WATER-QUALITY PROTECTION PROGRAM FOR THE
FLORIDA KEYS NATIONAL MARINE SANCTUARY
PHASE I REPORT
U.S. Environmental Protection Agency
Oceans and Coastal Protection Division
July 21, 1992
Contract No. 68-C8-0105
Work Assignment 3-225
Prepared by
Continental Shelf Associates, Inc.
759 Parkway Street
Jupiter, Florida 33477
Telephone: (407) 746-7946
Battelle Ocean Sciences
397 Washington Street
Duxbury, MA 02332
Telephone: (617) 934-0571
-------
WATER-QUALITY PROTECTION PROGRAM FOR THE
FLORIDA KEYS NATIONAL MARINE SANCTUARY
PHASE I REPORT
U.S. Environmental Protection Agency
Oceans and Coastal Protection Division
July 21, 1992
Contract No. 68-C8-0105
Work Assignment 3-225
Prepared ,by
Continental Shelf Associates, Inc. Battelle Ocean Sciences
759 Parkway Street 397 Washington Street
Jupiter, Florida 33477 . Duxbury, MA 02332
Telephone: (407) 746-7946 Telephone: (617) 934-0571
-------
CONTENTS
GENERAL INTRODUCTION
Task 2
WATER QUALITY ASSESSMENT
Task 3
CORAL COMMUNITY ASSESSMENT
Task 4
SUBMERGED AND EMERGENT AQUATIC VEGETATION ASSESSMENT
TaskS
NEARSHORE AND CONFINED WATERS ASSESSMENT
Task 6
SPILLS AND HAZARDOUS-MATERIALS ASSESSMENT
SUMMARY AND RECOMMENDATIONS
APPENDIX A
APPENDIX B
-------
GENERAL INTRODUCTION
CONTENTS
1.0 PURPOSE AND SCOPE . 1-1
2.0 DESCRIPTION OF THE FLORIDA KEYS NATIONAL MARINE SANCTUARY 1-3
2.1 SETTING -.'. 1-3
2.2 CLIMATOLOGY 1-3
2.3 'HYDROLOGY AND PHYSICAL OCEANOGRAPHY 1-4
2.3.1 Regional Circulation 1-4
2.3.2 Regional Hydrography 1-6
2.4 GEOLOGY 1-6
2.5 MARINE BIOLOGICAL COMMUNITIES 1-7
3.0 REFERENCES 1-7
LIST OF FIGURES
1-1. The Florida Keys National Marine Sanctuary 1-2
1-2. General bathymetry (fathoms) of the eastern Gulf of Mexico,
Straits of Florida, and the Bahamas and general configuration
of the Loop Current, Florida Current, and the Gulf Stream 1-5
-------
GENERAL INTRODUCTION
1.0 PURPOSE AND SCOPE
The Florida Keys National Marine Sanctuary (FKNMS) was created with the signing of HR5909 (Public Law
101-605) on 16 November 1990. Included in the sanctuary are 2600 nmi2 of nearshore waters extending from
just south of Miami to the Dry Tortugas (Figure 1-1). The Environmental Protection Agency (EPA) and the
State of Florida have been directed to develop a Water-Quality Protection Program for the Sanctuary. This
Program will be considered by the National Oceanic and Atmospheric Administration (NOAA) for inclusion into
the comprehensive management plan that will be prepared to guide the use of the Sanctuary. The purpose of
the Water-Quality1 Protection Program is to recommend priority corrective action and compliance schedules
addressing point and nonpoint sources of pollution. The Program will be developed in two phases.
The first phase of the Program, which is the subject of this report, involves a compilation and synthesis of
information on the environment within the FKNMS. The second phase of the Program will involve an
evaluation of the necessity and type of corrective action to be taken to restore and maintain the biological
integrity of the Sanctuary. Additional field data may need to be collected in Phase II to make an accurate
evaluation.
The scope of this report follows from the Work/Quality Assurance Project Plan for this work assignment. Five
tasks (Tasks 2 through 6) were identified in the work assignment that form this report. They are as follows.
• Task 2 Water-Quality Assessment
• Task 3 Coral Community Assessment
• Task 4 Submerged and Emergent Aquatic Vegetation Assessment
• Task 5 Nearshore and Confined Waters Assessment
• Task 6 Spill and Hazardous-Material Assessment
The Water-Quality Assessment includes information on point, nonpoint, and external sources potentially
affecting water quality. The existing information on physical oceanography and water quality of the region is
summarized. The potential for water-quality degradation in the future (Year 2010) is also discussed.
The Coral Community Assessment involves a compilation and summary of information on coral communities
within the FKNMS. Known and potential causes of adverse impacts to Caribbean and Florida Keys coral
communities are also discussed.
The Submerged and Emergent Aquatic Vegetation Assessment includes information on seagrasses and
mangroves within the FKNMS. The known effects of water quality on these types of communities are
discussed. Community trends in the FKNMS are discussed relative to existing and potential water quality.
The Nearshore and Confined Waters Assessment encompasses an evaluation of waters within the FKNMS.
Water-quality studies conducted in nearshore and confined waters are presented and discussed.
The Spill and Hazardous-Material Assessment includes information on historic spills and hazardous-material
contamination. Total numbers of previous spills, causes, and potential preventive measures are discussed.
Recommendations regarding data adequacy and the direction for the Phase II effort are provided.
Section 2.0 provides general background information on the environment of the FKNMS. This information is
provided to acquaint the reader with the general environment.
A list of acronyms used throughout this report is presented in Appendix A. Appendix 6 contains the Florida
Keys National Marine Sanctuary Water-Quality Protection Program Workshops Summary report.
1-1
-------
John Pewiekctmp
Cora/ Reel
Stale. Park
to
Evcmladcs National Park
f-r.»rf Jcllcrson
Naliot\al Monument
Kr.y Lnujo National
Marine Sanctuary
Lonn Key National
Marine Sanctuary
FLORIDA KEYS NATIONAL MARINE SANCTUARY
Figure 1-1. The Florida Keys National Marine Sanctuary.
-------
2.0 DESCRIPTION OF THE FLORIDA KEYS NATIONAL MARINE SANCTUARY
2.1 SETTING
The FKNMS includes the waters off all of the Keys between Key Largo and Key West. The Sanctuary extends
from the southern tip of Key Biscayne westward through the Tortugas Bank located on the western side of the
Fort Jefferson National Monument (Dry Tortugas island group). North of Key Largo, the Sanctuary
encompasses that portion of the Florida Reef Tract seaward of the boundary of Biscayne National Park down to
the 92-m (300-ft) isobath. West of Key Largo, the Sanctuary includes Barnes and Card Sounds (Figure 1-1).
These boundaries effectively cover the entire Florida Reef Tract from Key Biscayne through the Tortugas Bank,
protecting all of the inshore bays and sounds along this same stretch of coastline.
The Key Largo National Marine Sanctuary and Looe Key National Marine Sanctuary, as existing Federally
designated sanctuaries, will eventually be incorporated into the FKNMS. Until this incorporation is completed,
they will continue to operate as independent entities awaiting emplacement of the new, comprehensive
management plan. Everglades National Park, Biscayne National Park, and Fort Jefferson National Monument
are excluded from the new Sanctuary. John Pennekamp Coral Reef State Park will continue under the
jurisdiction of the State of Florida (NOAA 1991).
Exposed and sheltered mangrove shorelines dominate the fringing vegetation of the Florida Keys. Because the
shoreward boundary on the Sanctuary is the mean highwater mark (NOAA 1991), most of these mangrove
stands will lie within Sanctuary jurisdiction. Generally, the islands of the Florida Keys lie only 0.6 to 1.0 m (2
to 3 ft) above the mean high-tide mark. Maximum elevations, seen in the Key Largo area, reach only 5 m (18
ft) above sea level (Hoffmeister and Multer 1968).
Beyond the shoreline, extensive tidal flats and seagrass beds are seen on both sides of the Keys. Southward
toward the Straits of Florida, the Florida Reef Tract parallels the islands. The major living reefs seen along the
reef tract are concentrated on the reef tract's seaward edge. There, they form a discontinuous band showing
good development in the upper (northern) Keys, poor to marginal development in the middle Keys (i.e., in the
Seven Mile Bridge area), and better development again in the lower Keys and west from Key West.
The Sanctuary can be divided into three physiographic provinces distinguished by the shape, orientation, and
lithology of the banks and islands in each (Schomer and Drew 1982). The northernmost province (Key
Biscayne through Marathon), is characterized by long, narrow islands oriented northeast to southwest. These
narrow islands restrict water exchange between the Atlantic, Florida Bay, and the various sounds in this area.
It is here that the Florida Reef Tract is best developed. The central province (Bahia Honda through Key West)
is characterized by roughly triangular islands oriented in a northwest to southeast direction, or at right angles to
the Florida Reef Tract. These islands are built on an extension of the Miami Oolite Formation and their
northwest-southeast orientation results from the directional movement of tidal currents over differing sea-level
stands in the Gulf of Mexico and the Straits of Florida (Hoffmeister and Multer 1968). The western extension
of the Sanctuary (Key West through Tortugas Bank) is composed of scattered islands, described as distal atolls
by White (1970), and various shallow banks and shoals. The islands seen here are not actually atolls at all, but
a scattering of approximately 30 roughly circular sand keys lying west of Key West. Moving westward from
Key West, major features within this western extension of the Sanctuary are the Boca Grande island group, the
islands forming the Marquesas, the Quicksands Banks through Rebecca Shoals, and the islands of Dry Tortugas,
which are separated from Rebecca Shoals by a trough of relatively deeper water.
2.2 CLIMATOLOGY
The FKNMS has a mild, semitropical maritime climate, with a small daily range in temperatures. Water
temperatures and salinities vary seasonally and are affected by individual storms and seasonal events. The
winds that affect the Sanctuary are generally southeast to easterly, and they bring in moist tropical air over the
area. Major storms, usually hurricanes, historically have affected the area on an average of once every 7 years.
1-3
-------
During winter, cold fronts occasionally push rapidly through the area, and may cause rapid drops in temperature
and high winds from the northwest. These types of winter conditions generally last 4 to 5 days (Zieman 1982).
The Sanctuary is characterized by a relatively long, and sometimes severe, dry season (November through
April) and a wet season. Approximately 50% to 80% of the annual rainfall is received during the May through
October wet season (Schomer and Drew 1982). These wet/dry seasonal precipitation levels, coupled with the
winter increases in population seen in the Florida Keys, have numerous ramifications in terms of freshwater
resource allocation and potential nearshore pollution problems within the Sanctuary (Lapointe et al. 1990).
2.3 HYDROLOGY AND PHYSICAL OCEANOGRAPHY
In the South Florida coastal region, physical oceanographic processes (including tides, currents, and surface
waves) force local and regional circulation and, as a result, drive water-mass transport and exchange,
embayment flushing, and bottom-sediment transport. Working separately or in combination, these processes
affect the local water quality by transporting potential pollutants (polluted waters or sediments) in to or out of
the region, or by maintaining them in place.
The physical oceanography of the South Florida coastal region is distinguished by the fact that a major world
ocean current, the Florida Current, flows within the narrow boundaries of Straits of Florida, within a few tens
of kilometers of shore. The Florida Current connects the Loop Current of the Gulf of Mexico to the Gulf
Stream and flows through the straits bounded on the west by the Keys and the continental United States and on
the east by the Bahamian-Caribbean archipelago (Figure 1-2). The Florida Current is a surface current
restricted to the waters beyond the shelf break (i.e., beyond the edge of the continental shelf). Its influences,
however, are felt by the nearcoastal waters of the Keys and mainland Florida and has a measurable effect on
nearshore circulation.
2.3.1 Regional Circulation
The westward flowing North Equatorial Current splits at the Lesser Antilles and flows into the Caribbean as the
Caribbean Current and north of the Bahamas Bank as the Antilles Current. The Caribbean Current is persistent
and well defined, flowing westward throughout the year, with mean speeds at the core of about SO cm/s (DOD
1983). Countercurrents have been observed along the shores of the Caribbean. The Caribbean Current flows
into the Yucatan Current (at around 18° N Lat.) and passes through the Yucatan Strait with strong northward
flows. Surface speeds at the core range between SO and ISO cm/s, and eddies frequently occur north and south
of the western tip of Cuba. On exiting the Yucatan Channel, the Yucatan Current widens and looses speed as it
branches out into the Gulf of Mexico to form the Loop Current.
The Loop Current is so named because of the meandering loop it forms as it swings north then east then south
again as it passes through the Gulf of Mexico before exiting via the Straits of Florida as the Florida Current
(Figure 1-2). The extent of the intrusion of the Loop Current into the Gulf (its northern edge) fluctuates
considerably. There may be a seasonal pattern to these meanders (Leipper 1970) but some controversy remains
on this point (Vukovich 1986). Today, observations of the Loop Current are made using satellite thermal
images. Acceptable imagery can be collected 6 to 9 months of the year, typically during the late fall, winter,
and spring when thermal contrast and relatively clear skies allow. Satellite and other observations indicate that
the Loop Current does not normally intrude landward of the 100-m isobath. However, phenomena associated
with the Loop Current frequently intrude quite near the coast. These include perturbations that affect the
circulation of the eastern Gulf of Mexico, taking the form of alternating cold and warm filamentlike structures,
cold intrusions, and cold meanders. These perturbations are most pronounced in the north and east boundaries
of the Loop Current. They average 100 to 200 km in size, have translation speeds of 6 to 24 km/day, and
1-4
-------
Figure 1-2. General bathymetry (fathoms) of the eastern Gulf of Mexico, Straits of Florida, and the Bahamas [From Wennekens 1959]
and general configuration of the Loop Current, Florida Current, and the Gulf Stream.
-------
exhibit life cycles of 16 to 120 days (Vukovich and Maul 198S). Upwelling, an important mechanism for
transporting nutrients from deeper waters of the Gulf up onto the Florida shelf, is often associated with these
perturbations.
The Florida Current sweeps through the Straits of Florida, past the Florida Keys and the southeastern Florida
mainland, and moves into the Gulf Stream. Because of the very narrow continental shelf off southeast Florida,
the Florida Current is within a few tens of kilometers of the shore. The Florida Current dominates the offshore
transport of the region. Mean current velocity at the core is 100 cm/s, with maximums recorded as high as
300 cm/s (DOD 1983; Richardson et al. 1969). The total transport of the Florida Current has been estimated
from current-meter measurements as 3.2 x 107 m3/s (Schmitz and Richardson 1968). The Florida Current is
limited by the Channel of the Straits of Florida and does not meander like the Loop Current or the Gulf Stream.
Nearshore, a countercurrent has been observed with surface mean flows of 20 cm/s east to west off of Key
West (Brooks and Niiler 1975). This seems to be a persistent feature in the western Keys, and is probably a
cyclonic recirculation of the Florida Current. No such nearshore countercurrent has been observed in the
northern Keys. Surface measurements off Marathon Key and Miami recorded mean flows to the east and north
at 20 cm/s at 5 km offshore (Richardson et al. 1969). A deep countercurrent (below 400 m) has been observed
in the northern Keys and off the eastern Florida mainland (DOT 1990). However, this does not affect the
shallow coastal waters. Cyclonic eddies that spin off the western edge of the Florida Current have been
observed east of Miami (Lee 1975) and are probably common throughout the northern Keys. These eddies are
20 to 30 km long (north-south) and 10 km across (east-west), and they move northward through the coastal
waters with translation speeds of 25 cm/s (Lee 1975).
2.3.2 Regional Hydrography
The hydrographic properties of the water masses of the Straits of Florida and Florida continental shelf have
been well studied (see, for instance, Wennekens 1959). The hydrography of the offshore waters of the Florida
Keys region is greatly influenced by the flow of water originating in the Caribbean Sea and the Gulf of Mexico
and to a lesser extent by the waters of the western Atlantic Ocean. The Caribbean and Yucatan waters are
identified by their well-defined salinity maximum and are found all along the length of the Florida Current. A
new water mass is formed in the western Gulf of Mexico as original Yucatan water is modified by evaporation
and seasonal cooling. On the southwestern Florida continental shelf, a water mass that is intermediated between
the Yucatan and Western Gulf Waters becomes differentiated. This water is found along the entire nearcoastal
margin of the Straits of Florida, including the Keys, indicating the west to east transport of this water along the
southern coast of the Keys. An influx of western Atlantic water, detected by its higher oxygen content, is
frequently observed in the northern Straits of Florida off the northern Keys, but this is restricted to a narrow
band along eastern margin of the Straits.
2.4 GEOLOGY
The FKNMS lies atop the Floridian Plateau. The Floridian Plateau, characterized by nonclastic, chemically or
biologically produced sediments, underlies the Everglades, Florida Bay, the Florida Keys, and a large portion of
the west Florida continental shelf to a depth of 92 m (300 ft). The Florida Keys represent elevated remnants of
a Pleistocene coral reef tract that extends from Soldier Key through Key West (Hoffmeister and Multer 1964).
In the northeastern part of the Sanctuary, Key Largo through Big Pine Key, the surficial sediments are part of
an aerially weathered and recrystallized limestone formation known as Key Largo Limestone. At Big Pine Key,
this feature dips beneath another sedimentary layer known as the Miami Oolite, which continues through Key
West (Hoffmeister and Multer 1964). West of Key West, the oolitic facies submerge under a layer of recent
biogenic sediments, but they continue to form the bed rock underlying the Holocene features of the
1-6
-------
Marquesas Keys and Quicksands Banks. The Tortugas Bank and islands of the Fort Jefferson National
Monument are Holocene features again built on Pleistocene limestone, presumably the Key Largo Formation
(Shinn et al. 1989).
2.5 MARINE BIOLOGICAL COMMUNITIES
Broadly speaking, the FKNMS contains three unique and critically important marine biological communities:
(1) The mangrove forest lining its shorelines
(2) The extensive seagrass meadows, estimated to be some of the largest in the world, which lie on
both sides of the island chain and extent offshore to the reef tract itself
(3) The Florida Reef Tract, which contains the only shallow-water coral reef ecosystem within the
continental United States.
All these communities are tremendously complex within themselves, and each is made up of a vast number of
interacting organisms. As is the case with the redwood forests of California, a few key plant and animal species
.define each community. These species, the mangroves, seagrasses, and hard corals, actually build and define
the habitat, providing the structure that supports each community's countless individual inhabitants. Most of the
fish and invertebrate species that contribute so heavily to Florida's sports and commercial fishing economy, as
well as the majority of other mobile reef species, utilize all these different habitats at varying stages of their
development.
The biological communities of the FKNMS form an integrated and unique ecosystem. It is the recognition of
this fact that prompted creation of the Sanctuary. These marine biological resources are unique within the
United States, and it is the objective of the National Marine Sanctuary Program to preserve and enhance them
for future generations.
3.0 REFERENCES
Brooks, I.H., and P.P. Niiler. 1975. "The Florida Current at Key West: Summer 1972." J. Mar. Res.
33(l):83-92.
DOD. 1983. Defense Mapping Agency. Sailing Directions for the North Atlantic Ocean. 400 pp.
DOI. 1990. Synthesis of Available Biological, Geological, Chemical, Socioeconomic, and Cultural Resources
Information for the South Florida Area. Prepared for the Minerals Management Service by Continental
Shelf Associates, Inc. MMS 90-0019.
Hoffmeister, I.E., and H.G. Multer. 1964. "Pleistocene limestones of the Florida Keys." Pp. 57-61 in
Ginsburg, R.N. (Ed.), South Florida carbonate sediments: Guidebook for Fieldtrip No. 1. Geol. Soc.
Am. Annu. Meeting. Miami, FL.
Hoffmeister, J.E., and H.G. Multer. 1968. "Geology and origin of the Florida Keys." Geol. Soc. Am. Bull.
79:1487-1502.
Lapointe, B.E., J.D. O'Connell, and G.S. Garrett. 1990. "Effects of on-site sewage disposal systems on
nutrient relations of groundwaters and nearshore surface waters of the Florida Keys." Biogeochemistry
10:289-307.
1-7
-------
Lee, T.N. 1975. "Florida Current spin-off eddies." Deep Sea Res. 22:753-765.
Leipper, D.F. 1970. "A sequence of current patterns in the Gulf of Mexico." J. Geophys. Res. 75:637-657.
NOAA. 1991. Information package for the scoping meetings on the Florida Keys National Marine Sanctuary.
National Oceanic and Atmospheric Administration, Office of Ocean and Coastal Resource Management,
Washington, DC. 8 pp.
Richardson, W.S., W.J. Schmitz, Jr., and P.P. Niiler. 1969. "The velocity structure of the Florida Current
from the Straits of Florida to Cape Fear." Deep Sea Res. 16:225-231.
Schmitz, W.J., It., and W.S. Richardson. 1968. "On the transport of the Florida Current." Deep Sea Res.
15:679-693.
Schomer, N.S., and R.D. Drew. 1982. An ecological characterization of the lower Everglades, Florida Bay,
and the Florida Keys. FWS/OBS-82/58.1. Fish and Wildlife Service, Office of Biological Services,
Washington, DC. 264 pp.
Shinn, E.A., B.H. Lidz, J.L. Kindinger, R.B. Halley, and J.H. Hudson. 1989. A Field Guide: Reefs of
Florida and the Dry Tortugas. Prepared for the 28th International Geological Congress, 9-19 July
1989. Washington, DC. 47 pp.
Vukovich, P.M. 1986. "Loop Current boundary variations." EOS 67(44): 1049. Y
Vukovich, F.M., and G.A. Maul. 1985. "Cyclonic eddies in the eastern Gulf of Mexico." J. Phys.
Oceanogr. 15:105-117.
Wennekens, M.P. 1959. "Water mass properties of the Straits of Florida and related waters." Bull. Mar. Sci.
9:1-52.
White, W.A. 1970. "The geomorphology of the Florida peninsula." Fla. Bur. Geol. Bull. 51.
Zieman, J.C. 1982. The seagrass ecosystems of South Florida: A community profile. FWS/OBS-82/25.
Fish and Wildlife Service, Office of Biological Services, Washington, DC. 125 pp.
1-8
-------
WATER QUALITY ASSESSMENT
Task 2
CONTENTS
1.0 INTRODUCTION 2-1
2.0 HYDROLOGY/PHYSICAL OCEANOGRAPHY .-. 2-1
2.1 CURRENTS OF THE WATERS OF THE FLORIDA KEYS 2-1
2.1.1 Mean Currents , 2-1
2.1.2 Tides 2-3
2.1.3 Wind-Driven Currents 2-3
2.2 SURFACE WAVES 2-6
2.3 PROCESS CHARACTERIZATION 2-6
3.0 SOURCES AFFECTING WATER QUALITY IN THE SANCTUARY 2-8
3.1 POINT SOURCES 2-8
3.
3.
3.
3.
3.
3.
3.
.1 Definition 2-8
.2 Background 2-8
.3 Types of Facilities ." 2-9
.4 Size of Facilities 2-9
.5 Location of Facilities 2-9
.6 Water Quality Monitoring 2-27
.7 Canals 2-27
3.2 NONPOINT SOURCES 2-27
3.2.1 Definition 2-27
3.2.2 Groundwater Inputs 2-28
3.2.3 Marinas/Boat Live-Aboard 2-50
3.2.4 Mosquito Control Program - 2-69
3.2.5 Stormwater 2-74
3.3 EXTERNAL SOURCES OF POLLUTANT LOADS 2-91
3.3.1 Areas Adjacent to the Sanctuary 2-91
3.3.2 Areas Removed From the Sanctuary 2-102
4.0 WATER QUALITY 2-103
4.1. OVERVIEW 2-103
4.1.1 Florida Department of Environmental Regulation— 1985 2-103
4.1.2 Applied Biology, Inc. — 1985 2-103
4.1.3 Florida Department of Environmental Regulation — 1987 2-108
4.1.4 Florida Department of Environmental Regulation — 1990 2-114
4.1.5 Lapointe and Clark — 1990 . . . 2-116
4.1.6 Szmant — 1991 2-121
4.1.7 Lapointe et at. — 1992 2-123
4.2 SUMMARY 2-124
5.0 PROJECTED WATER QUALITY (YEAR 2010) 2-125
5.1 POPULATION AND LAND USE 2-125
5.1.1 Population 2-125
5.1.2 Land Use 2-126
5.2 WATER-QUALITY STANDARDS .' 2-126
5.3 NUTRIENT LOADINGS 2-127
6.0 REFERENCES 2-131
-------
LIST OF FIGURES
2-1. Bathymetry (fathoms) of the Straits of Florida and the general pattern
of mean currents measured on the U.S. continental shelf. 2-2
2-2. Schematic representation of shelf-water response to along-shore wind on the south coast
of the Florida Keys 2-5
2-3. Schematic representation of continental shelf processes and the Florida Current 2-7
2-4. Wastewater treatment facilities and discharge canals 2-13
2-5. Stratigraphic nomenclature for the late Pleistocene of peninsular Florida 2-29
2-6. Marina facilities ' 2-51
2-7. South Florida Water Management District Surface Water Management Permits ......... 2-77
2-8. Biscayne Bay and associated canals 2-101
2-9. Sampling locations summarized by the Florida Department of Environmental Regulation,
Szmant, and Applied Biology, Inc . .* 2-104
2-10. Sampling locations summarized by Lapointe and Clark [1990] 2-105
LIST OF TABLES
2-1. Tidal ranges and average maximum flood and ebb tidal currents
for selected locations 2-4
2-2. Inventory of NPDES point-source permits, January 1992 2-10
2-3. NPDES point-source flow and constituent data, January 1992 2-11
2-4. Sanitary wastewater facility discharges 2-12
2-5. Wastewater Treatment Facilities 2-33
2-6. Summary of average daily residential wastewater flows 2-43
2-7. Effluent characteristics by source 2-45
2-8. Characteristics of typical residential wastewater 2-46
2-9. Residential wastewater characteristics 2-47
2-10. Septic tank effluent quality 2-48
2-11. Typical effluent concentrations from septic tank systems '. 2-49
2-12. Marinas of the Florida Keys 2-65
-------
LIST OF TABLES
(continued)
2-13. Quantities of insecticides used by the Mosquito Control Group in the Florida Keys 2-72
2-14. South Florida Water Management District surface water management permits,
unincorporated Monroe County 2-75
2-15. Summary of water quality measurements reported from estuaries (Whitewater Bay,
Shark Slough Estuary, and Buttonwood Canal) in Everglades National Park .'..". 2-93
2-16. Summary of chemical water quality data collected in estuarine and marine waters of
Florida Bay in Everglades National Park, 1945-1976 2-95
2-17. Documents summarizing water quality in Biscayne Bay and the Miami watershed 2-97
2-18. Additional data sources and documents pertaining to water quality in the Florida
Keys region, including waters of the Florida Keys National Marine Sanctuary 2-106
2-19. Ranges of water-quality parameters measured during a survey to support designation of
the Florida Keys as Outstanding Florida Waters 2-107
2-20. Ranges of mean temperature, salinity, dissolved oxygen, dissolved oxygen saturation,
pH, turbidity, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, and phosphate
phosphorus at stations sampled by Applied Biology, Inc. (1985) 2-109
2-21. Ranges of water temperature, conductivity, dissolved oxygen, and pH measured at
stations occupied during the 2050) study conducted at Marathon, FL • • • • 2-110
2-22. Ranges of nitrite, nitrate, total Kjeldahl nitrogen, and ammonia measured in water
samples collected at stations occupied during the 205(j) study conducted at
Marathon, FL 2-111
2-23. Ranges of phosphorus, orthophosphate, and chlorophyll a measured in water samples
collected at stations occupied during the 205(j) study conducted at Marathon, FL 2-112
2-24. Ranges of biochemical oxygen demand, fecal coliform concentration, total suspended
matter concentration, turbidity, and Secchi depth measured in water samples collected
at stations occupied during the 205(j) study conducted at Marathon, FL 2-113
2-25. Mean values for water quality parameters measured at Boot Key Harbor Study
stations 2-115
2-26. Mean values of water temperature, salinity, turbidity, pH, chlorophyll a, and
dissolved oxygen at locations sampled by Lapointe and Clark (1990) 2-117
2-27. Mean values of nutrient parameters at locations sampled
by Lapointe and Clark (1990) -. . 2-119
2-28. Summary of wastewater pollution loads discharged to the upper Florida Keys study
area 2-128
2-29. Comparison of pollution loads discharged to the upper Florida Keys study
area 2-129
-------
Task 2 - WATER QUALITY ASSESSMENT
1.0 INTRODUCTION
This task report assesses the water quality in the Florida Keys National Marine Sanctuary (FKNMS). The
information presented in this report was obtained by review of the literature, Florida State agency reports, and
examination of Florida and Federal agency records.
