the glacial-melt water (i.e.. the major cstuarine
freshwater source) passes directly into the marine
environment. Fiords whose glaciers terminate on
land, so that the melt water reaches tide water via
a freshwater river system, are termed "turbid out-
wash fiords." In contrast to the clear water environ-
ment of the glacial fiord, \\\ the tin-bid outwash fiord
large quantities of glacially-ground sediments are
transported into the inlets by glacial-melt water
from the sediment deposits between glacier and
fiord. These sediments restrict light passage as well
as influence the inlet geochemistry.
Table 1.—Types ot coastal systems in Alaska
Glacial fiord
Turbid (terrestrial outwash) fiord
Rocky sea front and intertidal rocks
High velocity tidal channel
Neutral embayment smd associated shore waters
Medium salinity estuary
Sheltered and stratified estuary
Oligohahne river system
Sedimentary river delta
Marshes
High energy beach
Ice-stressed beach
Sea ice system
-------
NUTRIENTS
287
Estimated km
of tidal
shoreline
Percent of Coastal types
Table 2.—Distribution of Alaskan coastal systems by regions (See Fig. 1)
Region
1. Southeast Alaska _j 48,270 I 68 all but 12 and 13
Alaskan
shoreline!
(See table 1)
2. Pacific Coast, Cape Spencer
to Cape Elizabeth
3. Cook Inlet
4. Kodiak Island, Alaska Pe-
ninsula and Aleutian
5. Bristol Bay to Bering Strait,.
6. Arctic, Bering Strait to Ca-
10,460
800
12,070
2,900
1,600
14 all but 12 and 13
1 4, 5 and 8
16 3, 4, 5, 6, 7, 10
and 11
4 3, 4, 5, 6, 7, 10,
11 and 12
2 8, 9, 10, 11 12
and 13
Commonly, fiords contain an entrance sill, which
restricts the free exchange of waters within with
those outside (Pritchard, 19.52). However, all inlets
in southeast Alaska do not have such sills and the
amount of circulation restriction, a feature which is
very important in pollutant assimilative capacity,
varies from inlet to inlet. Most have entrance sill
depths which allow continuous contact with the
exterior source waters so that a slow circulation
prevents the basin from stagnating. Where shallow
sills penetrate the low salinity outflowing upper
layer, exchange of deep basin water is inhibited and
stagnation is theoretically possible1. No fiords in
southern Alaska, uninfluenced by man, show stag-
nation to the degree that extensive oxygen depletion
occurs. The circulation in Skari Bay, Unalaska
Island, one of the Aleutian Islands, however, is
restricted to the extent that complete oxygen de-
pletion occurs naturally once every year (Gocring
and Boisseau, personal correspondence). Stagnation
as a consequence of restricted circulation also occurs
in areas of limited freshwater inflow. Inflow is
strongly seasonal with a pronounced primary fresh-
water input maximum during the period of May
through July. The major energy sources within the
fiords are the total freshwater inflow and the effects
of tides, with the latter usually predominating.
SEA ICE SYSTEM
Sea ice is a coastal system unique to Alaska. The
ice itself is a type of beach with associated fauna
and flora. Seals and \\alrus breed on the ice; diatoms
and other algae grow on its undersurface; numerous
species of birds feed near it; Eskimos depend on it
for food and travel.
Ice is the major feature of the Arctic Ocean and
northern Bering Sea in winter. Heawatcr in this
system freezes to an average thickness of 2 to 3 m.
This thickness varies locally with the severity of the
winter. Losses due to surface melting are replenished
by accumulation of new ice on the undersurface.
The southern boundary of the sea ice varies from
year to year. This limit is frequently near the
Pribilof Islands (7>90 N., Fig. 1). The summer
boundary of the polar ice is between 10 and 100
miles off the Alaskan arctic coast. During August
and September the Arctic Sea adjacent to Alaska
has the least ice. Advancement of the sea ice begins
in late September and October but the north flowing
current through Bering Strait tends to keep the
southern Chukchi Sea open longer. Ice closes Bering
Strait by the end of October. In late October and
November Norton Sound freezes and the sea ice
progresses south to its maximum in midwinter.
Breakup begins in mid-April. Open water does not
extend into the Chukchi Sea until June.
Ice on the sea is not one continuous mass, nor is it
flat and uniform. Winds, currents, and other stresses
produce openings, hummocks, and ridges in the ice.
The surface topography generally reflects the under-
surface topography. Polvnyas and leads, a result of
stresses acting on the ice, are present at all seasons.
The boundary of ice and water may take a variety
of forms depending upon the given freezing and
melting conditions. In the open sea, only sea ice
formed by the freezing of seawater is important.
However, near the coast, and in particular near
river mouths, floating river ice is introduced into
the oceans.
ICE-STRESSED COAST
This system is characterized by ice formed by the
freezing of the arctic seas. Ice along a shore has
profound effects on the fauna and flora of the coast
in that it eliminates most organisms from the littoral
zones of the sea.
The ice-stressed littoral system reaches a maxi-
mum intensity on the northernmost coast of Alaska,
from Point Barrow east, where ice is present from
September through July and in extreme years may
be periodically onshore all summer. The effects of
ice on coastal systems diminish with the decreasing
latitude along the Chukchi and Bering Sea coasts.
The southern extent of the ice-stressed system varies
with the intensity of winter; it can extend as far
south as Izembek Lagoon near the tip of the Alaska
Peninsula (55° N., Fig. 1). In these lower latitudes
the ice effects are much less than in the Arctic. On
the arctic coast the pressure on sea ice from wind
-------
288
ESTUARINE POLLUTION CONTROL
stress and currents is transferred to the fast ice on
shore and causes scouring. Ice cover on the open
Bering Sea never extends as far south as the Aleutian
Islands.
Although the stress of ice influences long portions
of the Alaskan shoreline (approximately 4,500 km),
most studies have been limited to the region near
the Naval Arctic Research Laboratory at Point
Barrow. For other regions only inferences can be
made, based on the Point Barrow work. The best
studied ice-stressed coasts are those of the arctic
Soviet Union (Zenkevitch, 1963). They appear to
be comparable to Alaskan coastal systems.
SCOPE OF ALASKAN
COASTAL POLLUTION PROBLEMS
PRESENT AND FUTURE
Alaska's extensive coastline and corresponding
coastal estuarine systems are one of the state's most
important resources. Estuaries are as beneficial to
man as forests, lakes and rivers. They are very pro-
ductive biologically as well as versatile in usefulness.
A vast variety of finfish and shellfish spend all or
part of their life cycle in estuaries. These serve as
nurseries, as spawning and feeding grounds, and as
passageways between the open sea and the spawning
areas of freshwater streams. Most of the commercial
seafoods harvested in Alaska are associated with
coastal esttiarine systems (Table 3).
These systems also provide habitat for numerous
species of sea birds and marine mammals. They act
as buffers against the ravages of violent storms and
provide the harbors and transportation routes for
commerce, and are the best potential sites for certain
industrial plants. Also, Alaskan coastal waters offer
a wide variety of recreational opportunities for
fishermen, boaters, hunters, and wildlife observers.
It is thus very clear that Alaska's coastal systems
are very rich in renewable and non-renewable re-
sources—distinctive, aquatic systems which man
cannot afford to use carelessly or destructively. We
must obtain a keen knowledge of how these systems
function naturally before the stresses that they can
accept without significant change can be assessed.
Procuring information as to how these systems func-
tion naturally is the greatest challenge to wise man-
agement of their use. Without this knowledge for
management decisions, failure is inevitable.
Because of the state's great diversity, baseline
data on many systems is not available. Therefore,
the present water quality standards which are based
on the best information available, or taken from
other states and areas, have many weaknesses which
must be corrected as better information is obtained.
Table 3.—Alaskan commercial species of finfish and shellfish which are nurtured
In estuarine environments
Group
Common name
1. Finfish
Salmon ; coho (silver) salmon
pink (humpback)
chum (dog) salmon
king (chinook) salmon
sockeye (red) salmon
Trout | rainbow trout (steelhead)
arctic char (dolly varden)
Halibut.._ Pacific halibut
Herring | Pacific herring
Smelt capelm
Cod ! ling cod
Rockfish i redsnapper(yelloweye rockfish)
Whiting j sheefish
2. Shellfish
Scientific name
Crabs.
Shrimp.
king crab
tanner (snow) crab
' tanner(snow) crab
dungeness crab
., pink shrimp
side-stripe shrimp
coon-stripe shrimp
humpback shrimp
spot shrimp
Oncorhynchus kisutch
Oncorhynchus gorbuscha
Oncorhynchus keta
Oncorhynchus tshawytscha
Oncorhynchus nerka
Salmo gairdnen
Salvelmus malma
Hippoglossus stenolepis
Clupea harengus pallasi
Mallotus villosus
Ophiodon elongatus
Sebastes ruberrimus
Stenodus leucichthys
Paralithodes camtschatica
Chionoecetes bairdi
Chionoecetes opilio
Cancer magister
Pandalus boreahs
Pandalopis dispar
Pandalus hypsmotus
Pandalus gomurus
Pandalus platyceros
Scallop
Clams
j weathervane sea scallop
goe-duck
Panope generosa
Environmental baseline research is the only mech-
anism that can supply the required information
needed to upgrade and establish realistic marine
water quality standards. Once realistic water quality
standards are established then research to develop
more appropriate methods of waste treatment and
pollution abatement can begin. Without realistic
standards, the government requirement for indus-
trial and municipal installation of treatment facilities
is environmentally pointless, morally irresponsible,
and fiscally absurd.
Marine coastal pollution in Alaska is then caught
in a dilemma. On the one hand are the extremely
complex coastal ecosystems of widely diverse nature
that are sufficiently different from those of other
regions that the same criteria for water quality do
not apply, and on the other the strong commitment
on the part of the government to impose standards,
usually the same as for the rest of the United States
even though there is little evidence for their appli-
cability. To exemplify this point, there seems to be
very little reason to set effluent standards in Alaska
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NUTRIENTS
289
to help meet a dissolved oxygen concentration in
the environment, as may be necessary elsewhere,
since Alaskan waters are unusually rich in dissolved
oxygen. In one test case in Silver Bay a discharge of
112 metric tons/day of 5-day BOD under less than
ideal discharge conditions led to only a few viola-
tions of the state water quality standard for dis-
solved oxygen (6 nig/1), and this was associated
with low oxygen water input resulting from coastal
up welling. It would seem advisable to put the in-
tellectual resources available to bear on problems
other than BOD discharge. Likewise, docs it make
sense to impose the same temperature effluent stand-
ards in Alaska; most ecosystems would benefit from
higher temperatures, as in Florida or Texas where
the systems are thermally stressed under natural
conditions.
To protect Alaska's renewable resources it will
be necessary to develop environmental standards
especially directed toward local situations. In such
considerations full regard to the investigation of the
ocean's capacity for waste assimilation and disper-
sion should be given while being explicit about the
nature of the waste discharged and its effects on
the dominant ecosystems present.
The future marine pollution problems in Alaska
will be well managed, poorly managed, or managed
not at all, depending on how well the responsibilities
of the oceanographic scientific community are car-
ried out in the next few years and what kind of
management plan is developed. There will unques-
tionably be large offshore oil developments on the
continental shelves of the Gulf of Alaska. Beaufort
Sea offshore of the Prudhoe oil field, the Chukchi
Sea, Norton Sound, Bristol Bay, Xorth Pacific south
of the Alaska Peninsula, and the Bering Sea. These
continental shelves represent 74 percent of the U.S.
total. With these developments must come a pro-
liferation of docks, harbors and transportation cor-
ridors to move the product to market. Much of the
gas will be liquified before transport out of Alaska
thus providing enormous quantities of heat, which
under proper institutional arrangements, can prob-
ably be economically utilized to enhance renewable
resource production.
Some plants will be built to utilize oil and gas
within Alaska, particularly nitrogen based fertilizer
plants and some types of petrochemical plants.
Alaska is an underdeveloped mineral rich resource
area. Large reserves of copper, tin, molybdenum,
platinum, iron, antimony and coal are yet undevel-
oped. Only gold and some copper has been processed
until now, largely because of lack of transportation
and the world economic picture. Soon this will
change with the imminent world need for these raw
materials. The metal beneficiation mills that will
result will bring new sets of pollution problems to
the state.
The timber stands in Alaska are about the same
as Washington, Oregon, and Idaho combined, yet
the harvest is small compared to these three states.
With the shortages in wood and wood products now
facing the nation and the world a greater harvest
of this raw material in Alaska is inevitable. With
the increased harvest will come numerous new paper,
wood pulp, and wood mills with their associated
pollution problems. In addition, the increased cut-
ting will affect water quality, land erosion, and
stream habitation.
Marine food production, historically Alaska's most
important product, will continue to expand and
Alaska will long remain as one of the world's great-
est fisheries' centers. Pending the adoption of the
200-mile economic zone or some similar coastal state
jurisdictional arrangement, the continental shelf of
the Bering Sea, perhaps the most valuable fishery
in the world, will fall under Alaska's jurisdiction.
In addition, aquaculture should thrive in Alaska,
especially in the coastal fiords which offer promising
opportunities for marine food production without
expenditure of conventional energy.
For Alaska to be a supplier of mr-ine foods and
at the same time of such materials as petroleum,
lumber and associated products, place an extremely
heavy burden on those investigating environmental
effects to determine what stress the system can take
without significant damage, and provide for means
to control those stresses found to be incompatible
with desirable uses of the marine environment. Gov-
ernment, science, and private enterprise must face
these problems together realistically and with forth-
right determination to make thi.-- possible.
ALASKAN COASTAL POLLUTION
BY TYPES OF EFFLUENTS
Petroleum Industry
ficant pollution of Alaska's coastal systems
by oil has not yet occurred. Pollution b\ oil could,
however, become a problem as soon as large1 amounts
of it are tankered from Alaska to other areas. This
is slated to begin after completion of the Trans-
Alaska pipeline, about three .years from now. When
oil is handled, there is a spill risk, even under the
best control and intentions. We must develop a
data bank of its effects so that cleanup and control
may be systematic and effective.
In the development of the vast petroleum reserves
located in the state the danger of oil pollution must
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290
148°
ESTUARINE POLLUTION CONTROL
147° 146°
145°
60°
147" 146°
FIGURE 2.—Prince William Sound.
145°
be foreseen and forestalled. The most immediate
problems appear to surround the SOO-mile Trans-
Alaska pipeline which is to bring oil from the oil-rich
North Slope to the ice-free tanker terminal in Port
Valdez in south-central Alaska. The coastal systems
in region 2 (Fig. 1) are particularly vulnerable,
especially Port Valdez, Valdez Arm, and other sys-
tems located in Prince William Sound (Fig. 2).
Prince William Sound is one of the largest tidal
estuarine systems on the North American continent
not yet influenced by urban development. It is com-
parable in size to Puget Sound yet has only a perma-
nent population of about 5,000. The sound is an
area of rich biological resources and scenic splendor.
Important runs of silver, pink, and chum salmon
enter the sound each summer to spawn in its numer-
ous freshwater systems. Large stocks of king and
dungeness crabs, a variety of clt ins and scallops, as
well as commercially important pelagic fish reside
there. Large numbers of marine mammals and sea
birds are associated with the rich marine fauna.
When the Trans-Alaska pipeline is completed the
tanker traffic in Prince William Sound and along
the southeast Alaska coast will almost certainly lead
to sporadic oil pollution. Chief risk areas are near
the, loading terminal in Port Valdez; but with sensi-
ble organization for treating them, such oil spills as
occur need not cause environmental degradation.
Oil tankers returning from the west coast under
ballast to load at Port Valdez will not be able to dis-
charge dirty ballast water at sea. They will unload
it into a ballast treatment plant where the oil con-
tent will be reduced to less than 8 ppm before
release into the port. Thus Port Valdez will suffer
planned chronic pollution of a low level. The
Alyeska Pipeline Company, responsible for opera-
tion of the pipeline and terminal, commissioned a
study of the hydrography, geology, and biology of
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NUTRIENTS
291
the port by the Institute of Marine Science of the
University of Alaska to predict the impact of this
chronic pollution. The report (Hood et al., 1973)
provides information which has been used in the
design of the treatment plant and effluent dispersion
system to minimize the impact of this oil on Port
Valdez waters. The extreme care used to investigate
the pollution impact that the treatment plant might
have, and to design the outfall in such a way to
minimize effects, should be a model for all future
industrial and urban developments in Ihe sound.
A study to quantitatively define the magnitude
of oil pollution in Alaska's Cook Inlet has been de-
scribed by Kinney et al., (1909). Physical dissipa-
tion and biodegradation rates were determined and
combined with estimates of hydrocarbon input rates
to assess the extent of oil pollution in the inlet.
The authors report that as of the date of their
report, accidental spills and effluents contribute
from 10,000 to 17,000 barrels of oil per year or about
0.03 percent of the total produced and handled.
The most recent spill and discharge analyses show
that the 0.03 percent figure is now about 0.01 percent
and will further decline as XPDES discharge permits
go into effect between 1975 and 1977. When oil is
added to the surface1 the slick is dissipated rapidly
by the inlet's large tidal turbulence. This turbulence
and its geometry also tend to keep spilled oil out
in the inlet away from beaches, with the exception
of Kalgin Island. Tidal and river-driven flushing
reduces components in the inlet by 90 percent in
about 10 months. Evaporation effectively removes
hydrocarbon components smaller than C^ within
eight hours and the amounts of Cio — Gas hydro-
carbons in Cook Inlet waters and sediments are
below 0.02 /ig/liter.
A microflora of hydrocarbon oxidizing organisms
(about JOYliter) exists and functions as an inoculum
and suggests the persistence of transient, possibly
naturally occurring, hydrocarbons. Biodegradation
of oil in the inlet is complete in one to two months.
Thus biodegradation is more important than phys-
ical flushing in removing hydrocarbon pollutants
from this body of water.
Many questions concerning the influence of oil
on marine biota remain unanswered. The lack of
this information generally results in panic when oil
is spilled, although oil seeps occur naturally in coastal
waters of Alaska, particularly in southeast Alaska
near Yakataga, Malaspina, Icy Bay, and Vakutat
(Rosenberg, 1972j. The fate of oil once it reaches
Alaska's coastal system needs to be assessed. Bio-
degradation will occur; but just how fast in the
various systems isn't precisely known. Interaction
of oil with silt and glacial silt will occur, but where
does the silt deposit, what effects do oil-laden silt
have on the benthic community and what rates of
degradation may be expected? Arbitrary controls of
oil pollution other than cleanup of spills should not
be attempted without more knowledge of the fate
and effect of oil on the marine ecosystems involved.
Caution should be used when chemicals are used
to clean up oil because they may, in cold water, as
has been often found in warmer waters, have; more
detrimental effects to marine organisms than allow-
ing natural processes to degrade the oil left after
physical cleanup. It is obvious that the State of
Alaska and the U.S. Government must obtain de-
tailed knowledge1 of the interaction of oil and the
marine environment under Alaskan conditions to
avoid panic and tragedy in the event of major
accidental oil pollution incidents.
Timber Industry
Among Alaska's most important industries now
and in the future are those involved with forest
harvest and processing. Approximately 60 individual
logging companies operate within southeast Alaska
(State of Alaska, 1971). They supply timber to two
large pulp mills and about 20 smaller sa\v mills. In
1970, they harvested .360 million board feet of
timber, most of which was hemlock (Tsuga hetero-
phylla). Much of this timber was taken from
Baranof, Kruzof, and Prince of Wales Islands. About
2.6 square km of water was used for handling and
storing logs. Since some of the logging companies
move their cutting sites each year, a large area of
water has been used for log handling and storage
in southeast Alaska. Coastal pollution problems
originating from the timber industry are already
apparent in southeast Alaska. Logging practices
have influenced the water resources, particularly
small streams in the logging areas arid estuaries
utilized for log storage in log rafts. The absence of
roads and the distance between logging areas and
processing mills have resulted in the extensive use
of salt water for storage and transportation of logs.
Wood-boring organisms, such as teredos, inhabit
southeast Alaskan marine waters, so logs are gen-
eral!}' stored in intertidal areas of .shallow bays.
These areas are chosen for extended log storage
because1 grounding at low tide and the relatively
low salinities minimize infestation by wood-boring
organisms. Protection from strong winds is another
factor considered when choosing storage areas.
During the log dumping and rafting processes,
bark is knocked off the logs and sinks to the bottom,
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292
ESTUAKINE POLLUTION CONTROL
often in substantial amounts. This accumulation
can greatly increase oxygen demand, resulting in
the depletion of benthic organisms, and also can
cover the bottom to the extent that repopulation
by benthic forms is prevented (Pease, 1974). Or-
ganic compounds leached from logs when stored in
water, in addition to exerting an oxygen demand,
add color-producing substances to the water, and
some leachates (e.g. Douglas fir leachates) are
acutely toxic to marine and freshwater fish (Schaum-
burg, 1973). Steel bands and cables which an; used
in the rafting process also often accumulate on the
bottom.
The exact effects of water-based log handling in
southeast Alaska need to be better assessed before
restrictions or alternative methods of storage are
imposed. In general, any method which reduces the
accumulation of debris and log leachates in the
shallow storage areas would appear to be beneficial.
Pulp and Paper industry
The processing of timber by pulp mills has also
seriously affected water quality in certain southeast
Alaskan bays. A rather serious degradation of water
quality due to inadequately treated wastes from
pulp mills in Ward Cove and Silver Bay has been
documented by the Federal Water Quality Admin-
istration (1970). The Alaska Lumber and Pulp
Company located in Silver Bay and the Ketchikan
Pulp Company in Ward Cove both operate magne-
sium based sulphite process pulp mills which produce
a dissolving pulp for the rayon industry. Both plants
have relied upon chemical recovery and screening
to remove wastes and both discharge into the marine
environment from outfalls without the benefit of
dispersers. This treatment has been shown to be
insufficient to comply with Federal or Alaska Water
Quality Standards. Sulphite waste liquor concentra-
tions known to exceed the level toxic to phyto-
plankton and salmon food organisms have been
found throughout Ward Cove and Silver Bay. The
waste liquor discharges containing a high 5-day
BOD coupled with the release of solid materials,
plus the inability of the waters in these systems to
effectively disperse the pollutants, combine to re-
duce the dissolved oxygen at .some times during
the year. In the summer, coastal upwelling occurs,
resulting in low oxygen containing waters being
transported into the inlets. This event, coupled
with oxygen depletion resulting from the waste load.
causes the dissolved oxygen to fall below 6 mg/liter,
the minimum level allowed by the Alaska Water
Quality Standards. The permit requirements now
being imposed are based on a discharge level for
5-day BOD per ton of product produced with no
regard for environmental effects. It is not clear at
this time, in the case of the Alaska Pulp Mill at
Silver Bay, whether reduction of the 5-day BOD
discharge level to the proposed best practical level
will effectively improve the dissolved oxygen situ-
ation in Silver Bay, since it appears that the largest
contributor to the low oxygen values is natural
circulation and similar processes dominating this
system. More consideration needs to be given to
other components of the waste, and their distribu-
tion in the bay, to provide a sound environmental
disposal system.
Fishing Industry
Alaska ranks as one of the leading states in the
tonnage of seafood landed and processed (fourth in
1972, U.S. Dcpt. of Commerce, 1973). In 1972 there
were 131 salmon, 72 shellfish and 50 miscellaneous
fish processing plants operating along the coast of
Alaska. The wastes from this industry have already
brought on serious degradation of water quality and
impeded the various other important and economic
uses of that water. The main areas of environmental
degradation are in regions where several processors
are concentrated, whore currents carry wastes on-
shore, or where water circulation is restricted and
stagnation ensues.
A large percentage of the shellfish and finfish
processing in Alaska is done at Kodiak. In 1972,
113,268,000 pounds of fish were landed there; only
six other U.S. fishing ports had larger landings. In
Kodiak, the shrimp and crab industries are faced
with a complex problem. The wastes which are left
after the extraction of meat for freezing or canning,
the majority of the body weight (mainly entrails
and chitinous skeletons), always have been dumped
into Chiniak Bay beside the processing plants. This
practice has created serious environmental problems,
e.g., accumulation of organic debris resulting in near
bottom anoxia, release of toxic hydrogen sulphide
from anoxic sediments, and elevated concentrations
of potentially toxic inorganic nutrients such as am-
monium. The lowered oxygen concentrations have
undoubtedly affected the natural flora and fauna
of the bay.
Iliuliuk Bay, Unalaska Island is a site of increas-
ing seafood processing. It has been speculated that
the amount, of processing on or near Unalaska will
surpass that on Kodiak in the next few years. Large
concentrations of ammonium and depletions in oxy-
gen have already been observed in Iliuliuk Bay
(Brickell and Goering, 1970), and the decomposition
of seafood processing \\ astes, which are emptied
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NUTRIENTS
293
into the bay rather continuously, appears to be
respemsible for the observed changes in the nitrogen
and oxygen chemistry. An examination of the ammo-
nium concentration al stations off the mouth of the
bay suggests that ammonium originating in Iliuliuk
Bay influences the nitrogen economy of the1 sur-
rounding ocean. However, high concentrations of
ammonium, organic nitrogen, and oxygen depletion
are not restricted to waters receiving waste from
seafood processing plants. They can occur naturally,
as evidenced by the natural phenomenon of salmon
carcass decomposition which results in oxygen de-
pletion and elevated concentrations of ammonium
and other nitrogen compounds, closely simulating
the industrial situation (Brickelland Goering, 1970).
Municipal Wastes
Disposal of untreated municipal wastes in the sea
surrounding Alaska is common to coastal cities and
villages. Household waste1 is the' dominant ce>mpo-
nent with minor contributiems from small industries.
Larger industries dispose of their wastes separately.
The cheapest means of disposal is often used, i.e.,
untreated municipal wastewater is released into
the open sea. In most instances this appears to have
not se'riously stressed the marine environment. Only
in embayments with restricted circulation have
minor adverse effects been documented.
Disposal of sewage into seawater affects the phys-
ical and chemical nature of coastal waters. The
specific gravity e>f the waste products in relation
to the density of seawater will determine whether
the material disperses into water masses, settles to
the> bottom, or floats to the surface. These materials
will also affect light peiietratiem, poison plants and
animals, destroy botteim habitat by settling, and
destroy valuable re'cre'ation sites by floating to sur-
faces and washing onto beaches. More serious are
the primary and secemdary conseemences of the
chemical and biological oxidation of the organic
matter. Bioeh'gradable organic matter discharged
into the: sea is oxidizeel by microorganisms. The
initial oxidation is accomplished by organisms enter-
ing with the effluent, and after dilution with sea-
\\ate-r marine bacteria are probably the- major oxi-
di/ers. The bae'te-ricidal prope-rtie-s of seawater are
well doe-ume'iited (Retchum et al., 1949). In the
oxidation process, the dissolved oxygen in seawater
is utilized as the electron acceptor, and when the
rate1 of reme>val is greater than the rate of supply
by diffusie>n and the photosynthetic activity of
plants, the oxygen is de'plete'd. Anoxic microorga-
nisms begin to stabilize1 the remaining organic mat-
ter using the nitrate ion first, and when it is depleted,
the sulfate ion, as the electron acceptors. During
the latter process, noxious hydrogen sulfide1 is pro-
duced. The reduced compounds (e.g. hydrogen sul-
fide) an1 in reality also an oxygen debt which has
to be paid before oxygen can again accumulate. In
all of the bie>degradation reactions carbon dioxide,
ammonium, and phosphate are released into the
water, and become available for organic synthesis
in algal growth. Baalsrud (1967) showed that when
a mixture of seawater and sewage, having a certain
oxygen demand, was stored in the dark an oxidative
breakdown occurred, thereby reducing the oxygen
demand. However, when the mixture was inoculated
with a few algae and placeel in the light, algal
growth gave rise to organic matteT with an oxygen
demand much greater than that originally found in
the sewage1. His experiments clearly demonstrate
that the eirganic matter forme>d as a result of eutro-
phication potentially represents a much greater or-
ganic load than that added directly with sewage.
Therefore, it appears necessary to clearly understand
the secondary as well as the primary effects of
sewage addition to seawater.
Cook Inlet receives untreated municipal sewage
from all of the Anchorage populace, the largest
metropolitan area in Alaska. The 30-foot tidal range
of Cook Inlet is common knowledge. However, less
known are its other characteristics, such as extreme
turbulence, horizontal velocities of flow, suspended
sediment loads, natural biological productivity, the
effects of freshwater inflows, temperature, and wind
stresses. Because of heavy sediment loads in summer
and treacherous ice flows in winter, the upper inlet
has not been extensively used for commercial or
recreational purposes. Because of these negative
properties, little concern has, until recently, been
given to its capacity to assimilate man's wastes. Its
strong currents and mixing, however, make it much
more suitable for waste disposal than most other
Alaskan systems.
In Alaska only isolated cases of water quality
decline, resulting from municipal sewage discharge
into the sea, have been documented. Physical, chem-
ical and biological data indicate that some minor
pollution of Cook Inlet waters near the Chester
Creek and Cairn Point outfalls results from domestic
sewage, but the water mass as a whole has not been
adversely affected by it. Because of its extensive
turbulence and heavy sediment loads, large quanti-
ties of domestic waste, as much as 7.6 X 106 m3/day,
can be discharged into the inlet without causing
serious water degradation (Murphy et al., 1972).
Thus a population of two to three million people
could safely dispose of their domestic waste water
into the inlet.
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294
ESTUAKINE POLLUTION CONTROL
in Ketchikan, Alaska, domestic sewage disposal
consists of septic tanks and drain fields, cesspools
arid seepage pits, or piping raw sewage into the
tidewaters of Tongass Narrows (State of Alaska,
1967). Most of the sewage is believed eventually to
reach salt water either by surface or underground
drainage or by direct piping to points near water's
edge on shore. The raw sewage 0111 falls are responsi-
ble for the large numbers of coliform bacteria found
in the adjacent waters of Tongass Narrows, particu-
larly Bar Harbor. The eutrophication of the water-
front area by nutrients resulting from the sewage
has not been studied. Studies have indicateel, how-
ever, that state bacteriological water quality stand-
ards are exceeded in many areas along the Ketchikan
waterfront. Fecal solids and shredded toilet paper,
which are potential health hazards as well as aesthet-
ically offensive, are often observed .ilong the shoreline
and floating within Bar Harbor, near Bar Point and
alongside the Dock, Mission, and Mill Street area.
The stratification of the low density discharged
sewage near the sea surface, slovv ne.arsh.ore tidal
currents with net northward movement in Tongass
Narrows, and an onshore wind component all tend
to concentrate Ketchikan sewage discharges in the
surface waters of the1 waterfront area, and to move
it slowly northward past the city.
In other areas of Alaska, particularly where re-
stricted flo\\ of seawater is inherent or little has
been done to utilize the assimilative capacity of the
ocean for waste oxidation, isolated cases of water
quality decline have resulted. Often, as in the case
at Ilinkiuk Bay, Unalaska Island, and Kodiak
Island, the combined effects of fishing industry
wastes and municipal sewage wastes, have resulteel
in low oxygen water. Low oxypeii water is not,
however, a very serious problem in Alaska because
the environmental conditions generally prevailing
lead to very high surface water concentrations of
dissolved oxygen. The concentration of dissolved
oxygen seems more controlled by the oceanography
of the continental shelf than by locally imposed
influences.
EVALUATION OF PREVIOUS PROGRAMS
AND DISCUSSION OF TRENDS
Until recently, waste disposal in Alaska was done
by the least expensive way. Industries and munici-
palities have generally discharged their primary
wastes into streams, rivers, or estuaries without
even the benefit of deep water outfall disperser sys-
tems. Little control of effluent quality or quantity
was administered until the advent of the pulp mills
in southeast Alaska and petrochemical plants in
Cook Inlet.
The first modern waste disposal system in Alaska
was that of the Collier Carbon and Chemical Com-
pany liquid ammonia and urea fertilizer plant located
north of Kenai on the east banks of Cook Inlet. The
company, after careful examination of the waters
of Cook Inlet, including circulation, ammonium
and nitrate cycling, and biological population assays,
designed a discharge system which utilizes jet dif-
fusers and the turbulence of the inlet to lower the
concentration of the fertilizer ammonium well below
harmful levels within about 10 feet of the discharge
pipe. This system has operated according to de-
sign since 1969 with no evidence of harm to the
environment.
Municipalities are presently facing the require-
ments for secondary sewage treatment before dis-
charge into the environment. Studies conducted in
connection with municipal effluents released into
Cook Inlet from the city of Anchorage give no
evidence that secondary treatment is necessary or
even desired environmentally (Murphy et al., 1972);
likewise there appears to be no reason to demand
this level of treatment of other municipalities who
discharge into the coastal waters of Alaska. Each
situation and location should be examined to assess
the capacity of the receiving waters to assimilate
the planned discharge. The decision concerning
secondary waste treatment plant requirements should
rest on those findings. To systematically force most
coastal Alaskan cities to construct secondary treat-
ment plants when the environmental capacity to
assimilate municipal waste is enormous, is not in the
best public interest.
Many plants which process the fisheries products
of the State of Alaska are also being forced to
comply with the secondary treatment effluent re-
quirements. In the past, these plants have dis-
charged untreated wastes, often representing up to
75 percent of the catch by weight, into the water
immediately adjacent to the plant, and have
depended upon tides and scavenging organisms to
keep the solid residues at a low enough level to avoid
offensive surface exposure. Requirements no\v dic-
tate that solids be removed and processed in some
other mariner. At Kodiak, the major Alaskan
fishing port, many of these solid wastes are processed
commercially and converted to an animal feed
marketed on the west coast of the United States.
The water soluble portion of the fish wastes also has
considerable value for protein feed supplements,
but such processing plants have not yet been con-
structed in Alaska. To treat these water soluble
-------
NUTRIENTS
wastes by a secondary sewage treatment process
appears unadvisable for two major reasons. First,
the protein in the water has high food value; and
second, discharge of untreated waste through out-
falls designed to keep concentration levels com-
patible with the environment would at least return
some of the energy to the system from which it was
derived, thus yielding some environmental advan-
tage. This process could in most cases be accom-
plished at a lower cost.
The recent trend in Alaska, because of enforce-
ment by government regulatory agencies to adopt
effluent standards uniformly administered through-
out the country with no regard to environmental
quality, can only lead to devastation of Alaska's
renewable resources. We must understand the eco-
systems involved well enough to assess possible
damage resulting from the stress of added effluents.
Discharge of any amount of wastes that might result
in damage to an ecosystem is foolhardy. Likewise,
it is ludicrous to impose restrictions on waste dis-
charges if it can be clearly established that the
system can easily handle the loading involved
without damage. If the environment itself is the
real concern, as it should be, then industries must
develop and install effluent discharge systems that
are compatible with the environmental situation in
which they find themselves rather than being forced
to meet some general specified waste or water
quality standard. A scientifically alert and flexible
attitude toward Alaska's effluent practices is badly
needed as we begin developing the state's resources.
A much better understanding of the oceanography
of AJaskan coastal systems should be the first
priority followed by a management plan responsive
to environmental needs and not political expediency.
RESULTS WHICH OFFER
DIRECT USE IN ALASKAN
ESTUARINE MANAGEMENT
Throughout this paper we have attempted to
point out the uniqueness of the Alaskan environment
and emphasize the need for better environmental
understanding upon which decisions can be wisely
made that will protect it, and at the same time
utilize it for waste disposal and extraction of the
resources needed to benefit man. The concept of
trade-offs becomes important in environmental
management and, in general, is a viable philosophy
to be used in Alaska.
To comply with a recent NPDES permit, to
become effective January 1, 1977, a urea plant at
Kenai will need to spend $1,500,000 in capital
improvements and consume 500,000,000 BTU's of
energy per day to reduce its present ammonia
effluent (about 3500 kg/day) to meet the best
practical technology for ammonia effluents. Docu-
mentation has shown that the ammonia currently
released by this plant is not harmful and is probably
beneficial to the biota of Cook Inlet, and the revised
scheme would put the ammonia into the atmosphere
where the environmental hazards are much greater.
The expenditure of energy and capital investments
for what appears to be of questionable value environ-
mentally, cannot be justified. Even if there was
a slight environmental advantage, the justification
for using large capital and amounts of energy for
marginal environmental improvement is probably of
negative social benefit. Other cases in Alaska could
be indicated, particularly where heated effluents are
concerned, in which large expenditures of both
money and energy are being imposed without
realizing any apparent environmental benefits.
In today's modern world social benefit must weigh
heavily on decisions to utilize energy to reduce
effluent concentrations unless environmental benefits
can be conclusively demonstrated as a result of this
energy consumption. Most effluents of the chemical
industry are waste materials to that industry. They
could, however, be a feed stock of considerable; value
to the bioengineering industry. Alaska, with its
great potential for aquaculture (Kelley and Hood,
1973), should turn its attention to using these
wastes for enhancement of food or marine product
producing systems. Some institutional barriers will
need changing for such a system to be developed,
but it seems of such importance in helping meet
some of man's future needs that it should be
thoroughly explored and activated as soon as pos-
sible. Perhaps a more rational approach, other than
imposing strict effluent standards in Alaska, would
be a requirement for converting waste materials into
useful feed stocks for bioengineering projects in-
cluding aquaculture. Would this not be an en-
lightened attitude directed toward solving mankind's
ever increasing needs for food supplies?
