tinned States^
Environmental Protection
Agency
Research and Development
Environmental Research
Laboratory
Gulf Breeze FL 32561
Middle Atlantic Region 3
6th and Walnut Sts
Philadelphia PA 19106
Chesapeake Bay Program
TRENDS IN WATER QUALITY FOR CHESAPEAKE
BAY RELATIVE TO IMPROVED MANAGEMENT
DeMoss, Flemer, Strobel, Wilding
-------
60OD81179
TECHNICAL INFORMATION CLEARANCE
1 GATE PREPARED 2 LA8/OFRCE DRAFT NO 3 COPYRIGHT PER
M r- h 10*1 CBP-TP-001 t/one)
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5 PRESENT TITLE 6 AUTHOR. ORGA
Trends in Water Quality for Chesapeake .
Bay Relative to Improved Management °^as *
a TECHNICAL INf ORMATION PLAN TITLE AND REFERENCE * bLtob^1
FY'81 Tech Info Plan, ERL-Narragansett ona^lj 6
(NOT ON FY'81 TIP as submitted) ^°83 "***
MISSION 4 PEER REVIEW CLEARANCE
(/ one/
> £] N/A d YES O NO rf3 N/A
NIZATION. AND ADDRESS.
DeMoss, David A. Flemer, Charl-es
, Duane Wilding
Bay Program
EPA PROJECT DOCUMENTATION
7 SERIES 8. KeP9&&&£
10. TYPE OF MATERIAL (/ one)
SPECIFY (WHERE NECESSARY)
D RESEARCH REPORT
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D PROJECT REPORT AND PROJECT SUMMARY *»' -
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O UNPUBLISHED REPORT
O AUDIO VISUAL
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• - «_ e >
O MEETING/PUBLICATION*
O APPLICATIONS GUIDE
D SUMMARY/SYNTHESIS " r"v~
D RESPONSE REPORT
* Other - Speeches /Paper
"**.* * **
.— 11. PRO JECZJ^FFICER/IN-HOUSE AUTHOR
a SIGNATURE /* . I/ /? ( ) Tit
f Jc_ jf „_ Jg^ ^\^* _j£ /^^^.^
c. TYPED NAME AND ADDRESS
Thomas B. DeMoss
EPA, Chesapeake Bay Program, 2083
AnnaDoHs, MH 91 Am
6 °ATE April, 1981
d FTS TELEPHONE NO
West 9t.
q?.?_lQl ?
12 TECHNICAL INFORMATION (PROGRAM) MANAGER
a SIGNATURE ^-^ n /J . . s ^
C. TYPED NAME AND ADDRESS ^T I ^
Dorothy Vari Doren
EPA, Chesapeake Bay Program, 2083
Annapolis, Md. 21401
b DATE
Aoril. 1981
d FTS TELEPHONE NO j
West St.
922r3912
i
13 COMMENTS
Paper prepared for Forty Sixth North American Wildlife & Natural Resources
Conference & Related Meetings, March 21-25, Shoreham Hotel, Wash. D. C.
Sponsored by Wildlife Management Institute. Paper used as reference for
^speech. A i
-------
TECHNICAL INFORMATION CLEARANCE
1 DATE PREPARED
March, 1981
2 LAB/OFFICE DRAFT NO
CBP-TP-001
3. COPYRIGHT PERMISSION
(/one)
•d YES Q NO £] N/A
4 PEER REVIEW CLEARANCE
(O-^XSI -i*. VM oiy.m
EPA PROJECT DOCUMENTATION
7. SERIES
8 REPORT DATE
March, 1981
9 CONTRACT/GRANT/IAG NUMBER
10. TYPE OF MATERIAL (/ one)
SPECIFY (WHERE NECESSARY)
D RESEARCH REPORT
D PROJECT REPORT AND PROJECT SUMMARY
O JOURNAL PUBLICATION (include journal name)
D UNPUBLISHED REPORT
O AUDIO Vl«:i IAL
a MEETING/PUBLICATION*
D APPLICATIONS GUK3E
D SUMMARY/SYNTHESIS
D RESPONSE REPORT
* Other - Speeches/Paper
11. PROJECiOFFICER/IN-HOUSE AUTHOR
a SIGNATURE
c TYPED NAME AND ADDRESS
Thomas B. DeMoss
EPA, Chesapeake Bay Program, 2083 West £
AnnannHfi.
?1Am
b DATE
April, 1981
d 'FTS TELEPHONE NO
t.
12 TECHNICAL INFORMATION (PROGRAM) MANAGER
a SIGNATURE
C TYPED NAME AND ADDRESS ^T I
Dorothy VaTi Doren
EPA, Chesapeake Bay Program, 2083 West
Annapolis, Md. 21401
b DATE
April. 1981
' ' ~"
d.
TELEPHONE NO
922r3912
13 COMMENTS
Paper prepared for Forty Sixth North American Wildlife & Natural Resources'
Conference & Related Meetings, March 21-25, Shoreham Hotel, Wash. D. C. \
Sponsored by Wildlife Management Institute. Paper used as reference for ;
speech; - \
f ,
30>
-------
TRENDS IN WATER QUALITY
FOR CHESAPEAKE BAY
RELATIVE TO
IMPROVED MANAGEMENT
by
Thomas B. DeMoss, David A. Flemer,
Charles J. Strobel, and Duane Wilding
Chesapeake Bay Program
U.S. Environmental Protection Agency
2083 West Street
Annapolis, Maryland 21401
46th North American Wildlife and Natural Resources. Conference
Special Session No. 2
Washington, D.C.
March 21-25, 1981
-------
ABSTRACT
Title: TRENDS IN WATER QUALITY FOR THE CHESAPEAKE BAY RELATIVE TO
IMPROVED MANAGEMENT
Authors: Thomas B. DeMoss, David A. Flemer, Charles J. Strobel, and Duane
Wilding, Chesapeake Bay Program, U. S. Environmental Protection
Agency, 2083 West Street, Annapolis, Maryland 21401
Only limited and scattered information on nutrients has existed for
assessing historical trends in water quality. Nutrient factors are largely
limited to chlorophyll1^, a measure of phytoplankton biomass, ***"
orthophosphate-phosphorus, nitrite and nitrate-nitrogen—obviously a weak
position from which to interpret the effects of nutrient enrichment or
evaluate the significance of trends in these factors. Data on dissolved
oxygen, an important consequence of nutrient enrichment, are often poorly
represented in the historical data-base.
It appears that significant increases in the above nutrients have
occurred in the tidal and brackish water areas of the upper Bay proper, the
Patuxent, Potomac, and James River sub-estuaries and several small tribu-
taries near Annapolis and Baltimore, Maryland. These increases have led to
high levels of chlorophyll a_, often greater than 75 to 100 ug liter-
with a shift in algal species dominance to "nuisance" bluegreen algae, espe-
cially in the upper tidal freshwater Potomac, James, and tributaries to the
i
upper Bay proper. During the late 1970*s, some increase in dissolved
oxygen levels has been noted in the upper Potomac and correlated with a
decrease in nutrient supply. However, low dissolved oxygen levels, e.g.,
less than 1.0 ppm, are now typical of the two-layered estuarine region of
the Patuxent during the warmer months.
-------
Even less information on toxic chemicals exists. These data do not
permit a useful evaluation of trends.