Point and nonpoint sources of pollutants are identified and discussed. External sources that could potentially
affect water quality in the Sanctuary are also discussed. Information concerning the physical oceanography and
status of water quality in the Florida Keys is presented. Future pollutant loadings and their potential effect on
Sanctuary water quality are presented to the level possible through consideration of the available data.
2.0 HYDROLOGY/PHYSICAL OCEANOGRAPHY
2.1 CURRENTS OF THE WATERS OF THE FLORIDA KEYS
2.1.1 Mean Currents
Current-meter measurements made on the southwest Florida shelf (DOI 1987b) have observed long-term
(multiyear) mean currents flowing southward down Florida Bay along local isobaths (Figure 2-1). Currents
then turn westward along the north coast of the Keys, consistent with earlier hydrographic observations
(Wennekens 1959), before flowing south through the passages between Key West and the Dry Tortugas, and
then toward the east along the south coast of the keys. The mean velocities of near-surface and near-bottom
currents were observed between 1 and 3 cm/s nearshore and between 3 and 10 cm/s offshore. Along the south
coast of the Keys, a mean westward current has been observed associated with a countercurrent in the nearshore
waters of the western Keys (Brooks and Niiler 1975). For the northern Keys, no observations of long-term
patterns in current flow (e.g., mean flows) could be found in the literature. However, short-term observations
of northward-moving eddies spun off shoreward by the Florida Current (Lee 1975) suggest mean nearshore
currents flowing northward along the northern Keys.
Although mean currents give an indication of the continuous net transport of water masses, the transport of
bottom sediments is more complex. To initiate motion of bottom sediments, the near-bottom fluid velocity must
exceed a certain threshold that is dependent upon the sediment size, cohesiveness, and the presence of bedforms.
Under normal conditions, near-bottom mean currents may not exceed this threshold. However, currents
associated with episodic events such as large storms, powerful eddies shed by the Florida or Loop Currents, or
orbital velocities under large waves, may be strong enough to initiate sediment motion. An indication of the
likelihood of sediment resuspension by mean currents is available (e.g., by statistics of velocity exceedence
levels from near-bottom current meters). Measurements reported by the Department of the Interior (DOI
1987b) indicate that mean near-bottom currents measured in shallow waters (13 m depth) of Florida Bay
exceeded 20 cm/s only 14% of the time for the period December 1983 through October 1985. Near-bottom
velocities of 20 cm/s are generally considered sufficient to initiate the suspension of fine sediments. It should
also be noted that these values are hourly average velocities and do not represent wave velocities. Similar
statistics are not available for the south coast of the Keys.
2-1
-------
Figure 2-1. Bathymetry (fathoms) of the Straits of Florida [From Wennekens 1959]
and the general pattern of mean currents measured on the U.S. continental shelf.
2-2
-------
2.1.2 Tides
Tides of the south Florida shelf are driven by mixed diurnal (daily) and semidiurnal (twice daily) constituents,
exhibiting two high tides of unequal heights per day. Tidal exchange between Florida Bay and the Atlantic
Ocean is limited by the Florida Keys. The shallow inner shelf waters (<10 m depth) adjacent to shore are
dominated by the tidal currents (DOI 1987a). Tidal velocities range between 5 and IS cm/s on the shallow
shelf, but where tidal flows are channeled by the Keys, velocities are much greater and may reach 130 cm/s
(Enos 1977). Such velocities are great enough to cause substantial tidal flushing and sediment transport. Tidal
ranges and average maximum flood and ebb tides for selected locations are given in Table 2-1.
Although tidal currents are oscillatory, residual currents and net transport result from energy dissipation due to
bottom friction amplified by coastal bathymetry. On the shallow shelf south of the Keys, a net westward
residual has been measured (Enos 1977), although this may be associated with the countercurrent rather than
being tidally induced.
2.1.3 Wind-Driven Currents
The persistent trade winds of the Caribbean contribute a significant amount of energy to the water column in the
form of surface shear, resulting in large surface waves and wind-induced currents. The prevailing direction of
the tradewinds is from the northeast in the fall and winter and from the east in spring and summer, the latter of
which occurs as the Bermuda high shifts to a more northeasterly position (DOD 1983; Weber and Blanton
1980). Direct evidence of wind-forced currents in Florida Bay is seen in current-meter measurements reported
by the DOI (1987b). These showed significant statistical coherence between wind and current measurements in
the 3- to 6-day band. The highest coherence was observed in the shallow waters of the midshelf (10 to SO m).
On the east coast of the U.S. South Atlantic, the DOI (1984) reports that the midshelf of the South Atlantic
Bight is dominated by wind forcing. High correlations were observed between measured wind events and
currents in the 2- to 14-day period band.
In addition to an along-shore current, along-shore winds may set up a weaker cross-shore circulation. An
easterly wind blowing to the west along an east—west coast such as the south coast of the Florida Keys causes
an onshore movement of water in the near-surface layer. This onshore movement of near-surface water is due
to the earth's rotation; a comparable offshore movement of water occurs in the near-bottom layer, resulting in
downwelling of coastal water. Westerly winds (directed toward the east) will result in offshore movement of
the near-surface layer and upwelling of nutrient-rich deeper water. The strong east-to-west tradewinds of the
Florida Keys region result in the downwelling of near coastal water along the coast bordering the Straits of
Florida and an exchange of water with the Florida Current, which may have a significant effect on coastal water
quality. A schematic diagram of this response is shown in Figure 2-2. This effect is most pronounced during
periods of strong winds.
Hurricanes and tropical storms visit this region occasionally, and the associated high winds can result in large
increases in current speed throughout the water column. During Tropical Storm Bob, in November 1985, the
average near-bottom current speeds measured in Florida Bay showed over a fivefold increase for a period of 2
to 3 days (DOI 1987a). Bob was a moderate tropical storm with sustained winds of only 40 kn. The
temperature record from the same current meter showed a 3 °C change over the same period, indicating a large
water mass exchange, significant movement of shelf water, and possible upwelling.
2-3
-------
Table 2-1. Tidal ranges and average maximum flood and ebb tidal currents
for selected locations.
Location
Mean Average Flood Average Ebb
Tidal Maximum Direction Maximum Direction
Range Flood Ebb
(cm) (cm/s) (cm/s)
Key Largo (Garden Cove)
Pumpkin Key
Long Key Viaduct
Duck Key
Grassy Key (north side)
Flamingo Key
Fat Deer Key
Vaca Key
Sombrero Key
Knight Key Channel
Pigeon Key (south side)
Molasses Key
Bahia Honda Key (bridge)
No Name Key
Big Spanish Key
Cudjoe Key
Bird Key
Sand Key
Key West (Northwest Channel)
Gordon Key, Dry Tortugas
Channel Key
85
25
77
87
65
78
45
59
61
28
43
40
49
28
105
40
30
47
53
45
35
50
349a
60
170°
70
40
004°
312°
110
50
182°
142°
60
353°
70
162s
2-4
-------
N>
u,
Westward Along Shell Winds
0
Air 0
E 100 -
150 -
200
0
Outer ;
Shelf ••;
Figure 2-2. Schematic representation of shelf-water response to along-shore wind on the south coast of the Florida Keys.
[Adapted from DOT 1984]
-------
2.2 SURFACE WAVES
As suggested previously, oscillatory currents due to surface waves can penetrate to the bottom in shallow water,
and sediments (e.g., contaminated sediments) can be resuspended into the water column. This will affect water
quality by the simple process of mixing. Contaminated sediments, mobilized into the water column by wave
action, can be transported as resuspended particulates to other locales by mean currents. Typically, these mean
currents are otherwise too weak to initiate sediment resuspension alone. It is important to note that the transport
of sediments is most efficiently achieved, and most common, when waves as well as currents are present.
Orbital, to-and-fro wave motions are present under all surface waves. These motions vary with wave height.
They are strongest near the surface and weaker with increasing depth. Such wave motions result in little or no
net motion since the orbits are nearly closed. In the shallow waters near the coast, these orbital motions affect
the bottom and can provide enough energy to resuspend bottom sediments, but do not transport the sediments.
However, once suspended off the bottom, these sediments are free to be transported by any mean current.
The persistent trade winds of the Caribbean induce large waves. The prevailing direction of waves in the region
follows the prevailing wind directions, from the northeast in fall and winter and from east in spring and summer
(Jones et al. 1973). Data from offshore buoys maintained by the National Data Buoy Center, National Weather
Service, report mean monthly wave heights from 0.6 to 1.5 m for Florida Bay (DOI 1986). The highest waves
were recorded during the winter months when waves exceeded 1.5 m 51% of the time and 2.5 m 13% of the
time. As offshore waves move landward, they lose energy as a result to their interaction with the bottom. An
offshore wave with a wave height of 0.6 m (mean monthly value) and a period of 7 s will result in orbital
bottom velocities of 10 cm/s at 20-m water depths and 21 cm/s at 10-m depths. When the mean wave height
increases to 1.5 m and the period increases to 10 s, orbital bottom velocities reach 38 cm/s at 20-m and 64 cm/s
at 10-m water depths. These are monthly mean values and contrast notably with the 14% exceedence of 20
cm/s for the mean current velocities presented earlier. Inshore stations in the lee of land masses report reduced
wave heights (DOI 1987b). Despite this, the wave climate of the region will commonly penetrate to the bottom
and resuspend bottom sediments in shallow waters.
2.3 PROCESS CHARACTERIZATION
Available data from studies in the Florida Bay and the Straits of Florida show that the circulation of the Florida
Keys region is affected by several factors, including tidal currents, wind forcing, and the effects of the nearby
Florida and Loop Currents. These processes, which are addressed individually in Sections 2.1 and 2.2, may, at
times, act alone, but more typically they act in concert in a complex interrelationship that makes it difficult to
predict circulation patterns. However, it is possible to characterize these processes by considering separately
the regions of the continental shelf where different processes tend to dominate. A schematic characterization of
the shelf is presented in Figure 2-3.
On the inner shelf (<10 m water depth), the effects of the Florida Current (including related eddies or
countercurrents) are not present. Nearshore circulation and the exchange and transport of water masses are
dominated by tidal currents and atmospheric forcing (Lee 1985). In a study of the Key Largo Coral Reef
Marine Sanctuary, Lee (1985) found that approximately 80% of the cross-shelf variance and 50% of the along-
shelf variance on the inner shelf was due to tidal forcing, and that the remaining variance was due largely to
wind forcing. Although present everywhere across the shelf, tidal currents of the inner shelf are amplified by
shallow water and narrow channels around and between the Keys. Although the tidal currents can be quite
strong, the net transport is small because tidal currents are, oscillatory and net transport depends on weak tidal
residual currents. At the same time, sediment transport is most significant owing to the shallow nature of the
region. Wave velocities penetrate to the bottom, where they can suspend bottom sediments. The midshelf (20-
to 50-m water depths) is generally dominated by the effects of wind forcing, although in the western Keys, an
east-to-west countercurrent is also present. Currents on the midshelf show variability over a 2- to 10-day band,
2-6
-------
Wave Induced
Sediment Transport
E 100 -
150 -
200
Figure 2-3. Schematic representation of continental shelf processes and the Florida Current.
[Adapted from DOI 1984]
-------
roughly equivalent to the major periods of meteorological variability. In the midshelf, sediment transport is still
common because the moderate depths still allow considerable wave-induced currents
near the bottom. In Florida Bay, the midshelf is as much as 100 km wide; weak westward mean currents
flowing along the north side of the Keys are driven by regional circulation. The outer shelf (SO- to 100-m water
depths) is typically the interface between either the midshelf waters and the energetic Florida Current to the
south or the Loop Current to the west and north. Within this region, eddies and filaments shed by the major
currents can episodically increase transport processes. Beyond the 100-m isobath lies the continental slope, with
overlying waters under the direct influence of the Florida or Loop Currents.
The most important physical processes for the region from the viewpoint of water quality may be episodic
events such as hurricanes, tropical storms, and the shoreward incursion of energetic eddies and filaments
associated with the Florida or Loop Currents. Although infrequent, these processes may have a significant
effect, as they may produce large increases in current velocities throughout the water column, and result in
large-scale water-mass exchange and sediment transport. Unfortunately, few measurements of currents (and
measurements of sediment transport) have been made during severe storms. The anecdotal evidence suggests
their importance, but the available data are too sparse to quantify their 'climatological effect. A numerical
modeling study of the Keys using storm surge models including wave-current interaction may provide good
estimates of the importance of storms in water mass exchange, but that is beyond the scope of this study.
3.0 SOURCES AFFECTING WATER QUALITY IN THE SANCTUARY
3.1 POINT SOURCES
3.1.1 Definition
For the purposes of this study, point-source dischargers are defined as those facilities that discharge effluent
directly to surface waters. Important types of potential point-source dischargers include wastewater treatment
plants, water supply treatment plants, industrial facilities, and power plants.
3.1.2 Background
The Federal Water Pollution Control Act, also known as the Clean Water Act (CWA), requires that a Federal
permit be issued whenever pollutants are discharged into navigable waters from a point source (Basta et al.
1985). Therefore, all point-source dischargers must receive National Pollutant Discharge Elimination System
(NPDES) permits from the Environmental Protection Agency (EPA) in order to operate their facilities. Most
also receive permits from the Florida Department of Environmental Regulation (FDER). The FDER's
responsibility has been defined in Section 403.011, Florida Statutes, the "Florida Air and Water Pollution
Control Act."
The number of facilities discharging into surface waters has steadily decreased over the years. According to
EPA data (1991a), 71 NPDES permits have been issued in Monroe County since 1974. At the start of 1991,
there were 36 facilities operating with NPDES permits. As of January 1992, there were only 17 facilities with
permits. This attrition is attributable partially to the more stringent FDER water quality standards recently
adopted by the State (G. Rios, FDER, personal communication, 1991). The dischargers that have discontinued
releasing effluent into a receiving water body have either received permits from FDER to discharge their
effluent into injection wells (i.e., boreholes) or into on-site septic systems (G. Rios, FDER, personal
communication, 1991). Others were deactivated because the permittees closed their businesses (G. Rios,
FDER, personal communication, 1991). Several entities maintain NPDES permits for emergency purposes only
2-8
-------
(e.g., Fleming Key Animal Import Center). As of January 1992, only 13 of 17 facilities were still actively
discharging their effluent into one of the many receiving water bodies in the Florida Keys. Of those remaining,
several are planning to eliminate surface-water discharge by connecting to an existing treatment facility [Sigsbee
Park to Key West Sewage Treatment Plant (STP) (Solin 1991)] or discharge via injection wells or on-site septic
systems (G. Rios, FDER, personal communication, 1991). There is a single facility in Dade County (Florida
Power and Light) with an NPDES permit for discharging into surface waters of the FKNMS.
3.1.3 Types of Facilities
Domestic wastewater treatment facilities account for the largest number of active dischargers in the region (i.e.,
10). These include a campground, Florida Keys Community College, and municipal waste treatment plants
(i.e., Key West, Key Colony Beach). Five facilities are Federal installations and they discharge wastewater
daily. The remaining actively .discharging facilities include two industrial dischargers. They are the Key West
Steam Power Plant and the Ocean Reef Club, a large residential development in North Key Largo that operates
a desalination plant. There is also a single permit for stonnwater runoff from a Federal facility.
Figure 2-4 graphically locates all 17 facilities. Tables 2-2 and 2-3 list each facility and provide detailed
information pertaining to daily flow rates and the characteristics of individual discharges.
3.1.4 Size of Facilities
Table 2-4 summarizes the wastewater facility discharges. All but one of the wastewater facilities are considered
to be minor dischargers with volumes of less than five million gallons per day (MGD). The only major
discharger is the Key West STP. It has a design capacity of 10 MGD and discharges into the Atlantic Ocean
(Solin 1991). According to the City of Key West's contract engineering firm, CH2M Hill, average annual
discharge flow between March 1988 and February 1989 was 5.82 MGD. The maximum .daily flow was 7.22
MGD, which occurred during peak season. The Key West facility is subject to a considerable amount of
infiltration/inflow, both from the city's collection system as well as the Navy's collection system. The sewage
that flows to the Key West facility is composed of infiltration/inflow (36%), residential (32%), and commercial
(32%) (Solin 1991). The largest of the remaining wastewater facilities is the City of Key Colony Beach, with a
0.2-MGD design capacity and average daily flow of 0.17 MGD. The plant discharges to Bonefish Bay (EPA
199Ib). The remaining have a total combined flow of 1.02 MGD. Two facilities are industrial dischargers.
Key West Utility (Stock Island Steam) uses seawater for cooling. The average daily discharge from this facility
was 21.4 MGD for the first 8 months of 1991 (EPA 1991b). The second facility is a desalinization unit at
Ocean Reef Club. The average daily discharge from this facility was 0.39 MGD for the first 6 months of 1991
(EPA 199 Ib).
3.1.5 Location of Facilities
In general, most point-source discharge facilities are scattered throughout the Keys. The Key West area
represents the lone exception to this general tendency. Nearly half of the active point sources in the region are
located in Key West. A number of these facilities are military-related. The one major wastewater plant in the
Keys, the Key West STP, is located on Fleming Key, adjacent to Key West.
2-9
-------
Table 2-2. Inventory of NPDES point-source permits, January 1992.
Fig.
2-4
ro#
215
216
201
165
177
211
199
210
113
66
212
176
7
to
i 205
° 213
15
214
Facility Name
FL Keys Aqueduct — Long Key
FL Keys Aqueduct — Ramrod Key
FL Keys Community College
Key Colony Beach STP
Key West STP
Key West Util-Stock Isl Steam
Monroe Cnty Pub Ser Bldg
Ocean Reef Club
USCG Islamorada Station
USCG Marathon siation
USDA Animal Import Center
USDA FWS Key Deer NWR
USN Boca Chica STP
USN Sigsbee Park STP
USN NAS Key West
Venture Out in Am-Cudjoe Key
FP&L Turkey Crk Pt Power Plant
NPDES #
(EPA)
FL0035467
FL0035459
FL0033928
FL0021253
FL0025976
FL0002089
FL0030562
FL0025607
FL0025763
FL0021709
FL0033359
FL0029688
FL0020982
FL0020991
FL0001716
FL0034924
FL0001562
GMS#
(FDER)
_
—
5244S03349
5244M03028
5244M06172
5244M02019
5244C02855
5244P02472
5244F00025
5244F00026
5244F02036
—
5244F00020
5244F00021
-.
5244P03339
—
Latitude
Not available
Not available
24°34'50"N
24843'30"N
24°32'47"N
24°33'49"N
24°34'20"N
24°54'51"N
24°57'12"N
24a42'38"N
24635'05"N
24°40'00"N
24°35'14"N
24°35'56"N
Not available
24°39'27"N
Not available
Longitude
81°44'40"W
81°Ori8"W
81°47'54"W
81°44'03"W
81°44'59"W
80838'00"W
80°35'10"W
81°06'24"W
81847'47"W
81°20'00"W
81°41'46"W
81°46'35"W
81°28'22"W
Type of
Facility
I
I
D
D
D
I
D
I
F
F
I
F
F
F
F
D<
I
Receiving
Water
Atlantic Ocean
Atlantic Ocean
Gulf of Mexico
Bonefish Bay
Atlantic Ocean
Atlantic Ocean
Cow Key Channel
Atlantic Ocean
Florida Bay
Unknown
Gulf of Mexico
Gulf of Mexico
Gulf of Mexico
Gulf of Mexico
Gulf of Mexico
Kemp Channel
Biscayne Bay
Sources: EPA 1991a,b; FDER 1991b; CH2M Hill 1979; G. Rios, FDER, personal communication, 1991; M. Robertson, M. Donahue, and R. Phelps, EPA,
personal communication, 1991.
D: Domestic.
I: Industrial.
F: Federal.
-------
Table 2-3. NPDES point-source flow and constituent data, January 1992.
Fig.
2-4
215
216
201
165
177
211
199
210
113
66
212
176
7
205
213
15
214
Facility Name
FL Keys Aqueduct — Long Key
FL Keys Aqueduct — Ramrod Key
FL Keys Community College
Key Colony Beach STP
Key West STP
Key West Util-Stock Isl Steam
Monroe Cnty Pub Ser Bldg
Ocean Reef Club
USCG Islamorada Station
USCG Marathon Station
USDA Animal Import Center
USDA FWS Key Deer NWR
USN Boca Chica STP
USN Sigsbee Park STP
USN NAS Key West
Venture Out in Am-Cudjoe Key
FP&L Turkey Crk Pt Power Plant
Range of Range of
Max. Daily Daily Flow
Flow
(MOD) (MOD)
Range of
BOD
(mg/L)
Range of
pH
Range of
TSS
(mg/L)
Discharge Monitoring Report indicates not in operation
Discharge Monitoring Report indicates not in operation
0.003-0.007 0.002-0.007
0.2247-0.4990 0.135-0.195
9.06-9.41 5.585-7.546
14.83-36.00 14.83-36.00
0.003-0.008 0.002-0.003
0.666-0.752 0.287-0.411
0.003-0.0035 0.001-0.002
0.0027-0.0067 0.001-0.005
Only an emergency discharge point; has never
EPA discharge monitoring report not available
0.127-0.516 0.0115-0.99
0.787-1.040 0.713-0.793
Stormwater runoff permit for a fuel tank farm
0.029-0.062 0.020-0.054
Only for emergency discharge
0.0-15.0
2.0-11.0
5.0-13.0
No data reported
2.0-12.0
0.1-1.05'
1.0-3.0
4.0-13.0
been used
; discharge minor
3.3-8.1
7.4-12.7
6.0-7.5
6.8-6.9
6.8-7.2
6.9-7.0
6.9-7.2
7.3-7.7
7.0
6.9-7.2
6.7-7.3
7.2-7.3
6.0-7.5
0-15
3-6
4-8
1-12
1-12
2-4
3-12
2-6
8^1
3-24
Total phosphorus
Sources: EPA 1991a,b; FDER 199Ib; CH2M Hill 1979; R.J. Helbling, FDER, personal communication, 1992; G. Rios, FDER, personal communication,
1991; M. Robertson, M. Donahue and R. Phelps, personal communication, 1991.
MGD: Million gallons per day
BOD: Biological oxygen demand ,
TSS: Total suspended solids
-------
Table 2-4. Sanitary wastewater facility discharges.
Facility Name Average Daily Flow
(MGD)
Florida Keys Community College0 0.00600
Key Colony Beach STP* 0.17475
Key West STPC 5.82000
Monroe Cnty Pub Ser Bldgc 0.00200
USCG - Islamorada" 0.00186
USCG - Marathonb 0.00229
USDA FWS Key Deer NWR No data available
USN Boca Chica SIP* 0.13090
USN Sigsbee Park STP1 0.75383
Venture Out in Am-Cudjoe Keyb 0.03271
TOTAL: 6.92434
MGD: Million gallons per day
•FDER 199 Ic.
bKeith and Schnars, unpublished data 1991.
cSolin 1991.
2-12
-------
K>
Figure 2-4. Wastewater treatment facilities and discharge canals.