REFERENCES
Baalsrud, K. 1967. Influence of nutrient concentration on
primary production. In: T. A. Olsen and F. F. Burgess
(eds), Pollution and Marine Ecology. Interscience Pub-
lishers, New York: p. 159-169.
Brickell, D. C. and J. J. Goering. 1970. Chemical effects of
salmon decomposition on aquatic ecosystems. In: R. S.
Murphy and D. NyquLst (eds), International Symposium
on Water Pollution Control in Cold Climates. U.S. Govern-
ment Printing Office, Washington, B.C.: p. 125-138.
-------
296
ESTUARINE POLLUTION CONTROL
Federal Water Quality Administration, Alaska Operations
Office, Northwest Region. 1970. Effects of pulp mill wastes
on receiving waters at Ward Cove, Alaska.
Hood, D. W.. W. E. Shiels and E. J. Kelley (eds). 1973.
Environmental Studies of Port Valdez. Institute of Marine
Science, University of Alaska. Occasional Publication
No. 3.
Kelley, E. J. and D. W. Hood ('eds). 1973. Aquaculture in
Alaska Workshop: Sitka, Alaska April 10-13, 1972. Insti-
tute of Marine Science. Public Information Bull. 73-1,
University of Alaska.
Ketchum, B. H., C. L. Carey, and M. Briggs. 1949. Pre-
liminary studies on the viability and dispersal of coliform
bacteria in the sea. In: Limnological aspects of water supply
and waste disposal. American Association for Advancement
of Science, Washington, D.C.
Kinney, P. J., D. K. Button and p. M. Schell. 1969. Kinetics
of dissipation and biodegradation of crude oil in Alaska's
Cook Inlet. Present at the Joint Conference on Prevention
and Control of Oil Spills: American Petroleum Institute;
Federal Water Pollution Control Administration, December
14-17, 1969, New York, N.Y.
McRoy, C. P. and J. J. Goering. 1974. Coastal Ecosystems
of Alaska. In: H. T. Odum, B. J. Copeland and E. A.
McMahan (eds), Coastal Ecological Systems of the United
States. The Conservation Foundation, Washington, D.C.
1:124-131.
Murphy, R. S., R. F. Carlson, D._Nyquist and R. Britch.
1972. Effect of waste discharges into a silt-laden estuary:
A case study of Cook Inlet, Alaska. Institute of Water
Resources, University of Alaska. Report AO, IWR 26.
Pease, B. C. 1974. Effects of log dumping and rafting on the
marine environment of Southeast Alaska. USDA Forest
Service General Technical Report PNW-22.
Pederson, L. H. 1965. United States. 1. Area and boundaries.
In: Encvclopedia Americana. Americana Corp., New York
27: 473-475.
Pritchard, D. W. 1952. Estuarine hydrography. In: H.
Landsberg (ed), Advances in Geophysics Academic Press
New York 1:243-280.
Rosenberg, D. H. 1972. Oil arid gas seeps of the Northern
Gulf of Alaska. In: D. H. Rosenberg (ed), A Review of the
Oceanography and Renewable Resources of the Northern
Gulf of Alaska. Institute of Marine Science, Univorsitv of
Alaska, Report No. R72-23: p 143-148.
Schaumburg, Frank D. 1973. The influence of log handling
on water quality. Office Res. Monitor, EPA. Washington
D.C.
State of Alaska, Department of Environmental Conserva-
tion, Water Quality Control Section. 1971. Inventory of
water dependent log handling and storage facilities in
Alaska.
State of Alaska, Department of Health and Welfare, Division
of Public Health. 1967. Water supply and waste disposal
in the Gateway Borough.
United States Department of Commerce, National Oceanic
and Atmospheric Administration, National Fisheries
Service. 1973. Fisheries of the United States, 1972.
Zenkevitch, L. 1963. Biology of the Seas of the U.S.S.R.
John Wiley and Sons, New
-------
ENVIRONMENTAL STATUS
OF HAWAIIAN ESTUARIES
STEPHEN V. SMITH
University of Hawaii
Kaneohe, Hawaii
ABSTRACT
Hawaiian estuaries are small but numerous, and they are of importance to the State of Hawaii.
With a few exceptions, detailed environmental information about these estuaries is lacking. Circu-
lation in the estuaries is sluggish. Many of the estuaries fail to meet water quality standards set by
state law; this failure represents the combined effects of unrealistic standards governing excessive
discharges. The major human stresses imposed on the estuaries are the introduction of nutrients,
freshwater, and sediments. More research directed at the estuaries as total systems is needed.
INTRODUCTION
In simplest terms, an estuary is an area in which
fresh and salt waters conic together.* This mixing of
waters has led to the development of a rich and
productive coastal zone ecosystem, with an influence
that extends far beyond the physiographic bounda-
ries of the estuary. This biotic importance of estu-
aries, together with their widespread use for com-
mercial and recreational purposes, mandates that a
better understanding of estuarine ecosystems be
available for the intelligent management and preser-
vation of such a valuable resource.
Some Hawaiian estuaries contain beautiful quiet-
water coral reef assemblages unlike any biotic com-
munity found elsewhere in the United States (Smith
et al., 1973). The estuaries are breeding and spawn-
ing grounds for a variety of commercially valuable
fishes (Miller, 1973; Watson and Leis, 1974).
Several species of seabirds, listed as rare and en-
dangered, inhabit the nearshore. environment (Ber-
ger, in Armstrong, 1973). The estuaries are popular
areas for fishing, boating, swimming, and camping.
One estuary (Kaneohe Bay) also serves as the site
for ongoing research by both the state and the
federal governments. It is in the interest of ecology,
economy, recreation, and scientific research that this
report has been prepared.
According to the report by Cox and Gordon
(1970), approximately 50 features in the state may
be broadly classified as estuarine systems. Figure 1
* "... the term 'estuarine zones' means an environmental system con-
sisting of an estuary and those transitional areas which are consistently
influenced or affected by water from an estuary such as, but not limited
to, salt marshes, coastal and mtertidal bays, harbors, lagoons, inshore
waters, and channels, and the term 'estuary' means all or part of the mouth
of a navigable or interstate river 01 stream or other body of water
having unimpaired natural connection with open sea and within which the
sea water is measureably diluted with fresh water derived from land
drainage." (P.L. 89-753)
is an index map of the Hawaiian Islands, and
Figures 2 through 6 show each of the Hawaiian
Islands which have significant estuaries. The loca-
tions of these features are noted. Most Hawaiian
estuaries are small, with water areas well under
1 km2. Existing charts for most of these features are
not sufficient to show significant bathymetric or
other detail. The larger estuaries and other embay-
ments are illustrated in the atlas by Grace (1974).
Even the two largest estuaries are small in com-
parison with their North American (or other con-
tinental) counterparts. These estuaries are im-
portant, nonetheless. Because these features are
small, they are particularly vulnerable when sub-
jected even to relatively minor environmental insults.
The total estuarine area of the state is estimated
here to be about 100 km2. It is impossible to judge
accurately the coastal area outside the estuaries but
within the legally defined estuarine zone; however,
some; limits can be imposed. If the mean width of
the estuarine zone is 50 meters (surely an overesti-
mate for most of the Hawaiian coastline), then only
another 100 km2 of estuarine zone are added to the
100 km2 estimated for the true estuaries, bringing
the total Hawaiian estuarine zone to less than
200 km'.
This figure is probably satisfactory within the
legal limits of the estuarine zone, but it is deceptive
in terms of the importance of the Hawaiian coastal
zone. Because the State of Hawaii as a whole is a
small watershed in comparison with the North
American continent, the zone of freshwater influence
about the Hawaiian Islands is small in comparison
with the zone of such influence off North America.
In relative terms, however, the zone vulnerable to
impact from activities on land may not be greatly
different from Hawaii to the mainland of North
297
-------
298
ESTUARINE POLLUTION CONTROL
FIGURE 1.—The main islands of the Hawaiian chain. Of
these, Niihau, Lanai, and Kahoolawe lack significant estuaries.
Honalei River a Buy,
Waipa fl WQioli Streams
.Kolihiwoi Bay & Str
Kiloueo Bay 6 Str
Molooo Bay
Kapaa Stream ft
Canals
Hanamaulu Bay 8 Sir
Nowiliwili Bay ft Harbor
Huleia Stream
!anapepe River 9 Bay,/
"Wahiowo Bay
FIGURE 2.—Kauai Island, estuaries.
America. Indeed, the large bights which scallop
most of the Hawaiian Islands (Figures 2-6) are
already the subjects of concern to local environ-
mental scientists and should be the subject of
another report such as this one.
Table 1 helps to put the scale of Hawaiian estu-
aries into proper perspective. The ratio of estuarine
area to the state's land area is only about half the
equivalent ratio for the total United States. How-
ever, the ratio of tidal shoreline length to total land
area is an order of magnitude larger for Hawaii
than for the rest of the nation. That is, there is a
close spatial relationship between the land of the
state and the coastline.
The distribution of population is also instructive.
The recent Atlas of Hawaii (Armstrong, 1973)
reveals that about one-third of the state's population
lives immediately adjacent to one of the major
estuaries in the state. Both culture and climate have
FIGURE 3.—Oahu Island, estuaries.
10 KM
Fishponds
FIGURE 4.—Molokai Island, estuaries.
FIGURE 5.—-Maui Island, estuaries.
acted to enhance the utilization of estuaries and the
coastal zone by the people of Hawaii, so that even
those persons who do not live near the water are
likely to frequent it.
There are also small embayments in the state (e.g.,
Hanauma Bay, Oahu; Honaunau and Kealakekua
Bays, Hawaii) which are renowned for their beautiful
reefs. These bays are subject to insufficient fresh-
water inflow to qualify as estuaries, but nevertheless
could be devastated with a relatively small degree
of thoughtless activity. The summaries of the biology
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NUTRIENTS
299
Pololu Stream
Waipio Sfr«am
Hilo Bay,
Wailuku a
Woiloa Str
Keoukaha
FIGURE 6.—Hawaii Island, estuaries.
Table 1.—Comparison of Hawaiian estuarine dimensions with the scale of
estuaries found in the remainder of the U.S.
Total area (km2)
Estuarine area (km?)
Tidal shoreline (km).
Estuarine area/total area__
Tidal shoreline /total area j
U.S. exclusive
of Hawaii
9,350,000
117 000
136,000
0.013
0.015
Hawaii
16,700
100
1,700
0.006
0.10
of Kealakekua and Honaunau Bays (Doty, 1968a
and b) are particularly instructive in this regard.
Kaneohe Bay is the largest well-defined embay-
ment in the state. This embayment on the north-
eastern coastline of the island of Oahu (Figure 3)
occupies an area of about 50 km2, less than half of
which is truly estuarine in character. Pearl Harbor,
Oahu (Figure 3), with a water area of about 20 km2,
is the second largest estuary in the state and may
be considered a classical estuary throughout its
extent. These two estuaries are also the most widely
studied Hawaiian estuarine systems, although even
they are insufficiently known. Other large Hawaiian
estuaries include the Keehi Lagoon/Honolulu Harbor
complex, Oahu (Figure 3); Nawiliwili Harbor,
Kauai (Figure 2); and Hilo Harbor, Hawaii (Figure
6). Some data on water quality and circulation are
available for these last three systems, but virtually
no biological information, other than hearsay and
very limited biological observations, is available for
these estuaries.
Because of the general lack of adequate informa-
tion, an attempt to document the environmental
status of the Hawaiian estuarine zone has proven to
be a frustrating undertaking. Some aspects of this
problem for the state as a whole have been recently
summarized by Cox and Gordon (1970). That report
dealt with estuarine water quality, a subject for
which there is a great deal of information. Even
that data base is, for the most part, insufficient for
establishing trends through time. The circulation
patterns of several Hawaiian estuaries have also
been described, although these data have not been
so recently summarized as has water quality.
Quantitative information about the biological status
of most Hawaiian estuaries is almost totally lacking.
The biology of only two of the larger Hawaiian
estuaries (Kaneohe Bay and Pearl Harbor) has
been examined in any detail; some fragmented in-
formation about a few other estuaries is available.
Much of the information which has been collected
is difficult to locate because it is buried in private
or government files. It would be well worth the
expense to retrieve this information. There are
numerous studies of particular Hawaiian nearshore
regions aside from estuaries. As discussed above, the
degree of terrestrial freshwater influence on these
regions is so small that they do not qualify as part
of the estuarine zone, although even these areas may
be subject to damage, potentially or presently, In-
human activities along the Hawaiian coastline.
ESTUARINE CIRCULATION
Knowledge of the circulation of an estuary is of
particular importance in assessing environmental
integrity, because the characteristics of water circu-
lation determine the residence time of pollutants in
the system, or portions thereof, and hence determine
the possible damage those pollutants may do to the
system. There is limited information describing some
aspects of circulation in numerous Hawaiian estu-
aries.
The most comprehensive survey to date on this
subject is that of Laevastu et al., (1964), dealing
with the general currents of Hawaiian inshore
waters. Much of that information, plus some addi-
tional observations, is reported in the recent Marine
Atlas of Hawaii (Grace, 1974). Detailed circulation
studies of a few Hawaiian estuaries are available
(e.g., Bathen's 1968 description of Kaneohe Bay;
and Buske's 1974 description of Pearl Harbor).
Most available studies of Hawaiian estuarine circula-
-------
300
ESTUARINE POLLUTION CONTROL
Table 2.—Water quality standards pertinent to Hawaiian estuaries. From Cox
and Gordon (1970)
AA
Class of water
"A T
Substance
A. BASIC
tion are far less comprehensive than the ones cited
above, involving current measurements at only a
few localities within any particular estuary and
under a narrow range of oceanographic conditions.
Tidal ranges are relatively small in Hawaii (about
1 meter), and river input into estuaries is generally
small. Except during periods of heavy runoff, the
larger estuaries are not strongly stratified. Largely
lacking the energy SOUrCeS of tidal flushing and ' Se«leable materials forming objectionable de-^ ^
major river flow, the circulation o;' the estuaries is 2 Floating debris, oil, scum, etc "..'_"_....'; o o o
Strongly related to wind patterns (e.g., Buske, 1974), 3. Suostances producing objectionable color,:
i ] • a - i. J.L ± , T» ii odor, taste or turbidity - j 0 0 0
to wave-driven flow into the estuarme areas (Bathen, 4 Matena,s lnc|udmg Jm;mM^-m ~~: j
1968), and to tidal and wind-driven ocean currents trations or combinations which are toxic or j
Sweeping by, Outside of the estuaries (Wyrtki produce undesirable physiological responses i i
i ,;?/.«% ' i" human, fish and other animal life and ! !
etal., 196/). _ _ _ piants , o| o o
Despite their small size, Hawaiian estuaries 5. Substances, conditions, or combinations pro-'
generally flush rather slowly, chiefly because water . "ucing undesirable aquatic life.^ ^ o o o
' , , *>• Soil from controllable accelerated erosion _ __ 0 0 0
movement depends, to a large extent, on the least I
effective of the previously-mentioned energy sources. B'SPECIFIC j j
Buske (1974) has estimated that some of the water i. Microbiological I | i
in Pearl Harbor may have a residence time of more ' ^e'a°™ ctena(/ °°ml> ]t< n low)
than four days. Dr. J. Caperon (Hawaii Institute of upperdeciie < 2400
Marine Biology, personal communication) has sug- „ Ma*' 8.0 I 7.0 I 7.0
i- ,1 • , i? • j. iv A • r j (except fresh tidal water) _ ^ 7.0 !
emphasize the importance of intelligent, informed 3. Nutrients (mg/hter) 1 !
estuary management. Total phosphorus _j< 0.020 0.025 | 0.030
Total nitrogen J< 0.10 I 0.15 020
4. Dissolved oxygen (mg/hter)
WATER QUALITY (except from natural causes) J>6.0 J50 4.5
^ 5. Total dissolved solids.
TDS departure from natural (% of natural
Water quality is surely the best-documented fluctuation) 10
general environmental parameter of Hawaiian estu- 6 ™ ^[un«"Fj ~ Z8'°00
aries. The fact is undoubtedly true because water Departure from natural < 1.5 1.5 1.5
quality standards can be objectively spelled out, 7 Turbidity i
,. T ] i ,-t l-i i • i i i Secchi disk extinction coefficient, departure
routinely measured, and thus easily legislated. from normal (%) M «. 5 10 20
Table 2 gives the state's definitions for the three «. Radionuciides
coastal water classes; from best to worst, these are (Mpcn values by NBS> < i/so 1/30 1/30
... , „ „ j/~ij /ni-7n\ v. (concentration) < USPHS v!.'ues for drinking
AA, A, and B. Cox and Gordon (1970) have sum- 1 watef
marized the water quality Of Hawaiian estuaries (concentration in harvested organisms) < Federal Radiation Council
relative to those standards, and a modified version recommended limits
of their summary is presented as Table 3. Several
important aspects of water quality emerge from Table 3._Su.nmary of water quality relative to standards for coastal waters.
these data. Modified from Cox and Gordon (1970)
Most of the waters supposed to be pristine (AA) I j ] j
are considered by Cox and Gordon (1970) to be so. ^ esSes i ummeet,n°gb8bly 'NUnT,fenr,ePet0,ngbly i N,ns±,eWn!h
Kaneohe Bay is probably the most conspicuous I Istandards^ ^ _sta"dani^ J data
exception to this generality. It is obvious from the flA | u| n 3~T Q
data presented by Cox and Gordon that as soon A 65 J 5 j 39 j 21
as some deterioration of water quality is permitted B 1 10j [ I 5 4
or occurs (to class A or B), there is little chance _lllH"_ld i J i
that even these lower standards will be met. Over . Estu3ries with two or more c|asses of water qua|(ty rece,ve mu(t(ple (Wing ,„ this
half the estuaries assesed by Cox and Gordon table.
-------
NUTRIENTS
301
apparently fail to meet the legislated water quality
standards, and most of the violations involve class
A waters. Most of the class B waters for which
data are available fail to meet even these very
permissive standards. Even though water quality
has been cited as the best-known environmental
aspect of the Hawaiian estuaries, with rare excep-
tion, the knowledge of water quality is also, in
itself, insufficient to point to either trends of water
quality change with time for a particular estuary or
spatial trends within the estuary.
Some of the failure to meet legislated standards
lies with the standards themselves; they are arti-
ficially imposed water quality limits with little
allowance for natural variations within those limits.
For example, some nearshore areas with natural
freshwater seeps may locally exhibit salinities and
nutrient levels outside the legislated limits (e.g.,
Honaunau Bay; Doty, 1968). Natural freshwater
seepage may contain, for instance, many times as
much phosphate as open ocean waters, which form
the basis for legislation. Moreover, departures from
legislated limits may not harm particular environ-
ments. In other instances these standards are
probably too permissive for maintaining biological
integrity. We must conclude that water quality
standards are not adequate measures of estuarine
biological integrity.
RESOURCE DEVELOPMENT
RELATED TO HAWAIIAN ESTUARIES
Cox and Gordon (1970) summarized the resource
development pertaining to Hawaiian estuaries. Their
list, divided into various estuarine types within each
estuarine system, is summarized here in terms of the
45 major estuarine systems within the state. The
resource developments can be broadly divided into
water, agricultural, industrial, urban, and estuary;
and each of these divisions can in turn be sub-
divided.
Table 4 lists the divisions and subdivisions of
resource development and their distribution. Water
development, almost entirely in the form of irriga-
tion or storage, appears to be the least disruptive
use of the resources. It simply involves reduction of
water flow into the estuaries, with consequent
potential alteration of salinity and circulation pat-
terns. Most of the estuaries in the state experience
some water loss or diversion for irrigation.
A variety of agricultural developments is felt by
estuaries of the state. Moreover, the open-coast,
non-estuarine zones are subject to much the same
developments. Ranching and sugar cane cultivation
are the two most recurrent agricultural develop-
Table 4.—Summary of recurrent stresses, by island*
Development
Water
Agricultural
Sugarcane ___
Pineapple. _-
Ranching
Miscellaneous
Industrial
Sugar factory
Pineapple factory .
Petroleum refinery . i
Thermal discharge -
Miscellaneous
Urban
Urban cesspools J
Estuarine
Commercial /military harbor
Small boat harbor --
Sewage outfall -_ _.
Fishing**
Recreational**
Number of Estuarine Systems,.
Kauai
12***
12
1
4
14
0
!
0
1
1
,
2
9
2
2
2
2
8
15
Oahu
6
5
3
1
7
1
1
1
1
2
0
s
8
11
3
5
5
2
9
12
Molokai
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
Main
g
2
4
6
0
0
0
1
0
1
2
1
I
1
0
0
11
Hawaii
3
3
0
1
0
0
1
0
0
0
0
1
1
1
1
1
1
1
Total
29
22
8
7
28
1
3
3
1
4
1
8
12
23
7
9
9
5
18
45
* Niihau, Lanai, and Kahoolawe do not have significant estuaries.
** Some fishing and recreational use occurs in most Hawaiian estuaries. The estua-
ries listed experience heavy use.
*** These numbers represent the number of estuaries subjected to each kind of
development.
ments affecting Hawaiian estuaries, with most estu-
aries receiving materials from one or more of these.
Industrial developments are about as diverse as
the agricultural activities but are much more
localized. There are miscellaneous industrial devel-
opments, primarily on the island of Oahu. The
three major discrete categories of insults from in-
dustry are thermal discharges, discharges from sugar
factories, and discharges from pineapple factories.
It should be emphasized that these three activities
also exert profound influence on the open coastline.
The major thermal effect is simply that of heating
the receiving water. Discharges from sugar factories
include sediment, bagasse and other cane trash,
nutrients, soluble organics, and bacteria. The pine-
apple factory discharges include pineapple wastes
and soluble organics.
Urban discharges affect most Hawaiian estuaries.
Those areas with sanitary sewage disposal will
nevertheless contribute trash, detergents, miscella-
neous industrial pollutants, nutrients, and bacteria
during any period of runoff (i.e., heavy rains).
Those areas served with cesspools will contribute
all of the above pollutants, at higher levels. Most
urban areas, but particularly the multiplying hous-
-------
302
ESTUARINE POLLUTION CONTROL
ing developments less than 10 years old, are par-
ticularly susceptible to the erosion and runoff of
large volumes of water and sediment.
The last category of resource development is that
of the estuaries themselves. In terms of numbers of
estuaries affected, various recreational uses prevail.
These activities, as well as fishing, introduce miscel-
laneous boat sewage and trash into the waters.
The uses of estuaries in the state for commercial/
military harbors and small boat harbors contribute
the same kind of wastes (but in larger amounts
than recreational uses) plus oil, bilge discharges,
industrial pollutants of various forms (including
heavy metals), and disruptive activities from dredg-
ing. The stirring of the water column and sediment
has been recently pointed out as almost certainly
important (Evans et al., 1974), but it is not clear
whether the net effect of this activity is beneficial
or deliterious.
EFFECTS OF RESOURCE DEVELOPMENT
ON HAWAIIAN ESTUARINE BIOTA
Available information is inadequate for providing
an assessment of the biological status of most
Hawaiian estuaries. Only Pearl Harbor and Kaneohe
Bay have been studied in any detail. Hence an
alternative approach for discussing the status of
Ihese communities is taken. The various resource
developments listed in Table 4 lead to a relatively
small variety of kinds of stresses (or stimuli) to
which the environment is subjected. It is possible
either to document or to speculate how the biotic
communities could be expected to respond to these
stimuli. The stresses considered here include salinity
variation, sediment, discharges, nutrient enrichment,
and thermal enrichment. Insufficient data are avail-
able for tropical organisms to judge the damages
from oil, heavy metal, or biocide pollution, but
these and related stresses are judged from evidence
elsewhere to be severely detrimental to marine life.
Hawaiian estuaries arc subjected to two directions
of salinity variation by human intervention. Use of
stream water for irrigation lowers discharges into
numerous Hawaiian estuaries, hence raises their
salinities. Timbol (1972) studied the species dis-
tribution of Kahana estuary (Oahu) and determined
the salinity tolerances of selected species. Over the
salinity range examined (9 to I9%o (parts per
thousand), or 25 to 50 percent oceanic salinity) the
number of species increases with increasing salinity.
It is safe to assume that below 9%c, the species
count increases with decreasing salinity as freshwater
organisms became dominant. If the bulk of Hawaiian
estuarinc waters are considered to be more saline
than 9%o, then lowering the discharges of stream
water into the estuaries should cause an intrusion
of marine organisms into the estuaries.
There is another, perhaps more devastating,
salinity variation imposed upon some Hawaiian
estuaries—that of high freshwater lunoff. The
effect has been well-documented in Kaneohe Bay,
where changing patterns of land usage (including
paving a substantial portion of the watershed and
baring manj acres of topsuil during the construction
of housing) have resulted in tremendous flood dis-
charge into that bay. Banner (1974) has demon-
strated that such runoff creates a freshwater wedge
on top of the more dense seawater. During a single
storm in 1965, such a wedge killed marine organisms
(most conspicuously corals) to a depth of almost
two meters in some portions of the bay. Unpublished
studies by Smith, Jokiel, Key, and Guinther (Hawaii
Institute of Marine Biology) suggest that biotic
microcosms typical of shallow water communities
found in the bay can survive two or more days of
salinities as low as 25%c with little damage, but that
salinities below 20%o are immediately detrimental
to most of the biota. Hence, such freshwater dis-
charges lowering the salinity to near 0%o can be
expected to be immediately damaging to intertidal
and immediate subtidal biota in the marine portions
of the estuaries.
Sediment discharges into Hawaiian estuaries are
a conspicuous parameter arising from numerous
human activities. As described above, runoff from
changing land use is a prominent feature along much
of Hawaii's coastline. Many streams have been
channelized in urban developments and are now
more prone to flooding (Banner, 1974). That runoff
tends to run red with Hawaiian soil. At least one
industry—sugar milling—presently contributes sub-
stantial amounts of sediments (mostly to the open
coast rather than to estuaries). Again, data from
Kaneohe Bay are instructive. Hoy (1970) estimated
that 100 thousand tons of land-derived sediment per
year are being deposited in that bay. Later estimates
of the fraction of Kaneohe Bay sediments which are
land-derived (Smith et al., 1973) indicate that
Roy's figure may be low by a factor of two.
Such sediment inputs are deliterious to estuarine
biota in a number of ways. They may directly
smother corals and other organisms which live at
the interface between the substratum and the waters
of estuaries. They may contain material toxic or
noxious to the biota. In the water they may block
the light from those organisms which photosynthesize
organic products. They may foul the feeding mech-
nisms of those organisms which filter food from the
water. Organic material in the sediments may alter
-------
NUTRIENTS
303
the food-\veb relationships of the community in
question.
Another form of sediment input appears to be
fading from the Hawaiian scene—the discharge of
finely-milled cane trash (bagasse) from sugar mills.
Grigg (1972) has demonstrated that even on open
coastlines there may be tens of meters of accumulated
bagasse on the sea floor offshore from these mills.
Coral-reef communities subjected to such inputs
have been completely demolished. This material
is now finding use in the sugar industry as a valuable
fuel (R. Webb, Hilo Coast Processing Company,
personal communication), so this input should
terminate. Grigg's data demonstrate that the mate-
rial flushes from the open coasts within a few years
after the bagasse input stops. As yet, the time
required for community recovery is unknown. Biotic
population of submerged lava flows is apparently
measured in decades (Grigg and Maragos, 1973).
The flushing and repopulation characteristics of an
estuary may not be even that rapid.
Most Hawaiian estuaries are probably subjected
to some nutrient enrichment. Of course, elevated
nutrient levels are characteristic of most estuarine
systems, and this is one reason (as previously
mentioned) that even some unpolluted waters of the
state may fail to meet the legislated water quality
criteria. Nevertheless, it seems likely that Hawaiian
estuaries may not naturally experience the levels of
eutrophicatiori which typify mainland estuarine
systems. Caperon et al., (1971) have demonstrated
that the southern end of Kaneohe Bay is a highly
eutrophic system which is apparently not limited
by nutrient levels in the water, and Krasnick (1973)
has shown that this eutrophicatiori has increased the
primary productivity of that bay over the past
decade. A bulbous green alga which may be found
as small fist-sized masses on most Pacific coral reefs,
has grown to gargantuan size (some masses being a
meter or more across) in Kaneohe Bay, apparently
in response to this eutrophication (Banner, 1974;
Soegiarto, 1972; Smith et al., 1973). There is
evidence (Banner, 1974; Maragos, 1972) that this
alga has severely damaged the coral community of
the bay and has also otherwise altered the commu-
nity structure of the reefs. The growth of the alga
is likely to represent the combined effects of high
nutrients and low grazing pressures by fishes or
other reef herbivores.
Pearl Harbor is another estuary which has been
subjected to high nutrient inputs. Apparently
phytoplankton blooms ("red tides") are occurring
with increasing frequency and over an increasing
portion of that harbor. (Evans et al., 1974).
Some Hawaiian waters are subjected to thermal
enrichment. Until recent studies by Jokiel et al..
(1974) and Jokiel and Coles (1974) it had been
assumed that Hawaii, with its largely tropical biota
in a subtropical setting would probably not be
greatly damaged by thermal enrichment. That does
not seem to be the case. Summertime ambient tem-
peratures are about 27°C, and that temperature: is
about the optimum temperature for corals and,
apparently, for other biota found on Hawaiian
reefs. These organisms may be able to tolerate an
enrichment of 1 or 2°C above ambient, but further
temperature elevations are detrimental. Even open
water reefs have been damaged by thermal enrich-
ment (Jokiel arid Coles, 1974), albeit very locally.
Table ,"> lists the various resource developments,
the number of estuaries subjected to each, and the
likely stresses from each. The column sums provide
an index of the relative importance of the various
stresses on Hawaiian biota. Nutrient enrichment,
decreased salinity, and sediments are by far the
most recurrent stresses imposed upon the estuarine
communities. Inputs of biocicles and heavy metals
are also important. Only 4,5 estuarine systems were
used in the construction of Table 4, hence Table 5;
yet all of the above insults appear over 45 times in
Table o. This situation addresses the fact that the
estuaries are for the most part subjected to multiple
stresses—a consideration which will probably make
the job of removing insults all the more difficult.
Table (> summarizes the expected biotic responses
to five major stresses. It is clear that more experi-
mental data are sorely needed to verify most of
these responses in tropical communities. Equally
needed is an improved data base describing the
Hawaiian estuaries. In particular, there appears to
be a lack of foresight in obtaining baseline data
before any projected environmental alteration —
whether that alteration is predicted to be good, bad,
or benign --or to combine that data with post-
alteration descriptions, in order to describe the
biotic responses to that alteration.
NEEDS FOR ENVIRONMENTAL
MANAGEMENT OF HAWAIIAN
ESTUARINE SYSTEMS
Table ,"> suggests that nutrien ts may be the primary
stressing parameter imposed upon Hawaiian estu-
aries. Virtually every human activity appears to
have the potential of delivering nutrients to these
estuaries. Thus, any regulation to lower discharges
appears likely to improve the nutrient status of
Hawaiian nearshore waters. Various considerations
suggest that a change from uncontrolled nutrient
input to controlled input may be as satisfactory as
-------
304
ESTUARINE POLLUTION CONTROL
fable 5.—Stresses imposed by various resource developments.
Water ! 29
Agriculture
Sugar cane j 22
Pineapple _ \ S
Taro | 7
Ranching i 28
Miscellaneous ... , 1
Industry
Sugar 3
Pineapple _ ___ 3
Petroleum 1
Thermal _ J 4
Quarry.. __ _ __J 1
Miscellaneous _ J 8
Urban j
Sanitary sewage... j 12
Cesspool _ ..- 23
Estuaries
Commercial/military harbor 7
Small boats ._ 9
Sewage __ 9
Fishing | 5
Recreational _. ] 18
Total __ _ _ j
X
X
X
X
X
X
X
X
X
.£5
124
29
X
X
X
X
X
X
X
X
X
113
X
X
X
X
X
X
X
X
X
X
X
X
X
X
163
X
X
X
X
X
X
X
60
X
X
73
no input—or perhaps more satisfactory. Without
going into these considerations, suffice it to point out
that the uncontrolled discharge of nutrient-laden
water into Hawaiian estuaries must be slowed if these
environments are to be preserved and maintained.
Improved sewage treatment facilities are a major
move in the direction of controlling this nutrient
flow. The State of Hawaii is moving toward this
goal. Discharges of treated or untreated sewage
into the estuaries must stop. Indeed, federal and
Table 6.—Likely effects of major stresses on estuarine biota.
Nutrient Enrichment
Eutrophication, algal blooms (benthic and planktomc), oxygen stress, alteration of
community structure through food-web modification or competitive pressures,
buildup of organic material in sediment.
Lowered Salinity
Abrupt destruction of marine communities.
Sedimentation
Smothering, light blockage, blockage of feeding mechanisms, introduction of ad-
sorbed toxicants.
Biocides
Possible abrupt destruction of marine communities or portions thereof. Buildup in
marine organisms, with possible long-term effects on these organisms or on man.
Heavy Metals
Similar to biocide effects.
local agencies are working towards this goal; the
15,000 m3/day of sewage presently being discharged
into Kaneohe Bay is scheduled to be diverted by
the end of 1977. Runoff from agricultural regions
may be more difficult to control, but it should be
minimized. Dumping of material from ships is a
debatable practice at sea; in harbors, it should not
be allowed.
Slowing the freshwater and nutrient inputs into
the estuaries should simultaneously stop much of
the sediment input. Hence that input need not be
discussed as a separate topic.
Finally, more data are needed. The water quality
data, which are collected routinely, are certainly
vital, but they do riot substitute for an adequate
knowledge of the organisms themselves. Because
biotic data are more difficult to gather, the tech-
niques for gathering and reporting these data
should be increasingly researched and developed.
Some sort of local data bank for central storage of
these data is also needed; with adequate funding,
the Hawaii Coastal Zone Data Bank (University of
Hawaii) could serve that function. Increased fund-
ing is necessary to demonstrate quantitatively the
biotic responses to various environmental stresses.
Such work should include both field observation and
laboratory experimentation. The biotic experimental
and observational work cannot be expected to yield
-------
NUTRIENTS
305
short-term results. Because of the great disparity
in the longevities of organisms in any community,
the total community responses to external stimuli
take years. Therefore, the necessary field or labora-
tory observation times must be of similar magnitude.
Particular attention needs to be paid to low stress
levels as they affect total communities. The day of
assessing environmental insults from lethal bioassays
over periods of days on a few arbitrarily chosen
organisms should be over. For the most, part,
Hawaiian estuaries, or any other ones for that
matter, are not subjected to that kind of stress
regime. Yet Hawaiian estuaries are obviously chang-
ing in response to human perturbations. A new look
is necessary to learn why.
It is certainly desirable that EPA fund a portion
of the much-needed research, but other federal,
state, and local governmental agencies, and private
industries should fund environmental research as
it pertains to the effects of their activities on the
estuarine environment. Much of this funding could
be handled in terms of some kind of "blind trust"
and be administered by an appropriate agency, so
that the funding agencies or industries could not be
questioned about their influence on the research.
Alultidisciplinary. total-system research and moni-
toring must be encouraged and amply funded. It is
the lack of efforts such as these which makes realistic
assessment of the total environment not entirely
satisfactory. Research by the Hawaii Environmental
Simulation Laboratory (University of Hawaii) is a
step in the right direction. Their work is also not
entirely satisfactory; it concentrates primarily on
terrestrial considerations (hence inputs to estuaries)
without adequate consideration of effects on receiv-
ing waters and their biota. Nevertheless, that kind
of study carries the needed potential for interaction
between research units and governmental planning
agencies. That kind of effort needs expansion to
include the marine environment.
The small size of both the Hawaiian estuaries and
the watershed draining into them makes these S3rs-
tems particularly tractable to total-system descrip-
tion arid analysis. It is therefore appropriate that
Hawaii bo the site for concentrated efforts to describe
and improve the environmental status of estuaries.
Bathen, K. H. 1968. A descriptive study of the physical
oceanography of Kaneohe Bay, Oahu, Hawaii. Univ.
Hawaii, Hawaii Inst. Marine Biol. Tech. Report 14.
Berger, A. J. 1973. In: R. W. Armstrong (ed), Atlas of
Hawaii. Univ. Hawaii Press.
Buske, N. L. 1974. Tides, runoff and currents. Section 3.3.
In: E. C. Evans, III et al., Pearl Harbor biological survey—
final report. Naval Undersea Center TNI 128, Hawaii
Laboratory.
Caperon, J., A. S. Cattell and G. Krasniok. 1971. Phyto-
plankton kinetics in a subtropical estuary: eutrophication.
Limn. Ocn. 16:599-607.
Cox, I). C. and L. C. Gordon. 1970. Estuarine pollution in the
State of Hawaii. A statewide study on estuarine pollution
in the State of Hawaii. Univ. Hawaii, Water Resources
Research Center Tech. Report 31, V. 1.
Doty, M. S. 1968a. Biological and physical features of
Kealakekua Bay, Hawaii. Univ. Hawaii, Hawaii Botanical
Science Paper No. 8.
Doty, M. S. 1968b. The ecology of Honaunau Bay, Hawaii.
Univ. Hawaii, Hawaii Botanical Science Paper No. 14.
Evans, E. C. Ill et al. 1974. Pearl Harbor biological survey—
final report. Naval Undersea Center TN1128, Hawaii
Laboratory.