Future projections and consequences of nutrient enrichment will be
available in early 1982 based on a mathematical water quality model under
calibration and verification by the U.S. Environmental Protection Agency's
Chesapeake Bay Program. The Program will make a more qualitative
projection for toxic chemicals.
Because large ecosystems are too diverse and complex to manage as one
unit, analysis of water quality trends and impacts on estuarine resource
uses can be improved through use of a concept called zoning or
segmentation. This tool is based principally upon geo-physical criteria
and secondarily on cKeTriical and biological features. The benefits"-from
this approach to managing the Bay, both now and in the future, are: assist
in providing better trend analysis of past water quality data and
highlighting future data needs; provide a framework for establishment of
water quality objectives; facilitate public choice in making decisions
related to management of the Bay; and provide a framework for monitoring
changes in the future and insuring accountability for management of
Chesapeake Bay.
-------
TRENDS IN WATER QUALITY FOR CHESAPEAKE BAY RELATIVE
TO IMPROVED MANAGEMENT
I. Introduction:
The Chesapeake Bay is a moderately stratified estuary
characterized by temporally and spatially complex hydrodynamics
(Pritchard, 1967). As an estuary, the Bay is large —
approximately 195 miles long, with 8,000 miles of shoreline and a
surface area of about 4400 square miles including tributaries
(Figure 1).
The Bay'-s.'-size, its location near large population centers,
"*- *+#•
its value as an artery of commerce and a significant contributor
to the region and nation's fishery resources, and its high
recreational value make the Bay of exceptional interest to people.
These characteristics coupled with the widely held view
that the Bay and tidal tributaries are threatened by pollution
have focused increased attention on the Bay's water quality. In
recent years, these perceptions have been reinforced by incidents
such as Kepone in the James River sub-estuary, excessive nutrient
enrichment leading to large algal biomass and anoxic waters in
ochei areas, the loss of Bay grasses, and the relatively poor
^
status of several fisheries including shad, striped bass, and blue
crabs.
•
In 1976, in response to the above concerns, Congress
directed the U.S. Environmental Protection Agency (EPA) to
implement the Chesapeake Bay Program (CBP), a five-year program
operated at about $5 million annually. Three problem areas were
defined for Program consideration: nutrient enrichment, toxic
chemicals, and the decline of the Bay grasses. In addition, the
-------
Program was charged with examining a range of management options
for public consideration. Final reports on the major areas of
concern, e.g., nutrients, toxic chemicals, Bay grasses, and
management options, will be completed in the fall and winter of
1981.
~*
The objectives of this paper are to review Historical trends
in water quality in the tidal Bay ecosystem, discuss limitations
in those trend data, and suggest how assessing data might be
improved upon to facilitate management of the Bay.
%
We especially thank Elizabeth Macalaster of our staff for
helpful editorial comments.
-------
II. TRENDS AND LIMITATIONS -- - -
*,
A. Nutrients
Heinle, et al. (1980) reviewed the historical information on nutrients
and related information, e.g., chlorophyll £, Secchi depth, salinity,
temperature, rainfall, land use, and population trends. We have drawn
heavily on this analysis. The greatest.spatial and temporal coverage in
data exists for the upper Bay proper covering the region from the
Susquehanna flats to Annapolis, the Patuxent, Potomac, and James River
estuaries. We cannot review in detail this extensive literature but will
try to convey the essential features of trends in nutrients, phytoplankton
biomass, turbidity, and^related water quality information in an abbreviated
*^sy . **».
form.
Inputs:
There is no periodic compilation of total nutrient loading to the
Chesapeake Bay in which to infer trends. Some information on individual
watersheds, is available. 'Brush (1974) summarized all sewage discharges in
the Chesapeake Bay basin during 1973. Heinle, ££ £l- (1980) estimated the
percent of freshwater that is sewage for several larger tributaries, and
confirmed that those tributaries in which some enrichment problems have
occurred had the highest percent of sewage, e.g., 4.8 percent in the
Potomac (Table 1). Jaworski (1980) estimated the total nutrient loadings
to the Bay for the period 1969 to 1971 from a variety of sources and
estimated an annual nutrient budget for nitrogen and phosphorus and Champ,
Villa, and Bubeck (1980) have provided additional information (Figure 2).
Estimates made by the above authors could be extended with appropriate
assumptions to cover other periods that might permit first order estimates
•
of trends for nutrient inputs from point and nonpoint sources, e.g.,
forests and marshes, nonpoint sources from agricultural and developed area
and point sources, principally sewage treatment plants and industrial
sources. This would be a major task.
-------
Water Column Concentrations:
In many areas of the Chesapeake Bay and tidal tributaries, the effects
of nutrient enrichment were well developed before scientific documentation
became available. An exception is the Patuxent estuary where studies were
undertaken during the late 1930's. Typically, the only nutrient forms
t
measured regularly from the 1930's to the present were
othophosphate-phosphorus (PO*,-P) and nitrite (N0?) and nitrate (NO,)
- nitrogen. Chlorophyll £, an indicator of phytoplankton biomass, was
first measured quantitatively on a regular basis during the early 1950's.
Methods to measure turbidity have varied widely and make comparisons
difficult. Thus, these data offer only a weak position from which to
interpret the ef f ects ~&£ nutrient enrichme_nt^or evaluate the significance
of trends in the above factors.
Upper Chesapeake Bay
(Susquehanna Flats to Annapolis)
The upper Bay changes from spring and fall maximum (P0,-p)
concentrations to maximum concentrations in the summer (Table 2).
Typically, maximum NO and NO^-N concentrations occur in the winter and
minimum values occur in the summer. Chlorophyll a values generally are
highest in the summer and lowest in the winter in this region of the Bay in
contrast to occasional or possibly regular annual events of spring peaks in
chlorophyll &_ in the lower Bay. Studies during 1949 to 1951 (Chesapeake
^
Bay Institute (CBl), Johns Hopkins University—Hires, Stroup and Seitz,
1963 and Stroup and Wood, 1966); 1964 to 1966 (Whaley, Carpenter and Baker,
1966 and Carpenter, Pritchard, and Whaley, 1969); 1965 to 1967 (Chesapeake
Biological Laboratory, University of Maryland—Flemer, 1970); 1967 to 1968
(U.S. Environmental Protection Agency—Anon., 1968; Marks and Villa, 1969,
and Anon., 1971 a and b; Clark, Donnelly and Villa, 1973) and 1969 - 1971
(Taylor and Grant, 1977) document the major trends. Several more recent
papers (Heinle, e_t al., 1980) describe important nutrient-plankton dynamics.
4
-------
The data suggest that from 1949 to 1964 gradual increases "in nutrients
led to medium sized phytoplankton standing crops by 1964 to 1965. Between
1966 and 1969 increased standing crops resulted presumably from a continued
increase in nutrients. Some bluegreen algae were noted in small
tributaries, e.g., Sassafras River. Phytoplankton biomass has apparently
reached a "quasi-plateau" and PO^-p is judged to be in excess, as this
nutrient now remains in fairly high concentrations throughout the summer.
We suspect that light is now controlling the maximum biomass yield more
than nutrients, especially in the turbidity maximum area, a region of high
concentration of suspended sediments located at the interface between tidal
fresh water and brackish waters. Further evaluation of this hypothesis is
expected through the Chesapeake Bay Program's water quality modeling.