This Figure and its 13 components, which follow, indicate the geographic locations of the discharge canals (Turkey Point Cooling Canal, Model Land Canal, and C-lll Canal), the sanitary
wastewaler facilities that discharge via injection wells (indicated on the maps by O) or surface waters (NPDES; indicated on the maps by O), and other surface-water (NPDES) dischargers (indi-
cated on the maps by A). Numbers associated with NPDES facilities and sanitary wastewater correspond to the numbers in Tables 2-2 and 2-5, respectively. Locations of sanitary wastewaler
facilities compiled for the unincorporated Monroe County and City of Key West by Keith and Schnars (unpublished data 1991) and Solin (1991). Base maps redrawn from maps provided by
Wallace Roberts & Todd.
-------
Florida
Turkey Point
Cooling Canal
Discharge
Atlantic Oc»«n
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-4-1. Wastewater treatment facilities and discharge canals, (continued)
2-14
-------
V A
,;•.' .;>, Little Bl«ckw«t«f Sound f.
Atlantic Ocean
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION
OF THE EVERGLADES NATIONAL PARK.
Figure 2-4-2. Wastewater treatment facilities and discharge canals, (continued)
2-15
-------
"i-.A
t\ 7*
Florida Bay
1
s.? •$
'/•• • •'.•"'^.
Atlantic Oc««n
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-4-3. Wastewater treatment facilities and discharge canals, (continued)
2-16
-------
w
Florida Bay
'"• '¥•:•'.• •:'•#'•»''
Atlantic Ocean
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-4-4. Wastewater treatment facilities and discharge canals, (continued)
2-17
-------
Florida Bay
Honda Keys National
Marine Sanctuary
LignurmHa* Batln
Hawk Channel
Atlantic Oc*«n
NOTE. DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-4-5. Wastewater treatment facilities and discharge canals, (continued)
2-18
-------
Gulf of Mexico
Florida Bay
Hawk Ch»nn*l
Craig K«y
Atlantic Oc*an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-4-6. Wastewater treatment facilities and discharge canals, (continued)
2-19
-------
Gulf of Mexico
Duck Key
Hawk Chanrwl
Atlantic Ocaan
Figure 2-4-7. Wastewater treatment facilities and discharge canals, (continued)
2-20
-------
Gutf of Mexico
Pigeon
H«wV Chanrxl
Atlantic Ocean
Figure 2-4-8. Wastewater treatment facilities and discharge canals, (continued)
2-21
-------
Gulf of Mexico
No Name ^
Key ' •3
Bahla Honda Key
Spanish
Harbor
Keys
Little Duck Key
B.N. Hond. st... p.rv
Qhlo Key Key
AUantic Ocean
Figure 2-4-9. Wastewater treatment facilities and discharge canals, (continued)
2-22
-------
Atlantic Ocean
Figure 2-4-10. Wastewater treatment facilities and discharge canals, (continued)
2-23
-------
Gulf of Mexico
Saddlebunch Key*
Aflan tic Ocean
Figure 2-4-11. Wastewater treatment facilities and discharge canals, (continued)
2-24
-------
Gulf of Mexico
°e*o
Wonz K«y Baiin
G?
e>
Atlantic Oc«an
Figure 2-4-12. Wastewater treatment facilities and discharge canals, (continued)
2-25
-------
Gulf of Mexico
Fleming
Key
Atlantic Oc««n
Figure 2-4-13. Wastewater treatment facilities and discharge canals, (continued)
2-26
-------
3.1.6 Water Quality Monitoring
All point-source discharge facilities that receive operating permits from EPA or FDER are required to submit
monthly discharge monitoring reports. These reports monitor various water quality parameters such as
biochemical oxygen demand (BOD}), pH, and total suspended solids (TSS). Based on a review of the available
permit information from both agencies, these three parameters are reported most frequently; however, others
include dissolved oxygen (DO), chlorine (total residual), and fecal coliform. No permittee is required to
monitor for nutrients.
While the Key West STP presently operates under a discharge permit that does not require the monitoring of
nutrients, the City's engineering consultant has been recording nutrient measurements of the influent and
effluent. The average effluent concentrations for NH3-N, NO3-N, and PO<-P for 1990 were 2.0, 1.8, and 2.49
mg/L, respectively (Solin 1991).
3.1.7 Canals
The South Florida Water Management District (SFWMD) operates two canals that discharge into Sanctuary
waters, and are considered point sources to the Sanctuary. Both canals, C-lll and the Model Land Canal,
discharge into the northern area of the Sanctuary (Figure 2-4-1 and 2-4-2). The C-lll canal discharges into
Manatee Bay (Barnes Sound) west of Key Largo (SFWMD 1990). In August 1988, an earthen plug was
removed that allowed discharge of freshwater into Manatee Bay. For 8 days, approximately 2500 fiVs of
freshwater was discharged (Haunert 1988). Flow after this initial period was reduced to 600 fWs.
The SFWMD (1990) reported phosphorus and nitrogen levels within the C-lll canal for August 1985 to August
1987. Total phosphorus concentrations during this period ranged from 0.004 to 0.015 mg/L. Inorganic
nitrogen (nitrate plus nitrite plus ammonium) concentrations ranged from 0 to 0.45 mg/L.
The Model Land Canal has a connection to Card Sound (R. Alleman, SFWMD, personal communication,
1991). This connection consists of a length of canal that terminates at a culvert. Alleman (R. Alleman,
SFWMD, personal communication, 1991) stated that there are no extant water quality data for this canal.
3.2 NONPOINT SOURCES
3.2.1 Definition
For the purposes of this study, nonpoint sources are defined as those discharges that are not made directly to
surface waters. Such discharges would include all those made into the groundwater and stormwater runoff
flow.
2-27
-------
3.2.2 Groundwater Inputs
3.2.2.1 GEOLOGY, HYDROGEOLOGY, AND AQUIFERS
It is important to describe the geology, hydrogeology, and aquifers of the Florida Keys prior to describing the
inputs to the groundwater. A general discussion of these topics is provided in the following sections.
3.2.2.1.1 Geology and Hydrogeology
The principal geologic formations of interest in the region include the undifferentiated sand deposits of
Pleistocene to Recent Age, including the Pleistocene Age Miami Oolite Limestone and Key Largo Limestone;
Ft. Thompson Formation; and the Anastasia Formation (Figure 2-5).
The undifferentiated sands found in the Florida Keys can be classified as one of two types. The first and most
abundant type is the Pamlico Sand Formation, which has been described as very fine- to coarse-grained
permeable quartz sands, typically either black to white or red in color. These sands were deposited during
Pleistocene sea-level changes that occurred in response to global glacial activity. The second type of
undifferentiated sand, deposited in more recent times (postglacially), is described as calcareous beach sands with
lesser amounts of coral and shell fragments, white to cream in color. The areal distribution and thickness of
these undifferentiated sands varies widely throughout the Florida Keys. The most common terrestrial
occurrence of these sands in the Florida Keys is as sand dunes and old beach ridges. These same calcareous
beach sands form extensive offshore deposits along the Keys and in the Marquesas Quicksands area (Shinn et al.
1990).'
Formed as a shoal deposit in warm shallow seas, the Miami Oolite Limestone is a soft, yellow to white,
stratified to massive, cross-bedded limestone formation. The term oolite or "ooid" refers to spherical and
concentric ovules of calcite. These minute concretionary bodies, which average about 1 mm in diameter, are
distributed randomly throughout the Miami Oolite Limestone matrix. Miami Limestone is currently divided into
three distinct facies: the bryozoan facies; the bedded facies; and the mottled facies (Evans 1982). The bedded
and mottled facies are confined to the topographic high of the Atlantic Coastal Ridge, but the bryozoan facies
does not, as previously reported, underlie the Atlantic Coastal Ridge (Evans 1983). The bryozoan facies is
confined to the low lying area to the west of this ridge. This is an important point because it means that the
portion of the Miami Limestone that was an active ooid system (the Atlantic Coastal Ridge) originated and grew
in place; it did not migrate backward over the platform interior of bryozoan deposits. The bryozoan facies were
deposited as a direct result of the growth of the ooid system forming a bathymetric high to shelter them from
the open ocean (Halley and Evans 1983).
Recent shallow-water marine carbonate sediments are composed largely of metastable carbonate materials such
as aragonite and a variety of calcite containing more than 4% MgCO., (high-magnesium calcite). Such
sediments have a very high porosity, typically 45 to 50% for carbonate sands and 70 to 80% for carbonate
muds. Ancient carbonate rocks are composed of calcite and dolomite and show very low porosity. Miami
Limestone represents a geologic unit in transition; it is moving from modem sedimentary rock formations to
ancient limestone. Evans (1982) generated an average porosity of 45 % for Miami Limestone. The average
porosity volume within the Miami Limestone has not changed much from that of unconsolidated ooid sand. The
mineralogy has stabilized, but the rock has not begun to acquire the low porosity typical of ancient carbonate
rocks. As evidenced at several locations in south Dade County, karst development and internal dissolution are
actually increasing pore size within exposed sections of this formation. Although the mineralogical trends of the
Miami Limestone are leading toward a composition typical of ancient carbonate rock, the porosity trends are
2-28
-------
SOUTHEAST FLORIDA MAINLAND
P«rtdn»
1977
OS
03
02
Sartord
IMS
Miami
Dome
Hoflmeltter •< *.
1987
Miami
U
oolitic
laowt
bryozoan
fades
Mitchell-Tapping
1980
Fort Dallas
Oolite
Evam
1062
Miami Unwttont
B I C
lltholegy
GREAT
BAHAMA
BANK
Beach & Ginsburg
- I860
Lucayan
Limetton*
S
ft
£
2
FLORIDA KEYS
Sanlord
1909
Key West
Oolite
OOUTE
Cooka & Monum
I 19JB
Miami
Oolite
KEYS
HotlmeMer « a/.
1967
Miami
Limestone
Mitchell-Tapping
2
E
3
1960
Key Wesl
Oolite
CORAL KEYS
Sanlord
1909
Key Largo
Limestone
•
Parker & Cooke
1944
Key Largo
Limestone
Hoffmeisler
& Mutter 1964
£
£
1
coralline
lacies
oalcarenite
& caldlutile
lades
Figure 2-5. Stratigraphic nomenclature for the late Pleistocene of peninsular Florida [Evans 1982].
[Adapted from Halley and Evans 1983].
2-29
-------
not. This indicates that significant loss in the porosity of South Florida carbonates does not occur until
carbonate rocks are carried into the subsurface by continued subsidence and sedimentation (Halley and Evans
1983).
Preferential weathering of the ooids within the Miami Limestone creates voids or pore spaces that are commonly
replaced (filled) with deposits of very fine to medium quartz sands. The majority of these "secondary" deposits
have been described as sands from the Pamlico Group.
The Miami Limestone is a very cohesive formation. Consequently, the Miami Limestone does not possess
excessively high values with regard to transmissivity and hydraulic conductivity. Two factors that influence the
hydraulic characteristics of the Miami Limestone are (1) a large degree of porosity that is due to the preferential
weathering of the ooids characterizing this formation and (2) the lack of interconnection between solutional or
structural "pipelines" and the resulting restrictions on the horizontal intrinsic permeability (hydraulic
conductivity) that inhibits the lateral (horizontal) flow of fluids.
The Miami Limestone formation, which ranges between 6 and 12 m in thickness, can be found at land surface
from Big Pine Key to Key West, Florida, and is regarded as an offshore extension of the same formation found
in southeast Florida (i.e., within Collier, Broward, Dade, and Monroe Counties). It overlies the Key Largo
Limestone in this area.
The Key Largo Limestone is a complex carbonate unit that characterizes the depositional environment of an
ancient coral "back reeP area. It is described as a white to cream, compact to soft, cavernous coralline reef
rock. It is composed of reef building corals, amorphous limestones, shell fragments, and detritus from wastage
of the reef. A high degree of porosity and permeability characterize this formation, attributed to the
depositional environment from which it was formed. An abundance of solution cavities, which typically are
located between relict coral heads, allows the water to move freely in and out of this formation. It is a very
dispersive medium, conducive to the vertical and horizontal movement of water. Areas consisting of relict coral
heads have lower transmissivity and hydraulic conductivity values than do those areas immediately adjacent to
the coral heads. As described previously, adjacent areas consist of reef wastage such as clastic sediments and
shell fragments. These porous "zones" have, through the course of time, been exposed or subjected to
preferential chemical and physical weathering because of their poor structural integrity and lack of internal
cohesiveness (lithification). These areas have consequently become cavernous zones or pathways susceptible to
the transport of fluids, because they provide a route of least resistance by their higher transmissivity and
hydraulic conductivity values.
The Key Largo Limestone is found at land surface in the Florida Keys from Soldier Key (off Miami) to Bahia
Honda. Averaging approximately 18 m in thickness in the Florida Keys, it is recognized as an offshore
extension of the same formation that underlies southeast Florida.
The Key Largo Limestone possesses a higher degree of transmissivity and hydraulic conductivity than the
Miami Limestone. While the Miami Limestone is a fairly permeable and porous limestone, the absence of
interconnecting pore spaces reduces its effective transmissivity and hydraulic conductivity by several orders of
magnitude. However, the Miami Limestone's vertical hydraulic conductivity component is comparable to that
of the Key Largo Limestone.
Although the Miami Oolite and Key Largo Limestones can be differentiated based solely on their lithologic
structure, basic morphology, and fossil assemblages, Hoffmeister (1974) and others have demonstrated through
extensive field work that the Miami Oolite and Key Largo Limestones formed contemporaneously. Geologic
cross sections developed from drilling cores display zones where the Miami Oolite and Key Largo Limestones
"interfinger" or overlap numerous times. The transitions are not abrupt, which suggests that the transformation
from one formation to another was gradational in its response to a changing marine environment. The coral
reef environment in which these sediments were deposited may have shifted in response to any number of
reasons or causes.
2-30
-------
The Pleistocene limestone (Miami Oolite and Key Largo) of the Florida Keys ranges from 30 m thick in the
upper Keys to more than 60 m thick in the lower Keys (Perkins 1977). The porosity of the limestone ranges
from 35 to 50% and the permeability is very high (E. Shinn, United States Geological Survey Center for
Coastal Geology, personal communication, 1992). There are five distinct subaerial unconformaties or exposure
surfaces within the formation, with each unconformity representing a period when sea level dropped and
vegetative material accumulated on top of exposed reef platform (Perkins 1977). When this has occurred, the
pores in the upper 0.6 to 1 m of exposed limestone have largely been filled with a calcite material, reducing
their permeability. In addition to this, a calcrete crust (between 1 and 10 cm thick) of very low permeability
has been formed along the surface of these unconformities (Harrison et al. 1984; Shinn and Corcoran 1988).
This indicates that the formation consists of large, highly porous layers of limestone sandwiched between
narrow "aquatards" which prevent the vertical movement of fluids. This complex layering of permeability has
great ramifications in terms of pollutant transport and water quality monitoring. Of the five unconformities, the
thickest and most widespread is the Q3 (Q = Quarternary). It lies approximately 8 to 10 m below the surface
in the Keys (Harrison et al. 1984). Shinn and Corcoran (1988) found leachates from the Dade County landfill
concentrated in the highly permeable zone immediately above this unconformity (approximately 5 m below the
surface), and above the depth to which Dade County's monitoring wells had been drilled.
The Tamiami Formation, which consists of numerous lithologies that are primarily Miocene to Pliocene in age,
underlies the Key Largo Limestone at varying depths along the Florida Keys tract. The Tamiami Formation
grades downward from a poorly hardened limestone and calcareous sand of low permeability into a more highly
permeable sandy, fossiliferous limestone intermixed with coarse Miocene-age clastic sediments.
The Hawthorn Group, which underlies both the Miami Limestone, Key Largo Limestone, and Tamiami
Formation acts as a confining unit that serves to inhibit or reduce the downward migration of fluids. It forms a
boundary between the Surficial and Floridan Aquifer Systems. It is described as highly impermeable, green to
gray in color, consisting of silts, clayey sands, silty sands, and sand. This formation, which extends throughout
all of Florida, averages approximately 60 to 90 m in thickness throughout the Florida Keys area.
3.2.2.1.2 Aquifers
Two principal aquifers underlie Monroe County in the Florida Keys area. They are the Biscayne Aquifer, more
commonly, referred to as the Surficial Aquifer System, and the Floridan Aquifer, which is a confined or artesian
aquifer system.
The primary system of importance in this region is the Biscayne Aquifer, which is an unconfmed aquifer system
because it is under water-table conditions. Aquifers under water-table conditions are free to rise and fall in
direct relation to regional and local recharge mechanisms, such as precipitation, diurnal and seasonal tidal
fluctuations, or discharges to the canal systems, the latter of which constitute groundwater loss. The Biscayne
Aquifer System is regarded as the primary or "sole source aquifer" of potable water throughout most of
southeastern Florida, with the exception of the Florida Keys. It is one of the most productive and permeable
aquifer systems in the world (Parker et al. 1955). Unfortunately, because of its excessive chloride content
within the Florida Keys region, it is designated as a nonpotable water source. Water sources that contain
chloride concentrations greater than 250 mg/L are regarded as impotable waters and unfit for human
consumption. These guidelines are discussed in Florida Chapter 17-3, Florida Administrative Code (FAC).
Consequently, most of the water pumped from the Florida Keys Aquifer System is utilized primarily for
irrigation, cleansing, toilet flushing, and numerous other nonpotable water uses.
The Biscayne Aquifer in the Florida Keys comprises the Miami Limestone, Key Largo Limestone, and Tamiami
formations. The elevation, or mean distance to the surface, of the Biscayne Aquifer closely mimics surface
elevation contours and averages approximately 1 m below surface grade. These elevations vary seasonally in
response to periods of increased and/or declining rainfall amounts, and vary on a daily basis from tidal
2-31
-------
fluctuations, as well as with the seasonal variances that occur. Consequently, the residents of the Florida Keys,
despite their abundant supply of nonpotable water, must receive the bulk of their potable water from the Florida
Keys Aqueduct Authority. The Authority pumps this water from a wellfield located in Dade County at a rate of
18 MOD. It is pumped through 36- to 48-in. culvert pipes to transfer stations were the water is allocated
proportionately to residential, commercial, and industrial facilities.
While the primary water-bearing hydrologic units are presently unsuitable for drinking use by the residents of
the Florida Keys, it should be noted that on some of the larger Keys, with areas of high topographical relief
(i.e., Big Pine Key, Key West, Sugarloaf Key, and Cudjoe Key), there are thin lenses of potable freshwater that
typically average 6 m in thickness. Net volumes of this available freshwater are not sufficient to support the
current consumptive use of residents of the Keys. These lenses of fresh water essentially float or lie atop the
denser, more saline waters. The dimensions of these lenses vary seasonally and depend on pumpage rates and
volumetric discharge for irrigation usages and other related (nonpotable) use activities, natural freshwater losses
(discharge) to the sea across hydraulic gradients, annual recharge rates from rainfall, and evapotranspiration
from indigenous flora. Uses of these freshwater lenses for potable use would quickly deplete the supply and
enhance the encroachment of saltwater into the aquifers.
3.2.2.2 DOMESTIC WASTEWATER FACILITIES
3.2.2.2.1 Overview
Section 403.021(2) of the Florida Statutes, as amended, establishes that no wastes are to be discharged to any
waters of the State without first being given a degree of treatment necessary to protect the beneficial uses of
such water. Responsibility for enforcement was assigned to the FDER. In implementing this section of the
statute, FDER developed and adopted a set of minimum standards for the design of domestic wastewater
facilities and established minimum treatment and disinfection requirements for the operation of domestic
wastewater facilities. Domestic wastewater is defined as "wastewater derived from dwellings, business
buildings, institutions, and the like; . . ." (Rule 17-600, Florida Administrative Code [FAC], January 1, 1991).
3.2.2.2.2 Background
There are 209 wastewater treatment facilities operating in close proximity to the Sanctuary. Of this total, 197
facilities are located in unincorporated Monroe County (Wallace Roberts & Todd et al. 199 la) and 10 others are
located in the City of Key West (Solin 1991). In addition, the City of Key Colony Beach operates a municipal
sewage treatment plant. A package treatment plant serving the Goshen College, Marine Biology Facility, is also
located in the City of Layton. Table 2-5 provides a listing of the facilities. The facilities are also located on
Figure 2-4.
Of the 209 wastewater treatment facilities in the region, 10 discharge their effluent to surface waters. These
point-source discharges are discussed in Section 3.1.3 Types of Facilities. The remaining 199 facilities
discharge into boreholes (injection wells) (Wallace Roberts & Todd et al. 1991a; Solin 1991; FDER 1991b).
2-32
-------
Table 2-5. Wastewater Treatment Facilities.
[From Keith and Schnars, unpublished data, 1991; Solin 1991; FDER 1991a]
Figure
Reference #
1
2 '• .
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Name of Facility
Oceanside Marina
Boyd's Campgrounds
Roy's Mobile Home Park
Coconut Grove Mobile Home Park
Harbor Shores Mobile Home Park
Key Haven Utilities
USNAS (Boca Chica Field)
Seaside Resorts, Inc.
Geiger Key Marina
Lazy Lakes Campground
Sugar Loaf Lodge
Sugar Loaf Elementary School
Sugar Loaf K.O.A.
The Galley Restaurant • "
Venture Out @ Cudjoe Key
Looe Key Reef Resort
Breezy Pine Trailer Park
Big Pine Plaza Shopping Center
Big Pine Motel
Big Pine Key Road Prison
Bahia Honda #3
Bahia Honda #4
Bahia Honda #2
Sunshine Key Travel Park
Hawk's Nest Condo
The Quay Restaurant
Galway Bay Mobile Home Park
Boot Key Marina
Pelican Restaurant
Faro Blanco Resort
Stanley Switlik Elementary School
Hurricane Motor Lodge
Casa Cayo Condo
Coral Lagoon Resort
Fisherman's Hospital
Lady Alexander Condo
Marathon High School
Mid-Town Trailer Park
Monroe County Housing Authority
Schooner Condo's . •-'
Spanish Galleon Condo
Tradewind West Condo
Buccaneer Lodge
Cobia Point Condo
Marathon Key Beach Club
Key
Stock Island
Stock Island
Stock Island
Stock Island
Stock Island
Raccoon
Boca Chica
Big Coppitt
Geiger
Sugar Loaf
Sugar Loaf
Sugar Loaf
Sugar Loaf
Summerland
Suinmerland
Ramrod
Big Pine
Big Pine
Big Pine
Big Pine
Bahia Honda
Bahia Honda
Bahia Honda
Ohio
Knight
Fat Deer
Marathon
Hog
Vaca
Vaca
Vaca
Vaca
Vaca
Fat Deer
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
2-33
-------
Table 2-5. Wastewater Treatment Facilities.
[From Keith and Schnars, unpublished data, 1991; Solin 1991; FDER 199 la] (continued)
Figure
Reference #
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
Name of Facility
Sombrero Beach Village
Days Inn
Gulfside Village Shopping Center
Harbor Club South Condo Association
Harbor House Condo
International House of Pancakes
Island Club Condo
Key Lime Condo (Resort)
Marathon Country Club Condo
Sombrero Resort
Sombrero Ridge Condo
K-Mart Shopping Center
Lucy Apartments
The Reef at Marathon - -
Captain's Quarters Condo
Coral Club Condo
Howard Johnson's
Key RV Park
Marathon Manor Nursing Home
Perry's Restaurant
USCG Station - Marathon
Pizza Hut
Sea Watch Condo
Wendy's Restaurant
Winn-Dixie Plaza
Bonefish Tower
Treasure Cay Condo
Coco Plum Beach Apartments
Royal Plum Condo
Pelican Motel & TP
Jolly Roger Trailer Park
Hawk's Cay Resort
Long Key Ocean Bay Condo
Outdoor Resort's @ Long Key
Long Key State Park #1
Long Key State Park #2
Long Key State Park #3
Fiesta Key KOA
Kingsail Resort
Caloosa Cove Marina /
Sandy Point Condo
Papa Joe's Restaurant
Matecumbe Resort (Indian Key)
Aultman Construction Company
Ocean 80
Key
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca
Vaca.
Vaca
Vaca
Fat Deer
Fat Deer
Fat Deer
Fat Deer
Grassy
Grassy
Duck
Long
Long
Long
Long
Long
Fiesta
Fiesta
L. Matecumbe
L. Matecumbe
U. Matecumbe
L. Matecumbe
Long
Islamorada
2-34
-------
Table 2-5. Wastewater Treatment Facilities.
[From Keith and Schnars, unpublished data, 1991; Solin 1991; FDER 1991a] (continued)
Figure
Reference #
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
Name of Facility
The Palms of Islamorada
Sea Gulls Condo
Breezy Palm Resort Motel
La Siesta Resort
Fisherman's Kettle Restaurant
Goshen College (FIO)
Bay Colony Villas
Woody's Lounge
Cheeca Lodge
Pelican Palm Trailer Park
Caribbean Sunset Inn
Lore Lei Restaurant
Perry's Inn
Beacon Reef Condo
Coral Grill Restaurant
Chesapeake Motel of Whale Harbor
Howard Johnson's
Holiday Isle Resort
Pelican Cove Resort
B.C.'s Sand Bar
Brick's Floating Restaurant
Windley Key Trailer Park
USCG Station - Islamorada
Plantation by the Sea
Plantation Yacht Harbor Resort
Sea Breeze Trailer Park
Executive Bay Club
Consi Harbor Club
Futura Yacht Club
Mariner's Hospital
Summer Sea Condo
Plantation Key Governmental Company
Coral Shores High School
Sunset Acres Mobile Home Park
Plantation Key Elementary School
Turek Enterprise Inc.
Tavernier Towne Shopping Center
Harbor 92 Condo
Silver Shore M.H.P.