Grace, J. M. (ed). 1974. Marine Atlas of Hawaii, Bays and
Harbors. Sea Grant Misc. Report UNIHI-SEAGRANT-
MR-74-01. Univ. Hawaii Press.
Grigg, R. W. 1972. Some ecological effects of discharged
sugar mill wastes on marine life along the Hamakua Coast,
Hawaii. In: Papers presented Jan. 1972 to May 1972.
Water Resources Seminar Series No. 2. Univ. Hawaii,
Water Resources Research Center, pp. 27-45.
Grigg, R. W. and J. E. Maragos. 1973. Recolonization of
hermatypic corals on submerged lava flows in Hawaii.
Ecology 55:387-395.
Jokiel, P. L. and S. L. Coies. 1974. Effects of heated effluent
on hermatypic corals at Kahe Point, Oahu. Par. Sci.
28:1-18.
Jokiel, P. L., S. L. Coles, E. B. Gviinther, G. S. Key, S. V.
Smith and S. J. Townsley. 1974. Effects of thermal loading
on Hawaiian reef corals. Final Report for EPA Grant
# 18050DDN.
Krasnick, G. J. 1973. Temporal and spatial variations in
phytoplankton productivity and related factors in the
surface waters of Kaneohe Bay, Oahu, Hawaii, M. S. Thesis,
Univ. Hawaii.
REFERENCES
Armstrong, R. W. (ed.). 1973. Atlas of Hawaii. Univ. Hawaii
Press.
Banner, A. H. 1974. Kaneohe Bay, Hawaii: urban pollution
and a coral reef ecosystem. In: Proc. Second Int. Coral
Reef Syrup. V. 2, p. 685-702.
Laevastu, T., D. E. Avery and D. C. Cox. 1964. Coastal cur-
rente and sewage disposal in the Hawaiian Islands. Univ.
Hawaii, Hawaii Inst. Geophys. Report 64.
Maciolek, J. M. and R. E. Brock. 1974. Aquatic survey of
the Kona Coast ponds, Hawaii Island. Univ. Hawaii,
UNIHI-SEAGRANT-AR-74-04.
Maragos, J. E. 1972. A study of the ecology of Hawaiian
reef corals. Ph.D. Thesis, Univ. Hawaii.
-------
306
ESTUARINE POLLUTION CONTKOL
Miller, J. M. 1973. Nearshore distribution of Hawaiian
marine fish larvae; effects of water quality turbidity and
currents. Proc. Int. Syrap. on Early Life History of Fish,
Oben, Scotland.
Roy, K. J. 1970. Change in bathymetric configuration.
Kaneohe Bay, Oahu, 1882-1969. Univ. Hawaii, Hawaii
Inst. Geophys. Report 70-15.
Smith, S. V., K. E. Chave and D. T. O. Kam (in collaboration
with others). 1973. Atlas of Kaneohe Bay: a reef ecosystem
under stress. Univ. Hawaii, UNIH1-SEAGRANT-TR-72-
01.
Soegiarto, A. 1972. The role of benthic algae in the carbonate
budget of the modern reef complex, Kaneohe Bay. Ph.D.
Thesis, Univ. Hawaii.
Timbol, A. S. 1972. Trophic ecology and macrofauna of
Kahana Estuary, Oahu. Ph.D. Thesis, Univ. Hawaii.
Watson, W. and J. M. Leis. 1974. Ichthyoplankton of Kaneohe
Bay, Hawaii. A one-year study of fish eggs and larvae.
Univ. Hawaii, UNIH1-SEAGRANT-TR-75-01.
Wyrtki, K., J. B. Burks, R. C. Latham and W. Patzert. 1967.
Oceanographic observation during 1965-1967 in the
Hawaiian Archipelago. Univ. Hawaii, Hawaii Inst. Geo-
phys. Report 67-15.
This paper is Contribution No. 470 of the Hawaii Institute
of Marine Biology.
-------
INDUSTRIALIZATION
EFFECTS
-------
-------
THE EFFECTS OF
INDUSTRIALIZATION
ON THE ESTUARY
ROBERT B. BIGGS
University of Delaware
Newark, Delaware
ABSTRACT
Industrial dependence on the estuary is restricted to those industries which rely on the estuary
for waterborne transportation, for process water, or for products derived from the estuarine waters
or bottom sediments Among these, crude oil handling, refineries and petrochemical plants, utilities,
iron and steel production, paper manufacturing, and sand and gravel extraction are the more im-
portant industries. Channel dredging, spoil disposal, and a wide range of pollutants resulting from
industrial discharge are described.
Responsible federal agencies seem to be approaching the problem of industrial pollution from the
perspective of reducing impacts by adopting water quality standards. In the short term, that is the
most expedient solution. In the longer term, though, we must assess the possibility of reducing
impacts by relocating certain estuarine-dependent industrial centers to new, more environmentally
acceptable sites.
INTRODUCTION
When the United States was still an agriculture
based society, ports were developed to transport
goods and products from the hinterland. Ports were
generally located as far inland as possible and road-
rail transport systems were developed in response to
port location. A* the country evolved into an in-
dustrialized society, these ports became the hubs
of industrial activity. Industrialists took advantage
of the fact that water transportation for the ship-
ment of raw materials and products was cheap,
the harbors contained abundant water for cooling
and waste disposal, and a supply of workers was
already available'. Through the "late J9th and early
20th centuries, industrial activity, the quantity and
diversity of effluents, and the population all increased
around these ports. Technology of ship construction
developed so that drafts of larger ships grew beyond
the water depth" in most of these ports. Because
major industries were located at the ports, large
dredging programs were undertaken to deepen the
channels. After the channels were deepened, new
industries had to locate along them to receive or
ship materials.
Throughout the development phase of the ports,
occasional fish kills would occur and there was a
general decline in commercial nVhery production of
our estuaries. Beginning in 1 ho mid-20th century,
researchers studying estuarine processes began fo
document the biological importance of the estuary
as a spawning and nursery ground for a significant
part of the entire coastal area. Oceanographers
learned that circulation of waters in estuaries is
generally weak, and that they have a limited
capacity to absorb pollutants.
We find ourselves in the present situation of
having major industrial centers, dependent on water
transportation, located on estuaries which are not
deep enough to handle modern ships, are not large
enough to assimilate wastes, and which are incred-
ibly valuable as a biological-recreational natural
resource.
WlM n dealing with the effects of industrialization
on the estuary, this paper will address those problems
unique to estuarine areas which have arisen through
increasing industrial activities in the estuarine
environment, and will delineate individual industrial-
estuarine pollution problems and discuss possible
solution. Afore specifically, the report will examine
pollution problems in estuaries, identify factors that
actually pollute, investigate the effect of control on
the estuarine environment as a whole including
human activities, and describe the procedures, if
possible, for gaining control of such factors. For the
purposes of this report, the period from 1970 to the
present will be emphasized.
This paper will not deal with pollution resulting
directly from agricultural activity, from domestic
sewage or from non-point source discharges such as
storm runoff. Industrial effluents discharged into
the freshwaters or the nation's air and carried to
the estuary will not be considered.
309
-------
310
ESTUARINE POLLUTION CONTROL
INDUSTRIAL DEPENDENCE ON
THE ESTUARY
Uses and Projections
For purposes of this study, industrial "depen-
dence" on the estuary will be restricted to those
industries which rely on the estuary for waterborne
transportation, for process water, or for products
derived from the estuarino waters or bottom sedi-
ments.
Waterborne transportation of bulk materials for
the year 1971 is summarized in Table 1. Data are
presented for coastal U.S. ports, excluding the Great
Lakes.
Our basic industries (petroleum, coal and coke,
iron and steel) are the principal users of our coastal
waterways both for foreign and domestic commerce
(sand and gravel are significant commodities in
domestic commerce). The transportation of large
quantities of these bulk commodities implies that
related processing/refining/utilizing industries are
also located on our coastal waterways. From the
point of view of marine transportation, we have at
least three candidate industrial complexes which are
dependent on the estuary:
1. Crude oil handling, associated refineries, and
petrochemical plants;
2. Iron, steel, and closely allied metal fabricating
industries; and
3, Industries using coal, coke, asphalt, and tar
either as an energy source or as a raw material.
An estimate of the kinds of industries dependent
on large volumes of process and/or cooling water
can be obtained by examining Table 2. Industries
having major surface discharges have been cate-
gorized by the EPA. Three of these industries, the
chemical, paper, and utilities industries represent
47 percent of the major industrial discharges to the
Table 1.—Total waterborne commerce (Calendar, 19/1). Coastal ports of the
United States (millions of short tons).
Table 2.—Industrial discharges by industry group*
Number of Permits
Foreign
Total 506.5
Imports 333.8
Exports -- . j 172.7
Petroleum and Products . _' 38.7%
Coal and Coke 11.7%
Iron Ore and Steel ^ 12 5%
Sand Gravel and Stone _| 2.2%
Gram ., 6.8%
Chemicals . -- ..- . . _.H 5.8%
logs and Lumber j 3.8%
All Others 1 18.5%
Domestic
242.
44.
14.
8.
12
2
5
2.
11.
q
(1%
9%
?%
1%
n%
1%
a%
1%
Chemical and Allied Products,
Paper and Allied Products
Electric and Gas Utilities
Textiles
Fabricated Metal Products
Iron and Steel
Petroleum and Coal Products.
All Others
522
407
392
151
149
142
136
902
* Source- National Water Quality Inventory, 1974
surface waters of the United States. Some of these
large water users are the same ones which utilize
the estuary for transportation. These include the
iron and steel (including metal fabricating) and
petroleum and coal industries. The chemical industry
(including inorganic acids and salts, organic fibers,
plastics and pigments, and drugs, cosmetics and
soaps), paper industry, and utilities industry have
been added to the list.
The third group of industries which are estuarine
dependent are those which extract materials directly
from the water or bottom of the estuary. Desaliniza-
tion plants extract fresh water from estuaries while
other industries extract bromine, magnesium, cal-
cium, and sodium that is dissolved in the waters of
the estuary. Sea shells (a source of calcium and
lime), and sand and gravel, are taken in large
quantities from the bottom of our nation's estuaries.
Industry Projections
Where data are available, projections for future
requirements in each of the estuary dependent
industries have been made. These projections are
for the entire industry in each case, and do not
necessarily indicate the pressure to locate new
facilities on estuaries.
The industry profiles for petroleum refining, petro-
chemical manufacturing, and paper products have
been developed by D. M. Bragg, associate research
engineer, Industrial Economics Research Division,
Texas A & M University and have been extracted
here with the author's permission.
PETROLEUM REFINING
In the U.S. today, there are 247 petroleum refine-
ries with an average daily capacity of 57,555 barrels.
Three refineries have capacities of over 400,000
barrels per day each and four have over 300,000.
Many of these refineries can be expanded but some
cannot—either because of limitations of space or
-------
INDUSTRIALIZATION EFFECTS
311
Company
Table 3.—Refineries planned but not constructed
Location I Size (B/D)
Final Action Blocking Project
Shell Oil Co 1 Delaware Bay, Del.
Riverhead, L.I.
South Portland, Me.
Searsport, Me.
Fuels Desulfunzation (1)
Maine Clean Fuels (1)
Maine Clean Fuels (1)
Georgia Refining Co. (1) j Biunswick, Ga.
Northeast Petroleum ! Tiverton, R. I.
Supermarme, !nc i Hoboken, N.J. |
i
Commerce Oil | Jamestown Island, B.I. Narrangansett Bay ;
Steuart Petroleum (2)
Olympic Oil Refineries, Inc..
Pmey Point, Md.
Durham, N.H.
150,000 State Reacted by Legislature Passing Bill Forbidding Refineries in
Coastal Area.
200,000
200,000
City Council Opposed Project and Would Not Change Zoning.
City Council Rejected Proposal.
200,000 ! Maine Environmental Protection Board Rejected Proposal.
200,000 ] Blocked Through Actions of Office if State Environmental Director.
65,000 i City Council Rejected Proposal.
100,000
50,000
100,000
Hoboken Project Withdrawn Under Pressure From Environmentalist
Groups. Considering State Near Paulsboro, N.J.
Opposed by Local Organizations and Contested in Court.
Withdrawn Due to Pressure From Environmental Groups.
400,0001 Withdrawn After Rejection by Local Referendum.
(1) Maine Clean Fuels and Georgia Refining Company and subsidiaries of Fuels Desulfunzation and the refinery in question is the same in each case, so the capacity in B/D is
not additive, but the incidents are independent and additive.
(2) Again being introduced.
Source: "Trends in Refinery Capacity and Utilization," Federal Energy Office, Washington, D.C., June, 1974.
because they are not well sited logistically to meet
the increasing demand.
The gulf coast currently has 16 percent of the
U.S. demand but has approximately 40 percent of
the country's refining capacity. On the other hand,
the east coast has 40 percent of the demand but
only 12 percent of the refining capacity. Based on
assessments of site availability and limitations
arising from environmental pressures, it is now
anticipated that a number of the new refineries,
which otherwise would have been built in the east,
will be constructed instead on the gulf coast. Table 3
lists a large number of announced or planned
refinery projects which have been postponed or
have doubtful promise. It is significant to note that
all of the refinery sites listed in Table 3 are located
along estuaries.
PETROCHEMICAL MANUFACTURING
Historically, petrochemical production has been
closely tied to the output of natural gas liquids
CNGL) produced in natural gas processing plants.
In these plants natural gas, comprised of over 90
percent methane, is stripped of its butane, propane
and part of its methane.
As a result of the decreasing supply and increasing-
price of XGL, the future expansion of olefin manu-
facturing facilities will be based almost exclusively
on heavy oil feedstocks. Facilities using heavy oil
feedstocks accounted for only 12 percent of all
cthylene produced in 1970. This type of production
will be up to 24 percent of the total by 1975; and
by 1980, it is expected that just under 50 percent
of all ethylene produced will be generated from
heavy liquids. As a result, consumption of heavy
liquids in the manufacture of olefins will rise from
130,000 barrels a day at present to 780,000 barrels
a day by 1980. The heavy liquids, such as naptha
and gas oil, are produced from petroleum. And,
because of this, the locations of future petrochemical
complexes will be even more closely linked to those
of oil refineries than in the past.
The location of future expansion in the industry
will be determined more by the availability of
feedstocks than by any other factor. In view of the
transition to heavy cracker feedstocks, potential
feedstock availability will increasingly be determined
by refinery location which, in turn, will be deter-
mined by crude oil supply. Therefore, the gulf
coast would no longer continue to have a clear-cut
locational advantage, and the advantages of freight
savings on finished products should make the east
coast a more attractive location. If the oil refining
capacity of the east coast experiences large increases,
then a strong likelihood exists that there would be a
corresponding increase in basic petrochemical capac-
ity in the region,
ELECTRIC POWER
Fossil and nuclear energy sources form the basis
for almost all U.S. electric production. Presently
designed systems generate large quantities of waste
-------
312
ESTUARINE POLLUTION CONTROL
Table 4.—Growth of summer peak electric demand 1974-1983 as projected by
regional reliability councils April 1,1974; contiguous United States
Year
1974
1975
1976
1977
1978
1979
1980
1981...
1982
1983
MW
364 244
394 005
427,995
460 377
494 848
531 699
570,798
612.252
656 793
703 774
Annual Increase (%)
8 17
8 63
7 57
7 49
7 45
7.35
7.26
7 27
7.15
Source: Federal Power Commission, Bureau of Power Staff Report, June 24, 1974.
heat which must be removed from the plant site,
either by cooling towers, cooling ponds, or once-
through cooling with discharge into a body of water.
Demand for electrical energy, recently revised
downward due to conservation practices resulting
from the "energy crisis" are presented in Table 4.
A fossil fuel plant with once-through cooling
requires about 600 gallons per minute (GPM) of
cooling water for each megawatt (MW) of electricity
produced. Nuclear plants require about 900 GPM
of cooling water per MW of electricity. Some of the
waste heat of fossil plants goes directly up the stack
but nuclear plants dissipate almost all their waste
heat through the cooling system. In both cases, the
temperature of the discharged water would be 15°F
higher than the intake water.
Environmentalists had initially been most con-
cerned with thermal pollution of estuaries because
of the large volumes of hot water discharged. It now
appears that the major impact of once-through
cooling is not thermal pollution of the discharged
water but the killing of most or all of the organisms
sucked up by the pumps and passed through the
plant. Fortunately, the installation of cooling towers
can reduce the quantity of water required to 1 to
3 percent of the volume needed for once-through
cooling.
The solutions to this critical problem are: (1) to locate
power plants along the open coast where there is deep-
water nearby for strategic placement of intake and
outlet structures, and, (2) to reduce the volume of cooling
water by requiring plants to use closed cycle sysiems
which reeirculate cooling waters, rather than the open
cycle systems which continuously withdraw and dis-
charge large volumes of water from the environment.
(Clark and Brownell, "Electric Power Plants in the
Coastal Zone," American Littoral Society Publication
#7, 1973.)
Power generation facilities can be sited on the
coast; they do not require docks, large labor forces,
downstream or satellite industries and their product
can be shipped over long distances at modest cost.
_ PAPER PRODUCTS
Demand for paper and paper products has in-
creased about 3.5 percent per year. Capacity esti-
mates for the 730 paper plants are presented in
Table 5.
In addition to the; basic fiber ra\v materials, water
and limestone are used in paper making. The lime-
stone can be acquired from either mines or oyster
shells. Both sources are used quite extensively,
depending upon the proximity of the source, the
abundance of the material, and other factors.
There are two major papermaking processes, the
sulfite and the kraft. The sulfite process, however, is
a major water polluter and is gradually being
phased out. Although the. kraft process does not
pollute water as does the .sulfite method, it has an
odor problem resulting from the sulphur used in
manufacturing.
Large quantities of wastewater are discharged
into rivers and streams. Pollutants are either
stripped from the discharge or nullified by sufficient
treatment. Solid wastes, such as bark and particu-
lates, are burned.
SAND AND GRAVEL PRODUCTION
These products, used for fill, building, and paving
amounted to 914 million tons in 1970. About 90
million tons were mined from the estuaries of the U.S.
in that year. As land values increase in onshore
areas arid as industry recognizes that large quantities
of sand and gravel occur offshore and in our estu-
aries there will be increasing pressure to utilize these
materials.
Table 5.—United States paper and paperboard capacity, annual summary
1972-1976 (thousands of short tons)
Grades
1972
1373
19/4
1975
1976
Total All Grades Paper and
Paperboard .' 61,868 i 64.431 b6.09S 68,377
Total Paper
Total Paperboard,
69,736
26,545 I 2',394 ' ?/ 954 28,633 29,!2!-
29,328 3!),565 ' 31,482 32,986 ', 33.749
Total Construction Paper and
Board and Other
5,995 ' 6,47? 6 662 > 6,776
6,862
Source" "1972-1975 Capacity Survey," American Paper Institute, New fork, N.Y.,
May,1974.
-------
INDUSTRIALIZATION EFFECTS
IKON AND STEEL MANUFACTURING
Since 1950, the demand for metals in the United
States has tripled. By the year 2000 it is expected
to triple again. Recent forecasts put crude steel
requirements by the year 2000 at 293 million tons
for the United States.
Total iron ore requirements for the United States
should reach 156 million tons per year by the year
2000. As Table 0 shows, imports of foreign iron ore
through east coast ports should attain an annual
level of 37.8 million tons by the same year, nearly
one-fourth of United States consumption. It seems
as though there will be increased reliance on foreign
ore, shipped by water to U.S. ports, and presumably,
processed there.
ENVIRONMENTAL EFFECTS
OF INDUSTRIALIZATION
OF THE ESTUARY
The environmental effects of industrialization
include physical modifications of the estuary, the
introduction of substances toxic or harmful to aquatic
organisms, and the introduction of materials hazard-
ous to human health or which impact aesthetic
values.
Physical Modification
of the Estuary
Our ports are located at or near the heads of
estuaries and channels need to be dredged and
maintained to serve these ports. The size of ships
serving U.S. ports projected to the year 2000 is
presented in Table 1'. Note particularly the draft of
the vessels.
The maximum channel depth of any U.S. harbor
is 45 feet. It is quite clear that a large amount of
dredging must be accomplished or the docking
facilities must be moved out of the upper reaches of
our estuaries. Investment in existing harbors is
quite large (Table 8) and will serve as a deterrent to
moving the facilities.
Of the total investment for these U.S. harbors,
a significant portion is expended for dredging and
related spoil disposal activities.
The Corps of Engineers, in fulfilling its mission in the
development and maintenance of these (navigable)
waterways, i.s responsible for the dredging of large
volumes of sediment each year. Annual quantities are
currently averaging about 300,000,000 cubic yards of
maintenance dredging operations and about 80,000,000
cubic yards in new work dredging operations with the
total annual cost now exceeding $150,000,000. (Boyd
et al. Corps. Tech. Rpl. H-72-8).
Table 6.—Tonnage of iron ore imports to North Atlantic by origin and destination
(millions of short tons)
Destination
Baltimore
Delaware River
Total ]
1970
9.2
12.5
21.7
1980
14 8
14.1
28 9
,990 i
17 3 i
16.6 '
33 9 !
2000
20.3
17.5
37.8
Source: "Interim Report—Atlantic Coast Deep Water Port Facilities Study," U.S.
Army Corps of Engineers, Philadelphia, Pa., June, 1973.
Tsble 7.—Projected vessel characteristics 1970 to 2000
Freighters
Maximum DWT in world fleet.
Length (feet)
Beam (feet)
Depth (feet) j
Draft (feet) _
Average DWT in world fleet..
Bulk Carriers
Maximum DWT in world fleet.
Length (feet). . _,
Beam (feet)
Depth (feet)
Draft (feet)
Average DWT in world fleet.-
Tankers
Maximum DWT in world fleet..
Length (feet)
Beam (feet)
Depth (feet)
Draft (feet) ._,
Average DWT in world fleet
1970
25,500
850
108
74
36
8,168
105,000
870
125
71
48
14,750
300,000
1,135
186
94
72
39,825
1980
33,500
930
117
80
39
8,853
185,000
1 040
152
84
57
18,750
760,000
1,460
252
129
98
76,225
1990
43,500
1 010
127
85
40
9,043
317,000
! 230
183
99
66
23,575
1,000,000
1,570
276
142
104
94, 325
2000
50,000
1 050
132
88
40
9,350
400,000
1 3?5
198
106
71
27,350
1,000,000
! 570
276
H2
104
94,325
Source: Science and Environment, Vol. 1, Panel Reports of the Commission on
Marine Science, Engineering and Resources
Table 8.—Summary of federal investments in coastal harbors, 1824-1966
(in thousands of dollars)
Depth: 30 feet and over
Atlantic coast
Gulf coast
Pacific coast
Subtotal ...
Related Investments2
Gulf coast
Pacific coast
Subtotal
Construction
Expenditures
I
420,910
181 593
127 684
731,519
23 147
12 065
32 483
79 402
Maintenance
Expenditures
406,275
122,5%
128,363
657,314
5 665
6,387
23,723
49,958
Total 1
Expenditures
i
827,085 j
304 189
256 047
1,388,833
28 812
18,452
56 206
129 360
Non-Federal
CosH
29,624
29 844
38 227
97 695
2 579
3 609
14 215
20,479
> Monetary value of local contribution identified in project authorization documents
»Additional federal construction items required to sustain functional utility of
projects, but not incorporated in basic project.
Source: Science and Environment, Vol. 1.
-------
314
ESTUARINE POLLUTION CONTROL
The most obvious environmental effect of dredging
is the destruction of bottom-dwelJing organisms and
habitat. All other factors being equal, the same
kinds of organisms will repopulate the new bottom
so long as the substrate is the same as that of the
original bottom. If the material being dredged
contains silt or clay, a "plume" of turbid water will
drift down current from the dredging operation. In
extreme cases, the turbid water can cause clogging
of the gills or filtering apparatus of marine organisms
;m<] or smothering of bottom living organisms under
a Manket ot deposited materials.
Other potentially serious effec:s of dredging in-
clude changes in water circulation patterns (tidal
exchange, flushing rate, stratification, et cetera).
Effects of Disposal
of Dredged Material
If the material dredged for the channel consists
mostly of sand and/or gravel it is usually referred
to as "fill" and is suitable as a core for a breakwater
or an artificial island. On the other hand, if the
material is silt or clay it is referred to as "spoil"
and is a problem to dispose of without potential
environmental effects.
The worst possible environmental conditions for
spoil disposal would probably be similar to those
encountered in a dredging operation in northern
Chesapeake Bay. The material to be spoiled was
all :-ilt and clay, was hydraulically dredged, and was
dumped on a submerged disposal area. Even though
th< end of the discharge pipe «~as directed down-
ward, a large plume of suspended sediment moved
down current from the discharge point. The disposal
are i did not contain the deposited sediment within
its limits. The spoil apparently spread as a semi-
liquid across the relatively flat bottom, covering a
larger area than outlined as the disposal site. The
character of semi-liquid silt and clay is such that
maximum slopes measured are 1 :100 (on a flat
bottom, a pile of spoil built to a height of 1 ft. will
spread at least 100 ft. horizontally in all directions)
and average slopes are 1:500.
Biological effects observed in the Chesapeake
disposal operation were riot severe. The bottom
dwelling organisms in the spoil receiving area were
wiped out but new populations quickly reinvaded
the spoil. It was found that some seasons of the year
have less potential for damage both because or-
ganisms are less active and/or migrate from the
region. If silt and clay are anticipated in the dredg-
ing operation, then methods of dredging and sites
and seasons of disposal should be chosen to minimize
biological effects. As a generalization, silt and clay
are less likely to be encountered at port locations on
the shelf than at locations inside the estuary.
Estuarine silts also have a higher probability of
being polluted with materials transported from the
upper estuary.
Effects of Construction
of Breakwaters or Islands
These structures remove from productivity the
bottom environment beneath them. However, riprap
or other protective materials surrounding islands
and breakwaters create new habitat for marine
organisms. So long as these structures are not built
on ecologically "rich" bottom, the new habitat
created probably represents a neutral or beneficial
effect on the biota.
Breakwaters and artificial islands undoubtedly
cause changes in the current and wave patterns in
nearby areas. These structures can disperse or focus
wave energy on nearby coasts, or by changing cur-
rent velocities, can cause erosion or deposition of
sediments with associated effects on bottom living
organisms. Breakwater and island design must con-
sider the ecological effects of altered current or
wave patterns.
HEAT
Table 9 illustrates the use of cooling water by
U.S. industry.
One, of the major reasons why temperature is so
biologically important is that the rates of chemical
reactions are temperature-dependent. Since biologi-
cal processes are ultimately controlled by the rates
of enzyme-regulated reactions, it is not surprising
that digestion, circulation, respiration, and reproduc-
Table 9.—Use of cooling water by U.S. industry
Industry
Electric power
Primary metals
Chemical and allied products...
Petroleum and coal products...
Paper and allied products
Food and kindred products
Machinery ^
Rubber and plastics .,
Transportation equipment
All others j
Total
Cooling Water Intake
(billions af gallons)
40 ,680
3 387
3,120
1,212
607
392
164
128
102
273
50,065
Percent of Total
81.3
6.8
6.2
2.4
1.2
0.8
.3
.3
.2
.5
100.0
Source Federai Water Pollution Control Administration, "Industrial Waste Guide on
Thermal Pollution," September 1968.
-------
INDUSTRIALIZATION EFFECTS
315
tion increase with rising temperature. In fact, it has
been noted that in the vicinity of power plants
which discharge heated effluents into temperate
waters, many species will reproduce earlier in the
spring and continue to produce larvae later into the
fall than species in the ambient water. The use of
cooling towers and cooling ponds, although more
expensive, is replacing once-through cooling with
discharge to the estuary.
An innovative concept has been the proposal to
construct floating nuclear power plants. All of these
plants would be uniform in construction (present
ground based plants are custom made) providing
less difficulty in licensing procedures, and, presum-
ably, cost savings by production line construction
techniques. The construction of a sea defense system
(breakwater) to protect the plant from storms and
ship collisions is very costly, though. Perhaps such
plants, built at remote sites and placed in coastal
lagoons using the barrier island as a natural break-
water and cold seawater as a cooling medium would
be economically attractive and environmentally
acceptable.
Addition of Substances
Harmful to Estuarine Organisms
Oil spills in United States waters and documented
by the Coast Guard are presented in Table 10. Bulk
storage facilities account for almost twice as much
spilled oil as the next highest contributor, offshore
wells.
Major spills on water are difficult to control and
can cause great environmental damage, especially
if they reach beaches or marshes. The least harmful
spill is one that never occurs. Terminal location and
design should be such as to minimize the possibilities
of a spill. The less handling that the crude oil
receives, the less likely the chances of a spill. For
instance, a transfer operation involving pumping
from tankers to offshore tanks to lighters to refineries
requires three handlings while pumping from tankers
to pipelines to refineries involves only two.
Given that, sooner or later, a spill will occur
during the operation of a terminal, then containment
and recovery operations should begin immediately.
Their success depends on the size of the spill, the
availability of personnel and equipment, and wind
and sea conditions. The closer that a terminal lies
to shore, the more rapid must be the response to
prevent contamination of coastal margins. In an
environmental sense, then, there is greater risk of
shoreline contamination if a port is located within
an estuary or near the coast.
Organic wastes resulting from industrial processes
Table 10.—Polluting spills in U.S. waters—1970
Source
Incidents ! Gallons Spilled Percent of Total
(millions) I
Spills in excess of 10,000 gals. ;
Bulk Storage Facilities
Offshore Wells
Pipelines j
Barges _.j
Transfer Operations
Dumping _|
Industrial Accidents _|
4
14
19
Q
1 ;
6.676
3.553
1.316
1.238
1.021
.500
.367
43.5
22.8
8.4
8.0
6.5
3.2
2.3
L
Source: U.S. Coast Guard.
include compounds that have a high biological
oxygen demand (BOD), which cause a reduction in
the levels of dissolved oxygen in the receiving waters.
The food processing, textile, refining and petro-
chemical industries all contribute significant quanti-
ties of BOD to the environment. The 1974 National
Water Quality Inventory showed a decrease in the
BOD on 74 percent of the major waterways on
which water quality trends have been measured.
Industries most often control BOD of effluent waters
by secondary sewage treatment. Such secondary
treatment can reduce BOD levels by 80-90 percent
but produce about 0.75 Ibs. of sludge per pound of
BOD reduction. A problem then involves disposal
of the sludge. Significant progress is being made in
the reduction of BOD, phenol and ammonia dis-
charges from refineries.
Organic wastes from petrochemical, crude oil
handling, and refinery effluents may be Toxic to
aquatic organisms.
Trace metal concentrations, first publiciz»d by
the levels of mercury in swordfish, have come under-
close scrutiny. The major industrial sources of tlx'so
metals are chemical, metal refining and metal proc-
essing effluents. Toxicity levels of some of these
metals to estuarine organisms are presented in
Table ] 1. Trace metal levels may be low in effluents
but quite toxic to organisms in receiving wafers.
They are difficult and expensive1 to remove.
Health Hazards
Industrial effluents are not major sources of most
human pathogens regarded as health hazards.
Depending on the particular area, though, industrial
effluents may serve as the source of toxic concentra-
tions of trace metals concentrated in organisms
which are consumed by man.
Concentration by biological processes is a phe-
nomenon which is readily demonstrable. It is through
biological concentration that toxic metals find their
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316
ESTUARINE POLLUTION CONTROL
Table 11.—Toxicity levels of metals for several marine organisms (in ppm of
dosage)
Metal
Cadmium
Chromium-
Copper
Mercury
Nickel
Lead
Organism Tested
Eastern Oyster
Eastern Oyster
Eastern Oyster
Nereis sp.
Shore Crab
Small Shrimp
Soft Shell Clam
Soft Shell Clam
Soft Shell Clam
Soft Shell Clam
Mussels
Mussels
Nereis sp.
Nereis sp.
Five Marine
Phytoplankton
Eastern Oyster
Eastern Oyster
Lethal Level
0.10
0.20
0.102
2-10
50.0
10-80
0.50
0.20
0.20
0.10
0.05
0.025
1.5
0.5
0.006
0.121
0.50
Time
15 Weeks at 20°C
8 Weeks at 20°C
2-3 Weeks
12 Days
1 Week, 100%
3 Days at 10"C
23 Days at 10°C
8 Days at 20°C
10 Days at 20°C
10 Days at 20°C
24 Days at 20°C
2-3 Days
4 Days
10 Days
12 Weeks
Table 12.—United States Public Health Service 1968 interim standards for shell-
fish, in ppm of wet tissue weight. Numbers in parenthesis represent average
levels In organisms from Atlantic Coast (after Pringle, 1969)
way into the food web. As an example, let us look at
phytoplankton, the root of the marine food web. One
thousand pounds of phytoplankton support in the
food web the following:
100 pounds of zooplankton or shellfish
50 pounds of small food fish (anchovies)
10 pounds of small carnivores
1 pound of carnivores harvested by man
(Council on Environmental Quality, 1971)
Each level in the food web results in the concentra-
tion of at least some of the heavy metals concen-
trated in the previous levels. In addition, at any
point in this food web, biological concentration may
occur by uptake directly from the surrounding
water, thereby further enriching metal concentra-
tion levels. Table 12 illustrates the interim stand-
ards for acceptable concentrations of metals in
shellfish compared with the average levels found in
Atlantic coast organisms.
SUMMARY
The technology is available to curb most industrial
water wastes. Much has been done, by treatment
and by designing production processes that minimize
waste. More efficient production processes save
money and may improve product quality. Where
improved production processes are not available or
are riot economically feasible, treatment processes
usually exist. Their total estimated costs, as a
percentage of gross sales, are well under 1 percent,
Metal
Zinc
Copper
Cadmium.
Lead
Mercury .
Cadmium, Lead, Chromium and
Mercury Combined
1500 0
(1428.0)
100 0
(91.5)
0.2
(3.1)
0.2
(0.47)
0.2
2.0
Eastern Oyster ' Soft Shell Clam
50.0
(17.0)
15.0
(5.8)
0.2
(0.27)
0.2
(0.70)
0.2
Northern
Quahaug
50.0
(20.6)
15.0
(2.6)
0.2
(0.19)
0.2
(0.52)
0.2
although costs may be much higher for some in-
dustries.
Our major industries are easily identifiable and
the effluents that they discharge are subject to close
scrutiny. In 1968, though, 45 percent of the munici-
pal waste treatment water came from industrial
sources. These can prove very difficult to monitor,
particularly in our older metropolitan areas. We
are just now beginning to quantify and categorize
the pollutant sources to the estuary.
The greatest difficulties still to be solved involve
the effects of industrial activity on the biology of
estuaries. Decision makers need answers to questions
like "How much marsh can be filled without signifi-
cantly affecting the estuary?" and "Where is the
'best' place to locate the next power plant and to
dispose of 1,000,000 cubic yards of spoil?" The
estuarine system including its organisms, is suffi-
ciently variable in time and space that several
years (3-5) are required to get adequate data 011
the major components of the area. Only in the last
decade have we learned enough about estuarine
organisms' nutritional and environmental require-
ments to allow the consideration of controlled en-
vironmental laboratories. Results will not come
quickly from these labs, but they seem to be the
real hope for understanding the effects of environ-
mental perturbations.
By lacking a national policy, we are continuing to
encourage industrial development in the estuaries,
particularly those areas which are already stressed.
Let's look at an example, the refining industry. As
has been mentioned, refineries (at least east coast
refineries) have been established at most of our
ports. A number of new refineries have been proposed
but abandoned, usually on environmental grounds.
Clearly, the proposal to establish a refinery indicates
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INDUSTRIALIZATION EFFECTS
317
that a market exists for the products. But if the
refinery isn't built, where does the product come
from? Existing refineries, located on stressed estu-
aries, expand to increase production. We need a
strong national policy to help "noxious but neces-
sary" industries to find new locations. Offshore
industrial islands (out of state1 jurisdiction) whose
effluents must meet water quality standards may
be an alternative to continued development in
ecologically stressed estuaries. Agencies of the federal
government have been quite innovative and respon-
sive in dealing \vith water quality problems. As an
example, the FPA developed "Criteria for Deter-
mining thi' Acceptability of Dredged Spoil Disposal
to the Nation's Waters " The criteria are strict, and
a number of dredging projects, particularly estu-
p.rine projects, could not pass the EPA criteria. The
Corps of Engineers was responsive to the1 EPA
criteria and launched a .1-year, $30 million "pro-
gram of research . . to develop the widest possible
choice of technically satisfactory, environmentally
compatible, and economically feasible disposal
practices."
Inherent in the above case of cooperation is that
dredging of channels to the ports located at the
head of the estuary will continue indefinitely. The
question that has been posed seems to be "How can
we reduce the impact of industrial pollution in our
estuaries by adopting water quality standards and/or
allotments?" Federal policy seems to be responsive
to that most important question.
I submit that there is another, longer-term but
equally important question that may not have yet
been asked a.nd certainly has not yet been answered.
It is "How can we reduce the impact of industrial
pollution in our estuaries by assisting industrial
centers dependent on water transportation, located
011 estuaries which are not deep enough to handle
modern ships, are not large enough to assimilate
wastes, and which are incredibly valuable as a
biological-recreational natural resource, to find new,
more environmentally acceptable sites?"