***.
Middle Chesapeake Bay
(Chesapeake Beach to Smith Point)
This reach of the Bay is characterized by slightly higher levels of
P
-------
oxidation was not completed to NO_-N is poorly understood. Earlier data
of C.B.I, for 1964 to 1966 did not show unusually high NO -N values. The
relative control of nitrogen versus phosphorus is speculative at this
time. Ancillary information suggests that nitrogen may be in short supply,
as Flemer and Biggs (1971) noted that suspended particulate organic
material suffered a relative loss of nitrogen with respect to carbon.
This region of the Bay has historical Secchi disc data from the late
1930's which are difficult to interpret since the correlation is poor
between Secchi depth and chlorophyll £ values (Heinle, £t aj^., 1980).
Lower-Chesapeake Bay;
(Smith Point and seaward)
Phosphate-P concentrations show a slight increase from C.B.I, cruises
rs v--»- - *».-. it '1*~ • " *-,
from 1949 to 1951 to the late 1960's and early 1970's, and some evidence
suggests that chlorophyll a_ increased slightly during this period (Smith,
et £l., 1976; Patten, £t aU , 1963; Fleischer, £t a_l., 1976). Nitrogen has
not been measured long enough to establish trends; however, McCarthy4 et
al. (1977) describe seasonal patterns of nitrogen concentrations and use by
phytoplankton. Chlorophyll a_ in some years shows a spring peak in
concentrations with peak values approaching 20 to 25 ugl . Most values
approximate 10 ugl~ during the remainder of the year. Further increases
in P0,-p are not expected to lead to further increases in chlorophyll _a,
as nitrogen is believed to be a more important controlling nutrient in
higher saline waters ("Webb, 1980). The lack of historical data on forms of
nitrogen other than NO- and NO«-N is clearly shown to limit a thorough
interpretation of nutrient-phytoplankton trends in the lower Bay.
Eastern Shore Tributaries:
Some data are available for the Chester, Choptank, and Wiles Rivers and
Eastern Bay resulting from C.B.I, studies in 1949 to 1951 and 1964 to 1966
and E.P.A. (Anon., 1971 b) studied the Choptank in 1970. Though distant
-------
from large metropolitan areas, these tributaries have shown some increases
in PO^-p and chlorophyll £, but no clear trend is evident for nitrogen.
Since the circulation of those tributaries is probably dominated by the Bay
i
proper, it is difficult to separate the influence of changes in the Bay
from internal tributary dynamics.
Magothy, Severn, and South Rivers: '
These tributaries, located near Annapolis, apparently experienced
relatively high concentrations of PO^-p and chlorophyll £ in their lower
reaches by the time of the earliest survey conducted by C.B.I, in 1964 to
1966 (Hires, Stroup,,and Seitz, 1963 and Stroup and Wood, 1966).
Chlorophyll £ and PO.-P have increased in the upstream reaches of these
tributaries (Anon., 19J.I. b). By 1970, concentrations of PO.-P up to 4.6
'~
—1 -1
ug-at 1 and chlorophyll £ values from 50 to 100 ugl were observed
in the Severn River. Nitrate and NO?-N show no clear trend but tend to
correlate with concentrations found in the upper Bay (Heinle, _e_t _al . , 1980).
Patuxent River:
This subestuary has been surveyed extensively as indicated by 25 major
reports given in Table C-4 of Heinle, £t £l_. (1980). Mihursky and Boynton
(1978) summarized much of the water quality data. There have been
increases in the maximum concentrations of major nutrients, increases in
the concentrations of chlorophyll £ and associated rates of phytoplank tonic
photosynthesis, decreases in water transparency and dissolved oxygen
(especially in deeper waters seaward of the turbidity maximum which
approximates the region of the estuary near Chalk Point). Table 2
summarizes the major trends, and the extensive literature is cited in the
above references.
Ulanowicz and Flemer (1978) indicated a close coupling between primary
production and the rates of disappearance of nitrogen in October, and
evidence suggests that nitrogen may play an important role in controlling
phytoplankton biomass yield in the lower estuary. Photosynthesis
7
-------
integrated over depth in the upstream, more turbid areas is probably light
limited much of the year. Further work on the nutrient-phytoplankton
dynamics is under study by Dr. Donald O'Conner, Manhattan College; the
Chesapeake Bay Program water quality modeling will focus on the Patuxent.
Potomac River;
The Potomac, near Washington, received early attention regarding water
quality
-------
reported for 1965 to 1966. Heinle, et al. (1980) attempt to explain this
% «•— K^^B
phenomenon based on grazing pressure. Recent increases in the catch of
menhaden, a major grazer, is plausible but further work is needed to verify
this hypothesis.
Some of the smaller tributaries to the Bay in the Hampton Roads -
Norfolk area have been studied in recent years (Neilson, 1978). Many of
these rivers receive large volumes of runoff relative to their respective
volumes, and dense algal blooms have resulted with periods of low dissolved
oxygen as in the Elizabeth River. <
York and Rappahanock-Rivers:
Compared with the limited data available in the C.B.I, reports for 1949
to 1951 on P0,-p and .chLorophyll a, both of these rivers have shown
^ ~y ~ ' **».
increases in recent years in these factors. Insufficient data are
available to establish trends for concentrations of nitrogen. Low levels
of dissolved oxygen have been observed in the seaward reaches of the York
River in recent years (Haas, 1977 and Webb and D'Elia, 1980). These low
levels of dissolved oxygen were not noted in the early work of C.B.I.
during 1949 to 1951. In recent years these tributaries have shown dense
blooms of dinoflagellates, a condition not reported in earlier work.
-------
B. Toxic Chemicals
Inputs:
There is no comprehensive inventory of actual concentrations of toxic
chemicals, which include a number of metals and organic forms, introduced
into the Bay and tidal tributaries. Thus, little information is available
from which to infer trends. The present U.S. E.P.A. National Pollution
Discharge Elimination System (NPDES) permitting process provides a
mechanism by which just a very small fraction of all toxic compounds are
monitored and regulated. These compounds are very arbitrarily placed on a
discharge permit when they are generally believed to be found in a
particular effluent (industrial and municipal). This present practice
provides a limited assessment and control of toxics from industrial and
-T("ll-"- ,- >—-_ -,y, !.T- . ... «,y
municipal sources. Inventories of industrial processes give only a range
of what type of material might be expected to appear in an effluent.
Potentially toxic materials may have, a number of sources, e.g., sewage
treatment plant effluents, industrial discharges including power plants,
atmospheric inputs, and non-point source runoff from agriculture, forests,
and urban areas.
Ambient Concentrations:
There is relatively little published information on toxic materials in
the Bay and tidal tributaries from which to assess trends. More
information for metals than organic materials exists, probably the result
of the difficulty and 'expense in measuring organic compounds available in
environmental samples.
The limited available data concerning the water column are often so
variable that it is difficult to infer trends resulting from hydrologic
conditions. An example of the magnitude of the variability is evident in
the U.S. Geological Survey data collected at the Conowingo Dam on the
Susquehanna River (Lang and Grason, 1980). On October 31, 1979, the total
recoverable lead concentration in the water was 7 ppb and 13 days later it
10
-------
was 1800 ppb. This study also demonstrates seasonal fluctuation in the
concentrations of toxic chemicals.