Driftwood Travel Trailer, Park
Anchor Condo
Blue Water Trailer Park
Chico Commercial Building
Sunset Hammock Condo
Key Largo Ocean Resort
Key
Islamorada
Islamorada
Islamorada
Islamorada
Islamorada
Long
U. Matecumbe
U. Matecumbe
U. Matecumbe
U. Matecumbe
U. Matecumbe
U. Matecumbe
U. Matecumbe
U. Matecumbe
U; Matecumbe
U. Matecumbe
Windley
Windley
Windley
Windley
Windley
Windley
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Plantation
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
2-35
-------
Table 2-5. Wastewater Treatment Facilities.
[From Keith and Schnars, unpublished data, 1991; Solin 1991; FDER 199la] (continued)
Figure
Reference #
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
Name of Facility
Buttonwood Bay Condb
The Sheraton
Key Largo Yacht & Tennis Club
Harborage Condo Corporation
Rock Harbor Club
American Outdoors Key Largo
KOA Keys Restaurant
Holiday by the Sea Condo
Paradise Point M.H.P.
The Landings of Largo
Kawama Yacht Club
Pizza Hut
Ocean Divers, Inc.
Waldorf Plaza Shopping Center -
Florida Bay Resort STP
Best Wester Suites
Holiday Inn
Leeside Professional Building
Port Largo Villas
Coastal Waterway Trailer Park
Calusa Camp Resort
Glenn's Trailer Park & Campground
Key Largo Campground & Marina
Tradewinds/K-Mart Shopping Center
Coral Reef State Park
Howard Johnson's
Paradise Pub
The Quay Restaurant
Koblick Marine Center
Key Colony Beach STP
Florida Bay Club
Senior Frijoles Restaurant
Italian Fisherman Restaurant
Moonbay Condo
Tamarino Bay Club, Inc.
Key Largo Elementary School
Winn Dixie
Barefoot Key R.V. Resort
Gilbert's Motel & Marina
The Anchorage Resort /
USDA FWS Key Deer NWR
Key West STP
Waters Edge Colony Park
Mangrove Maria's
Casa De Los Tres
Key
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Fat Deer
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Big Pine
Flamingo
Stock Island
Sugarloaf
Vaca
2-36
-------
Table 2-5. Wastewater Treatment Facilities.
[From Keith and Schnars, unpublished data, 1991; Solin 1991; FDER 199la] (continued)
Figure
Reference #
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
Name of Facility
Sombrero Marina & Dockside Lounge
Susan's "Wobbly-Crab" Restaurant
Jim Green Marathon Veterinarian Clinic
Fantasy Harbor Condo
Sand Pebbles
Perry's Seafood Restaurant
Harbor Lights Motel/Holiday Isle
Tropical Reef Resort
Ocean Harbor Condo
North Key Largo Plaza
Lake Surprise Conto II
L'Oasis
Cross Key Marina/Restaurant
Marathon Trailerama
The Sanctuary
Hampton Inn
Martha's Restaurant and Benihana's Restaurant
Key Ambassador Resort
Monroe County Municipal Services Office
Complex
Gerald Adams Elementary School
Florida Keys Community College
Florida Keys Memorial Hospital
Key West Resort Utilities
Scotty's
USN Sigsbee Park STP
Key Largo Marina
Key Largo Anglers Club
S & H Seafood
King Shrimp Company
Key
Vaca
Vaca
Vaca
L. Matecumbe
U. Matecumbe
U. Matecumbe
U. Matecumbe
Windley
Plantation
Key Largo
Key Largo
Key Largo
Cross
Vaca
Key Largo
Key West
Key West
Key West
Stock
Stock
Stock
Stock
Stock
Key West
Dredgers
Key Largo
Key Largo
Stock
Stock
2-37
-------
3.2.2.2.3 Uses
Domestic wastewater facilities are utilized by many different domestic and industrial concerns. Large facilities
such as those located in Key West serve entire communities. However, the smaller facilities, commonly called
"package plants," tailor their services to individual uses, such as by schools, hospitals, restaurants, hotels/
motels, trailer parks, campgrounds, condominiums, resort complexes, and shopping centers. The FDER
maintains a large computerized data and information system known as the Groundwater Management System
(CMS). CMS consists of a number of different databases that contain information on different facility permits
(e.g., injection wells, dredge and fill, domestic wastewater plants, underground storage tanks, landfills). The
FDER (1991b,c) provides detailed information pertaining to domestic wastewater - treatment facilities.
Approximately 25% of all package plants are utilized by condominiums and apartments. An additional 24% of
the plants serve restaurants and motels. Nearly 20 trailer parks and mobile home parks, as well as most resorts
in the Keys, depend upon package plants (FDER 199Ib).
3.2.2.2.4 Injection Wells
Within the Florida Keys, there are many injection well facilities commonly termed "boreholes". They are used
primarily for wastewater effluent disposal, either from one of the many package plants or from aerobic
treatment units used by single family residences. Injection wells are also used as a means to dispose stormwater
drainage, laundry wastewater, or air-conditioning heat pump return-flow, however, very few such facilities exist
(FDER 1992).
Boreholes are permitted by both the FDER, and the Monroe County Health Department functioning under the
auspices of the Florida Department of Health and Rehabilitative Services (FDHRS). According to the FDER
CMS database, as of February 1992, there are 557 active FDER- permitted injection wells in the Keys. An
additional 113 wells are classified as inactive. Of the 226 aerobic plants permitted by the Monroe County
Health Department, 186 discharge their effluent via a borehole. The remaining aerobic plants utilize on-site
absorption beds similar to the on-site sewage treatment (septic tank) systems (C. Williams, Monroe County
Health Department, personal communication, 1992).
Boreholes in the Keys generally range in depth from 18 to 27 m with a casing depth ranging from 9 to 18 m
(FDER 1992). The FDER now requires boreholes to be drilled and cased to a depth of 27 m and 18 m,
respectively.
3.2.2.2.5 Facility Size
FDER Rule 17-600, FAC regulates domestic wastewater facilities. According to the Rule, wastewater facilities
are classified as being one of three types.
• Type I — A wastewater facility having a permitted capacity of 500,000 gallons per day (GPD) or
greater
• Type n — A wastewater facility having a permitted capacity of 100,000 GPD up to, but not
including, 500,000 GPD
• Type III — A wastewater facility having a permitted capacity of over 2000 GPD up to, but not
including, 100,000 GPD
2-38
-------
The Rule sets forth requirements regarding facility design and discharge treatment, with differing requirements
depending upon the classification of the facility (Rule 17-600, 1991).
There is no wastewater facility with a permitted capacity of 500,000 GPD (i.e., Type I) that discharges into a
borehole. The City of Key West STP has a design capacity in excess of 500,000 GPD; however, it discharges
its effluent into the Atlantic Ocean. According to EPA (199la) and the FDER (199Ib), six Type II facilities are
in proximity to the FKNMS, including
Facility Name Method of Discharge
• Key West Resort Borehole
• Key Haven Utilities Borehole
• United States Naval Air Station (Boca Chica) Surface waters
• Landings of Largo Borehole
• Key Colony Beach Surface waters
It is evident that the largest number of dischargers are the small package plants (Type HI), whose design
capacities range from 2000 to 99,999 GPD. In the Florida Keys, the typical size of these plants are in the
range of 10,000 to 20,000 GPD. The few larger facilities, those with an average daily flow of 40,000 to
75,000 GPD, primarily serve various resorts in the Keys.
3.2.2.2.6 Location of Facilities
i
While package plants are found throughout the Keys, the lower Keys have relatively fewer of these facilities
than do the middle and upper Keys. This is attributed to the population size within the City of Key West and
the handling of domestic wastewater treatment through a large, consolidated facility. Although several package
plants handle wastes from individual developments, most of the City is served by the City municipal wastewater
treatment facility.
Areas having significant concentrations of package plants include Marathon, Islamorada, and Key Largo.
Marathon alone contains 49 package plants concentrated in an area approximately 6 mi long. Average daily
flows range between 500 and 18,000 GPD. Most of the facilities are operating between 20% and 40% of
design capacity (Wallace Roberts & Todd et al. 199la). Key Largo has 48 package plants; however, unlike
Marathon, they are not clustered but are distributed along the length of the Key, which is approximately 24 mi
long. Islamorada and Plantation Key are two other areas where a number of package plants are located within
close proximity to one another. Twenty such facilities are located along a 4-mi stretch of U.S. Highway 1 in
Islamorada; another 15 plants are situated on Plantation Key, from Mile Marker 86 northward to Mile Marker
91.
3.2.2.2.7 Water Quality
Secondary treatment plants are required to report certain water quality parameters to the FDER (Rule 17-600,
FAC). Permittees generally are required to submit monthly operating reports. FDER enters the water quality
data into their GMS Monthly Operating Reports database, commonly labeled GMS36. Standard water quality
parameters and other pertinent information regarding facilities operation typically are entered into GMS36.
Archived information includes analytical data (e.g., BOD5', pH, TSS, fecal coliform) and operational parameters
(e.g., maximum daily flow, average daily flow, chlorine residual).
In 1988, the FDER conducted a chemical analysis of secondarily treated domestic sewage being disposed of via
20 boreholes to determine whether or not the "minimum criteria" for groundwater quality was being violated.
2-39
-------
The study results indicated that the groundwater was of relative good quality for disposal into Class G-III
groundwater. However, it was noted that the findings were not related to nutrients (Merchant and Haberfeld
1988).
There is no State administrative rule requiring permittees to monitor the effluent from their wastewater
treatment plants for nutrients (e.g., nitrogen and phosphorus). Wastewater treatment plants designed to meet
secondary treatment standards will not be efficient in nitrogen and phosphorus removal. Typical removal
efficiencies reported for secondary treatment were 10% to 20% of effluent concentrations for both nutrients
(Saarinen 1989). . ,
FDER has undertaken two studies in an attempt to evaluate the impact of domestic sewage discharged via
boreholes. Merchant and Haberfeld (1988) concluded that the secondarily treated domestic sewage being
disposed of via Class V injection wells is of relatively good quality for disposal into Class G-III groundwater.
However, it was also noted that nutrient enrichment of surface waters adjacent to the'groundwater discharges
studied was not addressed. In response to this concern, another monitoring study of a long-term nature was
initiated by the FDER Marathon Office in April 1989 (G. Rios, FDER, personal communication, 1991). The
purpose of the study was to assess water quality impacts from wastewater discharged into Class V wells on the
groundwater and adjacent surface waters. These wells are associated with a relatively new recreational vehicle
park that, to date, is less than 50% built. Preliminary results do not indicate significant nutrient enrichment,
however, in 1991, the plant was operating at only 5% of its design capacity. Continued monitoring is planned
along with a dye tracking survey (G. Rios, FDER, personal communication, 1991).
3.2.2.3 ON-SITE SEWAGE DISPOSAL SYSTEMS
3.2.2.3.1 Background
It is estimated that 65 % of the wastewater flow generated in Monroe County is treated by individual on-site
sewage disposal systems (OSDS) (Monroe County 1991; Wallace Roberts & Todd et al. 1991a). There are an
estimated 24,000 permitted septic tanks and 5000 cesspits in the Florida Keys (S. Lysik, Keith and Schnars,
P.A., personal communication, 1991). Although septic tank systems are regulated, cesspits are not. Cesspits
represent an unregulated, on-site disposal system that discharges directly into local groundwater without waste
treatment. Considerable concern has been raised over the impact of OSDSs and cesspits on water quality
(Lapointeand O'Connell 1988; Saarinen 1989; Burnaman 1991).
The regulation of OSDS facilities is the responsibility of the FDHRS, and is administered through the
Department's authorized agents, the individual county public health units. The Monroe County Health
Department operates three branch offices where OSDS permits may be secured, including Key West, Marathon,
and Tavernier.
In general, OSDS facilities are regulated in accordance with Rule 10D-6 (FAC), which applies Statewide.
However, in the case of the Florida Keys, there are other requirements that must be met. Due to the unique
soil conditions and water-table elevations, densities and setback requirements have also been enacted. The State
has implemented additional regulations for those counties where more than 60% of the soils are Key Largo
Limestone. These regulations apply also to those islands where more than 60% of the soils are Miami
Limestone. These supplemental requirements were added by the State in 1986 in a special section titled Part II
of Chapter 10D-6, FAC (Burnaman 1991). In a memorandum from the FDHRS Environmental Health Program
Supervisor, the Department sought "increased purification of OSDS effluent" to protect surface water quality
(Burnaman 1991). Since this rule change was enacted, no monitoring of the effectiveness of the Part II
provisions has been undertaken as required by the Department's own rules (Burnaman 1991). Modifications to
the Rule are presently being considered by FDHRS (K. Sherman, FDHRS, personal communication, 1991).
2-40
-------
The Florida Department of Community Affairs (FDCA), in exercising its authority with regard to its local
comprehensive plan review responsibilities (see Section 163.3161, Florida Statutes), indicated that it had
concerns about how Monroe County had addressed OSDS standards. Therefore, in accordance with its statutory
authority, FDCA and the County entered into a Stipulated Agreement that requires the County to adopt
standards for OSDSs that are based on an environmental carrying-capacity approach. This approach addresses
nutrient loading and attempts to maintain the quality of the nearshore waters. These OSDS requirements and
specific levels of service will be established as a result of undertaking a Sanitary Wastewater Master Plan. It is
expected that this study will be completed in 1995.
3.2.2.3.2 Soils
Due to their inherent physical properties, all soil types present in Monroe County are rated as having either
severe (29.5%) or very severe (70.5%) limitations for use as septic tank absorption fields (Ayers Associates
1987). To overcome the soil's limitations, septic tanks would require special design, would potentially generate
significant increases in construction costs, and could possibly realize higher maintenance costs. In general, most
soil types exhibit similar restrictive soil features. The most common soil features are depth to rock, wetness,
flooding characteristics and potential, and filter characteristics (DOA 1989).
OSDS can be a significant source of nutrient and bacterial groundwater contamination. The Monroe County
Health Department indicated that bacterial contamination is not a problem (H. Rhode, Monroe County Health
Department, personal communication, 1991); however, conventional OSDS do little in removing nutrients
(Ayers Associates 1987).
A general discussion of the Florida Keys geology is presented in Section 3.2.2.1 Geology, Hydrogeology, and
Aquifers.
3.2.2.3.3 Location
A majority of the OSDSs in the area of interest are located in the unincorporated portions of Monroe County.
As noted previously, nearly all areas in the City of Key West are served by the Key West STP (Solin 1991). It
is estimated that within the City there are fewer than 50 septic tank systems remaining. Further, it is
anticipated that, by 1995, all remaining septic tank users will have connected to the Key West STP (K.
Williams, CH2M Hill, personal communication 1991). In addition, the residents of the City of Key Colony
Beach have their own sewage treatment facility.
The firm of Wallace Roberts & Todd is presently completing an inventory of all permitted and unpermitted
septic tanks and cesspools in unincorporated Monroe County. However, even though the specific number of
OSDS units operating in the Keys cannot be determined, it is highly probable that the density of OSDS units
will mirror the distribution of population. Using this approach, the highest concentrations of OSDS units are
expected in areas such as Marathon and Key Largo.
3.2.2.3.4 Types of Facilities
Several OSDS designs are in use in the Florida Keys. They include conventional, mound, and aerobic systems.
The conventional system for on-site treatment and disposal of domestic wastes consists of a buried septic tank
and a subsurface infiltration trench or bed (Bicki et al. 1984). Septic tanks with conventional soil absorption
2-41
-------
systems can provide an effective method of treatment and disposal when site conditions, construction methods,
and maintenance requirements are considered. Based on existing soil conditions throughout the Keys, it is
apparent that an alternative means of treatment and disposal must be used in areas where the soil is insufficient
to provide adequate purification of the waste before it reaches the groundwater (CH2M Hill 1979).
Conventional and mound OSDS methods are not designed to remove nutrients. There is a minimal amount of
nutrient reduction through phosphorus absorption and precipitation in the natural soil system (Monroe County
1991).
The mound system utilizes a septic tank; however, its drainfield is constructed at a prescribed elevation in a
prepared bed of fill material (FDHRS 1991). As described in the Monroe County 201 'Wastewater Facilities
Plan (CH2M Hill 1979), the effluent flows by gravity into a pumping chamber. A pressure distribution network
is used to provide uniform application of the effluent in the seepage bed.
The aerobic system, unlike the traditional septic system, incorporates a means of introducing air into sewage so
as to provide aerobic biochemical stabilization during a detention period (FDHRS 1991). There are 226
aerobic treatment units serving both residential and commercial uses in the Keys. While there are 40 located in
the upper Keys, and 13 to IS in the middle Keys, the vast majority are situated in the lower Keys. The aerobic
systems can discharge effluent into either a drainfield system (similar to a septic tank) or through a gravel filter,
then into a borehole. Of the units installed, 186 systems discharge effluent into a borehole and the remainder
utilize drainfields (C. Williams, Monroe County Health Department, personal communication, 1992). The
FDER monitored these systems from 1987 through 1989. Data indicate that many of these systems do not
function in compliance with the .National Science Foundation standards (Wallace Roberts & Todd el al. 1991a;
Burnaman 1991; G. Rios, FDER, personal communication, 1991). In addition, these systems do not achieve
nutrient reduction (Saarinen 1989).
The RUCK system is an alternative wastewater disposal system being considered as an alternative to
conventional OSDS. It relies upon segregating toilet wastewater (blackwater) from other household wastewater
(greywater). "Under field testing, the RUCK system was found to have an overall nitrogen removal efficiency
of 70%. The final effluent before infiltration into the soil had a total nitrogen content of less than 10 mg/L and
a nitrate concentration of 0.2 to 5 mg/L" (Monroe County 1991).
3.2.2.3.5 Wastewater Flow
Projected wastewater flows generally are described in terms of average daily flow (ADF), either per equivalent
dwelling unit or by using a per capita method. This Section presents the various methods that have been used to
project future wastewater flow.
The Monroe County Comprehensive Plan (Monroe County 1991) cites an average daily flow of 250 GPD per
equivalent dwelling unit. All land uses are reflected in that figure. Before accepting the 250-GPD value,
Monroe County conducted a review of wastewater generation rates developed by Bicki et al. (1984). A
summary of sources and daily flow estimates developed by Bicki et al. (1984) is presented in Table 2-6.
The County evaluated whether or not the weighted per capita average of 44 GPD cited by Bicki et al. (1984)
was appropriate for the Florida Keys. Based on their findings, the County adopted the value of 250 GPD per
equivalent dwelling unit.
Camp Dresser and McKee, Inc. (1990) used per capita flow values of 100 GPD for residents and 60 GPD for
tourists. These per capita values were derived from the 1979 Monroe County 201 Wastewater Facilities Plan
(CH2M Hill 1979).
2-42
-------
Table 2-6. Summary of average daily residential wastewater flows. [From Bicki et al. 1984]
Study
Linaweaver et al. 1967
Anderson and Watson 1967
Watson et al. 1967
Cohen and Wallman 1974
Laak 1975
Bennett and Linstedt 1975
Siegrist et al. 1976
Otis 1978
Duffy et al. 1978
Weighted Average
#of
Homes
22
18
8
8
5
5
11
21
16
Study
Duration
(months)
—
4
2-12
6
24
0.5
1
12
12
Wastewater Flow
Study
Average
(GPCD)
49
44
53
52
41.4
44.5
. - 42.6
36
42.3
44
Range of individual
residence averages
(GPCD)
.36-66
18-69
25-65
37.8-101.6
26.3-65.4
31.8-82,5
25.4-56.9
8-71
—
GPCD: Gallons per capita per day.
2-43
-------
Another set of wastewater generation rates to be considered is the level of service standard adopted by the City
of Key West in its Comprehensive Plan, Sanitary Sewer Facilities and Services Subelement. The levels of
services, by facility, were
Residential Uses 100 GPCD (gallons per capita per day) for permanent residents based on 90
GPD for seasonal residents;
i
Nonresidential Uses 660 GPAD (gallons per acre per day).
3.2.2.3.6 Wastewater Characteristics
Septic tank effluent contains varied concentrations of nitrogen, phosphorus, chloride, sulfate, sodium, toxic
organics, detergent surfactants, and pathogenic bacteria and viruses. Several studies have investigated sewage
effluent constituents. Table 2-7 compares constituents by package plants, boat live-aboard systems, and
OSDSs. Tables 2-8 and 2-9 characterizes typical residential wastewater from several sources.
An indication of typical septic tank effluent is provided in Table 2-10. For septic tank effluent as it is
discharged into the drainfield, the soils provide additional treatment prior to contact with groundwater (Saarinen
1989). The degree of treatment depends upon the efficiency of constituent removal in the soil underlying the
drain system and the thickness of the unsaturated zone between the bottom surface of the drainfield and the high
water table. Table 2-11 describes typical reduction in effluent parameter concentrations as the effluent passes
from the septic tank to the drain system and finally to the groundwater.
3.2.2.3.7 Water Quality
If properly installed and maintained, OSDS units have functioned adequately in terms of their removal of fecal
colifonn and suspended solids (G. Rios, FDER, personal communication, 1991; H. Rhode, Monroe County
Health Department, personal communication, 1991), as required under Rule 10D-6, FAC. However, as
discussed earlier, conventional OSDS units do little to remove nutrients. The aerobic OSDS unit removes
slightly more nitrogen than a conventional OSDS (J. Bottone, FDER, personal communication, 1992). There
has been considerable energy put forth to establish a link between OSDSs and nearshore water quality (Bicki et
al. 1984; Lapointe and O'Connell 1988). However, there have not been definitive conclusions concerning the
exact relationship between septic tank effluent and nearshore water-quality degradation. There is, however,
reasonable suspicion that a portion of nearshore water-quality degradation can be attributed to the nutrient-
loading from regulated and unregulated OSDSs (Wallace Roberts & Todd et al. 1991a).
3.2.2.4 LANDFILLS
The Monroe County Municipal Service District (MSD) is responsible for providing solid waste services
throughout unincorporated Monroe County, including Layton and Key Colony Beach. The City of Key West
manages its own solid waste disposal operation (Monroe County 1991; Solin 1991).
In 1990, there were four active landfill operations in the FKNMS located on Stock Island (serves Key West),
Cudjoe Key, Long Key, and Key Largo. As of February 1992, only the Key West facility still had an active
landfill operation. This facility will also be closed by November 1993. Presently, the Key West facility is
operating under a FDER Consent Order (W. Krumbholz, FDER, personal communication, 1992). The landfill
2-44
-------
Table 2-7. Effluent characteristics by source. [From Applied
Biology, Inc., and Camp Dresser and McKee, Inc. 1985; Canter
and Knox 1985; Camp Dresser and McKee 1990]
Constituent Effluent Concentration
Package Plant OSDS
(mg/L) (mg/L)
Suspended solids 20 75
Biological oxygen demand 20 140
PO«-P 8 11
NHrN 5 30
N03-N 35 0
OSDS: On-site sewage disposal system.
2-45
-------
Table 2-8. Characteristics of typical residential wastewater.* [From Bicki et al. 1984]
Parameter Mass loading Concentration
(GPCD) (mg/L)
Total solids 115-170 680-1000
Volatile solids 65-85 .380-500
Suspended solids 35-50 * 200-290
Volatile suspended solids 25-40 150-240
BODj 35-50 200-290
Chemical oxygen demand 115-125 680-730
Total nitrogen 6-17 35-100
Ammonia 1-3 6-18
Nitrates and nitrites < 1 < 1
Total phosphorus 3-5 18-29
Phosphate 1-4 6-24
Total coliforms
(organisms/liter) - 10'°-1012
Fecal coliforms
(organisms/liter) — lOMO10
GPCD: Gallons per capita per day.
'For typical residential dwellings equipped with standard water-using fixtures and appliances (excluding
garbage disposals) generating approximately 45 GPCD or 170 L per capita per day.
2-46
-------
Table 2-9. Residential wastewater characteristics. [From Canter and Knox 1985]
Constituent Concentration
(mg/L)
BOD, 300
Chemical oxygen demand 750
Total organic carbon 200
Total solids 781
Total volatile solids 438
Suspended solids 250
Volatile suspended solids 194
Total Kjeldahl nitrogen 38
NH3-N 12
NO3-N 0.6
N02-N . -
Total phosphorus 25
PO«-P 8.8
Oil and grease 94
Methylene blue active substances . - 19
2-47
-------
Table 2-10. Septic tank effluent quality. [From Laak 1975]
Constituent Concentration
(mg/L)
BODS 90-348
Chemical oxygen demand 150-720
Total organic carbon 129
Total solids 820
Suspended solids (98% 0.5-5.0 /xm) 40-350
Volatile suspended solids 80% SS
Total nitrogen 25-36
Organic N 30% TN
Ammonia (NH4-N) 70% TN
P04 35-100
Grease 50-150
E. coli (organisms/100 mL) 106-108
SS: Suspended solids.
TN: Total nitrogen.
2-48
-------
Table 2-11. Typical effluent concentrations from septic tank systems. [From Canter and Knox 1985]
Parameters Septic Tank Drain System Removal from
Effluent Effluent Drain System
(mg/L) (%)
Suspended solids 75 18-53 29-76 -
BODj 140 28-84 40-80
Chemical oxygen demand 300 57-142 53-81
Total nitrogen 40 10-78" —
Total phosphorus 15 6-9 40-60
1 Reported as ammonia nitrogen
2-49
-------
operations at the Key Largo and Long Key facilities are now closed. The facility at Cudjoe Key no longer
accepts solid waste; however, the seven acre, synthetically-lined [50 mil high-density polyethylene (HOPE)]
expansion completed in December 1990, is being kept in reserve for emergency or future use (Monroe County
1991; W. Krumbholz, FDER, personal communication, 1992). In addition to these four facilities, the FDER
files document that there are four "old" landfills that have been closed for some time (W. Krumbholz, FDER,
personal communication, 1992). They include the old Key Largo, Saddleback Key, Fleming Key, and Boot
Key landfills. All landfills are located near coastal waters.