Regional groups must initiate work on the iden-
tification of the areas, in an environmental sense,
that can better accept the industrial wastes now
discharged into our estuaries. The National Coastal
Zone Management Act (1.0 IISC, Sec. 14,3-1464)
may serve as an excellent vehicle to achieve this
long-term objective.
REFERENCES
American Paper
API 1972-4975 Capacity Survey. 1974. .;
Institute, New York, N.Y.
Bartsch, Perry. 1974. The Pulp and Paper Industry. American
Paper Industry: pp. 24—25.
Federal Power Commission. 1974. Bulk Power Load and
Supply Information for 1974-1983. Bureau of Power Staff
Report, Washington, D.C.
Federal Power Commission. 1974. Bulk Power Load and
Supply Projections for 1984-1993. Bureau of Power Staff
Report, Washington, D.C.
Annual Review—Developments in the Iron and Steel In-
dustry. 1974. Iron and Steel Engineer, Vol. 51, No. 1:
pp. Dl-48.
Federal Energy Office. 1974. Trends in Refinery Capacity
and Utilization, Washington, D.C.
Gross, M. G. 1970. Analysis of dredged wastes, fly-ash, and
waste chemicals—New York Metropolitan Region (Stony
Brook: Marine Science Research Center, SUNY), technical
report no. 7.
Iledgpeth, J. W., and Gonor, J. J. 1969. Aspects of the po-
tential effect of thermal alteration on marine and estuarine
benthos. Biological Aspects of Thermal Pollution, edited
by P. A. Krenkel and F. L. Parker (Nashville: Vanderbilt
University Press), pp. 80-118.
IDOE. 1972. Baseline studies of pollutants in the marine
environment and research recommendations. The IDOE
Baseline Conference, May 24-26, 1972 (New York: IDOE
Baseline Conference).
Ketchum, B. H. 1969. Eutrophication of estuaries. Eutro-
phication: Causes, Consequences, Correctives (Washington,
D.C.: National Academy of Sciences), pp. 197-209.
Livingstone, D. A. 1963. Chemical composition of rivers and
lakes. Washington, D.C.: U.S. Geological Survey, prof.
paper 440G.
McAleer, J. B., Wicker, C. F., and Johnston, J. R. 1965.
Design of channels for navigation. Evaluation of Present
State of Knowledge of Factors Affecting Tidal Hydraulics
and Related Phenomena (Vicksburg, Miss.: U.S. Army
Engineer Committee on Tidal Hydraulics) report no. 3.
MacCutcheon, E. 1972. Traffic and transport needs at the
land-sea interface. Coastal Zone Management: Multiple
Use With Conservation, edited by J. P. Brahtz (New York:
John Wiley and Sons), pp. 105-148.
Miller, G. W., Garaghty, J. J., and Collins, R. S. 1962. Water
Atlas of the United States (Port Washington, N.Y.: Water
Information Center, Inc.)
Moss, J. E. 1971. Petroleum—the problem. Impingement of
Man on the Oceans, edited by D. W. Hood (New York:
Wiley-Interscience), pp. 381-419.
Oduna, H. T. 1963. Productivity measurements in Texas
turtle grass and the effects of dredging on intercoastal
channel. Publications of the Institute of Marine Science
(Texas), 9:48-58.
Pearce, J. B. 1969. The effects of waste disposal in the New
York Bight—interim report for 1 January 1970.
Reynolds, W. W. 1972. Investing in primary petrochemicals.
Chemical Engineering Progress, Vol. 68, No. 9, pp. 29-35.
SCEP. 1970. Man's Impact on the Global Environment
(Cambridge, Mass.: MIT Press).
-------
318
ESTUARINE POLLUTION CONTROL
Simmons, H. B. 1965. Channel depth as a factor in estuarine
sedimentation. (Vioksburg, Miss.: U.S. Army Engineer
Committee on Tidal Hydraulics), technical bulletin no. 8.
Simmons, H. B., and Herrmann, F. A. 1969. Some effects of
man-made changes in the hydraulic, salinity, and shoaling
regimens of estuaries. Proc. GSA Symposium on Estuaries
(in preparation).
Simmons, H. B., Harrison, J., and Huval, C. J. 1971. Pre-
dicting construction effects by tidal modeling (Vioksburg,
Miss.: U.S. Engineer Waterways Experiment Station),
miscellaneous paper H-71-6.
Sisselman, Robert. 1973. Iron Ore in the United States:
A Profile of Major Mining, Processing Facilities. Mining
Engineer, Vol. 25, No. 9, pp. 45-65.
Sykes, J. E., and Hall, J. R. 1970. Comparative distribution
of molluscs in dredged and undredged portions of a.n estuary
with a systematic list of species. Fishery Bulletin,
68:299-300.
Turekian, K. K. 1971. Rivers, tributaries, and estuaries.
Impingement of Man on the Oceans, edited by D. W. Hood
(New York: Wiley-Interscierice), pp. 9-73.
U.S. Tariff Commission. 1968. Synthetic Organic Chemicals.
U.S. Production and Sales (Washington, D.C.: U.S.
Government Printing Office)
U.S. Department of Interior. 1970a. Mineral facts and
problems (Washington, D.C.: U.S. Government Printing
Office), Bureau of Mines bulletin 650.
Zitko, V., and Carson, W. V. 1970. The characterization of
petroleum oils and their determination in the aquatic en-
vironment. Fisheries Research Board, Canada, technical
report no. 217.
-------
INDUSTRIAL WASTE POLLUTION
AND
GULF COAST ESTUARIES
ROY W. HANN, JR.
Texas A&M University
College Station, Texas
ABSTRACT
The status of gulf roast estuaries is explored with regard to degradation of water quality from a
variety of sources and mechanisms, emphasizing industrial waste effluents. The typical features of
gulf coast estuaries, particularly the limited tidal action, the presence of bays behind barrier
islands, and in many cases, limited flushing, are outlined.
Environmental modification as differentiated from environmental pollution is presented and exam-
ples of the impact of each on Texas gulf coast estuaries is discussed. A hierarchy of water quality
problems is presented and used to document the principal water quality problems in seven selected
Texas estuaries. The causes of the degradation which lowers water quality in these seven estuaries
are listed with emphasis on waste-generating industries.
The Houston ship channel is used as a case study to outline the potential solutions to each of the
individual water quality problems. A plea is voiced for the consideration of novel or innovative
solutions to water quality problems such as the concept of supplemental aeration which is proposed
for the Houston ship channel.
INTRODUCTION
This presentation will explore the status of gulf
coast estuaries with regard to degradation of water
quality from a variety of sources and mechanisms
with emphasis on the role of industrial waste
effluents. Since the .author's major work has centered
on the gulf coast of Texas, the greatest attention
will be directed at these estuaries as tvpical of the
gulf coast area. A map of the Texas gulf coast is
shown as Figure 1.
TYPICAL GULF COAST ESTUARIES
The major feature that differentiates gulf coast
estuaries from those on the east and west coasts is
the limited tidal range found along the gulf. This
phenomenon is demonstrated in Figure 2 where it
may be noted that the tidal pattern for several gulf
coast estuaries follows a pattern from diurnal to
semidiurnal with a range of only one to two feet.
The most significant gulf coast estuaries have
large, shallow bays, separated from the Gulf of
Mexico by barrier islands. These typically have one
or more major rivers entering their landward ends
which bring freshwater into the system. In the
Texas gulf, the inflows to the major estuaries west
of the Neches River arc often small, leading to
relatively slow flushings of the estuaries. For exam-
ple, the upper Houston ship channel has an average
flushing time of 38 days and a flushing time as
great as SO days over 10 percent of the time. The
median flushing period for the ship channel above
Morgan's Point is 30 days and that for Galveston
Bay is 175 days.
This combination of limited tidal mixing and
limited freshwater inflow creates a condition which
is particularly susceptible to the buildup of pol-
lutants and, consequently, to a significant impact
of these pollutants in the water quality.
In the deeper estuaries or in dredged channels,
gulf coast systems are partially stratified with
lighter, less saline water overriding a more saline
deeper layer. The degree of salinity difference varies
from day to day as a function of freshwater inflow
and turbulence generated by tides, wind, ship
traffic, and other forces.
In the shallow bays and the deeper systems after
extensive mixing, the salinity in the top and bottom
layers is the same, creating what is defined as a
homogeneous estuary. Evaluation of the impact of
man's activities on estuaries requires a thorough
understanding of the movement of \\ater masses
and pollutants in these systems.
ENVIRONMENTAL MODIFICATION
Gulf coast estuaries as they existed in the 19th
century have been exposed to a wide range of en-
vironmental modification, as well as environmental
319
-------
320
ESTT"ARISE POLLUTION CONTROL
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-------
INDUSTRIALIZATION EFFECTS
321
DAY
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FIGURE 2.—Typical tide curves for the United States.
-------
322
ESTUARINE POLLUTION CONTROL
pollution. The environmental modification may be
described in this context as changes in the physical,
chemical and biological characteristics of a system
as a result of engineered works and changes in land
use. Environmental modification may result in both
environmental costs and benefits.
In contrast, environmental pollution involves the
direct and indirect discharge of pollutant materials
as effluents from man's activities. Environmental
pollution predominantly results in environmental
costs or degradation with only occasional environ-
mental benefits being demonstrated.
A list of the most important environmental modifi-
cations which affect gulf coast estuaries is shown in
Table 1. The most significant of these in many
estuaries has been the dredging of ship channels
across shallow bay systems and river channels to
higher, more protected land as much as 50 miles
inland from the coastline.
These channels have changed estuarine flushing
arid circulation patterns and altered their salinity
structure. The upstream modification of the river
systems by reservoirs and other structures has also
drastically altered the estuarine systems by affecting
freshwater inflows, altering salinity structure, and
reducing sediment and nutrient inflows.
These environmental modifications have wrought
substantial and continual changes in these estuarine
systems, generally making them more useful to
man. They have also created the physical and
economic climate in which cities, industry, and
commerce have flourished and have brought the
spectre of environmental pollution to our estuaries.
ENVIRONMENTAL POLLUTION
Environmental pollution is defined as the dis-
charge of man's waste products into the environ-
ment. A convenient mechanism to consider environ-
mental pollution is to follow an outline which may
be called the "Hierarchy of Water Quality Prob-
lems" and assess the applicability of each parameter
at it relates to the estuarine environment. This
hierarchy is shown in Table 2. The ordering of the
initial items generally conforms to the order in
which water quality problems were perceived in
Table 1.—Environmental modifications affecting Texas estuaries.
1. Ship Channels
2. Upstream Water Resource Development
3. Water Withdrawals and Returns
4. Drainage of Marshlands
5. Urbanization
6. Sand, Gravel and Shell Dredging
7. Dikes, Jetties and other Structures
Table 2.—Hierarchy of water quality problems.
Pathogenic Bacteria and Related Cohform Indicating Organisms
Oxygen Demanding Organics and Resulting Oxygen Depletion
Inorganic Ions
Nutrients and Resulting Eutrophication
Sediments: Both Organic and Inorganic
Temperature Changes
Heavy Metals
Radionuchdes
Pesticides and Herbicides
Refractory Organics
Oil Pollution
Hazardous Polluting Substances
freshwater streams. However, with our present
technology, any parameter can be the dominant
problem in any given estuary.
Table 3 examines the relative significance of each
of these parameters in selected Texas gulf coast
estuaries. For each estuary, the relative significance
has been rated as H (highly significant, i.e. major
problem), M (moderately significant), L (slightly
significant), and Blank (no known problem). Addi-
tional categories are N for not known and P to
Table 3.—Hierarchy of water quality problems related to selected Texas estuaries
Pathogens
Oxygen Demanding
Organics
Nutrients
Sediments
Temperature
Heavy Metals -,
Radionuchdes
Pesticides &
Herbicides
Refractory Organics..,
Oil Pollution
Hazardous Polluting
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M—Moderate Problem
L—Slight Problem
Blank—no problem at this time
N—Not Known
P—Potential for Major Problem from Spill
Situation
-------
INDUSTRIALIZATION EFFECTS
323
Table 4.—Pollution sources for selected Texas estuaries
Domestic Sewage
Urban Runoff
Agricultural Runoff...
Petrocnenifcal
Petroleum Refining...
Pulp and Paper
Metal Processing
Fertilizer
Power Generation
Dredging of Virgin
Mtls. j
Maintenance Dredging
Marine Commerce
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L
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H
L
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H
H
H
H
H
H
L
H
L-P
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m
L
L
P
H—Major Waste Source
M—Moderate Waste Source
L—Minor Waste Source
Blank—No Significant Waste
P—Potential for Major Problem from Spill
Situation
indicate a potential problem exists, but is not a
chronic situation.
Table 4 carries the analysis further to identify the
sources of the pollution by class in each estuary.
Each of these estuaries, its individual problems and
status will be discussed in following sections.
SELECTED TEXAS ESTUARIES
Seven Texas estuarine systems were selected for
consideration in this presentation. The ones chosen
span the Texas coast from the Neches estuary near
the Louisiana border to Brownsville, the southern-
most ship channel-estuary only a few miles from the
Rio Grande River border with Mexico. The unique
features of the individual estuaries and the role that
industrial waste pollution plays in the overall water
quality problem will be discussed.
The Neches Estuary
The Xeches Estuary has its beginning at the
confluent of the Neches and Sabine Rivers, some
20—30 miles inland from the Gulf of Mexico. This
report is concerned with the lower 23 miles of the
estuary (up to Beaumont, Tex.), which has been
dredged for deep draft navigation. Saline water
penetration above this point will in the future be
prevented by a salt water barrier.
Since the city of Beaumont diverts its domestic
sewage to Taylors Bayou which does not enter the
Neches Estuary, very little domestic waste reaches
this estuary. Similarly, urban runoff loads are not
a major impact. Thus, for all practical purposes, the
Neches Estuary pollution problems result solely
from wastes discharged by the industries which line
its banks. These include a pulp and paper plant, a
sulphur mining operation, a metal processing plant,
two fossil fuel electrical generation plants, and
almost a dozen refinery and petrochemical plants
and related shipping terminals.
The development of these industries during the
1950's and 1960's led to a grossly overloaded condi-
tion with regard to the water quality of the Neches
River. A study carried out by the author in 1969
indicated that a freshwater inflow of over .5,000
cubic feet per second would have been necessary to
achieve the stated water quality standard for dis-
solved oxygen of 3.0 mg/1. Consistent flows any-
where near this figure are not possible from the
Neches River system, particularly as most if not
all of the summer freshwater flow is diverted from
the river for domestic use and irrigated farming.
An initially aggressive program to reduce the
then-loading of 278,000 Ibs. of BOD inflow per day
was begun in 1970, but was delayed to investigate
regional waste treatment. Since that time, the stream
standards have been drastically lowered to require
only 2.5 mg/1 dissolved oxygen one foot below the
water surface at a flow of 1000 cfs. These standards
are questionable because roughly 25 percent of the
time periods of flows below 1000 cfs are expected
in the Neches and the one foot below the surface
sampling location is not considered adequately
representative.
The target waste loadings specified by the Texas
Water Quality Board call for waste load reductions
by 1977 to 20,400 Ibs/day of ultimate oxygen
demanding wastes above River Mile 11 and 26,187
Ibs/day for the entire estuary. If these targets are
achieved along with similar reduction of heavy
metals and other contaminants, substantial im-
provement should be realized.
Further improvement could involve either further
treatment, supplemental aeration, or diversion of
the cooling water discharge from the Gulf States
Power Generation Station to the upper estuary in
order to assure a minimal flow throughout the
estuary.
-------
324
ESTUARINE POLLUTION CONTROL
The Houston Ship Channel
The city of Houston has achieved the distinction
of becoming the third largest port in the nation
even though it is located some 30 miles from the
coastline. Houston is connected to the Gulf of
Mexico by a dredged deepwater channel across 25
miles of the otherwise shallow Galveston Bay and
then, another 25 miles upstream from Morgan's
Point, up what was once the lower reaches of the
San Jacinto River and Buffalo Bayou to its terminus
at the turning basin near downtown Houston.
This deep draft channel is the major lifeline of
the city of Houston and it is along the upper 25 mile
stretch of the channel that the major industries of
the Houston industrial complex are located. The
dominant industries, of course, arc petroleum refin-
ing and petrochemical production, but others found
along the channel include: pulp and paper, metal
processing, fertilizer, power, cement, grain elevators,
and manufacturers of offshore oil field structures.
Warehouses and tank terminals also serve the
area's marine commerce. By 1969, the waste loading
from this industrial complex coupled with the
domestic waste effluents and urban runoff reached,
after treatment, the loading of over 500,000 Ibs/day
of ultimate oxygen demand. Almost all the other
pollutants discussed earlier as part of the hierarchy
of water quality problems were also discharged in
large amounts. The BOD ultimate load overtaxed
the allowable loading of 20-25,000 Ibs/day as deter-
mined by mathematical modeling by a factor of
between 20 and 25 to 1.
During this time the waters in the upper 16 miles
of the channel were completely depleted of oxygen
in every month of the year, black anaerobic sludges
were building up on the bottom at the rate of 2-5
feet per year from sediment and organic waste dis-
charge and the waters were so bacterially polluted
that one gallon of ship channel turning basin water
added to a 20,000 gallon swimming pool would
cause it to be unacceptable from coliform bacteria
count standards.
The industrial waste loadings to the channel
have been reduced dramatically. Whereas in 1969,
two-thirds of the loading excluding urban runoff
was due to industry, now only one-third is industry
related, according to Texas Water Quality Board
figures.
The domestic waste of the city of Houston now
is the major biodegradable organic pollutant load.
In addition to heavy overloads by infiltration, the
city still discharges large quantities of digested
sludge into the channel.
During qeriods of high runoff from Houston, it is
estimated that the urban runoff pollution loading
equals or exceeds the domestic waste loading thus
making it the dominant biodegradable pollution.
The urban runoff also brings nutrients, sediments,
and heavy metals into the channel.
The author has argued that specific pollutants
such as heavy metals, unusual nutrient loads, oil
and hazardous materials, and so forth must be
reduced at each individual source and precautions
taken to insure against major shock loads from spills
and plant upsets. He has also argued that organic
waste loading, being common to all polluters, is
a problem susceptible to a novel cooperative solu-
tion. This Houston ship channel problem and the
options for solution are discussed in greater depth in
a later section.
Galveston Bay
Galveston Bay is the largest bay on the Texas
gulf coast and considered to be most productive,
both economically and ecologically. The bay is
approximately 520 square miles in surface area. The
major freshwater source is the Trinity River which
drains central Texas, including the Dallas-Fort
Worth area. Other sources include the San Jacinto
River, Buffalo Bayou, Clear Creek, and other small
creeks and bayous.
The bay is generally believed to be of good quality
with the exception of coliform bacterial pollution
and the unknown effect of refractory organics dis-
charged by the Houston ship channel complex, and
thermal discharges. The major pollution sources
which impact on the bay and the major environ-
mental modifications to the bay system are listed
in Table 5. The solution to the pollution problems
of this important bay is that of insuring that each
of its inputs is of acceptable quality.
The impact of environmental modification will
probably be of more importance to the bay in the
future than environmental pollution.
Brazos River
The Brazos River differs from the other estuarine
systems in that the river runs directly into the Gulf
of Mexico without having a large bay at its mouth.
The Brazos River has the largest drainage area in
Texas and is partially controlled by upstream rivers.
Flows range from near zero to major floods. Natural
freshwater quality is affected by salt spring dis-
charge and agricultural runoff. The major industrial
discharges consist of saline waste streams from
seawater processing, and petrochemical production
wastes from several plants of a single company,
-------
INDUSTRIALIZATION EFFECTS
325
Table 5.—Environmental pollution and environmental modification of
Galveston Bay
Significant Pollution Sources
1. Houston Ship Channel
2. Bayport Industrial Complex
3. Texas City Industrial Complex
4. Trinity River Inflow
5. Galveston Ship Channel and City of Galveston
6. Power Plant Discharges
7. Clear Lake Drainage Area
Significant Environmental Modification
1. Houston Ship Channel and Associated Dredge Spoil
2. Galveston, Texas City, Bayport and Cedar Bayou Channels and Associated Dredge
Spoil
3. Upstream Water Resource Development on the Trinity River Including the Wallis-
ville Reservoir
4. The Water Diversion from Tabbs Bay and the Houston Ship Channel as Part of the
Cedar Bayou Power Generation Station
5. Upstream Water Resource Development on the San Jacmto River
6. Land Subsidence by Excessive Ground Water Production Centered Around the
Upper Houston Ship Channel
7. Urban Development and Associated Runoff Characteristic Changes Around the
Bay
8. Various Dikes, Jetties, Fish Passes and Other Structures
discharged a few miles above the river's mouth. The
lower reaches of the river also suffer from domestic
waste discharges from cities in the Freeport area.
Current plans for the construction of a superport
off the Texas coast near Freeport will undoubtedly
lead to increased industrial waste loading in the
lower portion of the Brazos River.
Corpus Christi and the
Corpus Christi Ship Channel
Corpus Christi Bay and its inland companion
bay—Nueces Bay, form one of the larger bay systems
on the Texas Coast. A ship channel has been dredged
across Corpus Christi Bay to the city of Corpus
Christi and thence alongside the city for a distance
of 8.5 miles. It is this inner harbor which receives
the heaviest industrial waste loading and which is
included as a separate system for rating purposes.
The quality in the inner ship channel is poor with
regard to some parameters, but is substantially
better than the major ship channels in eastern Texas
mentioned previously. The channel is a useful study
area to indicate how the Neches and Houston ship
channels will behave when their quality improves.
The channel is subject to oil spills from a variety
of commercial and industrial sources, and govern-
mental entities have joined to form the most effective
Oil Spill Control Cooperative on the Texas coast.
This group has cleaned up almost 100 oil spills
ranging from a few gallons to 13,000 gallons. This
organization is serving as a model to potential groups
elsewhere.
Brownsville
The port of Brownsville is a unique estuarine sys-
tem in Texas. Unlike most other Texas ship channels,
the Brownsville shipping channel was not dredged
up an existing river. Dredging the Rio Grande would
have had international implications as well as in-
volving the sediment and other pollutants of the
river. Thus, the channel is entirely manmade for
commercial and industrial purposes. The channel is
also blessed with good quality water and the govern-
ing authority, the port of Brownsville, is carefully
programming development to insure maintenance of
this quality. Only in Brownsville can one fish
successfully in a ship channel turning basin.
TRENDS AND SOLUTIONS
The Houston ship channel is an excellent system
to consider with regard to water quality manage-
ment because the system receives almost all types of
pollutants in significant amounts from nearly every
class and type of polluter. The upper 25-mile segment
of the Houston ship channel is shown in Figure 3.
The system is also significant because classical
solutions to water quality problems will not achieve
required or desired water quality in this system.
Thus, innovative techniques which go beyond tradi-
tional "dilution is the solution," "treatment at the
source," and "classical complete treatment" must be
developed.
These include new analysis techniques for exotic
pollutants, novel advanced treatment methodology
and in situ processes such as supplemental aeration
to improve quality. A brief outline of ship channel
problems and the appropriate solutions are shown in
Table 6.
The problem of oxygen demanding wastes will be
discussed in depth as it demonstrates several of the
points to be made in this presentation. As mentioned
previously, the Houston ship channel in 1969 was
receiving a daily loading of over 500,000 Ibs. of
BODu per day. In layman's terms, this is roughly
the equivalent of 500,000 Ibs. of sugar per day.
By 1973, the loading had been reduced to those
shown in Figure 4. In 1969, about 60 percent of the
problem was industrial wastes, 20 percent domestic
wastes, and 20 percent urban runoff. By late 1973,
the ratios were more like 45 percent urban runoff,
35 percent domestic wastes, and 20 percent industrial
wastes during periods of urban runoff, and 65 per-
cent domestic waste and 35 percent industrial waste
during periods of no runoff.
Also plotted on Figure 4 is the value range for the
assimilative capacity for oxygen demanding material
-------
326
ESTUARINE POLLUTION CONTROL
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INDUSTRIALIZATION EFFECTS
327
Table 6.—Solution matrix, Houston Ship Channel problems
Problem
Solution
Pathogenic Organisms
Oxygen Demanding Organic*
(Domestic)
Oxygen Demanding Orgamcs
(Urban Runoff)
Oxygen Demanding Orgamcs
Nutrients
Sediments
Temperature
Heavy Metals (Industrial)
Heavy Metals (Domestic)
Heavy Metals (Urban Runoff)
Refractory Orgamcs
Oil Pollution
Hazardous Polluting Substances
Higher level domestic waste treatment, effluent
chionnation reduction of sewer infiltration.
Improved secondary waste treatment, advanced
waste treatment and supplemental aeration.
Supplemental aeration.
Improved waste treatment and supplemental
aeration.
Advanced domestic and selective industrial waste
treatment.
Better sewage sludge handling and control of
sediment from land and highway development.
No major solution needed.
Process change and selective waste tieatment.
Elimination of heavy metal discharges to the
sewer system and waste treatment plant opera-
tion for heavy metal removal.
Better identification of pollutants—waste treat-
ment with existing or new treatment processes-
little known in some areas.
Better preventive action. Contingency planning
equipment and training of industry and govern-
ment personnel.
Better preventive action. Contingency planning
equipment and training of industry and govern-
ment personnel.
for each month of the year based on federal-state
water quality standards for the upper Houston ship
channel.
The solution is obvious: namely, the load curve
must be below the assimilative capacity curve. The
traditional manner is to only reduce the waste
loading; however, in this case, the residue waste
loads from high level industrial and domestic treat-
ment plus the urban runoff will still overload the
system. The current reduced loadings still overload
the channel by a ratio which varies from Gl 1 without
urban runoff to 10:1 during runoff periods. The
channel still remains depleted of oxygen in its
upper 10 miles during most of the year.
Occasional sitings of marine life in the channel
after prolonged high inflow-cool temperature situa-
tions, do demonstrate a modest improvment in
quality over that found five years ago, but this has
been publicized out of proportion to the true
situation.
The author has argued that an acceptable interim
solution to the Houston ship channel oxygen balance
is to increase the assimilative capacity of the system
L- DOMCSTI
C S INDUSTRIAL CARBONACEOUS
ASSIMILAIION CAPACITY
JF MAMJ JA SO ND
FIGIJKE 4.—Oxygen demand and assimilation capacity,
Houston ship channel, mile 9 to 24 (1972 values).
with supplemental aeration which can be achieved
at a very reasonable cost. In addition to its cost
effectiveness in terms of social cost and energy
efficiency, the proposed system also provides a
reserve or fail-safe capacity for shock loads and/or
future system loads by new discharges.
The concept is enthusiastically endorsed by the
local Gulf Coast Waste Disposal Authority, the
waste management entity with the authority to
finance, build and operate the system, but acceptance
of the concept has been slow on the federal level
because of the resistance to novel or innovative
solutions to achieve the desired end product of a
cleaner environment.
Surely, more objective consideration can be given
in the future—particularly, when it is realized on
the national level that the goal of zero pollutant
discharge is unachievable and that alternate tech-
nology which protects the environment must be
sought.
SUMMARY AND CONCLUSIONS
The author has presented the UIIHIUO factors
concerning gulf coast estuaries which must be con-
sidered in managing these systems. Foremost are
tide range, geometry inflow varieties, and density
structure. These parameters make their behavior
quite different from most east arid west coast estu-
aries. Environmental modifications within and with-
out the estuarine system which will continue to
bring about change in the physical, chemical and
biological characteristics of these estuaries in the
absence of waste loadings are reviewed. They include
ship channels, upstream water resource develop-
ments, water withdrawals and returns, drainage,
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328
ESTUARINE POLLUTION CONTROL
urbanization, sand, gravel and shell dredging, and
dikes, jetties, and other structures.
The classical hierarchy of water quality problems
is examined to determine their applicability and
importance in the gulf coastal zone in general and
the Texas gulf coast in particular. Included are
pathogenic organisms, oxygen-demanding organisms,
inorganic ions, nutrients, sediments, temperature,
oils and other floatables, heavy metals, radio-
nuclides, pesticides and herbicides, refractory or-
ganics, and hazardous polluting substances.
For several of the Texas gulf coast estuaries, a
matrix is presented which outlines the relative sig-
nificance of these parameters in each system. This
is followed by a matrix which summarizes the source
of the pollutants in these selected Texas estuaries.
Particular attention is given to industrial waste
discharges, with oil refining and petrochemical, pulp
and paper, mining and metal processing, fertilizer,
and power plants predominating. Particular atten-
tion is given to the problems of the Houston ship
channel as these display trends arid make pertinent
points.
Industrial wastes continue to be the dominant
pollutant source in many gulf coast estuaries and
a significant loading in others. Industrial attitudes
toward pollution control still range from public
spirited companies who lead the way in pollution
control to those few bad actors who resist and
avoid any major commitment toward pollution
control until dragged to the courtroom.
Industry as a whole, however, has generally
proved receptive to carrying its load when it has
been effectively demonstrated that a problem really
exists and that a true solution will be achieved by
the steps they have been asked to carry out and
the costs they are expected to bear. All too often,
however, an individual industr- has been asiiied to
clean up when his counterparts have not. This is
particularly evident in the Houston ship channel,
where some industries have had effective treatment
programs for almost a decade while some foot-
dragging industries and the city of Houston have
lagged far behind in cleaning up their effluents.
Even the most responsible industry personnel have
doubts as to the need and economic justification of
some of the requirements they are being asked to
meet—particularly, toward the goal of zero pollution
discharge.
It is validly argued that policy must be more
closely tailored to individual situations and to the
social costs and energy resource situations which
exist today.
With these thoughts in mind, the following list of
recommendations is formulated for consideration for
the country as a whole and particularly, for con-
sideration for gulf coast estuaries.
RECOMMENDATIONS
1. Programs to reduce industrial waste discharges
should be continued. We still have a long way to
go with some industrial discharges to achieve even
basic levels of treatment.
2. Additional programs to characterize wastes
and their impact should bo carried out. There are
still wastes that are not characterized and for which
environmental impact is unknown.
3. Greater effort should be made to use appro-
priate parameters in assessing impact and develop-
ing management plans.
4. Equal effort should be placed on reducing
domestic waste loadings with particular attention
given to reducing the industrial wastes discharged
into municipal systems.
o. Greater effort should be placed on the problem
of urban runoff from cities whose runoff drains into
estuaries. This must include erosion control to limit
sediments.
6. It must be, recognized that every estuary is
different and should be evaluated for its unique
situation, preferably using local scientists and engi-
neers who understand the system.
7. Policy should permit innovative and unique
solutions, i.e. different solutions are appropriate for
different estuaries.
8. Solution choices must include consideration of
social cost and energy efficiency. Policy must be
upgraded to consider the realities of the times.
9. Failsafe systems are necessary to prevent a
single plant breakdown from overpowering the effect
of expensive control programs.
10. Realistic terms should be used to describe
estuary quality or loading as compared to the
allowable loadings based on quality standards. For
example, claims of modest improvements in Houston
ship channel quality, particularly, during high
flow periods should not be allowed to hide the fact
that the system is still overloaded by a ratio of 10:1.
11. Effective control programs for industrial
wastes and domestic wastes should improve the
quality of sediments and reduce pollution potential
of dredged materials.
12. Enforcement activities to stimulate com-
pliance by the few "bad actors" should be renewed.
13. Expanded activity to identify and control the
danger from hazardous chemical substances shipped
in marine commerce should be instigated including
routine bioassay analysis of hazardous materials
shipped in bulk.
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iNDrSTRIAHZATION EFFECTS
329
14. The quest to determine the true cost of zero
pollutant discharge and the accompanying ultimate
disposal of residues should he pursued with the goal
of achieving reasonable solution of our estuarine
problems without generating a backlash which will
stop us short of our goals.
Jo. More attention should be placed on the effect
of environmental modification on estuarine ecology.
REFERENCES
"Waste Management in the Texas Coastal Zone," Environ-
mental Engineering Division, Civil Engineering Depart-
ment, Texas A&M University, prepared for the Office of
the Governor, Division of Planning Coordination, The
Coastal Resources Management Program, Interagency
Council on Natural Resources, September 1972.
Tide Tables—High and Low Water Predictions—East Coast
of North and South America Including Greenland, U.S.
Department of Commerce, 1973.
"A Study of the Flushing Times of the Houston Ship Channel
arid Galveston Bay," Harm, R. W., Jr., Sparr, T. M.,
Sprague, C. R., Estuarine Systems Project Technical
Report No. 12, May 1970.
"Neches Estuary Water Quality Study," Hann, R. W., Jr.,
Estuarine Systems Project, Technical Report, No. 14,
October 1969.
"Waste Load Evaluation for Segment 601 of the Neches
River Basin," Ilann, R. W , Jr , prepared for the Texas
Water Quality Board, Austin, Tex., May 1071.
"Waste Load Evaluation for the Houston Ship Channel,"
Harm, 11. W , Jr., prepared for the Texas Water Quality
Board, Austin, Tex., September 1974.
"Management of Industrial Waste Discharges in Complex
Estuarine Systems—Second Annual Report," Hann, R. W.,
Jr., Estuarine Systems Project Technical Report No. 15,
June 1970.
"Management of Industrial Waste Discharges in Complex
Estuarine Systems—Third Annual Report/' Hann, R. W,
Jr., Estuarine Systems Project Technical Report, No. 22,
September 1971."
"The Case for Inchannel Aeration of the Houston Ship
Channel," Hann. R. W., Jr., and Ball, John, presented at
the Texas Meeting of the American Society of Civil Engi-
neers, Austin, Tex., 1973
"Field and Analytical Studies ot the Corpus Christi Ship
Channel and "Contiguous Waters," Hann, R. W., Jr.
Withers, II. E., Jr., Burnett, N. C , Allison, R. C., and
Nolley, B W., prepared for the Texa,-, Water Quality
Board, August 1973.
"Environmental Study of the Brownsville Ship Channel
and Contiguous Waters," by Withers, R. R., Jr., Slowey,
J. F., Garrett, R L., prepared for the Brownsville Naviga-
tion District, October 1974.
-------
-------
POWER
PLANT
EFFECTS
-------
-------
IMPACT OF WASTE HEAT
DISCHARGED TO ESTUARIES
WHEN CONSIDERING
POWER PLANT SITING
J. W. BLAKE
United Engineers & Constructors, Inc.
Philadelphia, Pennsylvania
ABSTRACT
With present experience certain efficiencies can be brought to bear on evaluation of proposed power
plant sites. These concern (1) ways and means of determining what data are really needed for
thermal discharge impact evaluation, and (2) optimization of efforts to obtain such data.
Data relevance cannot be determined through comparison with a list of parameters which must
always be studied at every site, but rather through a list of topics to be considered for possible
study, i.e., questions to be asked (the answers to which determine the parameters which need study
at the specific site under consideration).
Optimization of data acquisition could be greatly improved through addition of geographic indica-
tors to all environmental data publications and indexing/storage systems, following the examples
set by EPA STORET and NODC listings for water quality parameters. Such complete data avail-
ability will make possible better predictions of significance of impact, and therefore more realistic
and consistent decisions on utilization of our environment.
INTRODUCTION
It is encouraging to see that progress is being
made in some quarters toward devoting appropriate
effort to evaluating the effects of thermal discharges
on the estuarine environment. Now is the time to
take advantage of the experience of the past few
years, and move into more efficient protection of the
environment and more productive utilization of
scientist and engineer hours.
The power industry has now docketed some 200
nuclear generating stations, and each of these has
required an environmental report—new ones of
massive proportions (on the order of 1,500 pages to
summarize studies). Similar, though generally less
massive, environmental impact statements have
been filed for new fossil-fueled generating stations.
Certainly in producing these documents con-
siderable independent effort has been oriented to-
ward obtaining data of much similarity. While it is
certain that many have long wished for standardized
descriptions of environments and environmental
impacts, biologists and ecologists have been more
modest, perhaps because of their familiarity with
environmental complexities. Their wish has been
for standardized programs for collection of the data
necessary for such descriptions. In fact, that item
which is of major concern in this paper is actually
composed of two subtopics: first, the seeking of
standardized criteria for the amount and kind of
data required for any given site, and second, im-
provements in how such data are acquired.
These then are the two topics which will be ad-
dressed in this discussion: (1) ways and means of
determining what data are needed for thermal dis-
charge impact evaluation; (2) optimization of
efforts to obtain such data.
DETERMINATION OF DATA NEEDS
Obviously, the first question—determination of
data needs—has been addressed, consciously or
subconsciously by every scientist, engineer, admin-
istrator, elected official, and voter confronted with
a change in his or her environment. Each of us is
either unfortunately vulnerable to bias, or fortu-
nately able to perceive the true picture, due to our
own experiences, training, and our career objectives.
We may be highly motivated to:
(1) Preserve the environment in its pristine
condition;
(2) Make possible most efficient utilization of the
earth's resources; or
(3) Take advantage of every opportunity to gain
further knowledge of the detailed interactions of
all creatures in the complex ecosystems.
333
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334
ESTUARINE POLLUTION CONTROL
Of course, all of these sometimes diverse inter-
mediate goals are expressed in terms of everyone's
final goal of "Betterment of Mankind." Certainly
within reasonable limits we should all be striving
toward all the above three intermediate goals as well
as the final one. But, before we rush to accomplish
one and all, we must look to the aforementioned
"reasonable limits" as we direct our efforts and re-
sources toward achieving one of the goals, or better,
toward some multiple use concept.