The concentration of toxic substances in sediments is probably the most
reliable data for establishing trends. These data must be interpreted with
care, because some studies have homogenized several feet of sediment
t
(Cronin, ££._£!.•» 1974); such bulk analyses are often done when the
objective is to estimate the amount of•toxic material available for a
channel dredging project. Such data have limited value in establishing
trends. Table 3 lists the sediment concentrations of several metals of
some Chesapeake Bay tributaries. Considerable variation exists in these
data. Seme recent information on heavy metals from the Bay proper is
summarized in Table 4*, ^
*r v»y-
An example of trend information for selected metals from Baltimore
Harbor is shown in Fig. 3 (U.S. E.P.A., 1977). With the exception of
mercury, all metals showed an increase in concentration from seven ft. up
to 0.5 ft. This increase can probably be attributed to industrialization.
The decrease in the top two inches may be due to increased regulation of
industrial effluents, increased pollution control technology or, at least
theoretically, the influx of "clean" sediment. Unfortunately, no dating
was performed on these sediment cores.
Other data are available from the lower Bay. U.S. EPA STORE! data, a
computer base, show a downward trend in zinc at two stations in the
*
Elizabeth River. Unpublished EPA air quality data show a downward trend in
cadmium and lead in the air over Baltimore since 1977. In addition,
nationwide atmospheric concentrations of the organic pollutant, benzo (a)
pyrene have decreased over the past decade (Faoro & Manning, 1981). The
relationship of atmospheric sources of toxic chemicals to the Bay
environment is poorly understood but is under study by the CBP.
The results of a sediment core study done in the Rappahannock River
11
-------
•showed no clear trend with little variability over depth in mercury
concentrations (Bender, et £l., 1972). Concentrations ranged from about
0.05 to 0.17 ppm over a depth of zero to 130 cm.
The paucity of published information on synthetic organic chemicals is
noteworthy with the exception of Kepone found in the James River (U.S.
E.P.A., 1978). A recent study of phthalate ester plasticizers in the
sediments of the upper Bay show some interesting trends (Peterson, 1980;
unpublished Doctoral Thesis, University of Maryland). These compounds are
generally considered relatively low in toxicity; however, they are
ubiquitous in the aquatic environment, especially in industrialized
regions. Peterson is preparing for publication information which
correlates the annual ^pjcoduction of synthetic organic chemicals from 1949
to 1979 with selected phthalate esters and the concentration of these
esters in the sediments of the upper Bay with their industrial production.
In the above study polycyclic aromatic hydrocarbons (PAH's) were
analyzed from sediment cores. The trend observed in benzo (a) anthracene +
chrysene concentrations generally increased from the early 1880's to about
1915 and then showed a general decline to the present. A slight increase
was noted during the early 1940's with a fairly precipitous drop in levels
about 1965. This pattern is not limited just to the United States and
seems to correlate with the production of fossil fuels (Peterson, 1980).
12
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.III. ASSESSING NUTRIENT AND TOXIC CHEMICALS— A VIEW TO THE FUTURE
Existing information has been used to describe the historical pattern,
up to the present, for nutrients and toxic chemicals. Though better
information is available for nutrients than toxic chemicals, even the
former becomes especially scattered prior to the early 1960"s. In order to
improve our ability to make future projections for nutrients, the CBP is
developing a computer-based water quality model that will incorporate
ecosystem processes including algal physiological uptake kinetics, grazing,
and hydrodynamics, and predict the effects of changes on dissolved oxygen
from variable rates of nutrient input to the Bay and tidal sub-estuaries.
This tool will help evaluate the relative importance of nitrogen,
phosphorus, light, and other factors as they effect changes in
phytoplankton biomass and associated changes in dissolved oxygen,
especially in the present "hot-spot" areas in or near tidal freshwaters and
in the deep channels of the Bay and tidal tributaries. Low levels of
dissolved oxygen have been apparently characteristic of the deep channels
as a consequence of natural processes and our water quality model will help
us assess whether increased nutrients will exacerbate the problem. Though
we have focused on dissolved oxygen, in the long-term there is a great need
to consider food web implications of an increased nutrient supply.
Thus, we feel that it is inappropriate to make simple extrapolations
of present trend lines as a basis for assessing future conditions, i.e.,
year 2000. Based on tlie Corps of Engineers Future Conditions Report (U.S.
Army C.O.E., 1977), existing nutrient problems are likely to be magnified
unless controls and management practices are given further consideration.
In the case of toxic chemicals, existing data severely limit an
assessment of past conditions. The CBP will contribute substantially to an
inventory of the distribution of toxic substances in the Bay and selected
sub-estuaries. Information on the concentrations of toxic chemicals,
13
-------
hydrodynamics, physical characteristics of bottom sediments, and associated
animal-sediment relationships will improve our ability to characterize the
mechanisms responsible for the sediments to serve as a medium of transport
and fate for toxic chemicals. This information, coupled with data on land
use practices, e.g., industrial and agricultural development, and
urbanization will be used to make future projections.
14
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IV. MANAGEMENT CONSIDERATIONS;
From the outset of the CBP, the following question has been asked:
"How does one interpret trends in water quality for the Chesapeake Bay,
particularly with respect to improved management?" To address this issue,
we explored what mechanisms and procedures from other sources, both within
the United States and internationally, have been used to address similar
questions about estuarine management. This led us to the Thames River
Authority (TRA), Great Lakes International Joint Commission, San Francisco
Bay Authority, and others.
The fundamental hypothesis was that large ecosystems are too diverse
and complex to either study or manage as one unit. The TRA and other
groups developed systematic methods to break or segment the ecoly'stem into
sub-units based upon physical, chemical, and biological parameters. They
used basic water quality parameter concentrations to assess the relative
condition of each segment along a degradation continuum and suggested
alternative approaches to meeting certain water quality objectives. They
at'no'time forgot that any activity in one particular segment directly
impacted several other segments, and this caveat was factored into all
their decisions. We will do likewise.
Not surprisingly, we believe that a segmentation approach, as a
management tool, would be a valuable asset to managing the Bay. The need
for segmentation or zoning of the Bay based upon natural processes and uses
has been discussed by Schubel (1975) and Ulanowicz and Neilson (1974) used
the Patuxent estuary to show the value of segmentation as a method of
spatially aggregating estuarine models for simplification with minimal loss
of information. Specifically, it can provide the following practical
benefits:
assist in the integration of scientific data both from the Bay
Program and elsewhere,
15
-------
- assist in providing better trend analysis of past water quality
data and highlighting future data needs,
- provide a framework for establishment of water quality objectives,
- facilitate public choice in making decisions related to management
of the Bay, and
- provide a framework for monitoring changes in the future and
insuring accountability for management of Chesapeake Bay.
How do these benefits come about—rationale?
We believe that an adjunct to understanding the assimilative capacity
of the Bay and tidal sub-estuaries—a key feature of understanding the
benefits to managing the Bay, is a fundamental understanding of the
ecological structure^ami functional relatTonships'of the system." Without a
broad conceptual framework, really an ecosystem perspective, we argue that
it is difficult to relate water quality trends to effects.
For comparative purposes, it is important to comprehend the components
of the estuarine system and understand how these components interact at a
scale that is scientifically meaningful yet is not lost in the potentially
great ecological detail and complexity that we know exists in the Bay.
Thus, a desirable framework would permit the estuarine ecosystem to be
divided into comparable units from an analytical perspective and represent
the continuity of system processes at the integrative level.
The principle criteria for segmentation should be based upon a
geo-physical basis since these factors set the boundaries 'for chemical and
biological features. For example, salinity and hydrographic structure are
useful parameters since salinity is widely recognized as a key parameter in
determining the nature and extent of biological communities and the
hydrographic structure characterizes the potential for materials, e.g.,
nutrients, dissolved oxygen, and toxic chemicals and organisms, e.g., true
plankton, eggs, and larvae of numerous Bay fishes, to be transported in the
system.