As of December 1990, Monroe County contracted Waste Management, Inc. (WMI) to haul the county's solid
waste out of the county. WMI hauls wet garbage, yard waste, and construction debris to a WMI landfill located
in Pompano Beach, Florida (Monroe County 1991). Although the landfills at Key Largo, Long Key, and
Cudjoe Key no longer function as active landfill operations, these facilities do serve as subdistrict transfer
locations where WMI picks up the waste for hauling (Monroe County 1991).
Hazardous and biohazardous wastes are not handled by the MSD. Those generating such wastes must contract
with a licensed hazardous-waste transporter, and have the wastes hauled to a Federally-permitted facility.
Ground water beneath the solid waste landfills is classified as G-III due to the influence of salt water (see Rule
17-3.403 Florida Administrative Code for definition of G-III). Based on available FDER monitoring data, the
G-III standards have not been violated (W. Krumbholz, FDER, personal communication, 1992). In addition,
bioassays have been conducted on the coastal waters adjacent to Stock Island and Long Key landfills. No toxic
levels were detected (R.J. Helbling, FDER, personal communication, 1992).
Landfills within the Florida Keys have operated within legal limits and/or have met Federal and State water
quality standards; however, like wastewater treatment systems the detectable limits may be set too high for the
oligotrophic waters present in the FKNMS. Also, monitoring of the nearshore marine waters surrounding the
existing and closed landfill facilities is vitally important in order to assess the long-term impact of these
facilities.
3.2.3 Marinas/Boat Live-Aboard
3.2.3.1 BOATING OVERVIEW
With a setting such as the Florida Keys, it is not surprising that water-oriented activities are of primary interest
and importance, not only to the resident population but to seasonal visitors as well. Certainly one indicator of
the popularity of water activities is boating. Based on Florida Department of Natural Resources (FDNR) data
summarized by the University of Miami Boating Research Center, in 1982 there were 462,765 boat
registrations. By 1988, this number had increased by 37% to 635,342 (Snedaker 1990). A sizeable number of
seasonal residents also bring their boats to the Keys during their stay. These boats are not reflected in the
Boating Research Center data.
3.2.3.2 MARINAS
Within the Florida Keys are 186 marinas. Marinas vary in size from those with only several wet slips to those
with multiple docking facilities having in excess of 100 wet slips. Based on the best available data, there are
estimated to be 1285 slips in the lower Keys, 589 wet and 696 dry. In the middle and upper Keys, there are a
total of 2053 and 1664 slips, respectively. The middle Keys has 1284 wet slips and 769 dry slips; in the upper
Keys, there are 830 dry and 834 wet slips (Monroe County 1986). The geographic distribution of marinas is
graphically depicted in Figure 2-6 and listed in Table 2-12. The services provided by each marina vary widely.
2-50
-------
K)
tin
The following 13 figures dircclly relate lo ihis key map
Figure 2-6. Marina facilities.
This Figure *nd its 13 components, which follow, indicate the geographic locations of marina facilities (indicated on the maps by O). Numbers correspond to those in Table 2-12. Locations of
marina facilities in unincorporated Monnw •" "
-------
Florida
mmm^ °»o» County
Monr°» County
Atlantic
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-6-1. Marina facilities, (continued)
2-52
-------
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK
Figure 2-6-2. Marina facilities, (continued)
2-53
-------
Florida Bay
&•:
K»y Largo
Atlantic Oc««n
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-6-3. Marina facilities, (continued)
2-54
-------
Florida Bay
Atlantic Oc*an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-6-4. Marina facilities, (continued)
2-55
-------
Florida Bay
Horlda Keys Nationa
Marine Sanctuary ugnomvtta*
Yellow Sharv Ch«nn*l
(w)
US HWY 1
T««t«bl« Key
77)Jpp«r Mtt»cumb« K«y
Atlantic OeMin
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-€-5. Marina facilities, (continued)
2-56
-------
Gulf of Mexico
Florida Bay
Craig K*y
Atlantic Oc*an
NOTE: DASHED LANOMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-6-6. Marina facilities, (continued)
2-57
-------
Gulf of Mexico
Fat D*«r K«y
Utt'« Crawl
Crawl K«y
K.v
H«wV Channel
Atlantic Oc*an
Figure 2-6-7. Marina Facilities, (continued)
2-58
-------
Gulf of Mexico
Stirrup
K«y
Hiw* Clwnrwl
Atlantic Oc««n
Figure 2-6-8. Marina facilities, (continued)
2-59
-------
Gulf of Mexico
No Nam*
Key -
.-A
I
Spanish
Harbor
K«y»
Bthli Honda K*y
Unit Duck K«y
^J ^ Mlrourl
B«*. Hond. St... P.CK Oh|o K K,y
AiJantic Ocean
Figure 2-6-9. Marina facilities, (continued)
2-60
-------
Figure 2-6-10. Marina facilities, (continued)
2-61
-------
Figure 2-6-11. Marina facilities, (continued)
2-62
-------
Gulf of Mexico
K«y
Atlantic OCMH
Figure 2-6-12. Marina facilities, (continued)
2-63
-------
Gulf of Mexico
Fleming
Key
rvu
Atlantic OCMH
Figure 2-6-13. Marina facilities, (continued)
2-64
-------
Table 2-12. Marinas of the Florida Keys. [From Solin 1991; Wallace Roberts & Todd,
"" unpublished data 1991]
n>#
i
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
Key Marina. Name
North Key Largo
Angler's Club
Carysfort Yacht Club
Ocean Reef Club
Key Largo
American Outdoors Marina
Anchorage Retort & Yacht
Atlantis Marina
Blue Lagoon Motel
Calusa Campgrounds
Camper's Cove Trailer Park
Captain Jax
Cross Key Marina
Deep Six Marina
Garden Cove Marina
Gilbert's Marina
Hideaway Motel
Holiday Inn Marina
Island Houseboat Motel
Italian Fisherman Marina
I. Ron's Marina
John Pennekamp Coral Reef
Marina State Park
Jules (Koblick) Marine
Key Largo Kampground Marina
Key Largo Ocean Marina
Key Largo Sheraton
Lake Largo
Manatee Bay Marina
Marina del mar Resort
Marina del Rey
Ocean Divert Marina
Palm Bay Yacht Club
Pilot House Marina
Point Laura Marina
Riptide Trailer Park
Rock Harbor Marina
Rock Reef Resort
Roger's Marine
Rowell's Marina
Tarpon Marina
Tortola Marina
The Fishing Club
Twin Harbor Motel
Upper Keys Sailing Club
Weekender Camping
Tavemier
Treasure Harbor Charter Yacht*
Island Bay Resorts
Curtis Marine
Campbell's Marina
Blue Waters Marina
Plantation
Cobra Marine
Coast Guard Station
Tavemier Creek Marina
Ragged Edge Resort
Seabreeze Trailer Park
n>#
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
Key Marina Name
Plantation Yacht Harbor
Plantation Key Marina
Windley
Tropical Reef Resort
Richmond's Landing, Inc.
Holiday Isle Resort
Ecte's Fishing Camp
Drop Anchor Motel
Sandbar Restaurant/Marina
Islamorada
Whale Harbor Resort
Sea Isles Resort
Kon-Tiki Resort
Sunset- Inn
Islander Resort
Islamorada Yacht Basin
Harbor Light*
Coral Bay Marina
Cheeca Lodge/Marina
Caribee Outboard Marina
Bayside Marine, Inc.
Pines/Palms Marina
Papa Joe's Marina
Max's Marina
Matecumbe Marina
Bud 'N Mary's Marina
Lower Matecumbe
Topsider Resort
Robbie's Boat Rentals
Caloosa Cove Resort
Long
Outdoor Resorts
Edgewater Marine
Bird Marina
Fiesta
KOA Kampground
Conch
Conch Key Marina
Duck
Hawk's Cay Marina
Duck Key Marina
Grassy
Pelican Motel
Coco Palma's
Rainbow Bend Resort
Jolly Roger Travel Park
Lion's Lair
Bonefish Harbor/Gulfside 59
Fat Deer
Bonefish Marina
Coco Plum Marinas
Coral Lagoon Retort
Driftwood Harbor
Hawaiian Village Botel
Marie's Yacht Harbor
The Boat House
Knight
7 Mile Marina-
2-65
-------
Table 2-12. Marinas of the Florida Keys. [From Solin 1991; Wallace Roberts & Todd,
unpublished data 1991] (continued)
n>#
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
Key
Marathon
Knight
Marathon
Hog
Marathon
\
Knight
Marathon
Boot
Ohio
Bahia Honda
No Name
Big Pine
Marina Name
Anchor Lite Botel
Banana Bay Resort
Becker Marine
Blue Waters Reiort
Boot Key Marina
BP Surfside Gulf
Buccaneer Lodge
Captain Hook'i Marina
Captain Pip's Marina
Coast Guard Station
Faro Blanco Marina
Fishermen's Point*
Galway Bay Mobile Home
Gulf Stream Travel Park
Halls Resort
Harborside Marina
Hawk's Nest Condo
Hidden Harbor Botel
Hog Key Marina
Hurricane Resort
Key Lime Resort
Key Trailer Park
Keys Boat Works
Key Vaca Marina
Kingsail Moul
Knights Key Park
Seahorse Lagoon Resort
Marathon Boat Yard
Marathon Seafood
Marathon Trailerama
Marathon Yacht Club
Ocean Isles Fishing Village
Oceanside Marine Services
Pinellas Marine Goods
Seascape Resort
Sombrero Marina
The Reef Resort
Winner Docks
Vaca Cut Botel
Bool Key
Sunshine Key Marina
Bahia Honda State Park
Bahia Shores/Dolphin Harbor
Big Pine Fishing Lodge
Halcyon Beach Trailer Park
n>#
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
, 182
183
184
185
186
Key
Little Torch
Newfound Harbor
Ramrod
Summeriand
Cudjoe
Sugarloaf
Getger
Big Coppitt
Stock
Key West
Marina Name
Keys Sea Center, Inc.
Outward Bound
Mariner Resort
Big Pine Shores
Old Wooden Bridge
Fish Camp
Seacamp
Farmer's Place
Dolphin Marina
Little Palm Island
Looe Key Reef Resort
(Near MM 26)
Summeriand Marina
Summeriand Key Marina
Cudjoe Gardens Marina
Bluefish Canal
KOA Kampground & Marina
Sugarloaf Lodge Marina
Geiger Key Marina
Caribbean Village
Seaside Resort
US 1 Marina
First Key West Marina
Boyd's Campground
Captain Billy & Key West
Diver
Cow Key Marina
Leo's Campground
Munro's Marine
Murray Marine
Oceanside Marine
Peninsular Marine
Safe Harbour
Sunset Harbor Trailer
Land's End Marina
Key West Oceanside Marina
Key West Yacht Marina
Key West Redevelopment
Agency
Key West Municipal Marina
Steadman Boat Yard
Garrison Bight
Mallory Dock
2-66
-------
The types of boating-related services that marinas offer may include food provisions, restaurants, boat
maintenance (including the scraping and repainting of boat hulls), boating supplies, and marine fuel
(diesel/gasoline).
3.2.3.3 LIVE-ABOARDS
The boating public is not limited to just the recreational boater. Another major segment are those individuals
who live aboard their boats. A live-aboard is defined as one whose continuous residence is a boat, not
necessarily at a fixed location, for a period of more than 2 months (Antonini et al. 1990). The largest number
of live-aboards are found in marinas, but many also anchor offshore (Schroeder 1987; Antonini et al. 1990).
Live-aboards comprise both permanent and seasonal residents. The types of vessel utilized by live-aboard
boaters vary. Generally, live-aboard vessels are of three types: a sailboat, a powerboat, or a floating home.
The Florida Keys is very attractive to those seeking to live aboard their boat for an extended period. Certainly,
the year-round warm-weather climate makes the Keys a choice place to live on a boat either permanently or
seasonally. In 1988, it was estimated that there were 1410 live-aboard boats in the Florida Keys (Antonini et
al. 1990). The total live-aboard population was estimated at approximately 3000 individuals (Antonini et al.
1990).
3.2.3.4 LOCATION OF MAWNAS/LIVE-ABOARDS
As indicated above, marinas are graphically depicted in Figure 2-6. Although marinas are found throughout the
Florida Keys, certain areas have a higher concentration than others. In the lower Keys, most marinas are
located in either Key West or Stock Island. In the middle Keys, most marinas are situated in Marathon and Key
Colony Beach. In the Marathon area, there are approximately 40 marinas (Wallace Roberts & Todd et al.
1991a). In the upper Keys, over 40 marinas are located in Key Largo (Wallace Roberts & Todd et al. 1991a).
A number of live-aboard vessels are present in Fat Deer Key and Grassy Key. Islamorada has nearly
20 marinas located within a 4-mi strip. One of the largest marinas, Campbell's Marina with 94 wet slips, is in
Tavernier (FDER 1988).
According to a survey of live-aboard vessels conducted by Schroeder (1987), live-aboard boats could 'be found
throughout the Keys; however, most were concentrated at a few locations. At the time of the survey,
Campbell's Marina (Tavernier) had between 45 and SO live-aboards docked at its facility. In Marathon, two
marinas contained significant numbers of live-aboards: they were Boot Key Harbor (65 to 70 live-aboards,
based on a ground count) and Faro Blanco Marina (70 live-aboards, based on ground count). On Stock Island,
it appeared that 30 to 40 boats were used for commercial fishing and shrimping. Another clustering of
waterborne vessels was present in the Garrison Bight area. Several marinas in the Key West area consist of a
series of smaller marina operations (Schroeder 1987). In addition to the live-aboard boats that are tied up in
marinas, a sizeable number are anchored offshore. When the Antonini et al. (1990) study was conducted, 274
live-aboard type vessels were anchored in the Keys. The number varied according to season (368 in February;
141 in October). According to Antonini et al. (1990), prominent locations where boats were anchored included
Lower Keys Upper Keys Middle Keys
• Christmas Tree Island • Matecumbe Harbor • Boot Key Harbor
• Garrison Bight • Islamorada • Key Colony Beach
• Houseboat Row • Mile Marker 84.5, Bayside
• Cow Key Channel • Community Harbor
• Boca Chica Channel • Largo Sound
• Pine Channel • Cross Key
• Card Sound Bridge.
2-67
-------
Schroeder (1987) substantiated the Antonini study; however, the Schroeder survey also documented that
60 boats were anchored in Sigsbee Park.
As authorized by Chapter 253, Florida Statutes, the State has had the right to regulate live-aboard vessels that
anchor in State-owned submerged lands. With the growing number and popularity of live-aboard vessels, the
FDNR has begun a rule-making process that will probably result in the development of a rule to assist it in
managing live-aboard vessels on sovereign submerged lands. Issues regarding live-aboards differ around the
State; therefore, FDNR is conducting a series of public workshops Statewide. Some of the issues that are
expected to be raised in the Keys include problems of finding appropriate places for off-shore mooring,
assessing the impacts of live-aboards on public services, and controlling the practice of discharging raw sewage
from moored boats.
The City of Key West has applied for a permit from the FDER to establish a mooring Meld. It is anticipated
that employing this technique would enable the City to effectively manage the large number of live-aboard
boaters who visit the City annually (D. Fry, FDER, personal communication, 1991).
Live-aboards fluctuate in numbers during the year. The seasonally of the Keys is reflected in the live-aboard
population as well. Almost twice as many vessels (1.78) were counted in November as were counted at the
same locations in August (Schroeder 1987). In the Antonini et al. (1990) study, the researchers found that the
number of year-around boats was substantial. An estimated 87.7% of floating homes were year-around,
followed by sailboats (76.9%) and power vessels (48.2%). Both studies documented a seasonality in live-aboard
presence in the Keys. The most recent winter-to-summer ratio for all boat types is 2:1 (Antonini et al. 1990).
According to Antonini et al. (1990), disposal of sanitary waste is accomplished by a variety of methods:
overboard flushing, holding tank storage and subsequent shoreside pump-out, and/or on-board pretreatment and
discharge. The mean sewage pretreatment capacity for live-aboard boats in the Florida Keys is about 30%
reduction of the biochemical oxygen demand (BOD5) of the sewage load, roughly equivalent to a primary
sewage treatment plant. The remaining 70% of the BOD5 load of sanitary waste is degraded in the receiving
waters (Antonini et al. 1990).
There are over 180 marinas in the Keys. However, only nine of these are equipped with sewage pump-out
facilities. Two of these marinas are located in the lower Keys: Key West (Galleon Resort) and Stock Island
(Key West Resort-Oceanside Marina). Five marinas are in the middle Keys: Marathon (Faro Blanco, Boot Key
Marina, Sombrero Resort), Key Colony (Marie's Yacht Harbor), and Duck Key (Hawk's Cay Marina). In the
upper Keys (extending from Lower Matecumbe Key to North Key Largo), there are two marinas with pump-out
facilities available, the Ocean Reef Club and the John Pennekamp Coral Reef State Park (Antonini et al. 1990;
A. Nielson, FDNR, personal communication, 1992)). Of the nine facilities, three are private clubs (Marie's
Yacht Harbor, Hawk's Cay Marina, Ocean Reef Club), making these locations unavailable to the general
boating public. Although there are only a limited number of pump-out facilities, marinas commonly provide
shoreside shower and toilet facilities.
3.2.3.5 WASTEWATER FLOWS
In the 1979 Monroe County 201 Wastewater Treatment Facilities Plan (CH2M Hill 1979), wastewater flows
were based on per capital rates of 100 GPD for residents and 60 GPD for tourists. In the Campbell's Marina
study (FDER 1988) the projected volume of wastewater per capita was 100 GPD per boat.
2-68
-------
3.2.3.6 WATER QUALITY
Water quality in marinas is affected by both general marina operations as well as live-aboard vessels docked in
the marina slips. Live-aboard boaters anchored offshore also have an impact on water quality (Antonini et al.
1990).
Water-quality degradation related to general marina operations has been detected in terms of concentrations of
heavy metals and the presence of copper and other metals such as zinc-cbromate, titanium dioxide, yellow iron,
lead oxide, and strontium (Heatwole 1987; Rios 1990; Snedaker 1990). As noted by Snedaker (1990):
"The absence of rich organic sediments in the oligotrophic carbonate environment of [the] Keys
suggests that marina pollutants are not as effectively sequestered in local sediments, but rather are
dispersed into the nearshore marine environment."
Besides the heavy metals that have been documented, water-quality studies of several marinas (e.g., Campbell's,
Boot Key and Faro Blanco) linked the presence of live-aboard boats to water degradation. Measurements of
coprostanol, an indicator of mammalian excreta, was identified in sediments directly below and around boat
slips (Heatwole 1987;'Rios 1990).
3.2.4 Mosquito Control Program
The Mosquito Control Program in the Florida Keys area is directed by guidelines from the FDHRS. While the
potential exists for mosquito control application from Dade County (where it is administered by the Department
of Public Works) to affect the FKNMS, the southernmost point that is sprayed is 9 mi from the county line.
The risk of spray drifting into FKNMS waters would be minimal, although water-borne transport from Dade
County is possible. Due to the nature of this program, which involves the application of insecticides by aerial
dispersion (i.e., by airplane or helicopter) and land application, it is regarded as a source of atmospheric and
land-based nonpoint loading on the Florida Keys environment.
The Mosquito Control Program in the Florida Keys acts to limit the mosquito population in one of two ways.
• The eradication of adult mosquitos through the application of adulticides prior to their ability to
develop a second generation mosquito population
« The eradication of mosquitos while they are in the larval or pupae stage, prior to development and
proliferation.
The Mosquito Control Program is in operation throughout the year, although the summer months (April through
September) are the most active months for the application of chemicals and insecticides. The most commonly
used insecticides (by tradename), along with the most active ingredient, are listed below
Chemical/Insecticide Active Ingredient
Baytex Fenthion
Dibrom 14C Naled
Malathion . Malathion
Biomist4 + 12 Permethrin + Piperonyl Butoxide
Abate Temephos
Altosid Methoprene
Arosurf POE isooctadecanol
Diesel Oil Petroleum oil
Telcnar Bacillus thuringiensis var. israeliensis
2-69
-------
Bactimos Bacillus thuringiensis var. israeliensis
Vectobac Bacillus thuringiensis var. israeliensis
Scourge Resmethrin + Piperonyl Butoxide
Fog oil Petroleum oil
The application of mosquito control dispersants is restricted on most, if not all, Federally owned properties
within the Florida Keys area. Other areas where their use is precluded include State Fish and Wildlife
Preserves and State and National Recreational Park locations. Most applications are limited to the areas
surrounding residential communities, commercial and light industrial site locations, within the boundaries of
local landfills (i.e., in areas of sewage and sludge burial), and within areas of standing water, all of which favor
the proliferation of mosquito development.
The ecological effects of some of the most commonly used insecticides is briefly summarized below based on
Material Safety Data Sheets (MSDS) from manufacturers and Pesticide Fact Sheets from EPA provided by the
Pesticide Information Office/Florida Cooperative Extension Service and other sources.
• Baytex (Fenthion)
Fenthion is an organophosphate insecticide that was widely used in aerial spraying programs because of
its effectivity. Like other organophosphate insecticides, it is readily adsorbed by soil. Fenthion is
phytotoxic and is highly toxic to birds and moderately toxic to fish. It should not be applied for
mosquito control in areas containing fish, shrimp, crabs or crayfish. Care in preventing contamination
of water bodies by Fenthion is recommended. Up to 50% of the original application can remain in the
water after 2 weeks.
• Dibrom 14 (Naled)
Dibrom is a non-persistent organophosphate insecticide that is toxic to fish and wildlife and should not
be applied directly to water. Although it is practically insoluble in water, it has a half-life of 2 days.
While no documentation is available, it is believed to be unlikely to bioaccumulate or biomagnify.
Contaminated materials such as soils or other absorbent laden with Dibrom 14 may be regarded as
hazardous.
• Malathion (Cythion)
Malathion is a wide-spectrum organophosphate insecticide that is non-persistent, unlikely to
bioaccumulate or biomagnify, and has a half-life of 1 week in river water. Malathion is toxic to most
types of aquatic life, particularly fathead minnows, bluegills, and mosquitofish. Malathion may
produce a pollution hazard if dilution water is improperly disposed of or runoff control from adjacent
land surfaces is not controlled.
• Biomist 4 + 12 (Permethrin)
Permethrin is a synthetic pyrethroid that is toxic to fish and should be kept out of all bodies of water,
including lakes, streams, ponds, and canals, which are particularly sensitive. Synthetic pyrethroids
tend to bioconcentrate in estuarine environments.
• Abate (Temephos)
Temephos is insoluble in water and is a highly effective organophosphate larvicide with long residual
action that causes death by respiratory failure in insects. Laboratory trials with rats and chickens show
low toxicity with similar effects as malathion.
• Altosid (Methoprene)
Methoprene is an insect growth regulator used as a larvicide. Altosid is non-persistent and is readily
adsorbed into soil. Although it has a half-life of less than 2 days in water, it has been documented as
harmful (and may cause death) to shrimp and crabs. Fish are not highly sensitive to Altosid.
2-70
-------
. • Arosurf
Used as a larvicide, it acts as a surfactant, producing a surface film with lowered surface tension
causing suffocation of larvae and pupae. It has low toxicity to humans, fish, and wildlife and is readily
broken down by naturally-occurring microbial populations.
• Diesel fuel
As a petroleum hydrocarbon product, diesel fuel is used in the aerial dispersal of insecticides. When
ignited and combined with the appropriate insecticide, a "fumigant" material is released. Toxicity or
contamination of ground and/or water surfaces has not shown diesel fuel to be detrimental to the
ecosystem.
• Bacillus thuringiensis var. israeliensis
BTI is an insecticide which causes death through the production of toxins when ingested by larvae. It
is considered to be relatively environmentally safe due to its specificity. It biodegrades and does not
persist in the gut of birds and has not been shown to be toxic to fish. While it can cause death of other
insects during mosquito control, experimental tests do not suggest that BTI adversely affects non-target
insects and aquatic invertebrates. It is a naturally occurring pathogen that is classified as immobile and
dissipates in water after 48 hours.
The use of Baytex has been discontinued as the product has been taken off the market. The manufacturer of
Baytex has tentative plans of re-registering the product. Currently, Biomist is the main product used in the
mosquito control program in Monroe County (L. Ryan, Monroe County Mosquito Control District, personal
communication, 1992). Dade County is using Dibrom 14C as its main mosquito control spray (M. Latham,
Dade County Public Works Department, personal communication, 1992).
The above listings present some, but not all, of the current insecticides that may be adversely affecting the
nearshore marine environment. The quantification of loads being dispersed into the Florida Keys area to control
mosquito populations during the period 1987 to 1990, including the type of chemical or insecticide being used,
the mode or method of dispersal, and the areal distribution of points being treated are summarized in
Table 2-13. However, to date there have been no direct, in-depth lexicological studies to correlate mosquito
spraying with deteriorating ecological and/or environmental systems in the Florida Keys.
A few unpublished studies on the environmental effects of mosquito control agents are available. Studies have
demonstrated the potential impact of the Baytex, Dibrom, and Malathion (adulticides) applications on estuarine
organisms. Baytex and Dibrom may have a devastating effect on Schaus swallowtail butterfly populations. The
applications rates for Dibrom in Monroe County are 400 to 4,000 x the lethal dose for third instar larvae of the
endangered swallowtail butterfly. Baytex is applied at 500 X the concentration that causes 50% mortality in the
third instar larva (Emmel 1986). While technical problems confounded the results of the bioassay tests,
calculated application rates of Baytex and Malathion were found to be lethal to eggs and larvae of snook (EPA
1981). While field tests with Dibrom, Malathion, and Baytex did not cause mortality in juvenile common
snook, tarpon snook, and sheepshead minnows, larval fish suffered increased mortality and decreased growth
and activity. Dibrom and Baytex caused acute mortality in copepods (Tucker et al. 1986).