Thus, this paper will discuss means of determining
the logical responsibility for environmental studies
which should be assigned to the power industry, or
indeed to any other industry wishing to utilize a
portion of our environment.
It is important to note at the very beginning that
aquatic ecological surveys and monitoring must be
carried out to ensure that impacts of thermal power
plants on aquatic communities do not exceed ac-
ceptable levels. To formulate these specific protec-
tive standards, an integrated overview approach
must be set up to identify potential for significant
effects upon important organisms at the earliest
possible time. Similarly, such a scheme should
quickly identify those areas in which limited or no
effort is needed. As a step toward providing a frame-
work for such an overview, this presentation will
draw upon a draft version of American National
Standards Institute's Standard No. N224 "Aquatic
ecological surveys required for the Kiting, design,
construction, and operation of thermal power plants."
This standard has been drawn up by a committee
composed of representatives of utilities, architectural
and engineering firms, consultants, universities,
private laboratories, and government agencies,
including the Environmental Protection Agency,
the Nuclear Regulatory Commission, the National
Oceanic and Atmospheric Administration, and the
Fish and Wildlife Service.
This ANSI draft standard has been constructed
on the theory that while no one set of prescribed
procedures will permit evaluation of all sites, a uni-
form set of questions can serve to rank parameters
and permit concentration of efforts on those actually
worthy of specific studies, for individual sites.
For example, the lower Mississippi River is, in
terms of saline distribution, a fairly typical estuary,
However, after only a brief investigation, one can
see that the river itself has been channelized and
confined by levees for many miles, so that it now
resembles a smooth walled pipe characterized by
high-speed, frequently unidirectional flow. The
classical estuarine functions of providing habitats
and nursery areas for aquatic organisms, have been
fulfilled in this area by the bayous and onshore is-
land/sandbars along the coastline of Louisiana and
adjoining states. Thus there is a reversal in the more
common rank of the estuary and coastline areas for
utilization as sites for energy production. This is not
to say that unlimited development should be allowed
to take place along the river, but only that overall,
the order of thoughtful utilization is somewhat dif-
ferent. Thus one may minimize the potential for a
large scale study of possibly non-useful parameters,
and find that a more directed study is really needed.
This paper is intended as an aid to, not a substitute
for, professional judgement on a case-by-case basis.
Designed to promote uniformity and efficiency, this
guide will assist those not familiar with some of the
complexities of the natural environment. Using it.
the executive or engineer may better understand a
specific environment's interrelationship with a steam
electric generating station.
A survey of environmental regulations, the biologi-
cal state-of-the-art, and recent power plant license
review cases, suggests some general needs for aquatic
ecological surveys. These basic needs (Table 1),
briefly described in this section, should help shape
the general philosophy of thermal impact surveys.
The first need is to recognize the limitations in-
herent in the current biological/ecological state-of-
the-art. Aquatic ecology is not generally a predictive,
science. Determination of cause and effect relation-
ships where natural variables cannot be controlled,
make data analyses of plant-induced impacts diffi-
cult. This is not to imply that monitoring for im-
pacts should not be attempted. Rather, it means
that surveys should be designed on the basis of what
can be accomplished with current sampling methods
and statistical analyses in differentiating aquatic
changes caused by various factors. A possible short-
cut to site-by-site impact prediction based on specific
field and/or literature data, is the use of national
chemical or temperature tolerance criteria. However,
such national criteria generally tend to overestimate
impacts at many sites in order to be completely safe
at the most sensitive. If using these criteria requires
costly designs, then would it be more appropriate to
derive specific data for that site through field or
laboratory bioassays. Another approach may be to
collect and review the thermal impact data at operat-
Table i.—Factors to be considered in design of thermal impact studies
(1) Recognize predictive limitations imposed by ecological state-ot-art
(2) Obtain ecological information appropriate !o stage of project development
(3) Limit ecological effort to those impacts relevant to specific site-plant combination
(4) Concentrate initial efforts on most sensitive organisms, with later expansion only
if necessary
(5) Incorporate good biometric techniques in design of surveys
(6) Recognize value of uniformity in design, conduct and analyses of ecological studies
in so far as appropriate
-------
POWER PLANT EFFECTS
335
ing power plants having similar site-plant configura-
tions and interrelationships. In short, survey pro-
grams should be developed from a practical stand-
point of what can be accomplished in the field.
A second need is to recognize the specific objec-
tives with respect to schedules for planning, con-
struction, and operating steam electric power plants.
This includes examining aquatic ecological informa-
tion appropriate to the stage of project development.
Information supplied out of sequence is often un-
necessary. Also, the considerations used in the en-
vironmental assessment should be integrated with
design engineering to weigh design cost against
potential environmental costs.
A third need is to develop aquatic ecological in-
formation based on impacts that are critical for a
specific plant and site combination. General survey
information is often useful. It appears, however, that
time, effort, and money have been wasted by surveys
that were too broad and general. A rational assess-
ment of effects of power plants on aquatic ecological
systems requires well-planned ecological surveys
which can detect impacts. Massive data collections
which fail in this objective or achieve the objective
with excessive redundancy, represent wasted effort.
Compliance with regulations, and a utility's own
economic interest, are both served by critical survey
designs which address specific problems related to
specific plant and site situations.
A fourth need concerns the sequence and priority
of surveys for potential aquatic impacts. Some
regulatory agencies request aquatic ecological in-
formation for essentially all trophic levels. This
seems to stem from the fact that all trophic levels
are interrelated so an impact at one level may be
felt throughout an ecological system. However, from
a practical standpoint, impacts initiated at one level
take time to be reflected in others and are riot gener-
ally reflected to the same degree. Thus it is more
efficient to concentrate surveys on biota which are
most sensitive to plant construction and operation
and can be expected to be the first to be affected.
These first-order groups are more often called indica-
tor organisms. An early focus on these would allow
surveys to be expanded to other trophic levels only
if unacceptable impacts on indicator organisms were
detected.
A fifth need is to incorporate good biometric tech-
niques in survey design so that, significant plant-
induced impacts can be distinguished from natural
stresses. The experimental approach to assessment
of impacts in the field is often not possible because of
lack of controls. The evaluation of data obtained
from sampling can only yield estimates of population
size and survival rates. Impact evaluation must rely
largely on approximate evaluation methods based
largely on observational studies. Such an approach is
presented in a recent report by Eberhardt and Gil-
bert (1974).
A sixth need is for greater uniformity in design,
conduct, and analysis of aquatic ecological surveys.
The advantage in working toward uniformity is
twofold. First, it will result in making the license
review process more efficient, and secondly, it will
allow comparison of data from one site to another.
This comparison could result in the development of
a body of information for examining the ecological
trends in a region and for making better estimates
of the possibility of power plant induced impacts.
This could also lead to more efficient design of en-
vironmental surveys for future power stations, and
better design of the power stations themselves. Com-
plete uniformity of surveys is not desirable because
of the uniqueness of each site-plant situation. How-
ever, special or unusual surveys that are proposed
on the basis of uniqueness should be carefully evalu-
ated to avoid unnecessary surveys based on arbi-
trary peivsonal preference of investigators.
A series of matrices (for examples see Figures 1—3
and Table 2) has been proposed corresponding to a
checklist of possible data needs, or questions to be
asked of the environment. These are to determine1
relative significance of parameters which have a
credible connection to the proposed construction
and operations of a power plant. Each matrix repre-
sents a survey stage and specifies parameters to be
considered, indicates the temporal distribution of the
data collections, and the qualitv of data to bo gath-
ered. It should be noted that the: survey matrices
were developed as a tool to determine information
needs, not necessarily study requirements, since the
desired information may be available from alternate
sources.
The sequential information-need phase's can be
functionally subdivided inte) as main' of the following
stagers as are useful in the specific case1 uiieleT con-
sideration (Figure 4). The Site-Selection Phase can
be divided into an Initial Evaluation Survey to
select candidate sites from candidate regions anel a
Site Selection Survey to rank those candidate sites.
The Preconstruction Phase can be divieled inte) an
Initial Plant Design Evaluation Survey to obtain
data needed for preliminary engineering, a Baseline
Survey to obtain data needed for the environmental
report and impact prediction, and where site explora-
tion ma}- be expect eel to cause1 significant environ-
mental impacts, a Site Exploration Monitoring
Survey. The Preoperational Phase- can be divided
into Construction Monitoring Survey to monitor
construction activities and, if warranted, to sample
-------
336
ESTUARINE POLLUTION CONTROL
Survey
Stage
Currents &
Other Water Flushing
Circulation Rate
Patterns
Initial Eval i 1,A,I
Site Select..-] 2,A,M
Baseline
4,E,III
Site-Plant De-
sign Eval 4,E,III
Site Explor
2,A,M
3,B,III
3,A,MI
Monitoring.. -i
Construe.
Monitoring.. 4
Preoperation
Survey 4,B,II
Startup
Monitoring-.J 4,E,III
Operation
Monitoring.. J 4,B,III
3,B,II
4,E,MI
3,B,NI
Existing
Tempera-
ture
Patterns
I.A.I
2,A,H
4,E,MI
' '
4,E,III
Bathymet-
nc Condi-
tions &
Contours
1.A.I
Bottom
D.O. of
Sediments &l Salinity
Sediment
Transport
Water and Turbidity
Sediments
1
2,A,H 2,A,H ++ ++
4AIII
4AIII
4,A,III
4,A,HI
4,A,MI
4,A,IH
4.EJII
4,B,III
4,A,IN
4,E,II 4.C.III
-H-
4.C.III
Dissolved
Solids
pH
I
++
4.C.III
+ +
Manmade
Nutrients Chemical
Stresses
++ ++
4.C.III 4.C.III 4.C.III
1 ,
4,E,II
4,E,II
4,E,II
4, A, III 4,B,II
4,A,HI
4,A,IM 4,A,III
'
4,E,II
4,B,III
4,A,IV ' 4,E,III 4,A,IV 4,A,IV ; 4,A,IV : 4,A,IV
4,B,IV
4,E,IV
4,C,IV
4,A,IV
4,C,IV
4,E,IV
4,B,IV 4,B,IV 4,B,IV
4.C.IV ; 4,C,IV
4,C,IV 4,C,III
4,A,IV
4,A,IV
4,B,IV 4,B,IV t 4,B,IV 4,B,IV
4,A,IV 4,E,IM
4,B,IV
Figure 1.—Physical-chemical matrix.
for significant ecological changes; a Preoperation
Survey to collect data necessary to provide baseline
information for operational monitoring; and Start-
up Monitoring Survey to include any special studies
needed to identify significant changes in the eco-
system caused by various activities occurring during
start-up. The duration of the Operation Phase is
determined by imposed environmental technical
Survey
Stage
Initial Evalua-
tion
Site Selection-
Baseline
Site-Plant
Design
Evaluation-.
Site Explora-
tion Moni-
toring
Construction
Monitoring.
Preoperation
Survey
Startup Moni-
toring
Operation
Monitoring.
Peri-
phyton
1
2
3
2
3
Macroin- | Any
Phyto- ; Zoo- verte- Macro- Fish , Organism
plankton plankton brates phytes ' Category
j i If Used
1 1 1 1,1,
2 2J 2 : 2 2
33333
i
2 2' 2 2 2
3
' 3
33333
•3
3
specifications, but greater detail would normally be
obtained for the initial operating years of the plant
as opposed to later years of operation, in order to
determine operating effects of the plant and to com-
pare them with those predicted in the environmental
impact statement.
All these aquatic ecological surveys should be
considered, but implemented only if appropriate and
necessary. If implemented, they should be designed
Table 2.—Key to level of biotic survey information
_ QUALITY OF INFORMATION
1. qualitative from available existing sources
2. qualitative from field observations
3. quantitative from field studies with statistical precision adequate for impact
evaluation
FREQUENCY OF INFORMATION COLLECTED"
A at least once by end of survey or annually if appropriate
B. quarterly
C. monthly
D. weekly
E. continuously
F. periodically**
GEOGRAPHICAL AREA STUDIED
I. regional
II. general site area
III. site impact area (for particular parameter)
IV. site impact area (particular parameter) plus control area
Figure 2.—Highest quality level of information collected.
* While the key gives some guidance to the frequency of sampling, it does not
provide guidance on best geographic spacing of sampling points. This is considered to
be a site specific parameter best decided on a case by case basis.
** Periodically means sampling as often as a professional in charge of a survey
considers necessary to identify a biotic change during the time it is likely to undergo
the change.
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POWER PLANT EFFECTS
337
Organism
Groups
Penphyton
Phytoplankton
Zooplankton...
Macromverte-
Drates
Macrophytes...
Fishes _
IS 1 PA
!
H
ucean
A ! PR
S ' SS
1
tstuary
IS i PA A '! PR
1
'
A
1
SS
IS
La
PA~T A
Ke
PR
|
S
SS
IS
PA
mver
A 1 PR
I
; 1
!
S SS
Physical-
Chemical
Refer to appropriate stage of Physical-Chenrcal Matrix 4.6
Project
Milestones
Major
Project
Activities
Survey/Monitoring
Stages
Recognize Need for Power
Figure 3.—Sample ecological matrix.
Site Selected
Nuclear Steam Supply System Contract Awarded
Apply for Construction Permit
Award of Construction Permit
Preliminary Engineering
Prepare ER & PSAR
AEC Review
Detailed Engineering
Award of Operating License
Operation
Startup
Construction
Site Clearance & Excavation
AEC Review
Update EIS
Initial Evaluation Survey
Site Selection Survey
Baseline Survey
Initial Site-Plant Design Evaluation
Site Exploration Monitoring
Major
Survey/Monitoring
Phases
S'te
Selection
Preconstruction
Construction Monitoring
Preoperatronal Survey
Preope.-ation
Startup Monitoring
Operation Monitoring
Operation
Figure 4.—Typical development schedule for nuclear power plants in the United States in 1974 with major survey phases and their corresponding survey
stages indicated.
to evaluate potential impacts of plant operations on
the biota of the immediate site area and to determine
other information required by regulation. The po-
tential major aquatic impacts to be considered are:
1. Attraction and impingement/entrapment of
organisms by intake structures;
2. Entrainment of aquatic biota through the cool-
ing system and resultant exposure to changes in
thermal, chemical, physical a7id mechanical param-
eters ;
3. Alteration of water quality in intake and dis-
charge areas;
4. Scouring and silting of bottom habitat near
intake and discharge structures;
5. Changes in water level or quality due to con-
sumptive use;
6. Changes in currents in intake and discharge
areas;
7. Thermal exposure of aquatic biota within mix-
ing zone;
8. Blockage or delay of fish and shellfish movement
by thermal or physical barriers ;
9. Removal of habitats by structures.
The potential for these impacts will vary in im-
portance between once-through and closed cycle
cooling systems; therefore, plant design alternatives
for the biological matrices acknowledge these varia-
tions.
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338
ESTUARINE POLLUTION CONTROL
Similarly, the ecological role or relative importance
of each grouping varies from site to site. Some sites
for example may have few or no important fish, or
macrophytes, or may have poor substrate for sup-
porting benthic invertebrates. Groupings actually
selected for study at each site should be based on
professional biological judgement. The life stage of a
particular group to be studied should depend on
specific site circumstances and the potential impacts
to be evaluated. Thus the matrices present the high-
est level of information suggested for each organism
grouping in relation to various survey stages. The
purpose of the matrix is to serve only as a check list
to be certain such groups are considered for possible
inclusion in studies, and it may frequently happen
that study will show that some groups should be in-
cluded, and that others have no credible link to a
specific proposed power plant project.
Consideration ought to be given to those organism
groupings and important species \vithin each which
would be utilized to evaluate the aquatic community
at a site. Important species or groups are those most
valuable and/or vulnerable by the criteria set by
civilization, but presumably will include protection
of major food-web pathways. Certainly it would be
unnecessary (and impossible) to study all or most
species within each organism grouping at a site.
Species considered should be of commercial or
recreational value, threatened with extinction, or
dominant at the specific site. If a species is essential
to the maintenance of an important species it should
also be considered. Important species should have
some plausible relationship to power plant operation.
Abundance or biomass of the species should be such
that sampling can occur without serious depletion
of the organism population. Species selected would
hopefully have taxonomic characteristics which
would facilitate accurate identification.
For those important species or organisms, detailed
studies may need to be conducted so plant-induced
impacts can be estimated and separated from natural
variations. In the early survey stages preliminary
estimates should be made of the particular role of
each organism grouping, at the site under considera-
tion, in order to determine whether important species
are within the group. Following selection of a site,
greater consideration should be given to determining
important species and important organism group-
ings. A checklist of organisms likely to be especially
vulnerable to the specific stresses proposed should be
developed.
Throughout all surveys, the site-plant design
evaluation should be performed through evaluation
of site specific information. The purpose of this
evaluation is to note ecological information on sensi-
tive or critical biological aspects of the site that need
to be designed around. The following are examples of
structures, systems, and plant outputs which could
affect aquatic ecological conditions and for which
alternatives exist for modifying the potential im-
pacts: maximum thermal power output, locations of
major structures, type of cooling water system, loca-
tion of access roads, rail lines, and transmission line
rights-of-way, locations and designs of intake and
discharge structures, and types of radiological,
chemical, and biocide waste discharge systems.
Initial information must be available from the eco-
logical studies at the early baseline survey stage
so that such data can be used in a timely evaluation
during preliminary engineering of the plant. The
aquatic ecologist in charge of the baseline survey
should consider, even on the basis of just a few
months of data from the initial survey, what aquatic
aspects of the site are important to safeguard.
OPTIMIZING SEARCHES
FOR EXISTING DATA
Finally, one must address efficient solutions to the
problems presently inherent, in obtaining necessary
biological information for environmental reports
from literature. Currently, it is not really possible to
keep up with the tremendous quantity of data, and
interpretation, appearing each year in the published
technical literature, and very difficult to even learn
what data have been collected but not published at
all, or published only in the "grey" literature of in-
formal or internal reports.
One may first try to use available biological
literature research tools, such as BioAbstracts, Oce-
anic Index, et cetera, and within limits they are
rather easy to use, if one wants to locate information
either in very broad categories such as physiology,
or taxonomy, or in very narrow categories such as
one specific organism. While these indexing categor-
ies are quite helpful to research projects concerned
with a single species, and perhaps a single aspect
thereof, they are of extremely limited use to those
who need to quickly and efficiently locate existing
knowledge relating to a specific geographic location.
This then is a basic need of bio-envirorimentally
oriented scientists and engineers working with both
industry and regulatory agencies.
It appears, however, that several potential solu-
tions are almost available; that is "almost available"
in the sense that they have been applied successfully
to similar purposes.
At least two computerized systems are now in use
for storage and recovery of physical-chemical water
quality data: The Environmental Protection Agency
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POWER PLANT EFFECTS
339
(EPA) STORET system and the National Ocean-
ographic Data Center (XODC) files. In each of
these a search can be conducted on the basis of
geographical location (and by chro.iology). The
NO DC data can be retrieved by Alarsden Squares—
each of which includes a large number of square
miles, but a size which is not inappropriate to the
relatively gentle gradients characterizing oceanic
parameters. The EPA STORET system is accessible
by specification of either geographic points (rivrer-
mile, or latitude/longitude) or area (between river
miles indicated as up and downstream boundaries,
or within a polygon each apex of which is indicated
by latitude and longitude). The further ability to
sort the data chronologically to contrast recent vs.
older data, or to look for seasonal patterns, is a signif-
icant additional aid to ecological analysis.
Another major source of information, which also
needs improved indexing, is the vast compilation of
data in the variety of water-use permit applications:
NPDES, Section 316, and federal, state and local
environmental impact statements. A comprehensive
index to these on a geographic locator system would
be extremely valuable.
Other major literature1 search services, e.g., Bio-
Abstracts, Oceanic Index, and the Smithsonian
Institution's Science Information Exchange, are set
up for "keyword" access searches.
Only a negligible, relatively minor expense would
be involved to ensure that a geographic locator, a
keyword, or latitude-longitude specification, were
used also in all papers/reports that relate to field
biological studies, or even those studies which utilize
organisms collected at field-locations. One must
assume of course that authors would cooperate, and
provide the needed information in the paper/report
(and in its abstract submitted for use of literature
search tools). Once that habit was ingrained, the
addition of this one extra index would represent a
very low cost to index services in absolute terms, let
alone in relation to the benefits accrued in being
certain all relevant data are integrated into impact
statements. If such geographic locators were to
include latitude-longitude, in addition to a named
body of water (lake, ocean, watershed, river basin),
or land area, utilization would be greatly enhanced
by the easier incorporation of references into the
STORET/\ODC type systems with a numerical
index access, without need for knowledge of the
name of each body of water or land area.
Similar organization of air quality data by "air-
shed" would greatly enhance full use of existing
knowledge1 in overall evaluation of more complete
environmental interactions.
Thus the key to continued progress in making
knowledgeable, realistic, and consistent evaluations
on environmental impact lies with improving both
the comprehensiveness of the data base available'—
at reasonable cost—and improving our ability to
determine which data are indeed important to the
decision under consideration.
REFERENCE
Ebehardt, L. L. and II. O. Gilbert, "Environmental Impact
Monitoring on Nuclear Power Plants, Section 3—Monitor-
ing Methods, Part 9—Biostatistical Aspects," National
Environmental Studies, Project No. 4, Atomic Industrial
Forum, Inc., Washington, IXC. (1974) 181.
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-------
THERMAL DISCHARGES
AND ESTUARINE SYSTEMS
JOSEPH A. MIHURSKY
University of Maryland
Solomons, Maryland
ABSTRACT
Interactions between steam electric station operations and estuarine aquatic systems are de-
scribed. Environmental problem areas are discussed under two broad categories: (1) the predator
role of a power plant in terms of larger organisms impinging upon water intake structures, or of
effects on smaller organisms upon passage through cooling water condenser systems; and (2) the
discharge water or plume impact on resident and migratory organisms in the receiving water.
Biological damaging effects are described from many factors other than excess heat alone, e.g.,
mechanical, biocides, et cetera. A number of siting and operating design options to achieve better
compatibility are described. Integration of field and laboratory programs is urged at both national
and regional levels. Present trends are reviewed. Four recommendations are made with regard to
national and regional policies. Eleven recommendations are made with regard to research
activities.
INTRODUCTION
Management, research and legislative concern
with the environmental problem of excess heat pro-
duction from the electric generating industry have
spawned the development of many new terms in
the last 10 years. Thermal pollution, thermal load-
ing, thermal addition, thermal enrichment, and
calefaction are the more common ones now used.
This same period, especially the last five years, has
seen the production of numerous bibliographies,
national and international symposia and workshop
volumes, review treatises, journal publications on
basic and applied research results, legislative com-
mittee documents, "pre- and post-operative" survey
reports, consultant reports, and environmental im-
pact statements, all in some manner pertinent to
the problem caused by excess heat release due to an
activity of man.
In spite of the above described efforts, a consensus
of opinion as to whether thermal discharges have
significant environmental effects on a site or region
is difficult to obtain. This difficulty can be traced to
a number of factors, among them:
1. Inadequacy of research data, attributed to:
a. The inability of field studies to overcome
the "noise" in natural systems caused by
inherent natural variations.
b. A lack of coordinated and well-designed in-
vestigations (both field and laboratory) of
a regional or national scope. We are still
shot-gunning and not always asking the
right questions.
c. A relatively large segment of the research
community being reluctant to engage in
applied research.
2. Adherence to traditional economic-ecologic phi-
losophies or activities.
a. As stated by recent administrations in Wash-
ington, energy independence and economic
recovery are believed best achieved by re-
laxing environmental concerns.
b. External diseconomies are still permitted
with regard to environmental losses, some-
times because of an inability to factor en-
vironmental values into economic input-
output models.
Thus, the man-environment excess heat problem
has not been solved, or resolved, and with regard to
waterways, the volume of thermal discharges has
been increasing.
WHAT IS THE PROBLEM?
Although all excess heat must eventually enter
the atmosphere, traditionally water has been used
as a "middle man" to carry excess heat energy away
from steam electric stations (SES). Water's unique
characteristics have provided useful economic and
engineering advantages to the electric utility indus-
try. These advantages have in turn been reported
as disadvantageous to aquatic resources (see Clark
and Brownell (1973) for one such treatment).
In general, for every 1 megawatt of electricity
produced, 1.7 megawatts of heat are rejected by a
341
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342
ESTUAHINE POLLUTION CONTROL
steam electric station, corresponding roughly to 33
percent energy conversion efficiency for a typical
fossil fuel plant (Engstrom, Bailey, Schrothe, and
Peterson, 1972a). Ne\v fossil fuel units achieve about
40 percent efficiency while nuclear units achieve
about 32 percent efficiency. A typical water require-
ment for a 1000 M\\V installation is about 1,500
cubic feet per second. Taking into account differ-
ences in plant and stack heat losses, fossil fuel units
reject about 4.2 X 10" BTlJ/hr., while nuclear units
reject about 6.6 X 10s BTLI/hr. to the condenser
cooling water supply. Thus, average increases across
condenser systems are 12°F for fossil and 20°F for
nuclear (Committee on Power Plant Siting, 1972).
Increasing size of single installations may require
up to 50 square mile feet of water per day to be
pumped for condenser cooling purposes if open once-
pass systems are used to dissipate excess heat. En-
vironmental concern with regard to excess heat in
aquatic systems stems from the acknowledged role
of temperature as the biological master factor in
these same systems (Kinne, 1963; Mihursky and
Kennedy, 1967).
OPERATING CHARACTERISTICS OF
OPEN ONCE-PASS COOLING SYSTEMS
OF STEAM ELECTRIC SYSTEMS
PERTINENT TO BIOLOGICAL EFFECTS
Given on Figure 1 is a schematic of an open
once-pass cooling water system used in a typical
steam electric station design. Included also are three
columns: (1) Design Parameter, (2) General Pref-
erence and (3) Ecological Basis. Although thermal
effects have gained the most attention as a possible
limiting factor of SES on biological systems, the
above figure calls attention to a number of addi-
tional features that may affect resident biota. Me-
chanical damage may occur to organisms such as
fish, crabs, combjellies, jellyfish, and salps that im-
pinge on intake screening. Smaller organisms, e.g.,
phytcplankton, zooplankton, fish eggs and larvae,
that are pumped into and through the cooling water
system can be mechanically damaged from impinge-
ment on the ends of condenser tubes and from
moving parts of pumps. These same "pumpcd-
entrained" organisms can be subjected to pressure
changes, turbulence (shearing forces) as well as to
damaging effects from biocides such as chlorine
which are used to keep metal surfaces clean of
fouling oiganisms (Coutant, 1970).
Still other more complex consequences of SES
operations must be understood. One, for example,
is the use of chlorine as a biocide. Although the
1 1000 M\V: 1,000,000 kilowatts of electricity.
chemistry of chlorine in seawater is imperfectly
known, information indicates that not only can
chlorine kill organisms but it can oxidize the organic
component of bottom sediments and thus release
absorbed heavy metals (Hill and Helz, 1973). These
effects, especially when combined with heavy metal
releases from SES condenser systems due to erosion
or corrosion (Leschber, 1972) can result in magnifier-
concentrator organisms such as shellfish incorporat-
ing and accumulating excessive levels of metals and
consequently being rendered unfit for human con-
sumption (Roosenburg, 1969). Becker and Thatcher
(1973) have produced a review publication entitled
"Toxicity of Power Plant Chemicals to Aquatic
Life." This review discusses the various chemicals
actually or potentially associated with power plants.
Eighteen chemical categories and over 125 separate
chemicals are listed.
From an aquatic resource viewpoint, two major
considerations are important when SES employ
open, once-pass cooling systems (Figure 2). The
first is the concept of the SES acting as a predator
and "cropping" or consuming organisms, the so-
called purnped-entrainment and/or pumped-entrap-
ment effects. Thus, site selection, engineering designs
and operating characteristics for minimum biological
damage becomes critical under such circumstances
and the relative rates of destruction and recovery
must be determined. If plant operations "crop-off"
organisms at a rate faster than organisms can regen-
erate in open receiving systems, depletions in natural
populations can be expected (Mihursky, 1969).
The second consideration deals with discharge
plume effects on near-field and far-field biota. Dis-
charge plumes may have various physical configura-
tions depending upon the characteristics of the
receiving water body and the design and location
of the discharge structure itself (Committee on
Power Plant Siting, 1972''. Biological effects of
plumes are determined by the following factors:
1. Temperature elevation
2. Rates of temperature change
3. Chemical characteristics
4. Hydraulics
Abnormal migrations of mobile animal species into
arid away from discharge plumes (Elser, 1965;
Moore, et al., 1972; Tremblcy, I960) and occasional
massive kills (Alabaster and Downing, 1966;
Mihursky, 1969; Trembley, 1965; Wagenheim, 1972)
under various seasonal and SES operating conditions
are recognized facts. Positive as well as negative
responses on the part of non-mobile benthic plant
and animal species are also known to occur (e.g.,
Anderson, 1969; Cory and Nauman, 1969; Nauman
and Cory, 1969; Warinner and Brehmer, 1966).
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POWER PLANT EFFECTS
343
Steam
Water Source —(8
DESIGN PARAMETER
1.Intake design
2.Volume of water pumped
3.Turbine backpressure
*4.Temperature rise
5.Length of cooling water
piping in plant
6.Length of transit to receiv-
ing waterway (canal or pipe-
line)
7.Discharge location
8.Discharge depth
GENERAL PREFERENCE
Behaviorally avoidable or
provide safe return to
environment
Low (but site dependent)
Lowest feasible heat rates
Site and season dependent
Short (minimum transit time)
Short (minimum transit time)
Beyond littoral contact
Semistrat ifled plume
9.Turbulence (exit velocity, High
port size or number)
10.Dilution (near field) High
11.Circulation (far field)
High
ECOLOGICAL BASIS
Poorly designed intakes trap
fish, crabs, etc.
Numbers of organisms affected
Lowest backpressure permit low
temperature discharges to
environment (7)
highest feasible efficiencies
Temperature-time relationships
of effects
Temperature-time relationships
of effects on entrained organisms
Temperature-time relationships
of effects, fish entrapment
Shoreline abundance of organisms
(may be seasonal)
Keep highest temperature water
away from resident bottom
organisms
Temperature-time relationships
and areal extent of effects
Plume entrainment, temperature-
time relationship
Temperature buildup for recircu-
lation may change overall
species composition
*Subject to mutual trade-offs at specific sites.
FIOURL 1.—Schematic of once-pass cooling water design and a summary of cooling .system design needs (from Committee on
Tower Plant Siting, 1972).
SOME MAJOR
UNANSWERED QUESTIONS
In brief, although the major interactions between
SES and aquatic environments can be mlurod to
(1) pumped-entrainment and entrapment (= pre-
dalion) and (2) discharge plume effects (= behav-
ior, growth and reproduction), and many studies
have attempted to sort out biological responses and
identity limiting factors, no single study has really
-------
344
ESTUARINE POLLUTION CONTROL
ORGANISMS NOT ENTRAINED BUT DEPENDENT ON SUSCEPTIBLE ORGANISMS
STHIPfcD BASS
IMMATURE AND MATURE ADULTS
STRIPED BASS PREY
ANCHOVIES
AND
YOUNG OF
ALEWIFES
MENHADEN
WHITE PERCH
CROAKER
SPOT
PREY SPECIES
INO CROAKER OR
MENHADEN EGGS)
MACROPLANKTON
(WATER FLEAS. COPEPODS
MYSIDS. ETC I
S>
-
SHRIMP AND MUD CRAB
LARVAE AND YOUNG
t
I
I
I
I
PHYTOPLANKTON
ORGANISMS SUSCEPTIBLE TO ENTRAPMENT
FIGURE 2.—Potential power plant effects on striped bass and associated food items (from Bongers et al., 1972).
answered the two most important questions:
1. Regardless of whether biological community
structure has been altered (different species mix or
different relative abundance of various species), is
biological energy flow still going into the production
of a similar quantity of useful biological material as
occurred before any SES influence?
2. If concern is for one or more target species, are
socially (= man's interest) acceptable sustained
yields still produced within the estuarine system or
subsystem for the species in question?
These questions are not easy to answer; however,
let us briefly examine some of the information that
should be acquired if we seriously try to answer
them and thus manage the energy-environment
question from a scientific as opposed to a political,
economic or emotional point of view.
1. Develop a better understanding of the processes
operative within estuaries.
a. Understand the population dynamics of key
estuarine organisms.
b. Determine limiting factors to a species' suc-
cess, e.g., predator-prey, host-disease, host-
parasite relationships, food web relation-
ships (who eats what and how much),
physical and chemical threshold levels for
biological success at the species and com-
munity level.
c. Determine sources, cycles and sinks of criti-
cal (or limiting) items, e.g., heavy metals,
biological energy and material flow.
2. Develop biogeographic maps of estuarine sys-
tems, identifying the following for key species:
a. Quantitative seasonal and daily distribu-
tional patterns in both horizontal and ver-
tical gradient systems for all life history
stages.
b. Spawning areas.
c. Nursery areas.
d. Over-wintering areas.
FIELD VERSUS LABORATORY RESEARCH
The importance of properly coordinated field and
laboratory programs cannot be overemphasized. De-
velopment of typical information needed requires
considerable laboratory as well as field efforts to
understand the processes operative within estuarine
systems; biogeographic mapping must depend on
extensive field operations.
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POWER PLANT EFFECTS
345
The variability inherent in field data due to patch-
iness in distribution of organisms both temporally
and spatially, will require one of two approaches:
(1) improve the design, sampling effort, and meth-
odologies to increase field quantification; or (2)
assist judgements through the use of appropriately
designed laboratory experiments.
Approach # 1 will add greatly to the cost of tra-
ditional field studies. As an example, our present
program to understand the population dynamics of
one species, the striped bass, and the relationship
to power production in the Potomac Estuary, Md.,
required the following for 1974.
Sub-program
Staff Direct Costs
Spawning stock assessment.. 8 $90,000
Ichthyoplankton 10 125,000
Hydrography 7 75,000
24 $290,000
If indirect costs are added, the total dollar expense
would approximate $500,000 for a coordinated field
project that is attempting quantification for a single
fish species. As another example, Carpenter's (1974)
recent analysis of the number of zooplankton field
samples needed to accurately quantify the com-
munity at a single station for a single collection
date at the 5 percent confidence level was over 300
discrete samples! Carpenter's work also is being
applied to power plant investigations. Such large
field efforts are not always possible due to limited
funds or staff.
Lack of statistically valid field quantification
forces one to resort to judgements. Such judgements
can be greatly improved if laboratory studies, co-
ordinated with field programs, are permitted to
assist in decision making. In many cases, laboratory
programs can provide exceptional insight and in-
formation at modest cost. For example, recent
laboratory work on time-temperature mortality
experiments on egg and larval stages of some cstu-
aririe shellfish species (Kennedy, et al., 1974) re-
quired the direct capita] outlay of less than $2,000/
year. Indirect costs (inhouse salaries) were less than
$30,000/'year. This latter work singled out various
temperatures and time exposure combinations neces-
sary for survival (Figures 3, 4, and oj. Such data
cannot be acquired under field conditions; however,
they are useful and necessary to be incorporated
into population dynamics studies, pumped-entrain-
ment effects and development of engineering designs
and operating characteristics of SES.
FIGURE 3.—Mercenaries mercenaria cleavage stages. Response
surface generated from multiple regression analysis of per-
centage mortality on temperature and time (from Kennedy
etal., 1974).
MS!
FIGURE 4.—Mercenaria mercenaria trochophore larvae. Re-
sponse surface as in Fig. 3 (from Kennedy et al., 1974).
SOME EXAMPLES OF SITING
AND ENGINEERING DESIGN OPTIONS
From an aquatic resource viewpoint, SES sites
should be selected on the basis of two considerations:
(1) Avoid sites that are environmentally vulnerable
to SES activity; (2) Locate in estuarine areas that
have environmental and biological flexibility to
accept SES operations. In order to achieve the
above one must first have adequate knowledge of
the biogeography of the region and understand the
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346
ESTUARINE POLLUTION CONTROL
Mercenana mercenar
straight hinge larvae
FIGURE 5.—Mercenaria mercenaria straight-hinge larvae. Re-
sponse surface as in Fig. 3 (from Kennedy et al., 1974).
processes responsible for maintaining its biological
integrity arid utility. For example, within the Chesa-
peake system the striped bass is an extremely impor-
tant commercial and recreational species providing
social and economic value to the region. The species'
spawning sites have been identified (Fig. 6) and
are recognized as important geographic areas that.
seasonally contain concentrations of critical life
history stages of this species.
A number of such critical estuarine zones can be
identified and located. Similarly, within the Chesa-
peake system, oyster growing areas, and areas of
important "seed" or spat production have been
described. Protection of this extremely important
economic species dictates that areas of high seed
production not be encroached upon by industrial
operations requiring large volumes of water for proc-
ess purposes. The oyster management program in
the bay svstem depends on redistribution of the
spat from these areas of high production, but slow
growth, to other areas of low or no production, but
high growth.
Certain environmental flexibilities can be recog-
nized within estuarine systems if one appreciates
their basic characteristics. For example, greater
\olumes of water (mass flow) move by a point in
an estuary as one proceeds from the low salinity
inland reaches to the higher salinity, oceanic end.
Thus more water is available for dilution purposes.