16
-------
Thus, a first level of analysis might lead to segments that correspond
to the following classification; tidal freshwater, turbidity maximum,
region of.two-layered circulation, etc. Each of these regions show similar
dominant biological features, e.g., the tidal freshwater is the spawning
area for several anadromous fishes and when under excessive nutrient
*»
supply, responds with "nuisance" bluegreen algae. The turbidity maximum is
believed to be an important nursery area for numerous juvenile species and
probably is a site for maximum exchange of toxic materials that strongly
adsorb to fine silts and clays. The description could be expanded;
however, our purpose,is to be indicative and not all-inclusive at this time.
Therefore, segmentation as a management tool will have its greatest
utility when it is based upon a fundamental understanding of the estuarine
"5ti' **+•
system. The voluminous data from the Bay can be better interpreted with
some systematic framework such as segments. The segmentation framework
likewise aids in assessing water quality trends since we are more specific
on "trends in what areas." The data base for nutrients was organized
within the framework of segmentation (Heinle, ejt alL^., 1980). Likewise,
this rationale extends to the setting of water quality objectives that can
be targeted for specific areas. To the extent that segmentation provides a
way to make meaningful comparisons within potentially a very complex
estuarine system, we feel that public choice should be facilitated in
making management decisions.
How does segmentation assist directly in management actions?
We feel that to manage any system, you have to perform at least five
basic activities. First, establish specific goals or targets. As
explained in the above rationale, goals whose basis are rooted in a
scientific framework are more likely to have realistic expectations.
Second, determine who will be accountable for meeting the goals or
targets. This may be largely determined through administrative procedures;
however, explicit goals can be more clearly stated when they are more
17
-------
closely tied to expectations based upon a sound conceptual framework —
this should help the public evaluate more objectively the role and
effectiveness of the identified agency(s). Third, define existing
conditions or status as to clarify how far away you are from the goals.
Again, this activity is aided by focusing on comparable areas. Fourth,
develop solution alternatives or plans of action for reaching particular
* »
goals. We assume that a meaningful compartmentalization of the Bay will
permit management to set realistic and achievable objectives that are
perceived as practical alternatives — not objectives necessarily across
the board for this complex system. Fifth, implement plans of action to
maintain constant monitoring and reporting of progress toward goals to
interested parties. The reasonableness of this action is predicated on the
-i VJ»- - »~. -f. >"-- — ,. .
previous actions.
The EPA Chesapeake Bay Program is concentrating on defining existing
conditions with respect to toxics, nutrients, and Bay grasses for the
segments and developing solution(s) for reaching water quality goals and
objectives in selected segments. Recommendations will be made on
approaches and parameters to be used to monitor progress of the Bay in the
future. These data will provide a baseline for effective public choice
among the possible water quality objectives. In addition, we feel that the
baseline status analysis by segment is only the beginning. In the future,
the appropriate responsible institutional body should:
- prepare an annual updated status report using the agreed upon
•
water quality parameters, and
- Prepare Bay plans of action
-------
segmentation process includes:
- dividing the ecosystem into sensible sub-units, based principally
upon physical criteria, and secondarily on chemical and biolog'ical
indicators.
decide what water quality parameters should be used to assess the
health of a segment, . - *
- assess water quality data along segments; modify segments as
necessary,
- using water quality parameters as indicators, attempt linkages to
biota and water quality uses, and
;
- identify management solutions necessary to reach certain water
quality objectives (determined by public choice process).
•--65' •*>*+.
We currently anticipate identifying some 15-20 segments and then using
parameters such as salinity, dissolved oxygen, phosphorous, chlorophylla ^,
trace metals, sediment data, and other information to assess the condition
of each segment along a degradation continuum. This will also highlight
differences among segments with similar physical characteristics and relate
all assessments to uses which are allowable and/or precluded under each
condition. The categories of "uses" might be as follows:
- water that can support all or most indigeneous species,
- water that can support some indigeneous species but not selected,
sensitive ones,
•t -
- water th,at ca'n support contact recreation (boating, skiing),
- water that meets swimmable/fishable requirements, and
- water that cannot support above uses but still has capacity for
industrial wastes and can serve as a transportation medium.
From this information we can begin to determine the action necessary to
control water quality problems in the segments and to reach certain desired
water quality objectives, i.e., enhancement, degradation, non-degradation,
etc. We must stress that the choice among water quality objectives, as
19
-------
well as among solutions to reach them, is a public choice. The data from
our program will facilitate these choices. The actual implementation will
be undertaken through existing agencies at the Federal and State level(s).
We have worked with, and through these groups throughout our s-tudy. The
solutions will involve going up the tributary and changing land use
practices. Here is where the trade-off among point and nonpoint source
pollutants will occur.
20
-------
REFERENCES
Adams, D. D., D. T. Walsh, C. E. Grosch and C. Y. Kuo. 1975. Investigative
monitoring of sewage oatfalls and contiguous waters of Hampton Roads,
Elizabeth and James Rivers and the lower Chesapeake Bay, Virginia, from
June 1973 to May 1975. Institute of Oceanography, Old Dominion Univ.,
Tech. Rep. No. 22, Norfolk, Va., 206 p.
Anonymous. 1968. Water quality survey of Northeast River, Elk River, C-D.
Canal, Bohemia River,.Sassafras River and Upper Chesapeake Bay. U.S.
Dept. of Interior, Fed. Wat. Poll. Cont. Admin., Chesapeake Field Sta.
Data Rep. No. 4, Annapolis, Md.
Anonymous. 1971a. Water quality survey of the Upper Chesapeake Bay. U.S.
Environmental Protection Agency, Annapolis Field Office, Region III,
Data Rep. No. 24, 12 p.
Anonymous. 1971b. Upper Chesapeake Bay water quality studies: Bush
River, Romney Creek, Spesutie Narrows and Swann Creek 1968-1971;
Chesapeake and Delaware Canal 1970; Chester River 1970; Severn River
1970-1971; Gunpowder, Middle and Bird Rivers 1971. U.S. Environmental
Protection Agency,^Annapolis Field Office, Region III, Data Rep. No.
32, 27 p. '-"** ***•
Bender, M. E., R. J. Huggett, and H. D. Slone. 1972. Heavy metals - an
inventory of existing conditions. J. Wash. Acad. Sci. 62:144-153.
Brehmer, M. L. and S. 0. Haltiwanger. 1966. A biological and chemical
study of the tidal James River. Virginia Institute of Marine Science.
Spec/ Sci. Rep. No. 6.
Brush, L. M., Jr. 1974. Inventory of Sewage Treatment Plants for
Chesapeake Bay. Chesapeake Research Consortium, Publication No. 28,
Annapolis, Md., 62 p.
Carpenter, J. H., D. W. Pritchard and R. C. Whaley. 1969. Observations of
eutrophication and nutrient cycles in some coastal plain estuaries.
Pages 210-221 in; Eutrophication: causes, consequences; correctives.
National Academy of Sciences, 2101 Constitution Ave., Washington, D.C.
20418, 661 p.
Champ, M. A., 0. Villa, and R. C. Bubeck. 1980. Historical Overview of
the Freshwater Inflow and Sewage Treatment Plant Discharges to the
Potomac River Estuary with Resultant Nutrient and Water Quality
Trends. Proceedings of National Symposium on Freshwater Inflow to
Estuaries. Sept. 9-11, 1980* San Antonio, Texas, sponsored by U.S.