Studies suggest that larvicides may have lesser environmental impacts than the adulticides. Abate applications
did not cause acute toxicity in mysid shrimp, brown shrimp, grass shrimp, sheepshead minnows, and pinfish
(Pierce et al. 1988a,b). Adult fiddler crabs were not affected by Abate though some retention was observed
(Pierce et al. 1989). Toxicity and bioaccumulation have not been observed in bivalves. Mussels did not suffer
toxicity from or bioaccumulate Altosid and Abate (Pierce et al. 1989). Oysters exposed to Abate depurate after
72 hours (Pierce et al. 1988a).
2-71
-------
Table 2-13. Quantities of insecticides used by the Mosquito Control Group in the Florida Keys.
Insecticide
Quantity
Area Treated
Baytex
Scourge (180)
Malathion
Teknar liquid (4: 100)
Teknar liquid (16: 100)
Vectobac 12
Dibrom 14 - Diesel fuel (4:100)
Altosid briquets
Bactimos briquets
Teknar granules
Bactimos pellets
(manual dispersement)
Abate 5% pellets
Vectobac granules
Bactimos pellets
(helicopter dispersement)
Bactimos granules
1987
289,812 ounces
46,980 ounces
43,614 ounces
4,434 ounces
4,018 ounces
1,039 ounces
105,050 gallons
1,399,532 briquets
2,555 briquets
5,662 pellets
390 pellets
223 pellets
1,400 pounds
75 pounds
50 pounds
45,508 miles
2,281 miles
2,042 miles
277 acres
251 acres
129 acres
840,416 acres
49,291 acres
26 acres
943 acres
70 acres
41 acres
140 acres
9 acres
5 acres
1988
Baytex
Scourge (180)
Malathion
Teknar liquid
Vectobac 12
Dibrom 14 - Diesel fuel (4:100)
Florida Larvacide
Altosid briquets
Bactimos briquets
Bactimos pellets
(manual dispersement)
Abate 5 % pellets
Altosid pellets
258,666
150,390
1,692
36,992.2
168
39,423
864
1,082,644
95,740
ounces
ounces
ounces
ounces
ounces
gallons
gallons
briquets
briquets
675 pellets
44 pounds
22 pounds
40,168
7,032
84
415
21
314,384
216
40,466
1,244
miles
miles
miles
acres
acres
acres
acres
acres
acres
130 acres
4 acres
11 acres
2-72
-------
Table 2-13. Quantities of insecticides used by the Mosquito Control Group in the Florida Keys.
(continued)
Insecticide
Quantity
Area Treated
Baytex
Scourge (180)
Teknar liquid
Abate 4E liquid
Dibrom 14 - Diesel fuel (4:100)
Abate SG powder
Altosid briquets
Bactimos briquets
Vectobac G
Vectobac
Vectobac 12
Altosid pellets
Abate 5% pellets
Bactimos pellets
(helicopter dispersement)
1989
204,3 15 ounces
103, 140 ounces
24,656 ounces
32 ounces
22,635 gallons
900 gallons
506,852 briquets
163,635 briquets
4,800 pounds
3,520 pounds
2,560 pounds
22 pounds
22 pounds
40 pounds
29,604 miles
4,905 miles
734 acres
32 acres
18 1,080 acres
450 acres
29,155 acres
2,842 acres
480 acres
110 acres
160 acres
10 acres
STP
40 acres
1990
Baytex
Scourge (180)
Malathion
Biomist
Pennanol
Vectobac 12
Dibrom 14 — Diesel fuel (4:100)
Vectobac G
Abate 5G
Altosid briquets
Bactimos briquets
Teknar concentrate
(2 ounces/gallon)
(8 ounces/gallon)
(16 ounces/gallon)
(8.5 ounces/gallon)
(10.6 ounces/gallon)
Altosid pellets
290,460
36,054
3,492
1,680
897
655
55,401
22,000
650
608,874
19,183
ounces
ounces
ounces
ounces
ounces
ounces
gallons
gallons
gallons
briquets
briquets
4 briquets
88 briquets
1,294 briquets
128 briquets
16 briquets
472 briquets
39,209
1,878
129
46
17
41
443,208
2,998
260
33,811
165
miles
miles
miles
miles
miles
acres
acres
acres
acres
miles
acres
1 acre
11 acres
58 acres
15 acres
2 acres
229 acres
2-73
-------
Larvicides are not persistent. Aerial spraying of Abate resulted in delivery to the mangrove forest floor of IS
to 78% of the amount deposited on the canopy. It did not persist in ambient water and sediment due to tidal
flushing, although it was observed to persist in tide pools and mangrove leaves up to 72 hours after application
(Pierce et al. 1988b, 1989).
No available information on the impact of BTI and Altosid on non-target insect populations in coastal areas has
been located. The impact of these agents should be investigated in monitoring programs.
3.2.5 Stonnwater
Stormwater is defined by Florida Chapter 17-25, Florida Administrative Code (FAC) as the "flow of water
which results from, and which occurs immediately following, a rainfall event."
The SFWMD is responsible for issuing surface water management (including stormwater management) permits.
The permitting of surface water management systems by the SFWMD is specified in Chapter 373, Part IV,
Florida Statutes. Permits are issued pursuant to the guidelines set forth in Chapter 40E-4, FAC. The SFWMD
regulates stonnwater quality through the provisions contained in Chapter 17-25, FAC, which are the State
stormwater discharge regulations. Table 2-14 lists the current permits for unincorporated Monroe County.
Figure 2-7 shows the locations of the permits. The following activities are allowed under the permits:
irrigation, construction and operation, potable water usage, surface drainage, hydrocarbon recovery systems,
and road improvement.
The SFWMD evaluated Nationally collected data (EPA 1983) in an assessment of urban land use and
stormwater runoff quality relationships. Treatment efficiencies for various stormwater management systems
were also summarized (Whalen and Cullum 1988).
The EPA study determined that stormwater runoff characteristics can vary significantly from one land use
location to another. As a consequence of this phenomenon, both water quantity as well as quality can be highly
variable. Although different land use(s) produce similar pollutants, quantification of pollutant loads varies from
one storm event to another (i.e., due to fluctuations in rainfall durations, pollutant accumulation rates between
storm events, and ratio of impervious to pervious land surfaces).
The SFWMD in its assessment of land use and stormwater runoff quality established numerous treatment
methods regarded as the current "Best Available Technologies" (BAT). These treatment technologies involve
the detention (the delay of storm runoff prior to discharge into a receiving water body) or retention (the
prevention of stormwater runoff from direct discharge into a receiving water body).
Unfortunately, there are very few available data from the Florida Keys regarding the chemical constituents of
the contained stormwater runoff. Literature values for typical stonnwater concentrations of nutrients and other
constituents according to land-use category are generally applied to the Florida Keys.
A study of environmental and hydraulic conditions within the Riviera Canal and adjoining salt ponds in Key
West, Florida, was conducted by CH2M Hill (1988). A component of the study involved estimating stormwater
loads. However, no site-specific field data of stormwater loading was performed. A preliminary evaluation of
probable stonnwater loads was performed with estimated drainage areas, average annual rainfall, land-use
information for the appropriate area of Key West, and typical runoff coefficients associated with specific land
uses. The calculations suggested that approximately 1.5 tons of both total nitrogen and phosphorus were
discharged to the Riviera Canal each year. Stormwater inputs to the Salt Ponds were estimated as 0.5 ton of
total nitrogen and 0.25 ton of total phosphorus each year. The preliminary evaluation of stormwater loads
suggested that they could be a contributing factor to poor water quality.
2-74
-------
Table 2-14. South Florida Water Management District surface water
management permits, unincorporated Monroe County.
[From Keith and Schnars, unpublished data 1991]
Map Permit
Number Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
GP-83-186
GP-83-199
GP-44-00078
44-00038
GP-44-00047
GP-44-00050
GP-86-119
GP-83-120
GP-44-00004
GP-87-12
GP-44-00102
GP-44-00044
GP-83-69
GP-44-00091
GP-85-101
44-00113
GP-84-75
44-00045
GP-44-00087
GP-83-5
GP-83-5
86-238
GP-78-71
GP-84-4
GP-44-00160
GP-44-00107
GP-86-66
GP-44-00156
GP-84-29
GP-44-00007
GP-87-82
GP-86-120
GP-44-00088
44-00036
GP-44-00053
GP-44-00092
GP-44-00006
GP-83-114
GP-44-00040
GP-44-00041
GP-44-00104
GP-44-00119
. •••"*
Receiving
Body
NA
NA
Gulf of Mexico
Gulf of Mexico
Lower Sugarloaf Sound
Florida Bay
NA
NA
Ground water
NA
Boot Key Harbor
Gulf of Mexico
Retention Pond
Atlantic Ocean
Tidal
On-site
NA
Gulf of Mexico
On-site
NA
NA .
On-site
NA
NA
FL Bay/Atlantic Ocean
On-site
On-site
NA
NA
Atlantic Ocean
Atlantic Ocean
On-site
On-site
Atlantic Ocean
Florida Bay
On-site
Atlantic Ocean
NA
Buttonwood Sound
On-site/Tidal
NA
NA
Land Acreage
Use
Highway
Highway
Commercial
Residential
Recreational
Vehicle
Landfill 1
Highway
Commercial
Commercial
Highway
Commercial
Commercial
Highway
Residential
'Commercial
Commercial
Highway
Residential
Residential
Highway
Highway
Commercial
Commercial
Highway
Highway
Residential
Commercial
Highway
Highway
Residential
Highway
Commercial
Commercial
Residential
Residential
Commercial
Residential
Commercial
Residential
Commercial
Highway
NA
NA
NA
2.90
56.00
11.47
20.00
NA
NA
8.8
NA
9.33
10.00
NA
14.00
NA
197.4
NA
43.8
22.3
NA
NA
60.8
NA
NA
21.8
5.76
NA
NA
NA
12.56
30.32
NA
0.69
69.4
13.7
4.2
29.22
0.75
24.0
25.18
83.66
NA
Location — Section/
Township/Range
34/67S/25E
22/67S/26E
29/67S/25E
14.15.23/67S/26E
8/67S/27E
19/66S/29E
32/66S/28E
26/66S/29E
23/66S/29E
4/66S/29E
10/66S/32E
10/66S/32E
4.5/66S/33E
14/66S/33E
11/66S/33E
1/66S/32E
6/66S/33E
5.6/66S/33E
35/65S/33E
25/65S/33E
33-35/65S/33E
21/65S/34E
5.6/65S/35E
ll,14,15,20-22/64S/34E
5,6,32/64,63S/37E
21/64S/34E
32.33/63S/37E
22.27.28/63S/37E
18/63S/38E
7.8.18/63S/38E
18/63S/38E
8/63S/38E
33/62S/38E
26.27/62S/38E
6.7/32S/39E
33/61S/39E
32.33/61S/39E
28/61S/39E
28/61S/39E
22/61S/39E
1,6,1 1-15/6 IS/39, 40E
11/61S/39E
2-75
-------
Table 2-14. South Florida Water Management District surface water
management permits, unincorporated Monroe County.
[From Keith and Schnars, unpublished data 1991] (continued)
Map
Number
43
44
45
46
47
Permit
Number
GP-83-115
GP-44-00122
GP-44-00108
44-00005
GP-78-190
Receiving
Body
NA
NA
NA
On-site Lakes
NA
Land Acreage
Use
Residential
NA
NA
Residential/
Commercial
Highway
8.15.
NA
NA
33.4
NA
Location - Section/
Township/Range
12/61S/39E
1/61S/39E
47-50/60S/40E
31.32/60S/40E
20.21.29/60S/40E
NA: Not available.
Missing Documents from SFWMD Files:
Permit No. 85-0074
44-00039
44-00051
44-00054
44-00124
44-00136
44-00142
44-00003
44-00147
44-00148
77-84
Source:
SFWMD 1991.
2-76
-------
K>
t . •
Florida •" • • (_ '"
Figure 2-7. South Florida Water Management District (SFWMD) Surface Water Management Permits.
This Figure and its 13 components, which follow, indicate the geographic locations of the SFWMD Surface Water Management Permits (indicated on the maps by •). Numbers correspond to
those in Table 2-14. Locations provided by Keith and Schnars (unpublished data 1991). Base maps redrawn from maps provided by Wallace Roberts & Todd.
-------
Florida
Atlantic Ocean
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-7-1. SFVVMD Surface Water Management Permits, (continued)
2-78
-------
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION
OF THE EVERGLADES NATIONAL PARK.
Figure 2-7-2. SFWMD Surface Water Management Permits, (continued)
2-79
-------
4'-'
Florida Bay
,'.:•.'•'.'•
/•': • • X'
v; •.••
.'/"'. '••£•
2> . Atlantic Ocean
NOTE: DASHED I.ANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-7-3. SFWMD Surface Water Management Permits, (continued)
2-80
-------
Florid* Bay
FI2Tld,a K
Marine Sanctuary
Atlantic Oc»an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Rgure 2-7-4. SFWMD Surface Water Management Permits, (continued)
2-81
-------
Florida Bay
-
^jy- ^-CrJv-.i.
3P*21
Lower M«t»cumb« K«y
' lor.da Keys National
Marine Sanctuary
Lignumviti* Satin
Upp«r Mat*cumb« Key
Hawk C^anrtfll
Atlantic Ocaan
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-7-5. SFWMD Surface Water Management Permits, (continued)
2-82
-------
Gulf of Mexico
Florida B«y
Crtlg K»y
Atlantic Oc»«n
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 2-7-6. SFYVMD Surface Water Management Permits, (continued)
2-83
-------
Gulf of Mexico
Hawk Channel
Atlantic Oc»«n
Rgure 2-7-7. SF\VMD Surface Water Management Permits, (continued)
2-84
-------
Gulf of Mexico
Stirrup
*r I
2!^$rP*i
Atlantic Oc««n
Figure 2-7-8. SFWMD Surface Water Management Permits, (continued)
2-85
-------
Gulf of Mexico
No Nam*
..K»y
Spanish
Harbor
K«y<
Bahia Honda K«y
Uttl* Duck K»y
Missouri
B.nii Honda Suit Park Oh)o Kty K«y
Atlantic Ocean
Figure 2-7-9. SFVVTMD Surface Water Management Permits, (continued)
2-86
-------
*•
il $ $ ^
'M^l £$ if:-*.
Atlantic Ocean
Figure 2-7-10. SFNN'MD Surface Water Management Permits, (continued)
2-87
-------
Gutf of Mexico
Upc*r Sug«rto«l Sound
2?
Buttonwood
S»ddl»bunch K»y»
Atlantic Ocean
Figure 2-7-11. SFWMD Surface Water Management Permits, (continued)
2-88
-------
Gulf of Mexico
Wan: Kty Biti
o Big
Rockland ° Copptt
K«y /r^ K«y
,sffi,.^t!
;':VV '^•^^•^ stoek
Atlantic Oc««n
Figure 2-7-12. SFNVMD Surface Water Management Permits, (continued)
2-89
-------
Gulf of Mexico
Fleming
Key
Atlantic Oc»«n
Figure 2-7-13. SFWMD Surface Water Management Permits, (continued)
2-90
-------
Camp Dresser and McKee, Inc. (1990) performed a stormwater pollution loading analysis for the upper Keys
(Sand Key to Windley Key) based upon data collected throughout the United States, with particular emphasis on
Florida-based information. Loadings were calculated for different land-use categories based on annual runoff
volumes and event mean concentrations for different pollutants. The impervious fraction of each land-use
category was used as the basis for determining the rainfall/runoff relationships.
The City of Key West is considering a comprehensive master stormwater drainage plan. All methods of
stormwater treatment will be considered and evaluated so that this plan can recommend the methods that are the
most practical and cost-effective, for the different conditions that prevail. This plan will establish a practical
level of service standard for the City as a whole and will consider all factors to set forth a recommended
schedule of upgrading the stormwater system to prevent the discharge of untreated runoff (Solin 1991). Monroe
County is in the process of developing criteria for a stormwater management ordinance. Additionally, the
County has identified issues related to stormwater management. New policy is currently being developed to
address the issues as part of the County's Growth Management Plan (Wallace Roberts & Todd et al. 199la).
The policies include the development of a comprehensive Stormwater Master Plan by 1995. The Plan will
consider both quality and quantity of stormwater runoff and will consider all current and proposed State and
Federal stormwater runoff regulations.
3.3 EXTERNAL SOURCES OF POLLUTANT LOADS
Water quality in the FKNMS can be affected by sources of poor water quality located outside the Sanctuary
bounds. These sources could potentially include Florida Bay, Biscayne Bay, and other nearby waters. Other
sources of contamination include water entrained from distant sites and carried over or through the Sanctuary.
Both categories would be considered as nonpoint sources that affect water quality within the Sanctuary, although
they may represent individual point or nonpoint sources whose initial location lies beyond Sanctuary bounds.
Sources of poor quality water may be either natural or manmade, or they may represent a situation where one
of these two sources exacerbates conditions caused by the other. Water-quality degradation may come in the
form of increased turbidity or suspended solids, temperature changes, increased nutrients, salinity changes, or
increased levels of heavy metals, synthetic organic chemicals, and anthropogenic organic chemicals.
3.3.1 Areas Adjacent to the Sanctuary
3.3.1.1 FLORIDA BAY AND EVERGLADES NATIONAL PARK
Florida Bay has been postulated to be a source of poor water quality affecting the reef tract adjacent to the
Florida Keys. Most causes of potentially poor water quality within Florida Bay might be considered to be
natural in origin. However, Fourqurean (1992) pointed out that, historically, freshwater inputs from the
Everglades have been an important influence on the salinity of Florida Bay; the tendency to hypersalinity may
have increased in modern times due to human engineering and diversion of water from the Everglades as a
result of water management in the watershed. Causes of poor water quality include wind-driven transport of
suspended particulates; the presence of soluble nutrients; decomposition; transport of mangrove detritus;
seagrass decomposition with associated biologic activity; and naturally occurring, low DO at night, attributed to
plant respiration. Very little quantitative information is available on the movement of poor quality water from
Florida Bay out onto the reef tract.
Florida Bay has shown no indications of a prevalent anthropogenic problem with contaminants other than
freshwater (Schomer and Drew 1982; SFWMD 1991). The natural quality of Florida Bay water is highly
variable, depending upon prevailing weather and climatic conditions. Periods of extreme cold or warm weather
cause drastic heating or cooling of Bay water. The Bay water then moves out into coastal waters and potentially
2-91
-------
over the reef tract (Shinn et al. 1989). The current and circulatory patterns of Florida Bay and the other
shallow estuaries of south Florida are primarily wind- and tide-driven. Extended windy periods cause highly
turbid water conditions (Lee and Rooth 1972; Lee 1975). This highly turbid water is then available to move out
of the Bay into oceanside coastal waters. Szmant (1991) documents the movement of turbid waters through
several channels between Florida Bay and oceanside waters.
Nutrients have been shown to be elevated in Florida Bay, primarily due to a seagrass die-off whose origins have
not been defined (Fourqurean et al. to be published). Fourqurean (1992) presented water quality data for 26
sample sites near the centers of relatively discrete basins defined by the mud banks in Florida Bay. Samples
were collected eight times between Summer 1989 and Summer 1990. Ranges of nutrients observed by
Fourqurean were as follows:
Nitrate below detection - 6.13 /tM
Nitrite below detection - .94 /tM
Ammonium .02 - 11.03 /tM
Soluble reactive phosphorus below detection - .33 /tM
The relative contribution of nutrients to Florida Bay from anthropogenic sources has not been defined (SFWMD
1991). Szmant (1991) reported levels of all nutrients measured to be higher in samples collected from Florida
Bay (at Long Key) than for samples taken from comparable proximal ocean sites. Several water quality
parameters in Florida Bay and the adjacent estuaries of the Everglades National Park have been defined and are
listed in Tables 2-15 and 2-16.
Shinn et al. (1989) discussed the development of the Florida reef tract and the basis for the formation of the
Florida Keys 6000-10,000 years before the present. As sea level rose and Florida Bay began to fill with water,
reefs opposite the major tidal passes began to decline due to nutrient-laden, high-salinity, variable-temperature
water. Shinn et al. (1989) reported reef development off Long Key to have been stunted from the movement of
water from Florida Bay out to the reef tract, and hypothesized this to be due primarily to the movement of high-
or low-temperature water onto the reef tract.
3.3.1.2 BISCAYNE BAY
3.3.1.2.1 Introduction
Biscayne Bay can be examined as a potential source of poor quality water to the FKNMS. Biscayne Bay
receives various forms of flow from the City of Miami, other local municipalities, and Metro-Dade County.
Water quality for this waterbody has been described in various documents, as listed in Table 2-17. These
documents and unpublished data from the SFWMD and Metro-Dade County Department of Environmental
Resources Management (Metro-Dade CDERM) form the basis for the following assessment of the potential for
water quality of Biscayne Bay to adversely affect water quality within the Sanctuary.
Water quality can be generally described based on physical location within the Bay and on circulation patterns.
For these purposes, the Bay can be divided into north Biscayne Bay, extending from Dumfoundling Bay to
Rickenbacker Causeway; South Bay, from Rickenbacker Causeway to the Arsenicker Keys; and extreme South
Bay, Card Sound, and Barnes Sound (from the Arsenicker Keys in South Bay to US Route 1).
3.3.1.2.2 North Biscayne Bay
Water quality in the north section of Biscayne Bay is largely defined by urban input. This area receives runoff
from the cities of Hialeah, North Miami, Miami Beach, and Miami, as well as from smaller municipalities.
2-92
-------
Table 2-15. Summary of water quality measurements reported from estuaries (Whitewater Bay, Shark Slough Estuary, and
Buttonwood Canal) in Everglades National Park [From SFWMD 1991].
K)
Period
of Study
1937/1938
Mar-May
1955-1957
Aug-Jun
1957-1959
Sep-Feb
1957-1967
Apr-Mar
1962-1967
Jan-Jun
1964-1965
Jun-Jun
1963-1964
1964-1975
Oct-Sep
1965-1966
Salinity
(PPO
26.9-17.5
14.0^40.82
0.0-43.8
0.0-39.8
0.0-40.0
15.5-45.2
22.0-51.5
0-28
0.0-30.3
Water Dissolved pH Turbidity
Temp. Oxygen
(°C) (ppm) . (NTU)
_ _ _ _
19.0-33.0 - - -
14.4-34.0 1.47-6.90 7.47-9.45 —
16.0-32.5 0.0-6.39 7.7-8.3 —
_ _ — ' —
15.8-34.0 - - -
14.0-31.1 - - -
15.5-33.0 43.3-10.4 6.4-8.5 0.0-27.0
14.8-32.2 — — 0.7-9.6
Number
of
Stations
—
4
26
25
44
1
1
9
17
Number
of
Samples
6
187
772
559
1209
89 (
••
145
158
„__
Frequency of
Measurement
Irregular
Weekly
Monthly
Monthly
Monthly
Bimonthly
Weekly
Irregular
Monthly
Sources
Davis (1980)
Finucance and
Dragovitch (1959)
Tabb et al. (1959)'
Tabb and Dubrow (1962a,b)'
Marshall and Jones
unpublished*
Roessler (1970)
Beardsley (1967)
USGS and McPherson"
Tabb et al. (1974)
-------
Table 2-15. Summary of water quality measurements reported from estuaries (Whitewater Bay, Shark Slough Estuary, and
Buttonwood Canal) in Everglades National Park [From SFWMD 1991]. (continued)
Period Salinity Water Dissolved pH Turbidity Number
of Study Temp. Oxygen of
Stations
(PP0 (°Q (ppm) (NTU)
Jan-Dec
1966-1967 23.5-37.4 16.4-31.8 — — — 1
Dec-Feb
1966-1967 0.0-16.8 — 1.3-6.8 — — 22
Oct-Dec
1967-1968 0.0-27.4 — — — — 3
Sep-Nov
1968-1969 2.6-30.9 15.9-32.1 5.0-9.0 — — 8
May-Feb
1971-1972 18.0-36.9 21.0-29.9 - - - 6
Oct-Sep
1973-1974 O.M1.6 13.2-31.8 0.0-9.5 5.8-8.5 0.4-41.0 26
1966-1969 0.0-50.8 13.7-35.5 — - - ' ' 5
Number Frequency of Sources
of Measurement
Samples
66 Weekly Janke(1971)
132 Monthly Tabb and Kenny (1967)
12 Monthly Odum (1971)
Heald (1971)
135 Monthly Clark (1971)
236 Quarterly Lindall et al. (1973)
416 Hourly Davis and Wilsenbeck (1974)
Monthly
42 Irregular Rouse (1970)T
•Citation not available.
-------
Table 2-16. Summary of chemical water quality data collected in estuarine and marine waters of
Florida Bay in Everglades National Park, 1945-1976.