Biologically speaking, along this same salinity gra-
dient (from low to high salinities) the biological
value of a given cubic meter of water seems to
decrease, e.g., primary production rates decrease,
quantities of fish eggs and larvae decrease (Dovel,
1970). Thus, if a given volume of water must be
utilized or sacrificed, lesser biological damage per
unit volume of water would occur as one progresses
from the lowest to the highest (oceanic end) salinity
reaches.
Concurrently, SES engineering design and opera-
tional characteristics must factor in other biological
information to avoid damaging effects on existing
biota:
1. Multiple intake and outfall options must be
considered for any given site. A surface water intake
may be desirable in the daytime when plankton are
concentrated in bottom waters, while a bottom
night-time intake location may be desirable when
plankton organisms tend to migrate to surface waters
(Figure 7). Such strategies are capable of minimiz-
ing pumped-entrainment of planktonic organisms.
Similarly, an offshore deepwater intake may be opti-
mum in summer while a nearshore shallow intake
may be optimum in winter due to temperature and
water quality advantages as well as differences in
distributional patterns of organisms.
2. Volume of cooling water pumped can be manip-
ulated in order to increase or decrease temperature
elevations or the number of pumped-entrained or-
ganisms. This approach may have value if mechan-
ical or shearing forces are limiting, rather than
temperature. Under these; circumstances, minimizing
water volume pumped can minimize cropping below
limiting levels for planktonic organisms. On the
other hand, if an absolute temperature is limiting
to a site, and "spreading it thin" is possible without
other limiting factors operative, then simply increase
pumping volumes.
3. Similarly, if biocide use for cleaning purposes
is limiting (Becker and Thatcher, 1973), dilution
may be one solution; however, use of mechanical
cleaning devices such as recycled sponge or brush
balls in condenser systems are decidedly to the
advantage of the biota.
4. Manipulation of discharge plume characteristics
(Committee on Power Plant Siting, 1972) has de-
cided biological advantages. Where important, one
may wish to (a) keep the plume in surface waters
in order to avoid impingement on important benthic
species, (b) minimize surface to bottom gradients
so as not to interfere with diurnal vertical migration
patterns (Clehrs, 1974), (c) maximize high grade
heat zone, or (d) maximize low grade heat zones.
5. Alternation of cooling systems to accommodate
the biota also has utility. Critical and entrainable
early life history stages may be present at a site
only for one or two months (Figure S); at such time
an SES could switch from an open once-pass cooling
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POWER PLANT EFFECTS
347
77'OO'
76*30
Chesapeake Bay
Region
} RIVER SPAWNING AREAS
LA.J OF THE STRIPED BASS
STATUTE MILES
I. .r-.».w .....-,_., ^ ^ Jj==pV. I
^•r ^M __ 77«L ^^ ^_ 76l^ ^L ^^ 76-oa ^. ^^ 75^3a ..^^ -^^75iS«
FIGURE 6.—Distribution of striped bass spawning areas in the Chesapeake Bay region.
o
o
j
-------
348
ESTUARINB POLLUTION CONTROL
PERCENT 50
Q_
UJ
a
VERTICAL DISTRIBUTION #2, 17-18 MAY 1974,
WHITE PERCH LARVAE - POST PINFOLD STAGE
50
TIME
0700
1100
1500
1900
2300
0300
INCIDENT
RADIATION!
TIDE
0.29
1.17
1.14
0.26
lLANGLEYS/Min
HS
FIGURE 7.—Kite diagrams giving percent vertical distribution of white perch larvae (post-finfold stage) at a single station in the
Potomac Estuary over a 24-hour period.
system to a closed or semi-closed one to minimize
damage.
PRESENT TRENDS
Many projections have been made on regional,
national and world-wide energy needs. The increase
in our national energy demand curve has been im-
pressive. Exactly what our growth will be in view of
recent energy supply developments is difficult to
ascertain. The recent discussion by Mihursky and
Cronin (1973) gives one prediction:
Based OB 1960 estimates of U.S. population of 300
million by 2000 A.D., energy usage per capita is expected
to increase some 250 percent, and electrical energy is
expected to increase by 1,350 percent in the same period
(Figures 9 and 10). Electrical energy use is projected to
go from 24 percent of the national energy consumption
total in 1970 to 34 percent in 1980, 42 percent by 1990
(Anon, 1970) and to 52 percent by 2000 (Jaske, 1970).
However, . . . Lees (1971) stated that. . . even assuming
near zero population growth, a drop to one half of the
present rate of growth in individual wealth, and a corre-
sponding 50 percent reduction in the current rate of
increase in power use in the next decade, U.S. consump-
tion of electricity will still triple by 1990! (See also
Hammon, Metz and Maugh, 1973). Landsberg (1970)
indicated that increases in per capita consumption has
accounted for 90 percent of electric generation since 1940.
It seems that in spite of possible changes in life
styles, and consequent energy use and consumption
patterns, substantial growth demands for electricity
FIGURE 8.—Percent weekly abundance of striped bass eggs
in Potomac Estuary for 1974 plotted against total hours of
sunlight, and 20 year average surface water temperature at
Solomons, Md.
-------
POWER PLANT EFFECTS
349
600
500
400
300 -
t 200
100-
0
FIGURE
200
data based on reference 2
TOTAL ENERGY
i960 1970 I960 1990 2000 2010
9.—Per capita energy use by decades through 2000
A.D. (from Jaske, 1970).
data based on FPC
electrical energy
protections and on
reference 2
ELECTRICAL
ENERGY
PRODUCED
1990
2000
2010
will continue. Present methods of electricity produc-
tion still require large volumes of water for excess
heat dissipation. Examination of alternative elec-
tricity production schemes for the near term (to
year 2000) and long term (after year 2000) is pos-
sible. Table 1 lists information on electrical power
generating technologies and presents data and esti-
mates for three categories: (1) present systems such
as hydroelectric, fossil and nuclear fueled SES, and
gas turbines; (2) developing systems for the short
term (1970-2000) such as breeders, magneto-hydro-
dynamics, and geothermal; and (3) developing sys-
tems for the long term (after year 2000) such as
thermoelectricity, fusion, and solar. In summary,
the major energy conversion systems presently em-
ployed and available for the near term (to year 2000)
dictate that great quantities of waste heat will be
discharged into our environment.
The next question is where and how the waste
heat should be discharged. Recent studies evaluating
waste heat assimilation capacities of various river
basins of the U.S. as determined by limitations
imposed by present state water quality standards,
conclude that much of these existing water resources
are insufficient to cool on a once through basis, the
anticipated growth in the electrical generating in-
dustry (Engstrom, et al., 1972a, b).
It seems, therefore, that SES siting efforts by
industry will continue towards larger water bodies
such as the Great Lakes, estuaries, coastal and
nearshore coastal zones. Recent rulings by the En-
vironmental Protection Agency (1974) with regard
to the possible use of cooling systems other than
once-pass, e.g., cooling towers, has recently added
10.—Projected total energy demand in U.S. (from
Jaske, 1970).
Table 1.— Estimated reduction In striped bass young of the year"
CONDITION
No plants (base)
Danskammer
Lovett
Bowline.. ...
Roseton, Danskammer
IP l &2
Roseton, Danskammer,
Lovett, Bowline
Roseton, Danskammer,
IP 1 » 2, Lovett,
Bowline
Percentage Reduction According to Flow Year Simulated
1949
0
5.9
12.4
13.9
15.1
32.9
37.1
55.4
1955
0
4.5
16.0
18.4
12.2
42.8
40.9
64.0
1964 1 1967
°
10.5
9.5
10.6
23.7
25.6
40.4
54.4
0
6.7
9.7
9.7
16.9
26.8
33.3
48.7
1968
0
1.8
4.5
21.9
5.3
14.4
29.2
38.2
1969 1970
0
3.4
15.6
22.6
9.4
41.7
41.5
63.8
0
4.8
15.1
18.5
12.8
39.9
40.5
61.4
K Assuming flow conditions similar to the year specified.
-------
350
ESTUARINE POLLUTION CONTROL
another dimension to the economic and engineering
aspects of SES construction and siting by the
industry. As presently stated:
With respect to any point source otherwise subject to
the provisions of section 301 or section 306 of this Act,
whenever the owner or operator of any such source,
after the opportunity for a public hearing, can demon-
strate to the satisfaction of the Administrator (or, if
appropriate, the State) that any effluent limitation pro-
posed for the control of the thermal component of any
discharge from such source will require effluent limita-
tions more stringent than necessary to assure the pro-
tection and propagation of a balanced, indigenous
population of shellfish, fish, and wildlife in and on the
body of water into which the discharge is to be made,
the Administrator (or, it' appropriate, the State,: may
impose an effiuent limitation under such sections for
such plant, with respect to the rherrnal component of
such discharge (taking into account the interaction of
such thermal component with other pollutants), that
will assure the protection and propagation of a balant-ed
indigenous population of shellfis'i, fish and widlife in
and on that body of water.
The final operating procedure may or may not
require a greater use of alternate cooling systems
such as cooling towers, than as had been required
in the past. Many alternate wet-evaporative cooling
methods require considerably less water than open
once-pass systems (^2 percent); however, chemical
discharges are increased from blow-down cleaning
of cooling towers (Becker and Thatcher, 1973).
Hence, in estuarine systems the investigator may
have a new task to contend with, namely, cycles,
sinks and biological responses to a large array of
chemical compounds.
The interaction between the electric utility indus-
try and biologists is expected to continue. In-
creasingly, industry will continue to develop less
damaging operations in response to biological and
environmental data.
Examples of such improvements are given in
Figures 11 and 12, which are schematic illustrations
of water intake and discharge arrangements of two
SES on tidal arms of the Chesapeake Bay in Alary-
land. These illustrations indicate temperature eleva-
tion patterns and transport times of cooling water
from point of intake to point of discharge into the
estuary. Scheme one (Figure 11) reflects on old
design (built in the early 1960's) that has summer
temperature elevations across the condensers of
6.5°C and a transport time from intake to discharge
in the estuary of 2.7 hours. Discharge temperatures
reached nearly 38°F, within the old water quality
standards of the state. The; recessed cooling water
intake is located in a relatively shallow shelf zone.
This installation used chlorine to keep heat exchange
surfaces clean of fouling organisms.
RIVER
TEMPERATURE CHANGES
Fioi'KK 11.—Cooling water system design, temperature
changes and discharge time for the Chalk Point SES on
the Patuxent Estuary.
Scheme two (Figure 12) is the design of a new
plant by the same company. Intake water is from
cooler and deeper zones (30-50 ft.) and water trans-
port time is 15 minutes from intake to the estuary.
Ambient temperature estuarine water is added im-
mediately on the discharge side of the condenser in
order to augment temperature reduction. Maximum
temperature differential between intake and outfall
water is designed to be 5.2°C and the summer dis-
charge maximum is designed to be approximately
32.2°C, which is about equal to the maximum
reached by surface waters in the bay under natural
conditions. The above conditions meet the new
state water temperature standards. In addition, con-
denser cleaning is assisted by using sponge rubber
balls forced through the cooling system. Scheme
two has less effects on entrained organisms than
scheme one.
The existing temperature isotherms for a cross
section of the Chesapeake Bay for a typical summer
day are given in Figure 13. Notice that the hottest
temperatures occur at the surface and on the shelf
zone. SES have typically pumped cooling water
from this shallow shelf zone, the zone that naturally
is the hottest during the summer. In the Chesapeake
Bay a number of important animal species are at
AMBIENT •
"BOTTOM" WATER"
TEMPERATURE CHANGES
' V.
FIGURE 12.—Cooling water system design, temperature
changes and discharge time for the Morgantown SES on the
Potomac Estuary.
-------
POWER PLANT EFFECTS
351
9240Q 9I8T 908 848E
92TSSI322Y/ 9I4S I 904N 85001 8346
CRUISE I
TEMPERATURE CO SECTION TEC
JULY I TO AUG. 3,1949
39*30' 34*00' 38*30' 36*00' 37*30' 37*00
FIGURE 13.—Various temperature isotherms in a cross section of the Chesapeake Bay (from Whaley and Hopkins, 1952).
their southernmost limit of distribution on the oast
coast, e.g., the soft shell clam. Its southern dis-
tribution appears to be limited by high natural
temperatures, and any relatively small heat addition
in its shallow shelf zone habitat can therefore have
detrimental effects (Kennedy and Alihursky, 1971).
It has been observed that below about 40 feet in
depth the bay system between Annapolis and the
mouth of the Rappahannock (Figure 14) tends to
become deficient in oxygen during the summer, and
as a result probably contains fewer organisms than
surface waters. Waters from these cooler depths
may be useful as an industrial cooling water supply
in summer. A new nuclear SES is locating in the
bay midsection (Figure 14, arrow) and will pump
in a cooling water supply from a depth of 28 to 40
feet. This same installation will also have a short
intake-discharge passage time (about 4 minutes)
and will use sponge balls for cleaning condenser
tubes instead of chlorine. A number of design deci-
sions have been made that reflect a certain awareness
of and response to environmental vulnerabilities and
flexibilities.
The field of ecology is also gaining in sophistication
by developing predictive models with regard to pro-
posed environmental modifications. Figure 1.5 is one
such thermal-biotic predictive model for an estuarine
system developed for use in the Chesapeake Bay.
The model presents optimal and sub-optimal summer
temperature levels for the bay animal community.
Figure 16 presents a model that describes the
flexible temperature zone existing for bay species for
the various seasons. From the maximum allowable
temperature elevation line (MATE—dotted line)
one is able to predict the maximum increase in tem-
perature that will still permit optimum functioning
and production of the bay ecosystem throughout
the year (Mihursky and others, 1974).
Biological data and analysis will continue to pro-
vide sound guidance to the establishment of proper
water quality criteria and standards pertinent to
thermal discharges. Coutant's (1972) recent review
-------
352
ESTUARINE POLLUTION CONTROL
Chesapeake Bay
SCtlC IN NiUTICAl Will
0 9 K> 19 20 29
BALTIMOR
HARBOH
CRUISE I
TEMPERATURE (°C)AT 40'DER,
JULY I TO AUG. 3, 1949
FIGURE 14.—Forty-foot depth areas (in white) in the Chesapeake Bay and existing water temperatures. Arrows indicate SES
locations (from Hopkins and Whaley, 1952).
-------
POWER PLANT EFFECTS
353
27 32
TEMPERATURE
FiGl'BE 15.—Thermal-biotic predictive model for an estuarine
system (summer condition).
entitled "Biological Aspects of Thermal Pollution
II. Scientific Basis for Water Temperature Stand-
ards at Power Plants" is an excellent example of
such guidance.
Another continuing and unfortunate trend is that
the initiative for selecting SES sites is still residing
with the electric utility industry. State and federal
management and regulatory agencies are still re-
sponding to industry's initiatives that are often not
Ambient or Acclimation Temp.
FIGURE 16.—Summary of laboratory TLm testing on estu-
arine organisms. Individual lines have been omitted and only
the extreme (minimum and maximum) TLm slopes are
plotted. The ''old" and "new" (1968) Maryland temperature
standards are also plotted. M.A.T.E. is the predicted maxi-
mum allowable temperature elevation permitted to protect
estuarine species.
based on natural resource interests. In addition,
considerable reliance is still being placed upon in-
dustry's data, or analysis and interpretation by
their consultants in describing "effects" and their
"significance."
RECOMMENDATIONS—POLICY
Everyone now recognizes that we have had in the
past, two important unwritten national policies with
regard to energy and water. Namely, that both
shall be abundant and cheap. It is quite clear that
our growing inability to provide our human popula-
tion with cheap and abundant energy and water is
forcing changes in our conceptual and operational
strategies.
• National and regional energy policies must be
established. Obviously we must establish energy
priorities and sound energy use policies. National
and regional management strategies should dictate
that we meet legitimate social objectives by means
of least energy use pathways. Regional thermal
loading should not exceed thresholds that cause un-
wanted natural resource or climatological responses.
• The objective of achieving a quality environment
in order to achieve a qualiiy society should not be
compromised. Recent commentary that we cannot
afford to maintain necessary environmental quality
standards fails to incorporate all hidden costs and
is an improper conclusion.
• Federal and state management and regulatory
agencies must maintain a high, level of internal expertise
in order to assess and evaluate actual or proposed
environmental changes. Reliance must not rest solely
upon the resource user to design studies, gather, and
evaluate data.
• Initiative and guidance for siting and operation
of SES must emit from agencies having national or
regional responsibilities, and step by step methodologies
must be followed in order to achieve siting and operating
of SES with the best environmental fits. The Water
Working Group of the Committee on Power Plant
Siting (1972) illustrated in a schematic fashion
(Figure 17), and discussed in some detail, the types
of procedures to follow. Their recommendations are
still valid.
RECOMMENDATIONS-RESEARCH
It is quite clear that we must proceed to manage
ourselves from an objective scientific basis, more so
than ever before. Environmental costs and benefits
are indeed social costs and benefits. Objective deci-
sions must be based on quantitative data, with "all
-------
354
ESTUARINE POLLUTION CONTROL
NATIONAL ENERGY POLICY
NATIONAL SITING POLICY
REGIONAL PLAN
MATRIX OF SITING AREAS
1. Ocean 4. Lake
2. Estuary 5. Reservoir
3. River 6. Cooling Pond
FIGURE 17.—Flow diagram for power plant siting considera-
tions (after Commiitee on Power Plant Siting, 1972).
the cards on the table." Future generations should
not resent our present decisions due to our lack of
honest objectivity in meeting legitimate social goals.
• Basic research activity must be maintained, e.g.,
the process important in estuanne systems must be
understood. In order to factor in proposed perturba-
tions due to SES operations, a full quantitative
understanding must be achieved as to how estuaries
function.
• Biogeographical mapping must be completed for
estuarine systems. Such mapping can provide dy-
namic regional impressions of priority resource char-
acteristics. Lippson's (1973) recent atlas of the
major natural resources of the Maryland portion of
the Chesapeake Bay is an excellent example of one
such effort.
• Management and research dealing with thermal
discharges should be based on natural estuarine biotic
zones. The Water Working Group of the Committee
on Power Plant Siting (1972) proposed the following
zones:
1. Canadian border to Cape Cod.
2. Cape Cod to Cape Hatteras.
3. Cape Hatteras to Ft. Lauderdale, Fla.
4. Fort Myers to the Mexican border.
5. Mexican border to Point Conception.
6. Point Conception to Canadian border.
7. Coast of Alaska—probably should be two or
three zones.
8. Tropical islands and tip of Florida south of
a line from Fort Lauderdale to Fort Myers.
• A list of important species should be determined
for each estuarine zone in order to establish priority of
target species for which critical data are to be developed.
Important species must meet one or more of the
following criteria:
1. Important as a commercial species.
2. Important as a recreational species.
3. Important in biological energy flow.
4. Present in large biomass.
Unique, e.g.
endangered.
for research, aesthetic value,
• Quantitative data must be provided concerning
population, dynamics of these important estuarine
species. Information should at least include the
following:
1. Quantitative estimates of numerical abun-
dance, as well as location of various life
history stages, from eggs to adult.
2. Estimates of natural mortality rates for each
life history stage.
3. Longevity times for each life history stage
and generation time (egg to egg) for each
important species.
4. Minimum numbers of spawning stock re-
quired to produce the next generation at
some desirable sustained yield.
5. Second order effects on population dynam-
ics from any altered predator-prey, host-
parasite, host-disease changes in the system.
-------
POWER PLANT EFFECTS
355
• It must be determined Whether cropping rates Table 2.-Electrical power generating technologies (after Anon., 1972)
from SES activity on these various life history stages '
J . . ,. . . , , ,. , , • , , , • 7 Heat Disc, to Cond. Expected % of
are interfering With production of a desirable Sustained Method of Generation Cooling Water Total Capacity
. ,, ,.,, • , , • .-,,-,c, •. i ,- i BTU/KWH ' Year2000
yield of the important species, ^hhi site and operational i__ ' ,
specific, pumped-entrapment and pumped-entrain- PRESENT SYSTEMS
merit studies, must be coupled with laboratory
experimentation to assess uhat, if any, cropping Hydroelectric (Con.endonai * p™Ped I
rates may be assigned to specific SES operating storage). o | 5
sites and to specific operational conditions. Fossil Fuel I 3,900 10-20
• Quantitative biological responses to physical and
. . . -i77 r /• Shale Oil, Coal Gasification & Coal Liquifica-
chevncal changes attributable to near and jar-Jieid dis- tion (new fossil fuel).. | 3,900 , 10-15
charge plume characteristics must he acquired. Behav-
, i , , ,• . . Internal Comb. Eng._ 0 <1
loral, growth, and reproductive responses of species
must be determined. Gas Turbine..... j oj
-------
356
ESTUARINE POLLUTION CONTROL
Bonders, L. H., W. F. Furth, A J. Lippsori and H. J Obrem-
ski. 1072. An aquatic program strategy-power plant suing
program. Research Institute for Advanced Studies. Marl in
Marietta Corp., Baltimore, Md.
Carpenter, K. 1974. Copepod and Chlorophyll a concentra-
tions in receiving waters of a nuclear power station and
problems associated with their measurements. Estua-inc
and Coastal Mar. Sci. 2:83-88.
Clark, J. and BrownelL 1973. Electric power plants m tbe
coastal zone: environmental issues American Littoral
Society, Publ. No. 7. Highlands, N J.
Committee on Power Plant Siting. 1972. Working Group
l(b) Environmental Protection: Water, pp. 81-150. In:
Engineering for Resolution of the Energy-Environment
Dilemma. National Academy of Engineering. Wash., D.C.
1972.
Cory, 11. L. and J. W. Nauman. 1909. Epifauna and thermal
additions in the upper Patuxent, Esti ary. Chesapeake Sci.
10:210-217.
Coutant, C. C. 1970. Biological aspects of thermal pollution.
I, Entrainment and discharge canal effects C.H.C. Critical
Reviews in Environmental Control 1 (3):341-38l.
Coutant, C. C. 1972. Biological aspects of thermal pollution.
II. Scientific basis for water temperature standards at
power plants. C.R.C. Critical Reviews in Environmental
Control. August, 1972.
Cumberland, J. H. 1966. A regional int erindustry model for
analysis of development objectives. Regional Sci. Asooe.
Papers 17:65-95.
Dovel, W. L. 1971. Fish eggs and larvae of the upper Chesa-
peake Bay. Univ. of Aid. Natural Resources Institute Spec
Rept. #4.
Elser, H. J. 1965. Effects of a warmed-water discharge on
angling in the Potomac River, Md., 1961-1962. Prog.
Fish. Cult. 27(2) :79-86.
Engstrom, S. L., G. F. Bailey, P. M. Schrothe and D. V..
Peterson. U)71a. Thermal effects of projected power growth:
North Atlantic River basins. HEDL-TME 72-141. Han-
ford Engineering Development Laboratory, Richland,
Wash.
Kngstrom, S. L., G. F. Bailey, P. M. Schrothe and D. E.
Peterson. 1972b. Thermal effects of projected power growth:
South Atlantic and Gulf Coast River ba.sins. JIEDL-TME
72-131. Hanford Engineering Development Laboratory,
Richland, Wash.
Gehrs, C. W. 1974. Yeitical movement of zooplankton m
response to heated water. In: Thermal Ecology. Sympo-
sium Proceedings. CONF-730505 Nat. Tech. Info. Serv.
Springfield, Ya. pp. 285-290.
Goodyear, C. P. 1973. Probable reduction in survival of
young of the year striped bass in the Hudson River as a
consequence of the operation of Danskammer, Roseton,
Indian Point Units 1 and 2, Loveti and Bowline steam
electric, generating stations. 'Mimeo) U.S. Atomic Energy
Commission. Hearings on Consolidati d Edison Company's
Indian Pt. nuclear generating ur.it No. 2 Docket No.
50-247.
Hammond, A. L., W. P. Met/ and T. II. Maugh II. 1973.
Energy and the future. American Association for the Ad-
vancement of Science.
Hill, J. M and G. R. Hel/. 1973. Copper and zinc in estuarine
waters near a coal-fired electric, power plant—correlation
with oyster greening. Environ. Letters. 5:165-174.
Jaske, R. T. 1970. Thermal pollution arid its treatment—the
implications of unrestricted energy usage with suggestions
for moderation of the impact (Mimeo). Paper for presenta-
tion and publication in session notes of Environmental
Management for Industry and Government- training course
sponsoied by the Industrial Management Center Inc.,
Austin, Tex.j 1970-71 sessions.
Kennedy, \. S. and J A. Mihursky. 1971. Upper temperature
tolerances of some estuarine bivalves. Chesapeake Sci.
12:193-204.
Kennedy, Y. S., W. H. Roosenburg, M. Castagria and J. A.
Mihursky. 1974. Mercenaria mercenana (Molhisca: bi-
valvia): Temperature time relationships for survival of
embryos and larvae. Fish. Bull. 72:1160-1106.
Kinne, O. 1963. The effects of temperature and salinity on
marine and brackish water animals. I. Temperature.
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170:1265-1274.
1970. Man-made climatic changes. Sci.
Lees, L. and others. 1971. People, power pollution, environ-
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Qnal. Laboratory, Pasadena.
Leschber, E. W. 1972. Premature failure of type 316 stainless
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Lippson, A. J. (Ed.) 1973. The Chesapeake Bay in Maryland,
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Press. Baltimore, Md.
Mihursky, J. A. 1969. Patuxen. Thermal Studies—Summary
and Recommendations. Univ. of Md. Natural Resources
Institute Spec. Publ. # 1.
Mihursky, J. A. and L. 1
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North American
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Cronin. 1973. Balancing needs
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Wildlife and Natural Resources Con-
Mihurskv, J \ and Y. S. Kenned}' 1967. Water tempera-
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water quality criteria. Amer. Fish. Soc. Spec. Pub. 4:20-32.
Mihurskv, J. A. and others. 1974. The thermal requirements
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Moore, C. J., G. A. Stevens, A. .). McErlean and F. H.
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POWER PLANT EFFECTS
357
Nauman, J. W. and R. L. Cory. 1969. Thermal additions and
epifaunal organisms at Chalk Point, Md. Chesapeake Sci.
10:218-226.
Roosenburg, W. H. 1969. Greening and copper accumulation
in the American oyster, Crassostrea mrgimca, in the vicinity
of a steam electric generating station. Chesapeake Sci.
10(344) :241-252.
Trembley, F. J. 1960. Research project on effects of condenser
discharge water on aquatic life. Prog. Rept. 1956-59.
Institute of Research, Lehigh Univ., Bethlehem, Pa.
Trembley, F. J. 1965. Effects of cooling water from steam
electric power plants on stream biota. In: Biological
Problems in Water Pollution. 3rd. Seminar, Aug. 1962.
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Wagenheim, K, 1972. Oyster Creek fish kill. Smithsonian
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EFFECTS OF THERMAL DISCHARGES
UPON AQUATIC ORGANISMS
IN ESTUARINE WATERS
WITH DISCUSSION OF LIMITING FACTORS
LOREN D. JENSEN
Ecological Analysts, Inc.
Baltimore, Maryland
ABSTRACT
A descriptive summary of both thermal and nonthermal power plant effects is presented with an
attempt to provide an insight into the total ecological impact of power generating stations operat-
ing in estuarine systems Specific effects of thermal and other plant associated stresses are sum-
marized for aquatic organisms exposed to a range of time and temperature exposures resulting from
once-through cooling systems. This review presents specific summaries of representative case his-
tories of thermal effects in east coast, gulf coast, and west coast estuarine systems with an attempt-
to identify regional characteristics that may influence the response of aquatic populations to
thermal effluents.
INTRODUCTION
Considerable attention has been given to the
effects of thermal elevations in the condenser cooling
system upon aquatic organisms exposed to the dis-
charges for once-through cooling systems. Certainty,
much of this concern is justified on the basis that
aquatic organisms are vulnerable to physiological
shock caused by such exposures. Indeed, thermal
deaths have occurred and short of outright death,
considerable stress has been detected within surviv-
ing members of individual species populations. While
we should attempt to keep thermal exposures to a
minimum in terms of both amplitude and duration
of exposure, other flow related influences should not
be overlooked. Indeed, in attempting to reduce the
effects of thermal exposures, many design and
operational changes at once-through power systems
have created new problems for aquatic organisms.
My comments are brief and summary in scope. We
can assume that our interests in protecting the
fisheries populations adjacent to electric power
generating systems require the consideration of
those aquatic organisms that are of ecological sig-
nificance to the survival of fisheries populations.
Briefly then, I would like to discuss biological
monitoring programs and the kinds and levels of
effects that have been noted in connection with
power generating stations operating within estuarine
systems.
FREQUENCY OF DATA
COLLECTION PROCESSES
Biological monitoring programs have been used
for the past 10 to 12 years to assess the influence of
thermal discharges upon surface waters used in
the condenser cooling systems of both fossil and
nuclear power plants. Initially, studies were limited
in both biological scope and frequency, stimulating
considerable confusion and debate over the value of
individual data programs. Although such studies
were intended to monitor effects from specific power
plant systems, necessary plant operational fluxes
were frequently omitted from data collection pro-
grams. Such operational data is relatively easily
obtained but, due to the necessity of using power
plant personnel with specific engineering expertise,
it was often not included by aquatic scientists during
either the formulative period in the data collection
processes or the interpretable phase of biological
data review.
Earlier studies of aquatic biological populations
influenced by individual power stations were con-
ducted by teams of specialists, on a quarterly or at
best, bimonthly basis. Such studies were assumed
to be sufficient to indicate significant effects, but
they often resulted in the documentation of seasonal,
temporal, and spatial fluxes of populations within
each surface water system with such statistical
variability from period to period as to make sub-
sequent correlation with physical data exceedingly
difficult, if not impossible, to make.
More recent biological monitoring programs have
359
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360
ESTUARINE POLLUTION CONTROL
been conducted on a much mor? intensive basis.
Data on daily fluctuations in vertical and horizontal
stratification are now commonly collected for all
major biological groups on a seasonal basis with the
results that monthly data efforts reflect a tremendous
range of technical skills and sampling techniques.
These studies involve an increasing effort to conduct
presiting data programs that can be used to avoid
the location of power plants within areas of critical
or high biological significance. Moreover, presiting
data collection programs have the potential value
of improving design criteria for minimizing biological
impacts at appropriate sites.
The incorporation of intense presiting biological
data programs to new power plant programs pro-
vides quantities of data spanning a longer number
of years before thermal and other condenser system
effects are initiated. The result of such programs is
to provide much more confidence to the documenta-
tion of the normal biological distributions around a
specific site. Annual pulses or fluxes in numbers of
individuals of a given species art' also much more
readily disassociated from the effects of the com-
bined influences of the condenser cooling systems of
individual power plants. The following lists of levels
of data and areas of potential effects represent
common efforts of current estuarine thermal research
projects.
WATER INTAKE AREA EFFECTS
The first engineered interface of a power plant
with its surface cooling water supply is the water
intake structure including, of course, screening
hardware and associated structures. Design engi-
neers currently expend both effort and ultimately
considerable expense to control approach velocities
to reduce the potential for hydraulic capture of
both debris and fish. Although most new screen
intake structures have velocities of 1 fps or less, the
experimental basis for this constraint is based more
upon the demonstrated fact that such velocities
have much less impingement potential than higher
velocities. Unfortunately, while these numbers are
on a practical basis useful to design engineers as
a general guide, the fact of life is that even at
these relatively low design velocities, hydraulic
capture of fish populations occurs on an all too
frequent basis and the reduction or the solution of
the problem is much more of an art than a science.
A more experienced applied biologist colleague of
mine once offered a very useful observation to me
on the occasion of his retirement from the faculty
at our institution. His observation was, essentially,
that the best explanation of natural events a.hd
incidents involving fish populations was that the
fish as a biological group were quite prone to suicide.
Since his retirement, I have found many a power
plant engineer who agreed with him. An obvious
explanation for the accumulation of fish at intake
screening structures involves the fact that screening
equipment does collect debris relatively efficiently
and dead or dying fish are easily collected along with
other debris at intake equipment. Obviously, not
all fish at such screening equipment are there on
the basis of chance. The attraction, of fish to hydraulic
flows is explained both physiologically and ecologi-
cally in terms of energy conservation. If fish are
prone to suicide, they, like many other biological
groups, do not waste energy looking for a food
source when they can remain relatively stationary
and just select appropriate food as it comes by.
Even predator species can take advantage of the
concentration of prey species in these current sys-
tems. The end result is, of course, the establishment
of a relatively concentrated biological food chain
within the area where these abnormal flow gradients
occur for the system. Other aquatic organisms such
as crabs, shrimp, and forage feeders can be found
at intake systems of gulf and coastal system intake
areas.
At those power stations where water quality is
uniformly high and where approach velocities are
not so high as to entrap and then impinge these
organisms, no particular significance can be made
for these accumulations. However, when the water
withdrawn and used for cooling purposes periodically
fluctuates to sub-optimum values for individual
species, stressing conditions and, ultimately, death
of concentrated populations in these areas occurs
and the screening equipment must handle the
removal and disposal of the bodies of these organisms.
Such events as upwelling, seiching, and surface
currents can also produce these events.
Unfortunately, many intake structures and areas
have been built with such high velocities that ex-
haustion and physiological collapse by fish in front
of the screening equipment occurs. The result is,
of course, that such fish populations are highly
vulnerable to additional and extraneous stresses that
can cause an "incident" at the screening equipment.
Unfortunately, discharges of heat into intake
areas, discharges of chlorine and other products
required by the condenser cooling system for either
fouling or corrosion control can also adversely
influence the survival of relatively dense populations
of fish in such intake areas. Solutions to these intake
and screening equipment problems will require con-
siderable research relative to the ability of fish to
maintain both sustained and darting swimming
-------
>\VEK PLANT EFFECTS
361
efforts in a mixed assemblage of species involving
both predator and prey species. Age-class differences
in endurance must also he considered in such experi-
mental svstems. Observations of plants where intake
problems are relatively scarce, or at least less
detectable, suggest that short, stubby cul-de-sac
or funnel shaped intakes have considerable potential
for the capture and impingement of fish. Such
systems have very few areas \\here recuperation and
resting by swimming organisms can occur. Flush
shore intake systems have not been involved with
fish impingement problems as frequently as have
intake channel sites. Presumably, opportunities for
bypassing screening equipment provide for the;
escape to lower velocity areas by swimming fish.
Tidal and shoreline currents also act to carry fish
tr.vav from screening surfaces in this area.
CONDENSER COOLING SYSTEM EFFECTS
The term "entrainment" has boon borrowed from
the hydraulics field and used to describe the com-
bined experiences of planktonic organisms from the
time of their first exposure to the intake pumps,
through the condenser cooling system and sub-
sequent mixing with receiving waters downstream
from discharge structures or canals. A distinction is
made between "pump entrainment" of planktonic
organisms that are subsequently exposed to maxi-
mum thermul elevation, turbulence, sheer, and
pressures, and "plume entrainment" or planktonic
interaction with the thermal plume by organisms
that have not experienced the combined experiences
of the condenser system. Obviously, the experiences
of these 1wo types of entrainment are quite dif-
ferent and tho\ should be distinguished because the
temperature and time of exposure as well a^- turbu-
lence, sheer, and other mechanical stresses are dis-
tinctly different for the two types of experiences.
Eesearch has shown strikinglv different results from
these two types of entrainment experiences. The
term plankton refers to organisms that arc1 at or
near neutral buoyancy and thus, the term is more,
indicative of the relatively free floating character
rather than taxonomic relationships between or-
ganisms composing the plankton. Thus, three major
groups of planktonic organisms can be described,
each with relatively different individual response
and population susceptibility to the entrainment
experience.
Phytopiankton
These microscopic algal cells are, by definition,
al\va\s planktonic (Euplanktonic) and thus as
primary producers of organic energy, they represent
a highly important and vulnerable level for entrain-
ment damage. Phytoplankters reproduce within
minutes to hours and thus the recovery potential of
these organisms is relatively high. That is, should
destruction of a portion of the population occur due
to either pump or plume entrainment damage, the
species population has a relatively high reproductive
potential for recovery within a few hours. Moreover,
death of these algal cells does not change the
nutriment value of the population since most aquatic
predators do not distinguish between dead and
living cells.
Experience in attempts to measure the stresses
upon phytoplankton during exposures to the com-
bined experiences in the condenser cooling system
suggest thai the response of phytoplankters is most
related to the prevailing ambient water temperatures
and the temperature rises (AT) of particular con-
denser cooling svstems. That is, if death of living
plankton occurs it is most predictable on the basis
of seasonal high water temperatures, usually occur-
ing only a, few weeks or months during each year.
At other times of the year the phytoplankton appear
to be stimulated by the entrainment experience as
indicated by increases in the rates of photosynthetic
processes, chlorophyll levels, and absolute numbers
of cells of individual species found in discharge and
mixing areas (\Varriner and Brehmer, 190G, Gurtz,
1973, Brooks, et al., 1974, Jensen, et ah, 1974,
Smith, et al., 1974).
The above effects should not be considered as
necessarily beneficial to the aquatic population
residing in a cooling water body. Numerous water
bodies do not need such stimulation by living plank-
ton populations and in some cases the; destruction of
phytoplankton can contribute to oxygen problems
due to the HOD demands of the dead plankters
downstream from the discharge areas. Thus, the
significance of damage to this level of aquatic
populations should be determined on a site specific
basis.
Zooplankton
This term describes a very rich assemblage of
invertebrates that are, in most cases, microscopic.