Fish and Wildlife Service.
Clark, L. J., D. K. Donnelley and 0. Villa. 1973. Summary and Conclusions
from the forthcoming Technical Report 56 "Nutrient Enrichment and
Control Requirements in the Upper Chesapeake Bay." U.S. Environmental
Protection Agency, Annapolis Field Office, Region III, EPA-9031
q-73-002-a, 24 p. plus Appendices.
Clark, L. J., S. E. Roesch, and M. M. Bray. 1980. Assessment of 1978
Water Quality Conditions in the Upper Potomac Estuary. U.S.
Environmental Protection Agency, Region III, Central Regional
. Laboratory, Annapolis, Maryland. EPA-903/9-80-002.
21
-------
Corps of Engineers. 1977. Chesapeake Bay Future Conditions Report.
Baltimore District. Summary Vol. + topical vols.
Cronin, L. E., D. W. Pritchard, J. R. Schubel, and J. A. Sherk. 1974.
Metals in Baltimore Harbor and upper Chesapeake Bay and their
accumulation by oysters - Phase 1. Joint report by Chesapeake Bay
Institute and Chesapeake Biological Laboratory, 72 p. and App.
Gumming, H. S., W. C. Purdy, and H..P. Ritter. 1916. Investigation of the
pollution and sanitary conditions of the Potomac watershed. U.S.
Treasury Dept., Hygenic Laboratory BuJ.1 No. 104,*239 p. plus plates.
Faoro, R. B. and J. A. Manning. 1981. "Trends in Benzo(a) Pyrene,
1966-1977. J. Air Pollut. Control Assoc. 31(1): 62-64.
Flemer, D. A. 1970. Primary production in the Chesapeake Bay. Chesapeake
Sci. 11:117-129.
Flemer, D. A. and R. 'fi. Biggs. 1971. Particulate carbon:nitrogen relations
in northern Chesapeake Bay. J. Fish. Res. Bd. Canada 28:911-918.
Fleischer, P., T. A. Cosink, W. S. Hanna, J. C. Ludwick, D. E. Bowker, and
W. G. White. 1976-..'- Correlation of chlorophyll, suspended matter, and
related parameters of waters in the lower Chesapeake Bay area to
LANDSAT-1 imagery. Inst. of Oceanography, Old Dominion University
Tech. Rep. 28, Norfolk, Virginia, 125 p.
Haas, L. W. 1977. The effect of the spring-neap tidal cycle on the
vertical salinity structure of the James, York, and Rappahannock
Rivers, Virginia, U.S.A. Estuarine Coastal Mar. Sci. 5:485-496.
Harris, R., M. Nichols, and G. Thompson. 1980. Heavy Metal Inventory of
Suspended Sediment and Fluid Mud in Chesapeake Bay. Special Scientific
Report 99, Virginia Institute of Marine Science, Gloucester Point,
Virginia.
Heinle, D. R., L. F. D'Elia, J. L. Taft, J. S. Wilson, M. Cole-Jones,
A. B. Caplins, and L. E. Cronin. 1980. Historical Review of Water
Quality and Climatic Data from Chesapeake Bay with Emphasis on Effects
of Enrichment. University of Maryland Center for Environmental and
Estuarine Studies, Chesapeake Biological Laboratory, Solomons, Maryland
(UMCEES Ref. No. 80-15 CBL).
Hires, R. I., E. D. Stroup, and R. C. Seitz. 1963. Atlas of the
distribution of dissolved oxygen and pH in Chesapeake Bay, 1949-1961.
Chesapeake Bay Institute, The Johns Hopkins University, Graphical
Summary Rep. No. 3., 411 p.
Huggett, R. J., M. E. Bender, and H. D. Slone. 1971. Mercury in sediments
from three Virginia estuaries. Ches. Sci. 12:280-282.
Jaworski, N. A. 1980. Sources of nutrients and the scale of eutrophication
problems in estuaries. (In press) in: B. J. Neilson and L. E. Cronin
(eds.), Proc. of a Symposium on Nutrient Enrichment in Estuariss,
Humana Press.
22
-------
Jaworski, N. A., L. J. Clark and K. P. Feigner. 1971. A water resource-
water supply study of the Potomac estuary. U.S. Environmental
Protection Agency, Annapolis Field Office, Region III, Tech. Rep. 35.
Jaworski, N. A., D. W. Lear, Jr., and 0. Villa, Jr. 1972. Nutrient
management in the Potomac estuary. Pages 246-273 in: G. E. Lickens
(ed.), Nutrients and eutrophication. Amer. Soc. Limnol. Oceanogr.
Spec. Symposia, vol. 1, 328 p.
The Johns Hopkins University. 1966. The Johns Hopkins Water sciences and
management program, report on the Patuxent River basin, Maryland, 222 p.
Johnson, P. G. , and 0. Villa, Jr. 1976. Distribution of metals in
Elizabeth River sediments EPA-903/9-76-023.
Lang, D. J. and D. Grason. 1980. Water-Quality Monitoring of Three Major
Tributaries to the Chesapeake Bay - Interim Data Report. U.S.
Geological Survey,, Water-Resources Investigations 80-78.
Marks, J. W. and 0. Villa, Jr. 1969. Water quality survey of the head of
the Chesapeake Bay Maryland tributaries. U.S. Environmental Protection
Agency, Annapolis Field Office, Region III, Data Rep. No. 12, 11 p.
McCarthy, J. J., W. R. Taylor and J. L. Taft. 1977. Nitrogenous nutrition
of the plankton in the Chesapeake Bay. I. Nutrient availability and
phytoplankton preferences. Limnol. Oceanogr. 22:996-1011.
Mihursky, J. A. and W. R. Boynton. 1978. Review of Patuxent estuary data
base. University of Maryland, Center for Environmental and Estuarine
Studies - Ref. No. UMCEES 78-157-CBL.
Neilson, B. J. 1978. Final report on water quality in the Hampton Roads
208 study area. Virginia Inst. Mar. Sci., Spec. Rep. No. 171 in
Applied Mar. Sci. and Ocean Eng., Gloucester Point, Va. 23062, 51 p.
Newcombe, C. L. 1940. Studies on the phosphorus content of the estuarine
waters of the Chesapeake Bay. Proc. Amer. Phil. Soc. 83:621-630.
Newcombe, C. L. and H. F. Brust. 1940. Variations in phosphorus content of
estuarine waters of the Chesapeake Bay near Solomons Island, Maryland.
J. Mar. Res. 3:76-88.
Newcombe, C. L. and A. G. Lang. 1939. The distribution of phosphates in
the Chesapeake Bay? Proc. Amer. Phil. Soc. 81:393-420.
Patten, B. C., R. A. Mulford and J. E. Warriner. 1963. An annual phyto-
plankton cycle in Chesapeake Bay. Chesapeake Sci. 4:1-20.
Peterson, J. C. 1980. Analysis of Phythalate Esters in Chester River and
Chesapeake Bay Sediments. Doctoral Thesis, Chemistry Department,
University of Maryland, College Park. - ......
Pritchard, D. W. 1967. Observations of Circulation in Coastal Plain
Estuaries, pp. 37-44. In G. Lauff, (ed.), Estuaries, AAAS, Publ. No.
83, Washington, D. C.