[From SFWMD 1991; Schmidt and Davis 1978]
PESTICIDES 0*g/L)
Aldrin
Dieldrin
Endrin
CUordane
Lindane
ODD
DDE
Ethion
Trithion
Methyl trithion
Malathion
CARBONATE SYSTEM (mg/L)
Calcium Carbonate (CaCO3) 11-315
Bicarbonate (HCCy) 104-439
Carbonate (CO3~) 0-17
NUTRIENTS (mg/L)
NH3-
N02-
NO,-
NO, and NOj'
Total ortho P
Total P
Dissolved PO4'J
Total PO4°
Organic carbon
Total carbon
METALS
Iron (>ig/L)
Magnesium (mg/L)
Strontium (/tg/L)
Sodium (mg/L)
Potassium (mg/L)
Arsenic 0*g/L)
Aluminum (/tg/L)
Manganese (jigfL)
Chlorinated
ND1
0.00-0.05
ND
ND
ND
0.00-0.01
0.00-0.01
Nonchlorinated
ND
ND
ND
ND
Nitrogen
0.00-2.8
0.00-7.0
0.00-39
0.00-6.3
Phosphorus
0.00-1.1
0.00-1.4
0.00-6.9
0.00-15.5
Carbon
0-61
49-104
Dissolved
0.00-810
1.1-1,800
0.2-9,500
8.6-14,000
0.2-14,000
0-10
0.8-40
0-80
DDT
Silvex
Toxaphene
2, 4-D
2, 4, 5-T
Heptachlor
Heptachlor Epoxide
Diazinon
Methyl Parathion
Parathion
Carbon dioxide (COj)
Total inorganic carbon
Organic N
Total N
Kjeldahl N
Total ortho PO/J
Inorganic PO/3
Dissolved PO/J
Silicon
SiO,
SiO/2
LeadOig/L)
Zinc Otg/L)
Copper (/tg/L)
Cobalt (fig/L)
Chromium G*g/L)
Cadmium O^g/L)
Calcium (mg/L)
0.00-0.02
ND
ND
0.00-0.05
ND
ND
ND
0.00-0.01
ND
0.00-1.00
1.2-23
16.8-72
0.36-8.4
0.02-9.3
0.23-2.0
0.07-1.3
0.00-3.5
0.01-0.10
0.00-20
0.00-7.0
0-5
3-40
2^0
ND
0-1
ND
7.3-1,910
•Not detected
bNo units provided in original citation (SFWMD 1991)
2-95
-------
Table 2-16. Summary of chemical water quality data collected in estuarine and marine waters of
Florida Bay in Everglades National Park, 1945-1976.
[From SFWMD 1991; Schmidt and Davis 1978]. (continued)
Lead
Manganese
Arsenic .
Cadmium
Aluminum
Arsenic
Cadmium
Mercury
Iron
Manganese
Lead
NONMETALS
Sulfate
Chloride
Fluorine
MISCELLANEOUS PARAMETERS
PCB Oig/L)
Dissolved Solids (mg/L)
Residue at 180 °C
Calculated
Sum of Constituents
kg/m3
ton/day
Oil and Grease (mg/L)
Color (PCU)
Participate fttg/L)
0-8
0-70
1
ND
Total fmg/L)
2-210
0-12
0-10
0.1-5.6
0-3,100
0-280
0-24
0-3,870
13-25,000
0-1.8
0.00-0.00
161-41,400
0.168-40,200
139-45,400
0.2-35.0
0.57
0-15
5-160
Chromium
Cobalt
Copper
Zirconium
Nickel
Chromium
Cobalt
Lithium
Boron
Copper
Zinc
Total bromine
Total iodine
Biochemical oxygen demand (mg/L)
Hardness (mg/L)
Calcium, Magnesium
Noncarbonate
Sodium Absorption Ratio
Protein
Carbohydrates
10
ND
ND
10
0-47
0-10
0-0.15
1.1-6.0
0-10
1.5-60
0-66
0-0.25
0-7.4
105-8,700
4-8,600
1.0-48"
0.0-18.5"
0.0-15.4"
•Not detected
bNo units provided in original citation (SFWMD 1991)
PCU: platinum-cobalt color unit.
2-96
-------
Table 2-17. Documents summarizing water quality in Biscayne Bay and the Miami watershed.
Alleman, R.W. 198S. Biscayne Bay water quality: baseline data and trend analysis report, 1979-1983.
Metrb-Dade County Department of Environmental Resources Management. 79 pp.
Church, P., K. Donahue, and R. Alleman. 1979. An assessment of nitrate concentration in south Dade
County groundwater. Metro-Dade County Department of Environmental Resource Management.
City of Miami, Department of Public Works. 1986. Storm Drainage Master Plan. Miami, FL.
Corcoran, E.F., M.S. Brown, and A.D. Freay. 1984. The study of trace metals, chlorinated pesticides,
polychlorinated biphenyls and phthalic acid esters in sediments of Biscayne Bay. University of
Miami, Rosenstiel School of Marine and Atmospheric Science, "Miami, FL. 58 pp.
Corcoran, E.F., M.S. Brown, F.R. Baddour, S.A. Chasens, and A.D. Freay. 1983. Biscayne Bay
hydrocarbon study final report. University of Miami Rosenstiel School of Marine and Atmospheric
Sciences, Miami, FL.
McNulty, J.K. 1970. Effects of Abatement of Domestic Sewage Pollution on the Benthos, Volumes of
Zooplaniaon, and the Fouling Organisms of Biscayne Bay, Florida. University of Miami Press,
Coral Gables, FL. 107 pp.
McQueen, D.E. 1980. Underground disposal of storm water runoff at Miami International Airport.
Prepared for Dade County Aviation Department by Lloyd and Associates, Inc., Vero Beach, FL.
83pp.
Metro-Dade County Department of Environmental Resources Management. 1978. An initial assessment of
nitrate concentration of the Biscayne Aquifer in Dade County. Miami, FL.
Metro-Dade County Department of Environmental Resources Management. 1979. A water quality
assessment of metropolitan Dade County, Florida. Miami, FL.
Metro-Dade County Department of Environmental Resources Management. 198la. An inventory of
stormwater pollutant discharges and their loadings into major surface water bodies within Dade
County, Florida. Miami, FL.
Metro-Dade County Department of Environmental Resources Management. 198Ib. Biscayne Bay today: A
summary report on its physical and biological characteristics. Miami, FL.
Metro-Dade County Department of Environmental Resources Management. 1983a. Biscayne Bay: A
survey of past mangrove mitigation/restoration efforts. Draft Final Report. Miami, FL.
Metro-Dade County Department of Environmental Resources Management. 1983b. Biscayne Bay water
quality: Reporting period March 1981-February 1982. Miami, FL.
Metro-Dade County Department of Environmental Resources Management. 1983c. Bottom communities of
Biscayne Bay. Miami, FL. Map with text.
Metro-Dade County Department of Environmental Resources Management. 1985. Biscayne Bay water
quality baseline data and trend analysis report 1979-1983. Miami, FL.
2-97
-------
Table 2-17. Documents summarizing water quality in Biscayne Bay and the Miami watershed.
(continued)
Metro-Dade County Department of Environmental Resources Management. 1987. Biscayne Bay and
Miami River: A water quality summary, Biscayne Bay through 1984 and Miami River through 1985.
Miami, FL.
Metro-Dade County Planning Department. 1962. A planning study of the Miami River. Miami, FL.
Metro-Dade County Planning Department. 1986. Biscayne Bay aquatic preserve management plan. Draft,
September 30, 1986. Miami, FL. 360 pp.
Metro-Dade County Planning Department. 1988. Proposed coastal management element, year 2000 and
2010, comprehensive development master plan. Metro-Dade County, FL. April, 1988. 258 pp.
Miami River Task Force. 1984. Miami River Outfall Study. Miami, FL.
Pierce, R.H., and R.C. Brown. 1986. A survey of coprostanol concentrations in Biscayne Bay sediments.
First quarterly report; Task I. Metro-Dade County. Department of Environmental Resources
Management, Miami, FL. 16 pp.
Ryan, J.D., F.D. Calder, L.C. Bumey, and H.L. Windom. 1985. The environmental chemistry of
Florida estuaries: Deepwater ports maintenance dredging study. Tech. Rep. #1; Port of Miami and
the Miami River. Office of Coastal Management, Florida Department of Environmental Regulation,
Tallahassee, FL. 41 pp. + appendices.
Ryan, J.D., F.D. Calder, and L.C. Bumey. 1985. Deepwater ports and maintenance dredging manual: A
guide to planning, estuarine chemical data collection, analysis, and interpretation. Florida
Department of Environmental Regulation, Tallahassee, FL.
Ryan, J.D., F.D. Calder, L.C. Burney, and H.L. Windom. 1985. The environmental chemistry of
Florida estuaries: Deepwater ports maintenance dredging study. Tech. Rep. Florida Department of
Environmental Regulation, Tallahassee, FL.
Schaiberger, G.E., T.D. Edmond, and C.P. Gerba. 1982. "Distribution of enteroviruses in sediments
contiguous with a deep marine sewage outfall." Water Resources 16:1425-1428.
Shinn, E.A., and E. Corcoran. 1988. Contamination by landfall leachate South Biscayne Bay, Florida.
Final report to Sea Grant, University of Miami, Miami, FL. 11 pp.
2-98
-------
Major tributaries to this area include Snake Creek, Arch Creek, Biscayne Canal, Little River, and the Miami
River. This portion of Biscayne Bay is connected to the ocean via three tidal inlets: Bakers Haulover Inlet,
Government Cut, and Norris Cut. Residence time (i.e., the average time that a theoretical water particle
remains in an area) for North Bay ranges from 3.2 to 13.2 days and is defined by the exchange characteristics
of the area being examined (van de Kreeke and Wang 1984). Transport of water from offshore Miami south to
the Sanctuary depends upon the prevailing physical circulation of the coast and the presence of a longshore
countercurrent moving south (S. Baig, NOAA, personal communication, 1991).
Water quality in North Bay is contaminated by large numbers of anthropogenic sources, including
manufacturing, boat building and repair, urban runoff, raw sewage from illegal connections, degraded systems,
and overflows during heavy rains. Poor water quality exists in several areas of North Bay. Corcoran et al.
(1983; 1984) indicated that 96% of all samples collected had phthalate acid ester (PAE) contamination. In
addition, several sites in north Bay show high levels of organic contamination, generally in conjunction with
marinas or boat repair facilities (SFWMD 1989; Corcoran et al. 1983, 1984). Average chlorophyll, coliform
bacteria, and turbidity are relatively high in north Biscayne Bay and have not shown significant changes over
time. (SFWMD 1989). Biochemical oxygen demand (BOD5) is elevated in north Biscayne Bay and is
particularly high in the Miami River and its outflow.
3.3.1.2.3 Miami River
The Miami River consistently has the poorest water quality in Biscayne Bay. Tributyltin (TBT), an organotin
antifouling paint for boats, has been banned for most uses in the United States because of its severely toxic
effects on marine organisms. TBT was found in water-column samples from the Miami River, ranging from 3
to 90 parts per trillion (pptr) (SFWMD, unpublished data). Florida State standards for this compound in the
water column are 10 pptr in freshwater and 20 pptr in saltwater (SFWMD 1989). Miami River sediments were
found to be of extremely poor quality [United States Army Corps of Engineers (USAGE) 1986]. A 1991
sample series of Miami River sediments failed to pass the toxicity tests necessary for ocean disposal of
sediments (USACE, unpublished data). Potential plans to dredge the Miami River and dispose of sediments
offshore may have implications to the maintenance of acceptable water quality levels within the Sanctuary. In
1990, the USACE dredged the Miami Harbor for a turning basin and disposed of sediments offshore. During
this process, a turbidity plume was created that carried extremely turbid water (>200 NTU) north in Biscayne
Bay to the 79th Street Causeway. Another extremely large turbidity plume was created offshore along the entire
path of the dredging vessel and its disposal site offshore (R. Alleman, SFWMD, personal communication,
1991). Offshore disposal of Miami River sediments may potentially have detrimental effects on the Biscayne
National Park reef tract and the FKNMS reef tract owing to longshore transport from the north.
3.3.1.2.4 Metro-Dade County Offshore Sewage Outfall
The Metro-Dade County offshore sewage outfall discharges treated sewage in 30 m of water off Miami Beach.
This outflow is currently being examined as part of the National Oceanic and Atmospheric Administration
(NOAA) Southeast Florida Outfalls Experiment. Results from Phase 1 of this work show that the movement of
water plumes from this outfall were erratic and tended to move as isolated parcels of water that resist mixing
(Dammann et al. 1991). Countercurrents in this area are documented, making it extremely difficult to predict
the fate of this plume (S. Baig, NOAA, personal communication, 1991). The potential exists for effluent from
this outfall to reach the Sanctuary, but probably in very low concentrations.
2-99
-------
3.3.1.2.5 South Biscayne Bay
South Biscayne Bay extends from Rickenbacker Causeway to the Arsnicker Keys. This area generally realizes
low input of external contamination, attributed to a lower urban density and the presence of only a few external
sources of contamination. Circulation within this area has been modeled by Swakon and Wang (1977).
Exchange with the ocean occurs across three major areas: Bear Cut, the Safety Valve, and Caesars Creek. The
northern part of South Biscayne Bay is a region of high salinity, with waters that are vertically homogeneous
and controlled by flow over the Safety Valve (Chin Fatt and Wang 1987). The southern part of South Bay is
generally well mixed, with salinity contours running north to south owing to restricted circulation (Chin Fatt and
Wang 1987). Water exchange rates in this area are primarily wind- and tide-driven. Residence times range
from 6 to 22 days (SFWMD 1989). Card Sound has poor circulation and long residence times of up to 1 year
(SFWMD 1989; Lee and Rooth 1972). Localized contaminants other than extremely fresh or extremely saline
water would be unlikely to reach the Sanctuary because of the extreme residence times and restricted
circulation.
Potential contaminant sources for South Biscayne Bay include agricultural runoff into adjacent canals, runoff and
leachate from the landfills located at Black Point, freshwater input attributed to canal operation, and hypersaline
water resulting from restricted circulation. Southern Dade County has extensive agriculture that represents a
potential source of agricultural chemicals. Major nitrate loading occurs in the South Bay from the C-103
(Mowry Canal) and C-102 (Princeton Canal) canals (R. Alleman, SFWMD, personal communication, 1991;
Cheesman 1989; Scheidt and Flora 1983) (Figure 2-8). Under the SFWMD Pesticide Monitoring Program,
pesticides have been detected at various places on an irregular basis (SFWMD 1991). Compounds detected in
the water column of local canals include chlordane, DDT, DDE, DDD, and atrazine (Pfeuffer 1991). There
have been no reports of these compounds in the water column in South Biscayne Bay (R. Alleman, SFWMD,
personal communication, 1991). Mercury and arsenic have also been detected in canal and Bay sediments.
However a source for these compounds has not been determined (SFWMD 1989).
Other nonagricultural sources of contaminants include Homestead Air Force Base and the Black Point Landfill
site. Homestead Air Force Base and Military Canal are sources of metals and of organic compounds. Two
EPA-designated Superfund sites are located in Homestead Air Force Base. These are the result of extreme
contamination within select areas of the base (E. Barnett, FDNR, personal communication, 1991). Military
Canal contains, severely toxic components that have not been thoroughly characterized (R. Alleman, SFWMD,
personal communication, 1991). United States Air Force plans to dredge the canal have been indefinitely
delayed. Dredging of this canal poses a severe threat to the water quality of Biscayne National Park and the
FKNMS.
The Black Point landfill site consists of two landfill locations. One, located to the south of Goulds Canal, is the
old South Dade Dump. This site is not lined and has documented leachate problems. The second, the newer
South Dade Landfill, is located north of Goulds Canal. This second site also has leachate problems due to
methods utilized in the initial construction of Cells No. 1 and 2 (Alleman 1990). Ammonia has been
documented in both surface water and groundwater. Ammonia in surface water is about one order of magnitude
above the Metro-Dade County surface-water standard for ammonia (Alleman 1990). Organic contamination was
documented by Shinn and Corcoran (1988) in groundwater between the Black Point landfill and Biscayne Bay.
However, the extent of this contamination was not investigated further (E. Shinn, United States Geological
Survey Center for Coastal Geology, personal communication, 1991). The signature of a surface-water plume
has been documented in the vicinity of the landfill. This signature has been documented for only a short
distance and it has not been found to extend far enough to affect the Sanctuary.
Groundwater movement represents a potential mechanism for the transport of contaminants. The Everglades
SWIM Plan documents the extent of groundwater contamination under South Dade agricultural areas. The
direction, -flow, and movement of groundwater under Biscayne Bay has not been well documented. As a result,
this contaminant transport mechanism (i.e., to the Sanctuary) has not been verified. It is likely that the shallow
aquifer located under the northern Florida Keys and Biscayne Bay has realized saltwater intrusion so that the
2-100
-------
®
Tamiami Canal '•^
3 « Niulictl Mill*
0 t 2 3 4 S 6 K'uomctirt
Cutler Drain
Black Creek Canal
Goulds Canal
C-102 Canal T
C-111
Model Land Canal .-.:.•:.'-..vSS
Florida Keys
National Marine
Sanctuary
Military Canal
Mowry Canal
North Canal
Florida City Canal
Turkey Point
Cooling Canals
25*40' —
25"30 —
Figure 2-8. Biscayne Bay and associated canals.
2-101
-------
movement of fresh or brackish water would be controlled by hydraulic pumping on the mainland. To date,
none of the work necessary to define and further address these problems has been done (E. Shinn, United States
Geological Survey Center for Coastal Geology,, personal communication, 1991).
Freshwater or extremely hypersaline water also represents a potential contaminant to the reef tract. Due to the
restricted circulation of Card Sound, Barnes Sound, and South Biscayne Bay, large volumes of freshwater
introduced into these areas remain as water masses that move as discrete parcels (Lee 1975; Lee and Rooth
1972). This is a potential problem when there are large freshwater releases from the Everglades-South Dade
canals. However, due to the restricted circulation and increased residence time of this region, such large
freshwater releases would most likely damage not the reef tract but Card and Barnes Sounds. Such an
occurrence was documented in 1988, when a large-scale release caused the destruction of bottom habitat in this
area (SFWMD 1991).
3.3.2 Areas Removed from the Sanctuary
It has been suggested that potential contaminant loading in the FKNMS can be attributed to the transport of
anthropogenic compounds from distant sources via water-mass movement. The magnitude of this problem and
the probability of this occurrence depend upon the physical oceanographic and circulation features of the region.
The Loop and Florida Currents are the main oceanographic features. As discussed in greater detail in Section
2.1, the Loop Current is formed by water from Caribbean drift that is piled up by the trade winds on the
western side of the Yucatan Peninsula. This current then funnels into the western side of the channel (that
becomes the Straits of Florida), moving through the Straits as the Florida Current.
Potential geographic sources of contaminants to be carried by these currents include the west coast of Florida,
the Mississippi River drainage and subsequent outflow, contributions from Central America, contributions from
northern South America (Orinoco Flow), and the island nations throughout the Caribbean. Only flows from the
Mississippi and Orinoco Rivers represent sufficient volume flux to remain sufficiently undiluted over large
distances. The large distance of the Orinoco plume from the Sanctuary and the flow's relative dilution rate
decrease the likelihood that this is a major source of contaminants. The Mississippi River represents one of the
world's largest riverine outflows (by volume). Its physical characteristics are such that it is possible for water
to be entrained along the west coast of Florida. Further, there is potential for this riverine-derived water to
move into Sanctuary waters (S. Baig, NOAA, personal communication, 1991). Water flowing out of the
Mississippi River into the Gulf is positively buoyant relative to ambient coastal water. Under conditions of
large outflow and minimal mixing, it is possible that water from the Mississippi River could remain at the
surface, flow around the Gulf, and be entrained into the Loop Current, the major current bringing water through
the Straits of Florida.
Because currents of the southwest Florida shelf are wind-driven, the Loop Current dominates the oceanography
of the eastern Gulf. The full northern extent of intrusion by the Loop Current is variable (S. Baig, NOAA,
personal communication, 1991). As an eastern boundary current within the eastern Gulf of Mexico (west
Florida), the Loop Current turns quickly to the south at the coast, generally in the vicinity of Tampa/Ft.
Meyers/Naples. However, precisely where it turns is variable and it has been traced as far north as Desoto
Canyon by the NOAA National Weather Service Hurricane Center (S. Baig, NOAA, personal communication,
1991). Other potential sources of contaminants have been described by Lee et al. (to be published) and are
made up primarily of discrete parcels of water that move up from depth under various oceanographic and
meteorologic conditions. In addition, Jaap (1984) noted that on rare occasions, entrained Mississippi River
spring runoff is carried along the inshore side of the Florida Current. Salinity reductions to 32 to 34 ppt have
been observed, and this water could serve as a potential source of contaminants. These latter sources should be
considered minor and insignificant.
2-102
-------
4.0 WATER QUALITY
The quality of waters within the bounds of the FKNMS can be assessed through a review of five major studies
that evaluate the present status and trends in water quality of the Florida Keys. These studies were selected
because they provided the best overview of the water quality in the region encompassing the Sanctuary. Three
of the reviewed studies (FDER 1985; Lapointe and Clark 1990; Szmant 1991) occupied sampling stations
throughout the Florida Keys. In two studies (FDER 1987; 1990), sampling efforts were concentrated in limited
areas of the Keys. The locations of the study areas sampled during these investigations are presented in
Figures 2-9 and 2-10. Other studies and data sources that were identified and evaluated in this assessment are
presented in Table 2-18. These other studies were not summarized because they did not add significantly to the
overall assessment of water quality. The raw data were not evaluated because of the extensive time required to
determine sampling locations, methods, and quality control procedures. Additional studies are identified and
summarized in Task 5 — Nearshore and Confined Waters Assessment.
4.1 OVERVIEW
4.1.1 Florida Department of Environmental Regulation — 1985
The FDER (1985) reported the results of an extensive water-quality survey of the Florida Keys. The purpose of
this study was to provide baseline water-quality data in natural and manmade waters of the Florida Keys in
conjunction with a proposal to designate the waters surrounding the Florida Keys as Outstanding Florida
Waters. Water-quality data and samples were collected at 165 stations that ranged from Key Largo to Key
West. An approximately equal sampling effort was expended on the Florida Bay and on the Atlantic Ocean
sides of the Keys. Ninety-five stations in ambient waters were occupied. Most of these stations were
positioned about 0.25 mile from shore, but occasionally stations were located within mangrove creeks. The
remainder of the stations (70) were in artificial waterways, which included canals, boat basins, and marinas
located adjacent to trailer parks, single- and multiple-family dwellings, and commercial operations.
The results of this survey are summarized in Table 2-19. DO levels below 6 mg/L were not observed at the
ambient stations. In contrast, levels in the artificial waterways were hypoxic at a number of locations, and
measurable DO was absent from one sample. The ranges of nutrient parameter concentrations overlapped
between the two station groups, but higher levels were observed at the artificial waterway stations in all cases.
The FDER (1985) reported that a majority of artificial waterway stations had higher levels of total phosphorus,
total Kjeldahl nitrogen, and ammonia. These investigators concluded that many of the artificial waterways
showed evidence of degradation, and they suggested that reduced circulation with influence from stormwater
runoff, septic leachate, and accumulation of floating organic debris contributed to the degraded water quality.
4.1.2 Applied Biology, Inc. — 1985
Applied Biology, Inc. (1985), reported the results of a water-quality survey that was conducted as part of the
Key Largo National Marine Sanctuary Water Quality Assessment and Modeling Program. The objective was to
measure the quality of the seawater, which was related to the biology of the reef tract in the Key Largo National
Marine Sanctuary. This survey was conducted from August 1982 to November 1983. These data were to be
used to calibrate a predictive model. Water-quality parameters measured during the survey included
temperature, salinity, DO, pH, turbidity, nitrate nitrogen, nitrite nitrogen, ammonia nitrogen, and phosphate
phosphorus. Data were collected at stations that had been selected to represent several environments. A series
of stations was aligned along the Atlantic coastline off Key Largo to represent Hawk Channel, the reef tract,
2-103
-------
Legend^
I ] =Florida Department of Enviromental
Regulation [1987]
DA ..;;;/-:
5fc =Florida Department of Enviromental
Regulation [1990]
=Szmant [1991]
Biology, Inc. [19851
• .// •.••-•
FUOROA KEYS NATIONAL MARtt SANCTUARY
ATLANTIC
OCEAN
10 STATUTE »«.eS
IS 30 M.OMETERS
•re 2-9. Sampling locations summarized by (he Florida Depar^^Mof Environmental Regulation, Szmant, and Applied Biology, \nr
-------
Reej
1 Sand Key
2 Looe Key National
Marine Sanctuary
3 Sombrero Reel
4 Aftgatof Reel
5 Molasses Reel
6 Carysfort Reel
Patch Reel
7 Sawyer Keys
8 Newfound Harbor
Patch Reel
9 Hens and Chickens
Patch Reel
to Shark Reel
Canal
14 Boca Chica Submarine
Pens
15 Port Pine Heights
16 Mariner's Resort
17 Doctor's Arm
18 Boot Key Harbor
19 Duck Key
20 Port Antigua
21 Venetian Shores
22 Port Largo
23 Largo Sound Canal
24 Glades Canel (C-111)
11 P«e Channel
12 Rachael Key
13 Little Blackwatei
Sound
ATLANTIC
OCEAN
FLDRDA KEYS NATIONAL
24 sampling sites in Monroe County, Florida representing bank reel,
patch reel, seagrass and canal ecosystems.
Figure 2-10. Sampling locations summarized by Lapointe and Clark [1990].
[Adapted from Lapointe and Clark 1990]
-------
Table 2-18. Additional data sources and documents pertaining to water quality
in the Florida Keys region, including waters of the
Florida Keys National Marine Sanctuary.
REPORTS
Bader R.G., and M.A. Roessler. 1971. An Ecological Study of South Biscayne Bay and Card Sound.
Progress report to the United States Atomic Energy Commission (AT(40-l)-3801-3) and Florida Power
& Light Company.
Nnaji, S. 1987. South Biscayne Bay water quality: A twelve year record for Biscayne National Park. A
report for the Biscayne National Park, National Park Service, Department of the Interior,
Washington, DC. 79 pp.
Schmidt, T.W., and G.E. Davis. 1978. A summary of estuarine and marine water quality information
collected in Everglades national Park, Biscayne National Monument, and adjacent estuaries from 1879 to
1977. A report by the National Park Service, South Florida Research Center, Everglades National Park,
Homestead, FL. 59 pp.
Skinner, R.H., and W.C. Jaap. 1986. Trace metal and pesticides in sediments and organisms in John
Pennekamp Coral Reef State Park and Key Largo Natural Marine Sanctuary. Report to the Florida
Department of Environmental Regulation Coastal Zone Management Office.