Many zooplankters are truly planktonic, and only
a few groups are consistently neutrally buoyant.
Thus, effects of the entrainment experience at this
level is likely to be much more specie's specific, and,
in fact, current research appears to verify this
assumption. Moreover, potential mechanical damage
to these types of organisms is considerable, especially
with larger crust.'icean forms of the zooplankton;
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362
ESTUARINE POLLUTION CONTROL
such damage has been found to be both size and
species dependent.
Behavioral excursions of zooplankton from lower
to upper water levels has been shown by Kelly, 1971,
Kelly, et al., 1971, Kelly and Chadwick, 1971,
Icanberry and Adams (1972), Davies and Jensen
(1974) and others to bring these zooplankters into
water volumes where they can be affected by both
pump and plume entrainment experiences. Con-
siderable variation has been found relative to the
vulnerability of different life cycle stages of zoo-
plankters to the effects of both thermal and mechani-
cal damage; eggs, early naupliar stages, appear to
be more resistent than larger, older and somewhat
more physiologically complex stages. Moreover,
prolongation of thermal exposures by residence
within long discharge canals has: been shown by
Davies and Jensen (1974) to promote thermal
damage to zooplankters. Sheer and mechanical tur-
bulence of discharge structures may inflict physical
damage on larger plankters. Little; evaluation of
zooplankters during turbulent plume mixing has
been made. Research by Carpenter (1974) suggests
that alterations in behavioral activities of micro-
crustacean zooplankters can result in decreases in
the population downstream from once-through power
plants. Depending on levels applied and individual
toxicity of each species, chlorination activities can
destroy all plankton organisms when and if used for
the control of biofouling in the condenser system.
llecirculated heat, as a control system, appears to
achieve the same degree of damage.
Meroplankton
By definition, these transient plankton forms are
only present for a brief period during which growth
arid development proceed to either a sessile or
swimming juvenile stage, leading ultimately to
either the sessile or nectonic adult form. Numerous
invertebrates such as crabs, lobsters, shrimps, clams,
oysters, and other taxonomic groups have mero-
planktonic eggs and larvae. Most fish have mero-
planktonic egg and larval stages (known as ichthyo-
plankton) that are present for a period of days to
weeks following spawning activities. Thus, prevailing
currents and tidal flows can bring these temporary
plankton into contact with thermal plumes with
effects that are not readily measured.
Moreover, entrainment damage' of meroplankton
stages can have considerable influence upon the
populations of fishes and invertebrates well beyond
those detected in the near field mixing aiea. These
organisms are likely to have a reproductive potential
considerably less than that of euplanktonic forms.
Damage to these stages can influence the population
structure of individual species and communities.
Thus, the ecological significance of this type of
planktonic entrainment within the condenser cooling
system is rather obvious. Experience by biologists
studying this problem suggests that considerable
physical damage occurs with the rather delicate
larval forms of both invertebrates and vertebrates.
Egg stages appear to be less susceptible to such
physical damage. Excessive turbulence and pressure
such as cavitation tend to promote this type of
damage. Indeed, some power stations have been
reported to produce near total destruction of mero-
plankton while other stations seem to produce much
less damage to the plankton. Current research and
modeling of condenser cooling structures should
reveal the reasons for these observed differences.
Obviously, the ecological significance of point
source types of entrainment such as has been
described above must be considered by the use of
biological modeling that has, unfortunately, not
been developed successfully at the present time.
Thus, the ecological significance of these types of
entrainment damage can only present!}' be approxi-
mated on the basis of percent of waters used for
cooling versus total water available for the support
of such planktonic stages. Special or peculiar con-
centrations of these stages such as clusters or
patches can lead to disproportionate effects of en-
trainment damage upon the individual populations
and thus, considerable sampling effort should be
made of the near and far field areas to ascertain such
distribution differences of individual power plants
and plant sites. Such sampling efforts represent a
relatively unusual and rather expensive effort.
DISCHARGE AREA EFFECTS
The geometry and site specific characteristics of
the discharge area have, like the intake area, a highly
plant specific impact on aquatic organisms. The
decision to either rapidly mix thermal discharges
into the receiving water body through such devices
as momentum jets or submarine diffusers can cut
the time of exposure to maximum thermal eleva-
tions, effectively reducing discharge effects, espe-
cially those affecting fish populations attracted into
the discharge area.
Discharge canals have been shown to produce
highly variable results in terms of impacts upon
local aquatic populations. Effects of thermal ex-
posures, cold shock, chlorination "incidents," and
other adverse influences have been promoted by the
use of long, low velocity discharge canals. These
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POWER PLANT EFFECTS
363
effects have been shown at west coast, gulf coast,
and east coast estuarine areas.
MIXING AREA EFFECTS
Considerable effort has been expended by hydrol-
ogists in an attempt to describe the dimension of
thermal effluent mixing areas. These modeling efforts
provide an existing and exceedingly useful series of
time-temperature distributions with information
relative to changes in these plumes caused by tidal
and other natural currents. Their high value and
significance to biologists who are attempting to
assess the ecological effects and interactions of these
effluents in surface waters is obvious. In fact, it
would be quite impossible to accurately model the
stresses of near field and far field distributions of
waste heat without such predictive hydraulic and
mathematical modeling research.
Measurements of these downstream effects from
the combined pump entrainment and plume entrain-
ment experience suggest that some of these effects
are so subtle as to not be readily detected by existing
field population census techniques. Certainly some
avoidance of and attraction to the thermal plume
has been historically seen by many workers.
SUMMARIES OF REPRESENTATIVE
CASE HISTORIES OF THERMAL
EFFECTS IN ESTUARINE AREAS
The estuarine environment is an exceedingly
complex ecological system. Indigenous finfish, migra-
tory fin fish, anadromous species, shellfish, and such
Crustacea as crabs and shrimp depend upon the
estuaries for at least some part of their life cycles.
The economic importance of specific fisheries in the
above categories can be- considerable.
Large tidal bodies of water, such as the Chesa-
peake Bay, (Jalveston Bay, and others, could,
theoretically, offer considerable quantities of cooling
waters if the aquatic populations of each estuarine
system could be protected from a uniform and
complete thermal elevation throughout the system.
Again, considerations of specific sites must consider
the amount of ''new water" passing by a given site
and thi relative quantity of such \\aters needed for
cooling waters by particular plants. Behavioral and
reproductive phenomena such as schooling, spawn-
ing, and nursery areas imist be protected from
thermal elevations. In such systems, mixing of dis-
charge effluents into tidal waters can reduce the
effCctive temperature rise (AT) to onl\ one or two
degree- above ambient levels. Caution muM be given
to intake and discharge levels so as to withdraw
only the least populated water levels. When the
cooler and more saline bottom \\aters are used as a
cooling water source, considerable research should
precede plans for the discharge of the thermally
elevated, saltier waters. Such discharges have been
shown to sink to a mid-depth in response to combined
thermal-saline density factors. When and if this
occurs, the influence upon local populations must be
predictable before alternative discharge plans are
rejected.
Moreover, in smaller bays and estuaries, with-
drawal of large fractions of water have altered
circulation patterns in local areas (Jensen, 1974).
As mentioned above, such influences can change
behavioral patterns with local populations of fishes
and invertebrates. Tidal influences in terms of the
direction of discharge plumes complicate the above
predictions to the extent that hydraulic models are
often used to simulate flow patterns. Such an
application has been made in the James River
estuary model located at the U.S. Corps of Engi-
neers Waterways Experiment Station in Vicksburg,
Miss. The model has a horizontal scale of t:1000
and a vertical scale of J : 100. The time scale is
f:tOO so that one day in the prototype occurs in
14.4 minutes time in the model. The proposed dis-
charge1 of the Virginia Electric and Power Company
Surry Nuclear Power Station has been simulated
in the model, and temperature measurements have
been recorded along various transects across the
model through many tidal cycles and under different
freshwater inputs. Since it was not possible1 to
simulate all condition* in the model, theoretical con-
ditions weie applied, and the empirical data were
thereby adjusted to conditions expected in the
prototype. The predicted distribution of excess heat
in the estuary will be verified in the James River
estuary, after the Surry Power Plant begins opera-
tion during the spring of 1973.
Another such model is being planned for the entire
Chesapeake Bay. Several hydraulic models of limited
areas of the bay and its tidal arms have been built
by the Alden Research Laboratory of the Worcester
Polytechnic Institute in Worcester. Mass., and are
used to predict the physical behavior of thermal
discharges. A similar model of the San Francisco
Bay and Sacramento-San Joaquin Delta has been
used to simulate thermal distribution at various
power-plant sites in northern California.
The control of biofouling in tidal systems is con-
siderably more difficult than in freshwater systems.
The application of wide-spectrum biocides for such
fouling control, both within the intake system as
well as the condenser system, must be made with
caution to avoid killing fish and invertebrates
-------
364
ESTUAKIXE POLLUTION CONTROL
residing in discharge canals and receiving waters.
Excessive chlorination and use of widely active
compounds such as copper sulfcte have lead to
dramatic incidents that have mistakenly been re-
ported as thermal kills.
As mentioned previously, the temperate estu-
arine populations of southern latitude species are
often living close to their upper thermal tolerances
during summer periods. These species have much
narrower thermal tolerance ranges than northern
populations of the same species which can withstand
wider thermal fluctuations. Thus, if an appreciable
heat load is introduced into a mid-latitude estuary,
it must be recognized that the local thermal distribu-
tion might actually favor the growth of more
southerly species (or subspecies) in limited areas.
One difficulty with such changes is that it is likely
that some disagreement will occur between local
biologists as to what constitutes a ''desired species."
A conservative ecologist might contend that only
those species that exist normally in the outfall area
are the desired ones, while other ecologists might be
willing to settle for a slightly different fauna and
flora in a limited area.
Studies made at the Chalk Point Generating
Station on the Patuxent River estuary in Maryland
before and after the operation uf the power plant
showed that local populations of striped bass
increased while concentrations of white catfish and
hogchokers declined. White perch populations re-
mained constant during the study. Total gillnet
catches by commercial gear were approximately the
same at the station nearest the power plant and
increased at the two other stations farther down-
stream. Sport fishing in the area has increased in
winter months (Maryland Department of Xatural
Resources, 1969).
Studies of the oyster Crassoslrea virginica on beds
within 1,200 feet of the discharge canal at the
Chalk Point plant showed no major effects on the
growth, condition, and gonadal development as a
result of plant operation (Rosenberg, 1968, Patrick,
1968). Invertebrates harmful to the oyster, the
oyster crab Pinnotheres osterum, and the worm
Polydora were no more common in 1965-67 after
the plant went into operation than in 1962-63- The
accumulation of copper in oyster tissues was also
reported from beds in the vicinity of the Chalk
Point plant. Subsequent investigations showed that
the copper concent rations in water upstream from
the power station were 1.97partn per billion, while
that in the outfall was 3.01 parts per billion (Patrick,
1968^. This apparently is not common to power
plant operation in estuarinc areas, but ft as the result
of improper design and metallurgy in the condenser
tubing. Cory and Xauman (L969) reported that the
number of fouling organisms, including barnacles,
increased at the locations influenced by the dis-
charge of the Chalk Point station, decreased upriver
from the power plant, and that the increase was
associated with the warmer effluent waters.
Studies by Patrick (1968) on the Chalk Point
station indicated a well-diversified flora throughout
the area influenced by the thermal discharge in
August, 1968. Nutrient additions upriver from the
plant w<>re reported by Patrick to complicate the
assessment of the plant's effects an tin- standing
crop of algae, though the cyclic seasonal patterns
observed before the plant went into operation were
lost at stations above and below the discharge canal.
Morgan (1969) studied the effect of temperature
and chlorination procedures on the passage of
phytoplarikton through the condensers at the Chalk
Point Plant and found that when the eflluent tem-
peratures were between S8.7 and 9'2.4° F (chlorina-
tion levels were not known), photosynthetic capacity
was reduced by 68.6 to 94.3 percent. During colder
seasons, photosynthesis was reduced by as much ac
85.7 percent. However, Morgan (1969), Mihursky
(1967), and others believe that chlorination proce-
dures were responsible for much of this reduction.
Patrick (1968- found no significant difference in
the composition of the zounlankton arid/or phyto-
planktori at the Chalk Point station at similar times
of the years 106,3, 1967, and 1968.
Two microscopic Crustacea, the copepods Acartia
tonsa and Eurytemora ajfims, were the dominant.
species, arid Acartia tonsa standing crop1' were
greater during the summers after the Chalk Point
station began operating. Two jellyfish, Mnemvipsis
leidyi (a comb jelly ctcnophorc) and Cryasora
quirtquecirrha (a sea nettle) w>-re more prevalent
before the plant began operating. Mihursky (1967)
reported that thermal changes were responsible for
this decline.
Warriner and Brehmer (1966) studied the. effects
of condenser discharge water on the benthic inver-
tebrates in the York River estuary at the Yorktown
Generating Station of Virginia Electric and Power
Company. Community composition nnc' abundance
were affected over a distance of 980 to 1,-300 feet,
from the discharge canal. All sampling stations,
including the controls, .showed a marked seasonal
change in abundance, with a minimum in sum me;
and a maximum in winter. The lowr-,1 diversity of
species was tumid in a small ana v*ithm 980 feet
of the discharge, and this was interpreted by the
authors to be an indication of stress on the bentliic
community m which only the JP
-------
POWER PLANT EFFECTS
365
Studies with a laboratory heat exchanger vising
natural York River water without chlorination
showed that primary productivity of natural phyto-
plankton was depressed by a 10.1° F increase in
water temperature when the ambient temperature
was 59 to 68° F. A temperature rise of 6.3° F was
sufficient to depress production when the ambient
summer water temperature was 80° F. In cold
weather, productivity was enhanced after passage
through the exchanger (Warriner and Brehmer,
1966).
Thermal studies at a power plant at Turkey
Point, a unique tropical area in South Biscayne Bay,
Fla., have been reported by Tabb and Roessler
(1970), Reeve and Cooper (1970), and Lackey and
Lackey (1972). The benthic macroalgae Acetabularia
crenulata and Batophora oerstedi were the only species
observed at the mouth of the discharge canal during
the period of February to September, 1969. The
number of species of macroalgae increased at in-
creasing distances from the discharge canal out into
the Biscayne Bay. The stations nearest the canal
mouth had the lowest numbers of species and thus
the lowest diversity index (Tabb and Roessler,
1970). However, these reductions in benthic algae
have been suggested to be due to the combined
effects of dredging and construction of the power
plant canal system along with the hydraulic scour
that the discharge canal system imposed upon the
areas of Biscayne Bay immediately adjacent to the
plant site.
In September 1968, turtle grass, Thalassia testudi-
num, was reported to be killed over a 30-35 acre
area which had apparently increased to 50 acres a
year later. Benthic invertebrates and fish popula-
tions associated with the turtle grass and macroalgae
populations were also reported to show decreased
numbers in an area of 170 acres surrounding the
discharge canal. An unspecified number of dead
fish were reported to have been associated with the
impact area in June of 1969.
Studies by Tabb and Roessler (1970) have sug-
gested that these effects were primarily due to the
thermal effluent from the Turkey Point Power Plant.
However, unusually low salinities (16-17 ppt) and
relatively high copper concentrations (15 mg/1)
were also detected in waters with temperatures of
91 to 95° F (Lackey and Lackey, 1972). Such low
salinities for the area (normal summer salinities are
27-33 ppt) coupled with the toxic levels of copper
could have been partially responsible for the reported
fish kill.
Moreover, the presence of such levels of copper
could also account for the reductions in benthic
grasses and their associated animal populations, as
noted above. In the absence of more definitive data,
however, such conclusions are speculative. Recent
observations by Lackey and Lackey, 1972 suggest
a recovery of the impacted area in the discharge
canal and adjacent Biscayne Bay areas since the
observations of earlier workers in 1968. Because of
the tropical and relatively shallow nature of the
Biscayne Bay, these ecological effects may suggest
the types of effects that can occur in such estuarine
systems.
Research on the thermal impact of a power gener-
ating station on Galveston Bay, Tex., was reported
by Strawn and Gallaway (1970). Seasonal abun-
dance, distribution, and growth of commercially
important crustaceans were investigated. Tempera-
ture, conductivity, dissolved oxygen levels, pH, and
biological samples of blue crabs, Callinectes sapidus,
white shrimp, Penaeus setiferus, and brown shrimp,
Penaeus aztecus, were taken once a month through
1968 and 1969. Collection stations were in and
around the discharge canal of the power plant. The
impact of the thermal effluent upon the above species
was related, significantly, to the season, the relative
abundance of each species, thermal tolerance, and
thermal preference of each species studied. Blue
crab populations appeared to be beneficially in-
fluenced by the power-plant activities (thermal
increases and circulation improvements caused by
pumping activities). White shrimp populations ap-
peared to show both detrimental as well as beneficial
effects, but the overall effect was judged by the
authors to be beneficial. Brown shrimp were ad-
versely affected in a limited area of the Galveston
Bay surrounding the power plant (Strawn and
Gallaway, 1974).
A study of the thermal impact of a Pacific Coast
generating station at Morro Bay was reported by
North (1968). Results of studies of the discharge
canal and the coastal zone immediately adjacent
to the power station indicated that seaweeds were
almost completely eliminated from the discharge
canal, while in a transition region beyond the canal,
seven algal species of a total of 20 species in normal,
non-thermally influenced areas were found. The
transition area was fished rather intensively, and
North suggests that schools of grazing Opaleye
((lirella miqricans) and various invertebrates ac-
count for some of this reduction. Thus, the marine
flora of Morro Bay appears to be much more ther-
mally sensitive than the fauna and the impact of
the Morro plant effluent on the seaweeds might be
explained by the thermal sensitivity of reproductive
cells in association with relatively heavy grazing by
fish and invertebrates within the area.
Mitchell aud North (1971) examined the tempera-
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366
ESTUARINE POLLT'TION CONTROL
ture and time of contact of marine plankton which
were passed through the cooling water systems of
two Southern California Edison Generating Stations
located on the Pacific coast. Sampling at intake and
discharge structures and subsequent incubation on
site at the San Onofre and Huntington Beach
Generating Stations simulated temperature- time
exposure met by plankters passing through the
condenser system and traversing the discharge and
mixing areas. Typical zooplankton mortality ranged
from 12.7 to 28.4 percent with the high mortalities
due to sampling error introduced during sample
examination. The copepods Acarlia tonsa, Euterpe
acutifrons, Corycaeus affinis, and Oithona helgolandica
and the mysid shrimps represented nearly all of the
mortalities. Smaller soft-bodied invertebrates (poly-
chaete larvae, Sayitta sp.) and protozoans showed
little effects of passage. Analysis of carbon-14 and
chlorophyll studied of phytoplankton populations
passing through the condenser cooling system suggest
that little damage: to the populations occurred as
evidenced by comparisons of 14C uptake rates and
chlorophyll a, phaeophytin a levels after a standard
incubation-culture procedure of intake and dis-
charge samples collected from the two generating
stations. Some evidence of phytoplankton stimula-
tion in discharge samples was noted during these
studies and normal chlorination procedures resulted
in obvious damage in the plankton populations
collected in the discharge area during the chlorination
period.
Icanberry and Adams (1972) have described the
survival of zooplankton after passage through the
cooling water systems of four California coastal
power plants. A statistically significant increase in
discharge mortalities of less than 11 percent com-
pared to intake mortalities was found at all plants,
suggesting average overall survival of approximately
90 percent. A statistically significant linear relation-
ship was noted between the discharge temperatures
and percent mortality in all four of the power plants
examined. Twenty-four hour delayed mortality did
not occur when intake and discharge samples were
held at ambient intake water temperatures. Con-
siderable mortality occurred when discharge samples
of zooplankton were held at discharge temperatures
for periods up to 24 hours of continuous exposure.
Immature zooplankton stages exhibited increased
mortality only after the first six hours, followed by
adult copepods which died between 12- and 24-hour
periods. Soft bodied invertebrate larvae were resis-
tant to these combined effects of temperature and
time of exposure. Surveys of actual temperatures
occurring around the discharges of these four power
plants revealed that these time and temperature1
conditions (discharge temperatures lasting 12-24
hours) do not occur due to the mixing and dilution
of the thermal discharges with cooler Pacific coast
waters. Thus, this research suggests that the very
small increase in mortality (approximately 11 per-
cent) due to passage through the cooling water
system of these four power plants does not (in all
probability) significantly affect the zooplankton
populations of the Pacific Ocean in the; areas sur-
rounding the power plants examined by these
researchers.
Extensive research has been underway over the
past five years to evaluate the impact of once-
through cooling systems of power plants located
within the Sacramento-San Joaquiii Delta area
under the sponsorship of Pacific Gas and Electric
Company. Field studies of the temporal and spatial
distributions of thermal effluents of the Pittsburg
and Contra Costa Power Plants in the central delta
area have been supplemented by biological sampling
in and out of the thermal plumes to locate popula-
tions of striped bass (Aforone saxatilis), king salmon
(Oncorhynchus tshawytscha), and other fish as well
as fish food organisms such as the opossum shrimp
Xeomysis airatKchensid (Adams, 1969, Adams and
Doyle, 1971, Chadwick, 1971, Hair, 1971, Kelly,
1971, Wickmire and Stevens, 1971, Kelly et al. 1971,
Kelly and Chadwick, 1971, Orsi, 1971, Rogers and
Stevens. 1971, Gritz and Stevens, 1971, and Gritz,
1971). Distribution of young striped bass indicated
that densities were always greatest, at mid-depth
and bottom as contrasted to surface areas in strati-
fied areas of the delta. Intensity of stratification
fluctuated with the stage of tides and size of fish.
Small bass less than 9 mm were1 higher than larger
fish and densities increased at all depths during
flood tide. Lateral distribution varied but densities
were lowest in surface and mid-depths of the Pitts-
burg thermal plume suggesting preference for the
cooler bottom areas in the vicinity of the thermal
effluent.
Further studies on fish distribution within the
thermal plume of Pittsburg (Gritz, 1971) have
revealed that striped bass, splittail, carp, white
catfish, American shad, Sacramento western sucker
and Sacramento blackfish were more abundant
within the thermal plume of the plant than in
control areas of ambient water temperature but
equivalent habitat tvpe. Stomach contents of striped
bass suggest that the importance of the opossum
shrimp Neomysis au'atsch&ti.sis diminished and the
importance of fishes (including small king salmon)
increased with striped bass size (Gritz, 1971).
Unfortunately, these studies did not distinguish
between increased predator concentration (striped
-------
POWER PLANT EFFECTS
367
bass) within the thermal plume and physiological
stress of king salmon which increased their vulnera-
bility to predators as was suggested by Coutant,
who described similar reactions within a thermal
plume discharged into the Columbia River (Coutant,
1969). In a laboratory study, Kelly and Chadwick
(1971), examined the tolerance of young striped
bass in the size range of 5 to 38 millimeters in length.
The LDW for striped bass held for 48 hours ranged
from 86 to 91° F with variations within this range
not related to either acclimation temperature or size
of fish. Instantaneous temperature increases (0 to
6 minutes duration) followed by return to ambient
temperature resulted in little mortality until the
maximum temperature approached 90° F. Below
this temperature instantaneous increases of up to
18° F caused little mortality. However, loss of
equilibrium was often noted at temperatures above
85° F.
By contrast to the distribution food habits and
thermal response of striped bass, Gritz and Stevens
(1971), studied the distribution of king salmon in
relation to the thermal plume of the Pittsburg
station. Occurrence of this salmon was primarily at
the surface (in contrast to the location of striped
bass at lower depths). Numbers of king salmon
decreased from the north shore to the power plant
on the south shore. Numbers of salmon caught in
the plume of warm water discharged from the plant
were significantly lower than numbers caught at
ambient water temperature. Catches of marked
hatchery-reared salmon released upstream suggest
that these young king salmon migrate rapidly
through the section of the estuary influenced by the
thermal discharges of the Pittsburg plant. Gritz
(1971) suggested that some of these salmon might
be more vulnerable to predation by the increased
number of larger (>16 inches) striped bass residing
in the thermal plume. Orsi (1971) studied the
thermal tolerances and thermal shock of king sal-
mon. Rapid temperature rises within the limits of
an 18° F increase and a 0-6 minute exposure period
did not cause mortality until the acclimation
temperature exceeded a temperature1 between 60 to
65° F. The ability of young salmon to withstand
short exposures to relatively high temperature im-
proved as acclimation temperatures were elevated.
Exposure1 time was crucial to survival at 83° F with
all fish surviving at 0-2 minute exposures to 83° F
and only half the test fish surviving at exposure
periods of 4-6 minute's.
The opossum shrimp Neomysis awatschensis has
been shown to be an important food source for game
species of fish in the Sacramento-San Joacnain
Delta. The distribution of these mysid shrimp has
been shown by Kelly et al. (1971) to be influenced
by light, tidal stage, and water velocity. During the
daylight period, density of Neomysis population
increased with depth and lateral densities indicating
little ability te> avoid being carried by intake and
discharge flows in the vicinity of the Pittsburg
plant (Kelly et al., 1971). The mortality of N.
awatschensis caused by passage through the Pitts-
burg plant was determined by Kelly (1971) from
comparisons of live and dead Neomysis at the plant's
intake and outlet. Observed mortalities correlated
with the water temperature of the discharge (less
than 10 percent at temperatures of 80-86° F coin-
pared to approximately 65 percent at temperatures
appre>aching 90° F). The>se Neomysis surviving
higher temperatures showed no evidence of delayed
mortality when helel under laboratory conditiems for
up to 36 hours.
These mortalities were similar to those induced by
Hair (1971) under laboratory conditions in which
the upper lethal temperature of adult Neomysis
awatschensis was found to be within the range of
75.6 to 77.8° F under conditions of 48-hour static
bioassay. Tolerances to rapid laboratory exposures
decreased as acclimatiem temperatures increased but
this species resisted temperature elevations of up
te> 25° F provided the ultimate temperature did
not i^ach 87° F. Temperature rises above 25° F
caused significant mortality even though the upper
temperature did not reach 87° F. As has been shown
with numerous other aquatic organisms, survival
decreased rapidly with increased exposure time at
temperatures approaching the lethal temperature for
these mysid shrimp.
In summary, these excellent field and laboratory
studies of ecologically significant aquatic organisms
in the Sacramento-San Joaquin Delta have revealed
both techniejues and information that can be used
to evaluate the impact of similar industrial opera-
tions in other estuarine systems. These studies have
shown iie> significant adverse effects upon aquatic
organisms in the Sacramento-San Joaquin estuarine
system. Volumes of water use>d for cooling purposes
constitute but a small fraction of tidal and river
flow in the Sacramento-San Joaquin Delta area at
Pittsburg. Consequently, thermal elevations (above
demonstrated upper lethal levels for important
aquatic organisms) occur over a relatively small
area and for a relatively short period of time. Thus,
consideration of these physical and biological factors
should permit the siting, design, and operation of
power plants in similar systems—where the volumes
of cooling water are sufficient to preclude adverse
local or system-wide impacts.
Lauer et al. (1974) have studied the response of
-------
368
ESTUARINE POLLUTION CONTROL
aquatic organisms in the Hudson River at Indian
Point from 1971 through 1974. An upper area of
the Hudson River estuary between Newburgh and
Ybnkers, N.Y., was sampled in order to establish
the kinds, numbers, and seasonal fluctuations in
aquatic organisms residing within this section of the
estuary. In these studies emphasis was placed upon
estimating the effects of both pumped and plume
entrainment of planktonic organisms during both
day and night sampling periods.
The rated thermal capacities of the combined
three units at the Indian Point Station, was approxi-
mately 15° F during these studies. Laboratory
studies of bacterial decomposers indicated that the
above thermal exposures did not decrease popula-
tions except during periods of intermittent chlorina-
tion when decreases in discharge samples were noted.
Primary producers indicated variable degrees of
effect during similar and varying thermal exposures
above ambient temperatures suggesting that season-
ally variable populations of algae respond with
increases, decreases, and relatively little change in
rates of primary production as measured by 14C
uptake and algal biomass. During periods when dis-
charge rates were depressed over intake rates,
recovery of populations as measured by restoration
of intake rates was noted. Ghloririation, when it
occurred, always reduced primary production rates
for algal populations entrained into the condenser
cooling units. No population shifts from the pre-
dominant diatom populations to any other algal
group within the Hudson River in the study area
were observed.
Laboratory studies of zooplankton populations
suggested that calanoid copepod populations might
experience some mortality at the rated AT of
15° F. Unfortunately, during these studies, discharge
temperatures did not reach design levels and field
verification of these laboratory results was not pos-
sible. Some degree of stratification of zooplankton
was noted in the area of thermal influence by the
Indian Point plant, but both species lists and
abundance of river populations of zooplankton were
similar, suggesting that the combined thermal and
chlorination effects that occurred within the con-
denser cooling system were not affecting populations
within the Hudson River in a significant way.
Laboratory studies of the dominant zooplankters
at Indian Point (Gammarus sp., Neomysis americana,
and Monoculodes edwardsi) suggested that a 1T>0
F AT during summer ambient water temperatures
would result in 50 percent or greater mortality of
entrained N. americana while the other two species
would not suffer mortalities as a result of the en-
trainment experience. Actual mortality due to en-
trainment was subsequently found to be 54 percent.
All three species showed diel periodicity with higher
abundances at night. Gammarus sp. occurred on a
year round basis at Indian Point while N. americana
occurred primarily during summer periods. M.
edwardsi was a year-round resident except for early
summer periods when it was not detected in the
area. Although laboratory studies of the design
AT of 15° F suggested no direct mortality would
occur to Gammarus sp., direct measurement of dis-
charge samples of entrained animals indicated a
small but statistically significant mortality had oc-
curred with this species. Chlorination levels during
daytime periods did not produce statistically signifi-
cant effects due to the low densities of these macro-
zooplankton forms. At higher nighttime densities,
mortality was approximately 40 percent of entrained
organisms.
Results of studies of egg and larval fish entrained
into the Indian Point Plant were variable as to
species, life stage, and plant operational features such
as number of cooling water pumps in operation
during sampling periods. Only six of the 50 species
of fish occurring in the Indian Point area were
actually represented in the ichthyoplankton entrained
into the condenser cooling system. These were, in
order of decreasing abundance: anchovy, alewife, and
blueback herrings, striped bass, white perch, and
tomcod. Most of the anchovy and clupeid larvae
were dead in both intake and discharge canal sam-
ples. Striped bass were too sparse to permit statis-
tical evaluation of entrainment effects.
Jensen et al. (1974) studied the thermal response
of aquatic organisms in a small mid-Atlantic estuary
in Delaware just south of the confluence of the
Delaware River estuary with the Atlantic Ocean.
The Indian River Plant is situated midway between
the freshwater and saltwater boundaries of a small
estuary east of Millsboro, Del. Cooling water at
148,000 gpm is elevated an average of 12° F and
rejoins the Indian River estuary 1-3 hours later
via a 2 mile discharge canal. Temperatures at the
mouth of the canal are typically 5° F above ambient
and are reduced to about 1° F above ambient within
about two miles downstream of the mouth.
Chemical data collected in the vicinity of the plant
suggests generally high water quality; dissolved
oxygen levels, for example, never fall below 5.00 mg/1
at the surface nor below 3 mg/1 near the bottom.
Diverse flow and fauna inhabiting this region of the
estuary reflect both high water quality as well as
the strong salinity gradient existing along the length
of the estuary.
Destruction of algal cells during passage through
the condenser system was consistently apparent
-------
POWER PLANT EFFECTS
369
during periods of chlorination (30 min. duration,
2-3 times daily), but was never observed in the
absence of chlorination. Algal production rates
measured at the discharge of the power plant were
depressed due to temperature elevations for approxi-
mately four months of the year when ambient tem-
peratures \vere about 71.(5° F, although there was no
evidence of lowered production rates at any distance
from the discharge canal. During the cooler periods,
(eight months), temperature elevations at the plant
discharge1 resulted in up to two-fold stimulation of
production rates and up to 20 percent increases
approximately | mile downstream from the mouth
of the discharge canal.
Little effect on the zooplankton behavior or
population distribution could be attributed to the
operation of the Indian River Plant. This lack of
influence was presumably related to the average
thermal elevation of only 10.S° F and the less than
two minute travel time through the plant. It
was concluded that the naturally wide range of
salinity in the vicinity of the plant (2.2-19 ppt) was
more influential to zooplankton ecology in this estu-
ary than direct effects of thermal discharges from
the Indian River Plant Little change in mortality of
zooplankton was observed throughout the entire
seasonal range of ambient intake temperatures, even
during periods of chlorination, which produced up
to 0.5 mg/1 free residual chlorine as measured in the
discharge canal.
During the summer, however, prolonged contact
with the thermal effluent resulted in a decrease in
population densities of zooplankton passing down
the discharge canal. By contrast, short-term intake-
discharge evaluations to the same temperatures
during passage through the condenser cooling system
showed no die-off of zooplankton. Other factors not
detected in these studies resulted in a decrease in
discharge canal populatkms. In spite of these reduc-
tions, zooplankton populations in the receiving
waters of the Indian River estuary did not. appear to
be affected by these losses.
The distribution of benthie invertebrates was
shown to be associated with the large salinity
gradient (0-22 ppt) within thr study area of
approximately o'.-S miles. Sediment temperatures
were highest in thr discharge canal and decreased
to ambient temperatures through the mixing zone.
Effect* fron: the (henna! discharges were limited
to the discharge canal and the confluence point of
th<- canal will) thij Indian River.
The upper Indian River estuary supports a large
fishery biomass in the form of forage species. The
'\stuary is also essential as a spawning arid nursery
area for game and commercially important specie^
of fish. Undoubtedly, the power plant has some
effects on the distribution of resident fishes in the
estuary, but this would seem to be in a rather small,
well-defined area within and adjacent to the dis-
charge canal from the plant. These distributional
effects appear to be restricted to the summer months
when ambient water temperatures reach the seasonal
and annual maxima. At other periods, the plant did
not appear to .seriously affect the survival, distribu-
tion, or well-being of any of the native' or anadromous
species residing within the estuary.
SUMMARY AND CONCLUSIONS
The rapid reduction of excess temperatures near
existing thermal discharges into relatively large
estuarine waters is largely a result of dilution rather
than heat dissipation to the atmosphere. The spatial
distribution curves for heated discharges can be
shown to be directly related to the momentum of
the discharge volume. In large, natural surface
waters such as the Chesapeake Bay, it can. be shown
that such momentum jet discharges offer consider-
able advantages in terms of thermal decay curves.
Thermal losses of waste heat to the atmosphere from
such large bodies of water involve rather large
surface areas at relatively small temperature in-
creases (5-10 percent of original AT).
With the possible exception of tropical waters, the
location of power-generating stations on large estu-
aries and open coastal locations appears to provide
the relatively large volumes of water needed for
modern once-through generating plants without
producing serious damage to the biota of such
areas. Ideological impacts can be minimized by
careful siting, design, and operation so as to reduce
temperature elevation and duration of aquatic
organisms to thermal effluents .Momentum mixing
of the heated discharge waters into receiving waters
appears to rapidly reduce the temperatures to only
a fraction of the original thermal rise. Such tem-
perature reductions vvithin a few minutes after the
passage through the coaling water condenser system,
would also appear to minimize the effects of entraiii-
ment upon planktonic forms residing in surface
waters used for once-through cooling
RESEARCH NEEDS-THERMAL EFFECTS
Physical Mixing Process
1. Knowledge of buoyant jet diffusion is nearly
adequate for the design of thermal outfalls, including
multiple port diffusers, to achieve a prescribed
initial jet. dilution and mixing plume. Further
-------
370
EsxrARiNE POLLUTION CONTROL
research is needed to fully undersland line sources
and to determine how well multiple jet diffusers may
be represented by line sources.
2. Research is needed to develop better methods
for predicting the size and .shape of heated effluent
mixing zones that are developed at the end of the
initial jet-mixing stage. Research is also needed (in
close concert with the above dimensional data) to
understand the phenomena of lateral spreading
caused by density differences bet \\eon the thermal
plume and receiving waters.
o. In coastal waters, submerged diffusion struc-
tures are not yet in use, and some problems of large
single jets, such as the behavior of a buoyant.
surface jet injected into a cross-current, need special
study. The impact of potential scouring of bottom
areas adjacent to such momentum discharges is
also needed.
Heat Dissipation Processes
1. Afore research is needed to establish the natural
temperature variations of future receiving waters,
especially large water bodies such as the Chesapeake
Bay. Such information pertinent to diurnal and
seasonal temperature fluctuations is essential for
the prediction and assessment of the relative impact
of proposed thermal discharges.
2. As more information becomes available on the
biological response's to thermal discharges in terms
of both thermal amplitude and duration relation-
ships, as well as rapid rates of temperature change,
improvements will be needed in methods for predict-
ing these characteristics of thermal discharges
relative to short-lerm fluctuations in power demand,
meteorological conditions, and operations of auxiliary
cooling devices.
3. Afore effort is needed to evaluate and verify
temperature predictions based on hvdraulic models
of thermal discharges, particular! v models of large
prototype receiving waters in which surface cooling
processes are not negligible and are generally rep-
resented inadequately.
4. Relative to item 3, more work is needed in
developing techniques for computer simulation of
thermal discharges in throe dimensions, taking into
account a'l the effects of momentum, entrainniont,
buoyancy, surface1 cooling, wind, coriolis forces, anel
other factors affecting receiving water behavior.