Schubel, J. R. 1975. Zoning - A Rational Approach to Estuarine Rehabilita-
tion and Management. Special Report No. 1, 7 p. Marine Sciences
Research Center, State University of New York, Stony Brook, N. Y.
23
-------
Smith, C. L. , W. G. Maclntyre, C. A. Lake, and J. G. Windsor, Jr. 1977.
Effects of tropical storm Agnes on nutrient flux and distribution in
lower Chesapeake Bay. Pages 299-310 in; The effects of tropical storm
Agnes on the Chesapeake Bay estuarine system. The Chesapeake Research
Consortium, Inc. Pub. No. 54, The Johns Hopkins Univ. Press, Baltimore,
Md.
Stroup, E. D. and J. H. Wood. 1966. Atlas of the distribution of
turbidity, phosphate, and chlorophyll in Chesapeake Bay, 1949-1951.
Chesapeake Bay Inst., The Johns-Hopkins Univ., Graphical Summary Report
No. 4, 193 p.
Taft, J. L. , W. R. Taylor, E. 0. Hartwig, and R. Loftus. 1980. Seasonal
Oxygen Depletion in Chesapeake Bay. Estuaries 3:242-247.
Taylor, W. R. , and V. Grant. 1977. Plankton ecology project, nutrient and
chlorophyll data, Aesop Cruises, April 1969 to April 1971. The Johns
Hopkins Univ., Chesapeake Bay Institute, Spec. Rep. 61, Baltimore, Md.,
121 p.
Ulanowicz, R. E. and D. A. Flemer. 1978. A synoptic view of a coastal
plain estuary. Pages -1-26 in: J. C. J. Nihoul (ed.) Hydrodyanmics of
estuaries and fjords. Elsevier, Amsterdam.
Ulanowicz, R. E. and B. J. Neilson. 1974. Segmentation of Chesapeake Bay:
A Representative Exercise. Chesapeake Research Consortium Publ. No.
30, Annapolis, Md.
U.S. Environmental Protection Agency. 1977. Evaluation of the problem
posed by in-place pollutants in Baltimore Harbor and recommendation of
corrective action. EPA-440/5-77-015 A, B.
U.S. Environmental Protection Agency. 1978. Mitigation feasibility for the
Kepone-contaminated Hopewell/ James River area. U.S. Environmental
Protection Agency, Office of Water and Hazardous Materials, Criteria
and Standards Division, Washington, D.C. EPA-440/ 5-7 8-004.
Villa, 0., L. J. Clark, S. E. Roesch and S. K. Smith. 1977. The Potomac
estuary current assessment paper no. 2. U.S. Environmental Protection
Agency, Annapolis Field Office, Region III, Current Assessment Paper
No. 2, 22 p.
Villa, Jr., 0., and P. G. Johnson. 1974. Distribution of metals in
Baltimore Harbor Sediments. EPA-903/9-74-012.
*•
Webb, K. L. 1980. Conceptual models and processes of nutrient cycling in
estuaries. (in press) in: B. J. Neilson and L. E. Cronin (eds.)
Proc. of a Symposium on Nutrient Enrichment in Estuaries, Humana Press.
Webb, K. L. and C. F. D'Elia. 1980. Nutrient and oxygen redistribution
during a spring-neap tidal cycle in a temperate estuary. Science
207:983-985.
Whaley, R. C., J. H. Carpenter and R. L. Baker. 1966. Nutrient data
summary 1964, 1965, 1966: Upper Chesapeake Bay (Smith Point to Turkey
Point) Potomac, South, Severn, Magothy, Back, Chester, and Miles
Rivers; and Eastern Bay. The Johns Hopkins Univ., Chesapeake Bay
Institute, Spec. Rep. 12, Baltimore, Md. 88 p.
Wolnan, M. G. 1971. The nation's rivers. Science 174:905-918.
24
-------
rr
..Chesapeake-Bay
Region
'SCALE
NAUTICAL MILES
0 5 10 iS 20
STATUTE MILES
Figure 1. The Chesapeake Bay.
-------
WASTEWATER NUTRIENT ENRICHMENT TRENDS AND ECOLOGICAL EFFECTS
UPPER POTOMAC TIDAL RIVER SYSTEM FROM CHAMP, VILLA, AND BUBECK - 1980.
23.000
O
i
O >»
o -
I -o
a. ~
20.000
15.000
10.000
S.OOO
75.000
80.000
0 45.000
ui -
O o
O -O
<£ V
5
30.000
15.000
0-
1910
NO MAJOR
PLANT
NUISANCES
WATER CHESTNUT
INVASION
WATER MILFOIL
INVASION
LOCAL
BLUE-GREEN
ALGAL
BLOOMS
MASSIVE
PERSISTENT
BLUE-GREEN
ALGAL
BLOOMS,
INCREASING
ALGAL POPULATION
DIVERSITY
SMALLER
ISOLATED
BLUE-GREEN
ALGAL BLOOMS
/ SHORT \
IDURATIONj
CARBON
PHOSPHORUS
I
1920
I
1930
1940
I
I960
250.000
- 200.000'
150.000 2
_ O
or
too.ooo
o
i»
O
50.000
I960
1070
1000
Figure 2
-------
12
11
10
9
5 8
00
S 7
2
c 5
0)
u
I 4
Hg
Cu
-,, zn
— Cr
3500
3300
3100
2000
1800
1600 o -
1400 o
•w
2
1200 |.
o
c
1000' -o
800
600
400
200
1234567
Depth In sediment (In feet)
'' Figure 3 Concentrations of 6 metals in inner Baltimore Harbor sediments (In mg/kg).
Adapted from USEPA, 1977.
1650
1200
1100
1000
900 c
N
800
700
CL
O
600 I
500 §
o
c
o
400 °
300
200
100
0
-------
TABLE 1.
Twenty-seven year average freshwater flow from data of the U.S. Geological
Survey annual summaries of stream fl.ow entering Chesapeake Bay (December,
1951-1978); point sources of sewage (from Brush, 1974) and calculated
percent of annual flow that is sewage._/a
River
Susquehanna
Patuxent
Potomac
James
Chesapeake Bay
27-yr. Average
Flow (cfs)
Point Sources Percent of Freshwater
of Sewage (cfs) That is Sewage
38,800
l,085_/b
TV.3-
13,900
10,100
75,200
557 ^
41.15
**•-- -»> '--•-
670
302
2,034
1.4
3.8
" *•,
4.8
3.0
2.7
_/a - From Heinle, et. al., 1980.
_/b - Patuxent flows were taken from the Johns Hopkins University (1966)
rather than the U.S. Geological Service data.
-------
TABLE 2. • Summary of Trends in Inorganic Phosphate - Phosphorus (PO,-P), Nitrite and Nitrate-Nitrogen
(N0~ + N0~ - N) and Chlorophyll £ for Chesapeake Bay and Tidal Tributaries. Plus sign (+)
represents increase over time, -H- represents significant increase, 9 sign represents no
discernible trend. (Adapted from Heinle, £t al., 1980).
POf-P
4 -n
(ug-at 1 '
NO-+N03-N
(ug-at I"1)
Chlorophyll
(ug I"1)
Comment
Upper Chesapeake '
Bay
(Susquehanna Flats
to Annapolis)
Middle Chesapeake
Bay
(Chesapeake Beach
to Smith Pt. on
Potomac River)
Summer from 1949-1951
to 1969-1971 values>
from about 0.2-0.5 to
1.0. Summer minimum
noted in 1949-1951
but changed to summer
maximum.