Biological Processes
1. Both field and laboratory research is nee-ded
concerning the biological response to time-spatial
and thermal amplitude levels characteristic oi
situations involving e>nce-thre>ugh cooling in surface
waters. Unfortunately, much of the existing labora-
tory elata does not appear to be relevant to such
thermal histories due to the' atypical temperature-
time exposures. Additional field stuelies of existing
thermal discharges are' essential if adequate con-
sideration of the' biological response1 (both physio-
logical anel behavioral) is to be1 used in predicting
the ecologie'al impact of propose'd thermal dis-
charges into natural Mirfaco waters.
2. Long-range, properly de.signed, detailed, quan-
titative1 baseline1 studies of the structure' anel dy-
namics of animal and plant communities anel the'ir
relationship to increasing domestic anel industrial
influence' should be established and supported. These
areas should include those that are presently
relatively little1 affected, those1 that are being af-
fected at an increasing rates and those that are1
already seriously afTe-cted.
3. There is enough promise in the various possi-
bilities of beneficial uses of heated water effluents
that research and demonstration-level work shemld
be encouraged as adjuncts 1o energy development.
Discharges have been vised to provide water flow and
favorable temperatures for the culture of molluscs,
crustaceans, and fishes such as catfish and pemipano.
Major fish kills due to low-water temperatures are
of regular occurrence in shallow inshore waters of
the Gulf of Mexico anel many lakes in temperate
areas. Heated effluents could be used to save fish
that otherwise would be lost from such systems It is,
of course, important that all possible benefits of
thermal effluents be included in site selection plan-
ning, and projecteei cost-benefit analysis.
4. Evaluations of the effects of the entrainment
anel subsequent exposure io condenser cejoling sys-
tems are specific to individual power plants operating
on specific estuarinc systems. Studies of macro-
zooplankton and meroplanktem effects appear to be
worthy of much of this entrainment research effort.
."). Impingement and post-impingement studies of
intake systems are also highly site and plant specific
and they should be conducted with sufficient fre-
quency tei permit a determination of the relative
importance of such effects upon local populations
of important species. Research efforts de-signed to
clarify behavioral characteristics of fish in intake
systems should be1 intensified to provide data for
the refinement and redesign of both operational and
mechanical characteristics o) .•vcrreniug devices used
at power plant intake systems.
6. Research is also needed relative to the' environ-
mental impact of alternative cex>Hng devices, such us
cooling towers. The1 impact of mineral loss through
drift upon vegetation anel setalic surfaces in sur-
-------
POWER PLANT EFFECTS
371
rounding areas has not been evaluated for cooling
towers of a size applicable to modern fossil or
nuclear-fueled plants. The blowdown of dissolved
solids and biocides such as chlorine and heavy
metals from such towers must also be evaluated in
terms of their impact on receiving waters and their
associated biota.
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Fish and Game, Anadromous Fisheries Branch. Adm.
Report Number 71-12. Sacramento, Calif.
Rosenberg, W. H. 1968. A study of the effects of thermal
pollution on Crassostrea virgimca (Gmelin) in the Patuxent
River estuary. November 1966-1967, Final Report, Sub-
project Number 3-23 R-2. U.S. Department of the Interior,
Bureau of Commercial Fisheries.
Smith, R. A., A. S. Brooks and L. D. Jensen. 1974. Chapter
4, Primary Productivity. In L. D. Jensen (ed.) Environ-
mental response to thermal discharges from the Chesterfield
Station, James River, Virginia. The Johns Hopkins Univ.
Cooling Water Res. Project, Report Number 13, Electric
Power Res. Inst., Palo Alto, Calif.
Strawn, K. and B. Gallaway. 1974. Final report on the
seasonal abundance, distribution, and growth of commer-
cially important crustaceans at a hot water discharge in
Galveston Bay. Cont. Mar. Sci., University of Texas,
September, 1974.
Tabb, D. C. and M. A. Roessler. 1970. An ecological study of
South Biscayne Bay, Florida. Progress Report to FWPCA.
Univ. of Miami, Rickenbacker Causeway, Miami, Fla.
Warriner, J. E. and M. L. Brehmer. 1966. The effects of
thermal effluents on marine organisms. Int. J. Air Water
Pollution. 10:277-289.
Wickmire, R. H. and D. E. Stevens. 1971. Migration and dis-
tribution of young king salmon, Oncorhynchus Ishawytscha,
in the Sacramento River near Collinsville. California Fish
and Game, Anadromous Fisheries Branch. Adm. Report
Number 71-4. Sacramento, Calif.
-------
EFFECTS OF SELECTED
POWER PLANT COOLING
DISCHARGERS ON REPRESENTATIVE
ESTUARINE ENVIRONMENTS
R. H. BROOKS
Pacific Gas and Electric Co.,
San Francisco, California
A. S. AUTRY
Tampa Electric Co.,
Tampa, Florida
M. L BREHMER
Virginia Electric and Power Co.,
Richmond, Virginia
F. N. MOSELEY
Central Power and Light Co.,
Corpus Christi, Texas
ABSTRACT
Results of investigations into the effects of power plant cooling water discharges into selected,
representative estuaries are presented. These studies performed at mid-Atlantic, mid-Pacific, and
Gulf of Mexico locations indicate that, at these stations, the cooling water discharges have not
adversely affected the surrounding, estuarine receiving water environment. The conclusion is
reached that power plants can be operated on estuaries without adverse effects with the result
that each potential or existing estuarine site should be evaluated on a "case-by-case" basis.
INTRODUCTION
Large estuaries around the continental United
States are used for the cooling and dissipation of heat
resulting from thermal electric generation. It is
realized that estuaries generally constitute ecosys-
tems of unique importance where adverse intrusions
should not be tolerated. However, actual field studies
have failed in most instances to reveal such adverse
effects resulting from power plant cooling. As an
example, the results of environmental studies con-
ducted at electric generating stations on selected
representative estuaries are described in this paper.
The power plants' studies as described herein
employ conventional once-through cooling systems
with one exception where thermal dilution is also
utilized. The information presented herein is sum-
marized from reports on studies conducted by:
1. Pacific Gas and Electric Company—Pittsburg,
Contra Costa, and Moss Landing Power Plants,
Pacific Coast of California.
2. Virginia Electric and Power Company—Surry
Power Station, Surry County, Va.
3. Tampa Electric Company—Big Bend Station,
Hillsborough County, Fla.
4. Central Power and Light Company—E.S.
Joslin Power Generating Station, Cox Bay, Tex.
PACIFIC GAS AND ELECTRIC COMPANY
Pacific Gas and Electric Company (P G and E)
operates three electric generating facilities in estu-
arine environments. Two plants, Pittsburg Power
Plant and Contra Costa Power Plant, are located on
the Sacramento-San Joaquin Estuary, the great
tidal estuary at the head of the San Francisco Bay.
The third station, Moss Landing Power Plant, is
located on Elkhorn Slough, a coastal lagoon that
drains into Monterey Bay and then into the Pacific
Ocean.
Facility and Site Description
SACRAMENTO-SAN JOAQUIN ESTUARY
Pittsburg and Contra Costa power plants are
located in similar environments, on the south shore of
the Sacramento-San Joaquin estuary. (Contra Costa
Power Plant is actually on the San Joaquin River,
just above its confluence with the Sacramento Riv-
er). Typical vegetation types in the area include
tidal and impounded salt marsh, and drained land
that is used agriculturally. On the northern shore of
the estuary is Suisun Marsh, a large and productive
area for waterfowl and shorebirds. Several federal
and state wildlife refuges are found in the area.
The nutrient-rich waters of this system are well-
mixed by the diurnal tidal cycle. Salinity variations
are seasonal, with ranges from 4 to 10 parts per
thousand (ppt). Regulated freshwater inflows de-
termine these salinity profiles. Ambient water tem-
peratures also vary with the season, ranging from
45-72°F.
373
-------
ESTUARINE POLLUTION CONTROL
This iiutricnt-rich system supports a diverse
aquatic food chain, at the top of which are king
salmon and striped bass. These anadromous fishes
constitute a major sport fishery. Shad, sturgeon,
and catfish also form the basis of a growing sport
fishery. These fishes feed largely on opossum shrimp,
which in turn is supported by a variety of other
planktonic species.
The turbid waters of this system, and other
available evidence, lead to the conclusion that
primary production is limited by low light penetra-
tion. The phytoplankton of the estuary is dominated
by diatoms, green algae, and flagellates, with some
seasonal variation in species composition of these
organisms. Blucgreen algae are rare in this estuary;
thus, noxious blooms associated with eutrophication
have not been a problem.
ELKHORN SLOUGH
Moss Landing Power Plant takes in water from the
oceanic Moss Landing Harbor and discharges into
Elkhorn Slough. This body of water has experienced
several shoreline changes, beginning as a freshwater
lagoon draining the Pajaro River. In the early 20th
century, the area was developed as a whaling station
and smuggling port. Construction of Moss Landing
Harbor in 1946 altered the flow characteristics, so
that Elkhorn Slough was left with an outlet to the
ocean and became subject to the resultant tidal
action.
Elkhorn Slough exhibits characteristics of both a
true estuan, and a coastal lagoor, depending upon
the time of year. During the fall and winter rainy
season, runoff from local creeks and land drainage
provides the slough with sufficient freshwater to
dilute the salt incursion from the ocean. In the sum-
mer dry season, however, the creeks dry up and land
drainage decreases, so that salinities rise and Elk-
horn Slough displays most of the characteristics of a
lagoon.
Water quality in Elkhorn Slough is primarily
dependent upon tidal action and the dairy and
cannery waste discharges that have contaminated
the Slough and Moss Landing Harbor for several
years. Salinity in the system ranges from approxi-
mately 20 to 37 ppt. Ambient temperatures range
fromaO-61°F.
The marine environment of Elkhorn Slough is
characterized by muddy bottoms, with a benthic
fauna dominated by venus clams. Crabs, shrimps,
and oysters are also found. Stands of eelgrass provide
sheltered spawning areas for flatfish, which are a
major sport fish in the area. Other important sport
fish, such as perch and Pacific herring, spawn in
Elkhorn Slough.
POWER PLANT
OPERATING CHARACTERISTICS
These three power plants are fossil-fuel fired and
employ once-through cooling water systems. Signifi-
cant characteristics of these facilities are as follows:
Power plant
Pittsburg
Units 1-4...
Units 5-6. __
Contra Costa
Units 1-3.. _
Units 4-5...
Units 6-7...
Moss Landing
Units 1-3.._
Units 4-5.._
Units 6-7.._
Year of
initial
operation
1954
1960
1951
1953
1964
1950
1952
1964
Rated
output,
MW
630
650
348
232
680
348
234
1,478
Cooling Tempera-
water ture
flows, increase,
cfs °F
900
722
600
245
681
629
223
1,354
15.0
18.0
16.0
12.0
24.0
15.5
24.0
20.0
Moss Landing's Units 6 and 7 do not affect the
estuarine environment, as the cooling water source
and discharge sink is the Pacific Ocean.
Results of Studies Performed
P G and E conducted 1-year studies at these and
five other coastally-located power plants during
1971-1972. Requirements for these physical and
biological studies were set. by the Regional Water
Quality Control Boards. The general objectives of
the studies were to determine the areal distribution
of the thermal plume in the physical environment,
to investigate the effects of each thermal discharge
on the principal levels of the local food chains, and
to determine measures of protecting the beneficial
uses of the receiving waters.
PHYSICAL STUDIES
Synoptic physical studies were performed to
simultaneously measure water-quality characteris-
tics over a wide area at each power plant. Parameters
measured included surface water temperature,
horizontal and vertical water temperature profiles,
salinity and dissolved oxygen at three depths, ba-
thymetry and temperature decay rates. Analysis of
these measurements not only delineated the extent
-------
POWER PLANT EFFECTS
375
and physical impact of the thermal plume, but also
enabled the biological investigators to select appro-
priate sampling stations and methods.
Physical studies showed that the average extent
of the thermal plume (area enclosed by the 4°F
isotherm) was 50 acres at Pittsburg and Contra
Costa and 230 acres at Moss Landing. No effects
were found on salinity and dissolved oxygen con-
centrations.
BIOLOGICAL STUDIES
Quantitative biological studies focused on three
major groups of organisms: zooplankton, benthic
organisms, and fish. Standard methods of collection,
such as Ponar grabs for benthic sampling and otter
trawls and gillnets for fish sampling, were used
wherever possible. Some situations required the
development of special equipment. In most studies,
organisms were collected in a systematic fashion,
usually by transect, and identified as precisely as
possible. The data were analyzed to give the total
number of individuals present, the total number of
species present, and an index of species diversity.
These parameters were correlated with physical
parameters such as temperature, salinity, depth,
and time of year.
The zooplankton studies at Moss Landing Power
Plant made a further analysis of mortality to zoo-
plankton passing through the cooling water system.
This was done by sampling with a specially-designed
filter pump at the intake and discharge, coordinating
the sampling with the measured travel time of 10.9
minutes. Live and dead zooplankters were manually
counted under a stereomicroscopc and percent mor-
talitv due to passage through the cooling water
system was determined by subtracting intake mortal-
ity from discharge mortality.
In general, the biological studies yielded the
following results:
1. Zooplankton mortality varies from plant to plant
and from species to species, within a range of zero to
15 percent. At Moss Landing, the average net mor-
tality was about, 11 percent. That is, 89 out of 100
zooplankters passing through the cooling water
system can be expected to survive the expected
physical and thermal effects.
2. Benthic species diversity was not significantly
correlated with temperature differentials. This re-
sult is consistent with the observation that the
dominant plant influence, the thermal plume, lies in
a buoyant surface layer separated from the benthic
organisms by water of ambient temperature.
3. Different fish species showed preferences for
different temperature regimes. In the Sacramento-
San Joaquin estuary, for example, white catfish were
most often found near the power plant discharge
areas.
Summary of Effects
Upon Receiving Waters
The studies conducted at Pitlsburg. Contra Costa,
and Moss Landing Power Plants have shown that
the major detectable influence upon the environ-
ment is the thermal plume. No other physical-chemi-
cal parameters have been affected. Biological studies
show that the aquatic communities have not been
significantly altered. Finally, the power plant opera-
tions have had no detrimental effects upon beneficial
uses of the receiving waters.
VIRGINIA ELECTRIC AND POWER COMPANY
Facility and Site Description
The Surry Nuclear Power Station of the Virginia
Electric and Power Company (Vepco) is located on
Gravel Neck in Surry County, Va. adjacent to the
tidal James River, a major tributary of Chesapeake
Bay. The station consists of two Westinghouse
pressurized water reactor units, each capable of
generating 822.5 MW. Water is required at a rate of
1871 cubic feet per second (cfs) per unit to handle a
heat rejection rate of 11.8 X 109 Btu/hr by once-
through cooling. This results in a temperature rise
across the station of 14°F.
The cooling water discharge structure, located on
the upstream side of the Gravel Neck peninsula, is
about five miles from the intakes, and is designed
with an exit velocity of 6 feet per second to promote
rapid mixing with ambient water in the three-mile-
wide James River. Physical model studies at the U.S.
Army Corps of Engineers facility at Vicksburg,
Miss., were conducted to determine the optimum
design of the discharge structure.
The James River in the vicinity of the station is
shallow, but has a maintained shipping channel.
River widths vary from about three miles at the
discharge to about four miles at the intakes. Salinity
varies from freshwater to about 15 ppt, being de-
pendent on freshwater inflow from the upstream
9,886-square mile watershed of the James.
Surry Units 1 and 2, which began commercial
operation in late 1972 and early 1973, are base-load
units that operate at an annual average capacity
factor of approximately 80 percent.
-------
376
ESTUARINE POLLUTION CONTROL
Results of Studies Performed
PHYSICAL STUDIES
The James River around Surry has been, and is,
the object of a continuing and intensive physical
study that began in 1969. As stated previously, the
distribution of the summertime thermal plume was
predicted through the use of a physical model.
Wintertime thermal predictions; were made by
Ptitchard-Carpc-nter, Inc., using a mathematical
model.
Several methods are being used to field-test model
predictions. Tower and buoy locations in a 10-mile
section of the river encompassing the station have
been instrumented to provide continuous tempera-
ture data. In addition, monthly boat surveys are
conducted to determine surface to bottom profiles.
Since, during the course of a year, salinity in this
part of the James is highly variable, monthly boat
surveys are also used to determine cross-sectional
and longitudinal salinity profiles. These studies will
determine if the pumping of 3740 cfs of slightly
higher salinity water into an area of lower salinity
will alter the natural salinity regime.
Results of the temperature studies indicate that
the physical model predictions were conservative;
that is, the excess temperature plume mixes rapidly
with the river water, and water at a given tempera-
ture does not. encompass as large an area as had been
predicted. Studies have shown that the salinity
regimens of the liver have not been significantly
altered by the present station operation.
Biological studies at Surry have attempted to
determine thepreoperatioiial "health" of the aquatic
ecosystem by examining specific food chain compo-
nents; and to determine the effects, if any, of Surry
Power Station operation on that health. Studies to
date, which include both preopeiational and post-
operational data have shown that operation of the
Surry Power Station has had no observable adverse
effect on any of the various components of the aqua-
tic community in the James River.
Studies that are site-specific to Surry were begun
in early 1969 by Vjrginia Institute of Marine Studies.
These studies encompass almost every level of the
food chain and include phytoplankton, zooplankton,
bottom organisms (benthos), and -'ouling organisms.
In the spring of 1970, Vepco personnel began a study
of the young fishes that inhabit 1he shallow water
zones of the area.
Although many theoretical, but as yet unproved,
implications of thermal discharges have received
widespread publicity, one parameter of power station
operation is of immediate concern. That parameter,
fish impingement on intake trash screens, receives
adverse publicity when fish numbers become rela-
tively large even though the biological significance
might be small.
To alleviate the problem, Vepco invented and
installed at Surry a uniqi"> intake screen designed
specifically to return impinged fish to the water alive.
Results of studies to date show that an average of
85 percent of the impinged fish are returned alive to
the water; survival of most species approaches 100
percent. This screen represents a significant develop-
ment in the industry and may prove to be (me of
the best available technologies in dealing with the
impingement of fish at intake structures.
Summary of Effects
Upon Receiving Waters
The data developed from comprehensive biological
(phytoplankton, zooplankton, benthos, fouling or-
ganisms, and finfish), chemical, and physical studies
in the tidal segment encompassing the Surry Power
Station indicate that operation has not modified any
of the measured parameters beyond the limits of
natural associated variation. Finfish, the major class
of organisms with commercial or recreational im-
portance in this tidal segment, have exhibited con-
sistent diversity, evenness, and richness during the
four years of study. This is illustrated by the enclosed
figure.
TAMPA ELECTRIC COMPANY
Four years of intensive investigation at Big Bend
Station have shown that the operation of the plant
has not significantly altered the marine life of Hills-
borough Bay. The study began in April 1970, seven
months before the startup of the first unit and has
continued through the operation of two 375 MW
coal-fired units.
Facility and Site Description
Big Bend Station is located on the eastern shore of
HilLsborough Ba\, an extension of Tampa Bay, in
Hillsborough County, Fla. Tampa Bay is located on
the west central gulf coast of Florida and is a complex
system of bays and estuaries including the Hills-
borough River, Manatee River and Alafia River
estuaries, and Tampa Bay, Old Tampa Bay, Hills-
borough Bay, and Ale Kay Bay.
Hillsborough Bay, a natural arm of Tampa Bay,
is approximately eight miles long and four miles
wide. Two rivers, the Hillsborough River and the
Alafia River, and numerous streams flow into Hills-
-------
POWER PLANT E
377
FK.UTKL 1. -Composue of numbers of species, diversity (H'), evenness (,]), and richness (D) by season for seine and trau'1
samples—Surry Power Station.
borough Bay. The natural shore line is typical of this
section of Florida, with coastal mangrove lowlands
and pine-palmetto uplands. Much of the natural
shore lint1 has been developed and altered by dredge
and fill activities.
The, maximum natural depth in Hillsborough Bay
is 2S feet with improved ship channels maintained at
34 feet. The surface area ;s o9.(> square miles The
diurnal fide range is 2.S feet and the wan level is 1.4
feet. Th'1 average depth at mean tide is 8.95 I'eet.
Water quality in Hillsborough Bay is the worst of
the bay systems. ! fluent from numerous industries
and M'veral sewage treatment plant- Hows mto the
bay. AJouthlv temperature averages vary from t>l. milligrams pel liter) indicate thai Hills-borough.
iiay exists in a high iropl'Ic .-.late, carrying a iarge
plant, bi^rnas,-'. 'Phi- is cioi'-i.-l'Mt n'lth tlie high 'intri-
!'!!• {•'v^'.1* geii'-r.'ill.r i->!ii'(l ) • the, e ":,!(" . '^igh^
[jeiK-f ration iv '-uilieieutiy low to preclude sigiulu.ant
stands of rooted algae. Alost of 1 he biomass is present
as plankton and floating algae.
Benthic organisms present in the bay are mostly
iiiter feeders, which utilize the laige amount of
plankton present.
Big Bend Station is a coal-fired station consisting
of two operating units rated at 37<~> MW each. One
4'2-~> M\V unit is und.'-r constructor).
Unit No. 1 went into operation in October 1970
\\itli once-through cooling and a maximum tempera-
ture increase of 17°F. The cooling water thm rate
was 240,000 gallons per minute (gpm I. Because of
pressure from Ilie Florida Department of Pollution
Control, Tnit
which wetit mto operation
in April 197.S, uas constructed with a iherma! dilu-
tion c,o(>ling system. This system consist ()f ;i, 100,000
gpm purnp r-nd af.soci^ted ^nei ( pile \\uiK to deliver
the un!iea,t''d mixing \\<>ti r to the discharge point oi
Units 1 and '.'. This i:1 dihition reduces b\ 50 percent
the temperature rise i o th;' ba)-, ,-,0 thsi* the maximum
tpmpery!;'i'e mi TUS^ .-• 'j~ '^-th r> jjv i> i. , -v ap^r.o.i-
mateiy U0]'1.
-------
.->, X
ESTUAHINE POLLUTION CONTROL
Unit No. o. which should go into operation in the
i-prmg oi ii>7('i, will have a closed-loop .spray cooling
s\ stem for control of thermal efliuont.
Results of Biological
Studies Performed
Beginning in April 1970, regular sampling \\as-
. one ••(••i!' the Bit.1, Bend Station to determine the
>t • v !•- -I,' ,,].vration on ",he !>a> Trawls, semes, traps,
,,lmi 'on ii'1;.-, bottom dredge- Dimple bi;ttles et
cetera, <\»re t mployed lo gather tjie necessary data.
The program begyn \\itii t\\o fuli-tnne scientists con-
ducting rhi' study and peaked Ia-t year with six full-
tirm biologists and several other part-time people
\\orkiiig on the project. Seven months of preopera-
liorud data were gathered, and data collection has
continued through the .startup and operation of t\vo
unit-.. 'I he aiea around ih" plant u as divided into
io-n- i-c()-\ "tenib with '20 Campling stations. The
,-l.itions \\ero visited at len^t monthly; many were
sani[)Si' ear
I'll" water around Big Bend Station \\as analvzed
;o: 1 be ,oUov,ing parameters; temperature, salinity,
U:in-,parenc\ , depth. •'lis(! oxvgen, pH, carbon
d.'oxid*., phi^phaie, hsxh'ogen sulfide, trace- metttls,
Ui)d p< sfidd."S.
Studies fo date indicate there is little differenc.'}
><>t\ven 'In i.irakc \\atei and the discharge water
• lUi me exception of {enipeivtTure, Mhich can bo
.iUribnted to the operation of the power plant.
The following biological paranu t(-r,^ were studied
;e 'he viciiiit\ of Big Bend ^hslit.n. fish, plankton,
ben'iiiic urganisnis a'fae. hivi'rt'-brat''s. chknophyll
(/ and miscellaneous observations.
('),s :l' ti.di from the Hia Bend --tudy \\ere
(','!',;;>,'I''".! uiih i"' 22-mon'h ?*ud\ of the fish of
'i-i'i'pi Jiay •••or.ductcd during J\)~)7 19.">9 b> the
Honda Department, ol \atu'•;•.! Resource-^ (DXU)-
\' BiH(>cfed bv ttie IHg B''iid I.ab. The Big
„,•• '' ! -ib coilecli'd 24 spec'"1- IHI! • ullidliv ihe DXH
-,.i(b' y! ',\;i'b'l, theM't'ore, ',pne:'.r that tl"1 area
:i'o\i)i(i Biu Bijid Sh>'ion co,iiain, a fish species ;li-
"ei'^uv ind'cativ1 «>f a low sires-; rcndilion.
\'.ire ih.'h l")l)s]'ec!i ^ ,-;'n1:-, loplanlcton have bei^n
•' • , ! :!• i'i-.',\' ' ' , '•' riu ,v '.-H'lVu'ci 1o
V>e little significant difference between the number of
species and individuals in the intake water and the
discharge water. The biggest variations in numbers
occurred during plankton blooms, and were not
associated with plant operation.
Over 70 species of zooplanktoii have been identi-
fied during the study. These represent a normal,
balanced community typical of waters of this type.
Benihie populations in the vicinity of the plant
and other portions oi the b;;\ are sparse, primarily
because of the poor substrate in the area. Years of
improper dredge and fill operation.? and other activi-
ties have left a layer of soft, silty mud over much of
the bottom.
As mentioned previously, turbidity of the water
precludes significant stands of rooted algae and the
most abundant species of algae found in the area
are (jracilnria and I'lva. Both of these occur in
nuisance proportions and are indicative of the nu-
trient-rich bay waters.
Difference!? in chlorophyll a readings at the in-
take and discharge were slight. The biggest variation
occurred during plankton blooms that were not as-
sociated with plant operation.
After evaluating all of the data gathered in four
years of study at Big Bend Station, the staff con-
cluded that the operation of Big Bend Station has
not significantly altered the marine life in the vicinity
of the plant.
Summary of Effects
Upon Receiving Waters
Studies completed to date show that little change
attributable to power plant operation has occurred.
Although temperatures have increased in the re-
ceiving waters, other physical and chemical effects
are imdetcctable. The biological studies have shov.ii
that phytoplankton, zooplankton, and fish popula-
tions near the plant have similar, if not greater di-
versity and richness than that found in all of Tampa
Bay, The bent hie comimmitA is sparse, but this is
probably unrelated to plant operations.
CENTRAL POWER AND LIGHT COMPANY
The K S. Joslin steam electric power generating
siation i.s O~A ued and operated b\ Central Power and
Light Company and is located near Point Comfort,
Tex., on a small, tertiary estuary called Cox Bay.
Cox Bay K part of a larger estuarine system known
as the Aiatasri rda Bv. System located in central
south TV\a .
-------
POWER PLANT EFFECTS
Facility and Site Description
Cox Bay, the receiving bay for Joslin Power
Station, is similar to most Texas estuaries. It has an
area of approximately 6,000 acres with an average
depth of five feet or less. It generally varies from an
oligohaline (brackish water) to a mesohahne (medi-
um salinity) bay. It serves as a nursery area for many
marine organisms and is valuable as a shrimp nursery
area, particularly for white shrimp.
Texas estuaries are among the most productive of
the estuarine systems. A number of characteristics
separate them from many of the classic examples
referenced in the literature. Among these character-
istics are: 1) Lunar tidal influences are slight (less
than 1 foot), and as a result, tidal variations arc1
more susceptible to wind velocity and direction. 2)
Texas estuaries are generally very shallow and often
vertically mixed rather than stratified (exceptions
being deep areas in channels"). For this reason, these
areas are subject to wide temperature ranges. Sudden
temperature1 variations may occur within a short
period of time, resulting in lish kills due 1o cold
weather. 8) In many areas, primary productivity is
from the watersheds of the coastal streams or by
marine' grass flats rather from phytoplankton. 4)
Salinities vary widely from low saline systems along
the northern coast to high saline1 systems in the
south. Salinity characteristics of these s\ steins are
governed primarily by freshwater runoff via coastal
streams, which also regulates to some- extent the>
abundance and types of organisms present in each
system.
As in the case- of most coastal systems, Texas
estuaries serve as important nursery areas for main
marine' organisms. Most of the organisms present in
these bays are migratory, and spawning e>ccurs off-
shore in the1 (Julf of Mexico. Postlarvae and jnxenilcs
migrate1 into the bays to grew up. This immigration
movement is timed so that peaks occur in spring and
autumn, corresponding to peak annual precipitation
patterns. These two peaks ceiincide because1 most
nutrients and e>rganic materials are available- in the
estuaries following heavy fresh\\ater runoff, so that
"dinner is on the table1" when the young organisms
arrive1. Thus, Texas estuaries are- very dynamic sys-
tems, varying continuously on a daily, annual, and
seasonal basis.
POWER PLANT
OPERATING CHARACTERISTICS
Joslin Power Station has a generating capacity of
240 MW and utilizes once-through cooling. Cooling
water is taken from the Matagorela ship cHimte!
and discharged into the northern portion of Co-;
Bay. Pumping rate of the power plant is approxi-
mately 150,000 gpm with a maximum lo°P" increase
across cooling condensers. Two additional waste
stream discharges enter into the cooling water pr'-ir
to its discharge info the bay. These" are the waste
material from a secondary sewage treatment, plant,
located em the power plant property, and a de-
mineralizer waste discharge that, has been Iron led
for neutralization.
Originally, the power plant was equipped v, ifh
amertap as a cleaning device for cooling conden.«e'>.
However, after one year's operation, the s} stem
was found to be inefficient for keeping condenser
tubes cleaned, and chlorination was added to I'"'
treatment facilities. Chlorination gcnoralh occur?
two hours a day, five days a week, with a discharge
residua] of 1 part per million.
The power plant began operation in June !9V1
and has continued to operate until the present time.
Two years prior to power plant operation, an envi-
ronmental study was initiated on the Cox Bay
estuary. That study has continued to the1 prese i>t
time. Therefore, data are available to evaluate the
bay prior to the operation of the power plant and to
determine its effects upon the receiving waters.
Results of Studies Performed
Biological samples we're collected monthly at 21
stations, beginning in August 19f>9, and continuing
to the present. Samples consisted of phytoplankton,
zooplankton, benthos (bottom-dwelling organisms
such as clams and worms', and nek*on
the; load on the plant ar any given time. Mt^i-nal
temperature increase above ambient varied from C
to 13°F at the discharge. The ^hape and extent >f
the plume is also dependent upe-n wind speed ,.i>d
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380
ESTUAKINE POLLUTION CONTROL
direction. Prevailing winds in the area are from the
southeast and tend to keep the plume pushed against
the northwestern shore. However, in wintertime
when northern winds are common, the plume may
extend over a larger area of the bay surface.
Another way of looking at temperature effects is
to determine the average temperature rise at the
discharge, and to determine the temperature die-off
and distance away from the discharge. In 1971-72,
when average temperature increase was slightly less
than 12°F, a sharp temperature decline occurred
about 1,000 to 1,500 feet away from the discharge.
Temperatures were then steady for some distance
out to about 3,000 feet away from the discharge. It
should be noted that the discharge area in the
northern portion of Cox Bay is extremely shallow,
with depths of less than five feet, along the shoreline.
Thus, plume size may be larger than would be ex-
pected in deeper water bodies, especially where
bottom discharges are feasible.
Circulation changes resulting from power plant
operations were minimal. Prevailing winds are from
the southeast, and currents in the bay are for the
most part wind-driven. Little change could be seen
from power plant operation except, of course, the
flow of water southward from the north shore in the
vicinity of the discharge with some eddying effect
in that area. Circulation patterns over the rest of
the bay remained the same. Xo recirculation of
heated water was determined during the course of
the study.
Diversity indices were calculated for all groups
sampled, i.e., phytoplankton, zooplankton, benthos,
and nekton. In all cases, no significant changes in
diversity patterns were observed after the power
plant went into operation. This js true of both the
discharge area as well as the unaffected areas of the
bay. In fact, during the two years of power plant
operation, nekton diversity indices remained higher
in the outfall area than anticipated. Diversity indices
were generally highest in Cox Bay at the discharge
area, both before and after power plant operation
began. Since diversity indices, not only of nekton
but all other trophic levels, were relatively un-
changed resulting from power plant operations, it
appears that the overall health of the community
has not been significantly affected by the operation
of the power plant.
Another way of examining the effects of the power
plant is to look at spatial distributions in Cox Bay
rob ted 10 seasonal occurrence. As stated earlier,
Texas estuaries are highly transient systems with
migrations of organisms occurring in arid out of the
ba\'s almost continuously. Seasonal distribution data
for total nekton biomass (total weight of free-
swimming organisms) indicate that no significant
change occurred after the power plant went into
operation. These data, coupled with no significant
changes, indicate clearly that there is no significant
impact on the bay resulting from power plant
operation.
It shoxild bo noted, however, that there are vari-
ations from season to season and from year to year.
These are deemed natural fluctuations and are influ-
enced little, if at all, by power plant operations.
White shrimp exhibit some avoidance of the im-
mediate area of power plant discharge, especially
during summer months. Since these data were col-
lected, additional studies have indicated that white
shrimp generally avoid the hottest portion of the
discharge. However, at certain times, especially
during early fall and late summer, the white shrimp
tend to congregate in the general mixing zone area
where temperatuies are generally ?> to 4°l( above
ambient.
Patterns similar to white shrimp distribution have
been indicated for other organisms. It generally
appears that most organisms avoid the immediate
vicinity of the discharge during extreme summer
conditions. However, thfse same areas am often
used even more heavily during spring, winter, arid
fall. Thus, considering the overall annual utilization
of the area, there appears to be little, if any, total
loss of habitat. As in the case of nektonic organisms,
phytoplankton, zooplankton, and benthic samples
seem to follow the same general distributional
patterns.
Summary of Effects
on Receiving Waters
Study results indicate that the thermal plume
generated by the E. S. Joslin Power Station is rela-
tively small, with rapid temperature die-off occur-
ring within approximately 1 ,'200 feet of the discharge
under normal wind conditions. It appears that spe-
cies diversity indices at various trophic levels re-
mained relatively unchanged after the power plant
•went into operation, and that the overall health of
the community is not endangered. Additionally,
seasonal and spatial distributions indicated that,
with some minor exceptions, minimal distributional
change had occurred. Thus, it appears that little
environmental degradation has occurred as a result
of the operation, of the power plant.
CONCLUSION
Examples have been selected to demonstrate that
power plants can be sited and operated on estuaries
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POWER PLANT EFFECTS
381
without adverse effects on the receiving water envi-
ronment. However, since it is recognized that there
are instances where adverse effects have been found
due to a variety of site dependent reasons, any
conclusions as to the effects of power plants on
estuarine environments must be drawn for site spe-
cific factors as supported by actual field data.
REFERENCES
Pacific Gas and Electric Company
Browning, B. M. 1972. The natural resources of Elkhorn
Slough: Their present and future use. Calif. Dept. Fish &
Game, Coastal Wetlands Ser, No. 4 p. 33.
Cayot, R. F., R. H. Brooks, M. J. Doyle, Jr., and J W.
Warrick, 1974. Environmental studies at eight thermal
power plants. Presented at ASCE Nat. Meet, on Water
Resour. Eng. Los Angeles, Calif. Jan. 21-24, 1974.
PGandE, 1973a. Evaluation of the effect of cooling water
discharges on the beneficial uses of receiving waters at
Contra Costa Power Plant. Rep. to Calif. State Water
Resour. Contr. Board.
PGandE, 1973b. Evaluation of the effect of cooling water
discharges on the beneficial uses of receiving waters at
Moss Landing Power Plant. Rep. to Calif. State Water
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PGandE, 1973c. Evaluation of the effect of cooling water
discharges on the beneficial uses of receiving waters at
Pittsburg Power Plant. Rep. to Calif. State Water Resour.
Contr. Board.
Virginia Electric and Power Company
Information contained in this report was derived from
Semi-Annual Operating Reports submitted to the Atomic
Energy Commission in compliance with Technical Specifica-
tions for Vepco Surrv Power Station, Units 1 and 2, Docket
Nos. 50-280 and 50-281.
Tampa Electric Company
Hagen, J. E., III. et al. 1969. Problems and management of
water quality in Hillsborough Bay, Fla. Southeast Reg.,
Fed. Water Pollut. Contr. Admin.
Ingle, R. M. 1973. Preliminary notes on the ecology of Tampa
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Stewart, V. N. et al. 1973. Third annual report to Tainpa
Electric Company. Conservation Consultants, Inc.
Stewart, V. N. et al. 1974. Fourth annual report to Tampa
Electric Company. Conservation Consultants, Inc.
Central Power and Light Company
Carpenter, E. J. 1971, Annual phytoplankton cycle of the
Cape Fear Estuary, N.C. Chesapeake Sci. 12:95-104.
Copeland, B. J., and E. G, Fruh. 1970. Ecological studies of
Galveston Bay. Rep. to Texas Water Qual. Board.
Gunter, (!. 1945. Studies on marine fishes of Texas. Univ. of
Texas. Publ. lust. Mar. Sci. 1 (1):1-190.
Moseley, F. N., and B. J. Copeland. 1972. Ecology of Cox
Bay, Texas. Rep. to Central Power and Light Co.
Odum, E. 1971. Fundament of ecology. W. B. Saunders Co.,
Philadelphia, Pa.
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