From 1936 to 1951
values ranged from
undetectable to 1.3.
By 1964-1966 max.
vai'ues approx. 2.0
and by mid-1970's
values of 2.5 were
noted.
e
Winter/Spring peaks
of 80-100 with summer
minimums of approx.
1.0 to 10.0. No
clear trend.
Insufficient data for
trend. In early
1970's region of fall
pulse in NO -N.
Maximum values by 1965
reached 80 in summer
and slight > by summer
of 1971. Typically
single annual peak in
summer, no spring
pulge.
Chlorophyll a^ increased
in cone, from 1951 to
1966 with max. values
approx. 25 in surface
waters, with somewhat
higher values in deeper
waters. From 1966 to
1977 not changed.
D. Flemer (unpubl.)
noted occasional
bluegreen algae
in main stem of Bay
in 1965-1966 and
single field observa-
tion of bluegreen
form in Sassafras
River. Bluegreens
commonly noted by
1971 in many tribu-
taries by others.
Dissolved 0? values
in deep channel may
be depressed for
longer periods and
over larger reaches
of Bay in late 1970's.
-------
Lower Chesapeake
Bay
(Smith Pt. and
seaward)
Potomac River
Upper
(Woodrow Wilson Br.
to U.S. 301 Bridge)
Lower
(U.S. 301 to
Mouth)
From 1949-1951 to
late 1960's and early
1970fs see slight
increase in cone, but
values mostly less
than 1.0.
Insufficient data for
trend. By 1970 max.
values approx. 30 at
W.W. Br. and 6 at
Indian Head; by late
1970's values show
substantial decrease,
e.g., at W.W. Bridge
values of 1.3 and
Indian Head values of
0.3 were common.
Insufficient data in
seaward section of
lower area. By 1949-
1951 values ranged
from 0.0 to 0.3. By
1965-1966 values
ranged froft 0.04 to
2.6 and by 1970 max.
values approx. 6.0
at U.S. 301 Br. and
10.15 at Piney Pt.
By 1978 values approx.
2.3 at U.S. 301 Br.
and no change by
summer 1979 (L. Clark,
pers. com.)
Insufficient data
for trend.
Insufficient Data
for trend. By summer
of 1965 values approx.
128 at W.W. Br. and
36 at Indian Head. By
summer of 1978, values
approx. 60 at W.W. Br.
and 70 at Indian Head.
Insufficient data for
trend. By summer of
1965 at U.S. 301 Br.
values approx. 1.8.
By 1970 values here
approx. 80 in winter
and 12 in summer. At
Piney Pt. in summer of
1970, values at trace
to 100. Not much
change by summer 1978.
Data only suggests
possible increase over
last 25 years.
v •*+
By 1970 max. values
approx..200 or greater
at Indian Head with
excessive growths of
bluegreen algae. By
late 1970's max. values
about 43 at W.W. Br.
and 64 at Indian Head.',
No'; summer values
available in 1949-
1951. By 1964-1966
values range from 9 to
26 in Aug.-Sept. and
slightly higher in
deeper waters. By 1970
at U.S. 301 Br. values
reach 50-60 and Piney
Pt'. bloom of 80. By
summer of 1978 values
approx. 12-15.
Region often still
shows spring phytopl.
bloom in contrast to
upper Bay.
In late 1960's
anoxic conditions
common in bottom
waters in summer;
slight improvement by
late 1970's with
occasional late night
values possibly
reaching 1-2 ppm D.O.
(personal com. of
L. Clark).
In summer of 1977
deep channel ift
lower river showed
D.O. values about
1.0 ppm.
-------
Patuxent River
Upper
(Turbidity max. -
approx. Lower Marl-
boro to Benedict
Br.)
Lower
(Benedict Br.
Mouth)
to
James River
Upper
From 1936-1939 values
approx. 1.0. By 1968
and thereafter values
ranged between 1 and
15.
From 1936-1939 values
usually approx. 2.0
with max. values in
summer in contrast to
upper Bay. Ey summer
of 1968 and thereafter
values reach 3.5 and
winter values approx.
0.2 to 1.0.
Data started too
late for trend.
From 1936 to 1965
values approx. 1-10
and thereafter many
values range between
50 and 100.
From 1936-1965 values
approx. 1 to 5 and
1968 and thereafter
values in winter
approx. 50; summer
values dropping to
about 1.0. In mid-
19 70' s note NO~-N
peaks in fall at
Benedict Bridge.
Data started too
late for trend.
Max. summer values
increase from early
1960's to late 1960's,
from about 10-20 to
40-50 with occasionally
higher values. In tidal
fresh waters values
approx. 80-100. Winter
values show some
increase.
Max. summer values in-
crease from early 1960's
to late 1960's from
about 5-10 to 30-40.
By late 1970's max.
values occasionally
up to 100.
In 1965-1966 max.
values approx. 50-80 in
tidal freshwater and
2q|-50 in mid-estuary.
Apparently D.O. levels
not serious problem.
Bottom waters
show D.O. less than
1.0 ppm at times in
summer by mid to
late 1970's. Some
surface values
approx. 2.0 ppm.
Some low D.O. values
noted in tidal fresh-
water in mid 1960's.
-------
Lower + +(?) +
In 1949-1951 max. In 1965-1966 max. In 1949-1951 max. Note: High nutrient
values approx. 1.0. values approx. 40 and values approx. 10. levels not reflected
By 1965-1966 max. by 1973 values By 1965-1966 max. in Chlorophyll &
values approx. 1.0 ranged betw. 4-6 with values approx. 15-20 levels.
to 1.5 and by 1973- occasionally 40-60 with indication of
1975 max. values high values. spring and fall
approx. 2.0 to 3.0. bloom. By 1973-1975
values similar to
1965-1966.
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TABLE 3. .
METALS IN SEDIMENTS OF
CHESAPEAKE BAY TRIBUTARIES (IN PPM)
River
Elizabeth
Potomac
James
York
Sediment Cd
Depth Hi Lo
5-15 cm 26 <1
? 0.60 0
Upper 1cm
Upper 1cm
•? '
f?
jj
Cr Cu H£ Pb Zn
Hi Lo Hi Lo Hi Lo Hi Lo Hi Lo Reference
f
110 9 395 <2 2.73<0.01 382 <3 2380 38 . Johnson & Villa
75.85 5.93 61.88 7.90 85.83 0 349.3 54.3 Jaworski et al.
2.60 0.40 v Huggett et al.,
2.02 1.03 "• Huggett et al.,
, 1976
, 1971
1971
1971
Rappahannock Upper 1cm
Patapsco 10 ft. Avg 111 1 1848 23
1661 14
1.70 0.42
3.30 0.04 941 14 1712 91
Patapsco
5-15 cm 654 <1 5745 10 2926 <1 12.20 <0.01 13,890 <1 6040 31
30-40 cm
2102 14
2000
2 10.98 <0.01 2218 <1 3730 48
Huggett et al., 1971
US EPA, 1977
Villa & Johnson, 1974
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TABLE 4.
CONCENTRATION RANGES OF SELECTED HEAVY METALS
IN THE MAIN BAY
Parameter
Sediment
Concentrations
Surface Sediment
CFluid Mud)
Susp . Sediment
(Dry
Weight)
References
ug/g
ug/1
Cadmium
Chromium 18-42
Copper
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