Skinner, R.H., and E.F. Corcoran. 1989. John Pennekamp Coral Reef State Park Water Quality Monitoring
Program. Assessment of water quality data from five stations, Volume 1. A report for the Florida
Department of Natural Resources. 47 pp.
Strom, R.N., R.S. Braman, W.C. Jaap, P. Dolan, K.B. Donnelly, and D.F. Martin. 1990. Analysis of
selected trace metals and pesticides offshore of the Florida Keys. Final Report to the Florida Institute of
Government star grant 88-009. 46 pp.
DATA SOURCES
Biscayne Bay National Park
Dade-Metro Department of Environmental Resources Management
Florida Department of Environmental Regulation STORET database
National Oceanographic Data Center
Environmental Protection Agency STORET database
2-106
-------
Table 2-19. Ranges of water-quality parameters measured
during a surrey to support designation of the Florida Keys as
Outstanding Florida Waters. [From FDER 1985]
Water-Quality Parameter
Ambient Stations Artificial
Waterway Stations
(mg/L, except pH) (mg/L, except pH)
Dissolved oxygen
pH
Total phosphorus
Total Kjeldahl nitrogen
Ammonia nitrogen
Organic nitrogen
Nitrate plus nitrite
6.0-9.4
7.0-8.4
0.001-0.054
0.128-0.693
0.051-0.160
0.019-0.580
0.000-0.027
0.0-9.6
7.0-8.3
0.005-0.083
0.196-1.15
0.057-0.239
0.066-0.850
0.002-0.054
2-107
-------
and the ocean. In addition, stations were located at potential system (Sanctuary) inputs, such as the Snake,
Broad, and Caesar Creeks, and in Biscayne Bay.
The results of the water-quality survey are presented in Table 2-20. Seasonal mean temperatures in Biscayne
Bay and the creeks tended to be lower than the offshore mean temperatures. Inshore (creeks and Biscayne Bay)
seasonal mean salinities were lower than those at the offshore stations, which reflected the influence of
freshwater drainage in Biscayne Bay. Strong differences between inshore and offshore mean DO concentrations
were not apparent, but mean oxygen saturations were lower at the inshore stations as a result of the lower
temperatures and salinities observed there. For the offshore station types (Hawk Channel, Florida Reef Tract,
and ocean), the ranges of the mean values suggest that the turbidity tended to decrease as the distance from
shore increased. Levels at the inshore stations tended to be higher than at the reef tract and ocean stations.
Mean nitrogen nutrients did not appear to vary much among the offshore station types and were generally higher
inshore. Distinct differences among mean phosphate levels were not apparent among the station types.
4.1.3 Florida Department of Environmental Regulation — 1987
The FDER conducted an EPA-funded 205(j) study at Marathon, Florida, to determine the impact of five
pollution sources on water quality (FDER 1987). The five pollution sources of interest included
• Raw sewage and petroleum hydrocarbon discharges from live-aboard vessels in marinas
• Discharges from seafood processors and commercial fishing operations
• Discharges from stormwater collection systems
• Treated effluent from sewage treatment plants
• Septic tank leachate through groundwater seepage
To evaluate these pollution sources, five study sites were selected. These study sites were isolated as much as
possible to avoid compounding the impact of the pollution sources and thereby avoid hindering interpretation of
study results. The sites selected for study included
• Faro Blanco Marina (marina with live-aboard vessels)
• City Fish Market (seafood processor)
• Winn-Dixie Shopping Center (parking lot drainage)
• Key Colony Beach (sewage treatment plant)
• 90th Street Canal (leachate from septic tanks)
The primary station at each study site was located in a canal in the immediate vicinity of the pollution source.
A secondary station was located near the mouth of the canal to investigate dispersion of the water-quality
impacts away from the pollution source. In addition, two ambient control stations were also established, one in
Atlantic Ocean waters (i.e., oceanside) and the other in Florida Bay (i.e., Bayside).
Water-quality measurements were collected over 12 months. Temperature, pH, DO concentration, conductivity,
Secchi depth, turbidity, and fecal coliform concentration were measured weekly. Total coliform concentration,
total suspended matter concentration, biochemical oxygen demand (BOD5), chlorophyll a concentration, nitrite,
nitrate, total Kjeldahl nitrogen (total and dissolved components), ammonia (total and dissolved components),
phosphorus (total and dissolved components), and orthophosphate (total and dissolved components) were
measured monthly.
A summary of the water-quality results is presented in Tables 2-21 through 2-24. This summary was prepared
from summary STORET printouts provided by the FDER. Investigators found that DO levels in the canals
were reduced as compared to the ambient controls for the five sites. The levels at the canal mouth stations were
also reduced, indicating that water quality was impaired in the nearshore waters. The pH levels also tended to
be lower at the canal stations as compared to those at the ambient sites. The lowest pH value of 6.9 was
2-108
-------
Table 2-20. Ranges of mean temperature, salinity, dissolved oxygen, dissolved oxygen saturation, pH,
turbidity, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, and phosphate phosphorus
at stations sampled by Applied Biology, Inc. (1985). Stations are grouped by their location —
Hawk Channel, Florida Reef Tract, Ocean, Creeks, and Biscayne Bay.
Temperature (°C)
Salinity (ppt)
Dissolved Oxygen (mg/L)
Dissolved Oxygen
Saturation (%)
PH
Turbidity (NTU)
Ammonia Nitrogen (/tM)
Nitrate Nitrogen (/iM)
Nitrite Nitrogen G*M)
Phosphate Phosphorus (uM)
Hawk
Channel
25.2-25.5
36.13-36.67
6.10-6.23
91-95
8.02-8.09
0.80-1.09
0.45-0.88
0.16-0.20
0.03-0.04
0.14-0.21
Florida Reef
Tract
26.0-26.3
36.67-36.87
6.02-6.32
93-96
8.04-8.13
0.30-0.49
0.56-0.16
0.17-0.20
0.02-0.03
0.14-0.26
Ocean
26.3-26.5
35.92-36.86
5.93-6.09
92-94
8.02-8.12
0.27-0.36
0.56-0.95
0.17-0.23
0.02
0.20-0.22
Creeks
24.7-25.3
34.01-35.77
5.80-6.02
85-95
7.92-8.12
0.91-1.40
1.28-1.81
0.50-0.64
0.06-0.11
0.16-0.21
Biscayne
Bay
24.4-24.7
32.75-35.81
5.79-6.36
85-88
8.01-8.03
0.68-0.76
0.77-1.66
0.21-1.03
0.06-0.11
0.17-0.29
2-109
-------
Table 2-21. Ranges of water temperature, conductivity, dissolved oxygen, and pH measured at stations occupied
during the 2050) study conducted at Marathon, FL. [From FDER STORE! database1]
Study Site
/
Faro Blanco Marina
City Fish Market
Winn Dixie
Shopping Center
Key Colony Beach
Sewage Treatment Plant
90th Street Canal
Bayside ambient
Oceanside ambient
Station
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Control
Control
Temperature
(°Q
15.1-31.3
14.6-31.1
17.0-31.5
14.7-31.1
17.1-31.5
13.0-31.2
15.9-31.7
15.5-31.8
11.9-31.1
12.2-31.2
15.1-30.9
15.3-31.4
Conductivity
(mmho/cm)
52.4-57.8
52.2-58.1
50.6-58.4
52.2-58.6
46.4-58.1
51.2-57.9
50.7-56.9
51.6-56.8
50.5-57.2
51.2-57.2
51.5-58.1
51.8-57.5
Dissolved
Oxygen
(mg/L)
2.8-7.3
3.2-7.4
0.0-7.4
3.7-7.8
0.2-7.2
3.6-9.0
3.2-9.3
2.9-9.3
0.0-7.4
2.5-10.0
4.4-8.4
5.1-8.0
Dissolved
Oxygen
(% saturation)
31.8-79.5
41.0-90.8
0.0-97.4
47.4-93.4
-
42.1-107.6
36.7-110.3
0.0-86.4
32.1-119.0
56.8-100
63.0-101.3
pH
7.4-7.9
7.4-7.9
6.9-7.8
7.3-7.9
7.2-7.9
7.4-8.0
7.4-8.1
7.5-8.1
7.0-7.9
7.5-8.0
7.6-8.1
7.6-8.1
*: Minimum values reported in the STORET database for some ranges are detection limits and not numerical
measurements.
2-110
-------
Table 2-22. Ranges of nitrite, nitrate, total Kjeldahl nitrogen, and ammonia measured in water samples collected at stations occupied
during the 205 (j) study conducted at Marathon, FL. [From FDER STORET database*]
Study Site
Faro Blanco Marina
City Fish Market
Winn Dixie
Shopping Center
Key Colony Beach
Sewage Treatment
Plant
90th Street Canal
Bayside ambient
Oceanside ambient
Station
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Control
Control
Nitrite
(mg/L)
0.006
0.006
0.006
0.006
0.006
0.006-
0.006-0.220
0.006
0.006
0.006
0.006
0.006
Nitrate
(mg/L)
0.06
0.06
0.06-0.09
0.06
0.06-0.08
0.06-0.07
0.06-0.12
0.06
0.06-0.08
0.06
0.06
0.06-0.46
Total
Kjeldahl
Nitrogen
(mg/L)
0.31-0.68
0.21-0.54
0.65-1.79
0.19-0.51
0.18-0.58
0.23-0.55
0.33-0.60
0.27-0.56
0.26-0.53
0.11-0.62
0.20-0.52
0.06-0.49
Total
Dissolved
Kjeldahl
Nitrogen
(mg/L)
0.25-0.63
0.11-0.54
0.37-1.08
0.02-0.56
0.19-0.55
0.19-0.53
0.09-0.59
0.25-0.50
0.16-0.53
0.15-0.56
0.11-0.45
0.18-0.45
Total
Ammonia
(mg/L)
0.02-0.14
0.02-0.07
0.05-0.42
0.02-0.14
0.02-0.08
0.02-0.07
0.02-0.15
0.02-0.13
0.02-0.09
0.02-0.06
0.02-0.06
0.02-0.07
Dissolved
Ammonia
(mg/L)
0.03-0.10
0.02-0.08
0.03-0.31
0.02-0.12
0.02-0.08
0.02-0.10
0.03-0.11
0.02-0.13
0.02-0.08
0.02-0.06
0.02-0.07
0.02-0.07
•: Minimum values reported in the STORET database for some ranges are detection limits and not numerical measurements.
-------
Table 2-23. Ranges of phosphorus, orthophosphate, and chlorophyll a measured in water samples collected at stations
occupied during the 205(j) study conducted at Marathon, FL. [From FDER STORET database*]
Study Site
Faro Blanco Marina
City Fish Market
Winn Dixie
Shopping Center
Key Colony Beach
N> Sewage Treatment Plant
*-*
10 90th Street Canal
Bayside ambient
Oceanside ambient
Station
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Control
Control
Total
Phosphorus
(mg/L)
0.010-0.030
0.010-0.230
0.030-0.136
0.010-0.023
0.010-0.040
0.010-0.020
0.020-0.087
0.010-0.040
0.010-0.040
0.01-0.031
0.010-0.020
0.010-2.000
Dissolved
Phosphorus
(mg/L)
0.010-0.020
0.010-0.190
0.020-0.084
0.010-0.020
0.010-0.027
0.010-0.014
0.010-0.060
0.010-0.040
0.010-0.023
0.010-O.020
0.010-0.013
0.010-2.000
Total
Orthophosphate
(mg/L)
0.002-0.018
0.002-0.008
0.009-0.082
0.002-0.008
0.002-0.010
0.006-0.005
0.003-0.060
0.002-0.029
0.002-0.006
0.002-0.007
0.002-0.006
0.002-0.006
Dissolved
Orthophosphate
(mg/L)
0.004-0.016
0.002-0.006
0.005-0.085
0.002-0.008
0.002-0.010
0.002-0.005
0.002-0.056
0.002-0.029
0.002-0.016
0.002-0.007
0.002-0.005
0.002-0.005
Chlorophyll
0*g/L)
0.00-4.46
0.00-1.79
0.00-69.38
0.00-10.25
0.00-8.56
0.00-3.42
0.00-8.26
0.00-5.98
0.00-29.02
0.00-5.56
0.00-29.16
0.00-4.41
*: Minimum values reported in the STORET database for some ranges are detection limits and not numerical measurements.
-------
Table 2-24. Ranges of biochemical oxygen demand, fecal coliform concentration, total
suspended matter concentration, turbidity, and Secchi depth measured in water samples
collected at stations occupied during the 2050') study conducted at Marathon, FL.
[From FDER STORE! database*]
Study Site
Station Biochemical Fecal Total Turbidity Secchi
Oxygen Coliform Suspended Depth
Demand Matter
(mg/L) (#/100mL) (mg/L) (NTU) (cm)
Faro Blanco Marina
City Fish Market
Winn Dixie
Shopping Center
Key Colony Beach
Sewage Treatment Plant
90th Street Canal
Bayside ambient
Oceanside ambient
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Canal
Canal mouth
Control
Control
0.4-1.2
0.1-0.9
1.8-6.2
0.3-1.6
0.3-2.2
0.0-1.2
0.2-1.2
0.3-1.4
0.5-1.5
0.2-2.0
0.0-1.1
0.0-0.8
5-2,100
0-1,960
0-910
0-300
0-990
0-18
0-3,400
0-210
0-1,220
0-65
0-120
0-12
1-15
2-19
4-15
3-14
3-9
2-40
4-12
4-14
3-14
3-17
0.6-15
2-25
0.7-4.9
0.4-8.1
0.8-12.0
0.7-5.8
0.2-2.1
0.2-3.6
0.9-4.2
0.8-14.5
0.7-4.6
1.4-9.0
0.7-9.2
0.6-33.0
137-264
112-231
36-295
140-259
208-368
104-178
137-300
155-239
137-295
71-152
122-257
43-290
': Minimum values reported in the STORET database for some ranges are detection limits and not numerical
measurements.
2-113
-------
observed on two occasions at the station near the seafood processing plant. Elevated fecal coliform
concentrations were observed at the three sites exposed to discharges of raw sewage, whereas fecal coliforms
evidently somewhat controlled at the sewage treatment plant site. BOD5 was elevated at the five canal sites as
compared to BOD3 at their respective ambient sites.
Nitrate and nitrate concentrations were similar among the canal, canal mouth, and ambient sites. Ammonia
concentrations were similar, except near the seafood processing plant, where concentrations at the canal station
were elevated in comparison to those at the offshore ambient site. Total Kjeldahl nitrogen concentrations were
elevated at three canal stations but not at the canal station exposed to septic leachate. Total phosphorus
concentrations were elevated at the canal stations located near the marina and seafood processing plant.
Orthophosphate and chlorophyll a were also elevated at three canal sites.
4.1.4 Florida Department of Environmental Regulation — 1990
The FDER conducted an extensive study to assess and document the water quality in Boot Key Harbor and to
examine the impacts of various pollution sources on the water quality, as reported by FDER (1990).
Investigators measured water-quality parameters over 1 year (January 1989 to February 1990) at 14 stations.
Stations were designated by STORET number and divided into three major categories. Stations were located in
artificial (manmade) canals and basins, Outstanding Florida Waters within the Harbor, and offshore Outstanding
Florida Waters. Station designations and their respective locations are summarized in Table 2-25.
Temperature, conductivity, pH, and DO concentrations were determined during monthly surveys, using in situ
instrumentation. Also, water samples were collected with a Van Dora sampler. Samples were analyzed to
determine fecal coliform concentration and turbidity at monthly intervals. Chlorophyll a, total Kjeldahl
nitrogen, total phosphorus, and nitrate plus nitrite concentrations were determined every other month.
A summary of the water-quality results of the program are presented in Table 2-25. Mean DO concentrations
in artificial canals and basins ranged from 3.4 to 4.9 mg/L as compared to mean levels of 5.9 to 6.5 mg/L at
the ambient control stations. Mean concentrations at the Outstanding Florida Waters Harbor stations were
intermediate between the artificial waterway and ambient control stations, ranging from 4.8 to 5.7 mg/L. The
FDER (1990) attributed this pattern to differences in flushing and the nature of the poorly flushed canals to
serve as sinks for organic matter. The FDER (1990) also noted that during the summer the DO values in the
study area were lower because the oxygen solubility decreased as temperature increased. However, DO levels
in the artificial canals and basins were reduced throughout the year.
Mean pH levels for all stations exceeded 7.0; however, the mean levels at the artificial canal and basin stations
were lower than at the ambient control stations. At one station (2804-2298), pH values below 7.0 were
observed. The FDER (1990) suggested that this might be due to the presence of sulfides generated from
anaerobic decomposition of organic material in the sediments at this station. The sulfides would lower pH in
the water column.
The highest mean concentrations of coliform bacteria were observed at artificial waterway stations. They
exceeded concentrations at ambient control stations, where the coliform bacteria were practically absent.
Because coliform bacteria commonly are considered as indicators of sewage in water and because these
organisms do not survive well at higher salinities, their presence probably indicated substantial contamination.
The FDER (1990) concluded that leakage from septic tanks and discharges from live-aboard vessels were
responsible for these elevated coliform counts.
In addition, the two Outstanding Florida Waters Harbor stations that had elevated fecal coliform levels were
located in close proximity to live-aboard facilities. The FDER (1990) observed that the highest fecal coliform
counts generally occurred during the winter months at the stations where live-aboard vessels were anchored on a
2-114
-------
Table 2-25. Mean values for water quality parameters measured at Boot Key Harbor Study
stations. [From FDER 1990]
Station
Location
Total Fecal Kjeldahl Total Chlorophyll a pH Turbidity
Dissolved Coliform" Nitrogen Phosphorus
Oxygen
(mg/L) (*/100mL) (mg/L) (mg/L) QigfL) (NTU)
Artificial Waterway
Station 2804-2290" Boat basin marina; 4.9
operational pumpout
facilities
2804-2292 Residential canal;
septic tank systems
2804-2299 Basin with commer-
cial fishing docks
2804-2298 Boat basin; poor water
circulation; exposure to
charter fishing-boat, live-
aboard, septic-tank dis-
charges
Outstanding Florida Waters
Harbor
Station 2804-2289 Near seafood marine 4.8
2804-2291 Near no site where dis- 5.5
charges could impact
water quality
2804-2294 Edge of tidal channel; well- 5.1
flushed by tidal currents.
Potential exposure to septic-
tank, surface-runoff dis-
charges from nearby subdivision.
2804-2295 Near condominium complex 5.6
with STP discharging into
injection well
2804-2296 Dredged area used by live- 5.6
aboards as main anchorage
2804-2316 Adjacent to navigational 5.1
channel; natural substrate
inhabited by turtle grass
2804-2297 Near live-aboards, with no 5.4
pumpout facility
2804-2317 Natural turtle grass area 5.6
Offshore (Outside Harbor)
Station 2804-2288 Ambient control station 5.9
In turtle seagrass bed
2804-2293 Ambient control station 6.5
In hard-bottom, with turtle
seagrass patches
45.1
13.1
2.6
0.513
0.031
0.444
0.444
0.027
0.029
1.6 0.417 0.027
4.4 0.474 0.029
8.2 0.479 0.035
7.6
15.5 0.470 0.039
0.3 0.397 0.029
0.0 0.406 0.027
1.4
1.0
1.2
1.0
1.6
1.5
1.9
1.1
1.1
7.7
7.7
7.6
7.9
7.9
2.5
4.1
4.5
3.4
5.0
34.2
13.6
0.469
0.493
0.446
0.037
0.037
0.041
1.7
1.0
5.7
7.7
7.6
7.5
2.1
2.5
2.2
7.7 2.8
7.8 2.2
7.8 2.2
7.8 3.0
7.8 3.0
3.8
1.9
1.1
NTU: Nephclomelric turbidity unit.
STP: Sewage treatment plant.
I'STORET number.
kNTU: Geometric mean.
2-115
-------
seasonal basis, and that the highest coliform counts were observed at stations associated with on-site disposal
systems or septic tanks after a heavy rainfall.
Mean total Kjeldahl nitrogen and total phosphorus concentrations were elevated at the artificial waterway
stations as compared to the ambient control stations. Outstanding Florida Water harbor stations exhibited
concentrations that were intermediate between these two station groups. The FDER (1990) suggested that
important factors in the nutrient enrichment at the artificial waterway stations were anthropogenic sources of
nutrients (i.e., sewage, industrial discharges, and surface runoff) and the decomposition of wind-blown weed
wrack and other organic debris trapped in the canals. Mean chlorophyll a concentrations also were elevated at
some of the artificial waterway stations, compared to the ambient control stations. Elevated mean turbidities
were noted at artificial waterway and Outstanding Florida Waters stations compared to the ambient control
stations.
4.1.5 Lapointe and Clark — 1990
Lapointe and Clark (1990) conducted a study between 12 September 1989 and 19 September 1990 to investigate
the water quality in nearshore areas throughout the Florida Keys. During this study, water-quality parameters
were measured at 30 monitoring sites. The monitoring sites were located in canals, seagrass beds, patch reefs,
and bank reefs. Sampling sites located in the FKNMS were
• Canals
Boca Chica "sub pens," Port Pine Heights, Doctors's Arm, Mariner's Resort, Boot Key, Duck
Key, Port Antiqua, Venetian Shores, Ocean Shores, Largo Sound, and Glades Canal (C-lll)
• Seagrass beds
Pine Channel, Rachel Key, Blackwater Sound
• Patch reefs
Newfound Harbor, Sawyer Key, Hens and Chickens, and Shark Reef
• Bank reefs
Sand Key, Looe Key National Marine Sanctuary, Sombrero Reef, Alligator Reef, Molasses Reef,
and Carysfort Reef
Sampling at each site was performed along an onshore/offshore transect. Samples were collected at 0.5 m
below sea surface and at 0.5 m above the seafloor. Water-quality parameters determined during the study
included temperature, salinity, turbidity, pH, and chlorophyll a concentration. Nutrient water-quality
parameters included measurements of DO, nitrate plus nitrite, ammonium, soluble reactive phosphorus, total
dissolved nitrogen, total dissolved phosphorus, participate carbon, participate nitrogen, and paniculate
phosphorus. Temperature, salinity, pH, and DO were measured in situ. Water samples were collected using a
S.O-L Niskin bottle. Three aliquots from each water sample were filtered and analyzed for chlorophyll a,
paniculate phosphorus, and paniculate carbon and nitrogen. Chlorophyll a was determined by fluorometry.
Paniculate carbon and nitrogen were determined by using an elemental analyzer, and paniculate phosphorus was
determined via persulfate oxidation. Filtered-water samples were analyzed for ammonium, nitrate plus nitrite,
total dissolved nitrogen, total dissolved phosphorus, and soluble reactive phosphorus. Ammonium, nitrate plus
nitrite, total dissolved nitrogen, and total dissolved phosphorus were determined with an autoanalyzer. Soluble
reactive phosphorus was determined by spectrophotometry. Turbidity was determined with a turbidimeter.
A summary of the results for this study is presented in Tables 2-26 and 2-27. Water temperature at the study
sites varied with season, whereas salinity generally was consistent over time at individual study sites and more
variable among the sites, depending on location. DO concentrations generally were higher at stations located
offshore (bank reef stations) as compared to the stations in the nearshore. Although not specifically reflected in
the mean DO concentrations of Table 2-26, oxygen. levels at some canal stations were at time hypoxic,
particularly during the summer. At Doctor's Arm Canal, DO concentrations were below 4 mg/L near the
surface and bottom at several stations during summer and winter; at one near-bottom location, the concentration
2-116
-------
Table 2-26. Mean values of water temperature, salinity, turbidity, pH, chlorophyll a, and
dissolved oxygen at locations sampled by Lapointe and Clark (1990).
Location
Sand Key
Looe Key National
Marine Sanctuary
Sombrero Reef
Alligator Reef
Molasses Reef
Carysfort Reef
Sawyer Key
Newfound Harbor
Hens and Chickens
Shark Reef
Pine Channel
Rachael Key
Little Blackwater
Sound
Boca Chica
Submarine Pens
Port Pine
Heights
Survey
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Temperature
(°Q
29.77
24.74
30.20
24.90
29.96
25.14
30.65
24.48
29.92
24.76
30.18
24.44
30.28
23.98
30.83
24.19
30.16
25.19
30.56
24.80
31.67
22.67
29.34
25.06
31.00
26.94
29.96
23.16
31.49
23.39
Salinity
(PPO
36.8
36.2
36.6
36.3
36.5
36.4
36.8
36.5
35.6
36.4
35.4
36.5
38.7
37.4
36.5
37.1
36.6
36.2
35.6
36.4
37.5
38.0
38.7
38.1
29.9
42.4
42.5
40.0
39.0
37.8
Turbidity
(NTU)
0.46
0.57
0.20
0.47
0.60
0.27
0.34
0.15
0.16
0.27
0.17
0.57
0.57
1.20
1.12
0.66
0.59
0.41
0.23
0.17
0.57
0.36
1.60
1.78
0.70
3.86
0.63
1.12
0.49
0.48
pH
7.96
7.97
8.00
7.72
8.02
8.02
8.01
8.02
7.90
8.01
8.02
7.73
8.12
8.03
7.98
8.12
7.96
8.00
7.85
8.02
8.07
Chlorophyll a
(Mg/L)
0.087
0.031
0.091
0.049
0.044
0.230
0.038
0.422
0.046
0.250
0.052
0.482
0.112
0.156
0.081
0.221
0.058
0.186
0.053
0.141
0.075
0.069
0.059
0.600
0.160
0.305
0.092
0.542
0.114
Dissolved
Oxygen
(mg/L)
6.64
6.58
6.25
6.42
6.58
6.71
6.05
6.77
5.86
6.41
5.81
6.51
6.52
6.83
5.66
6.65
6.49
6.77
6.14
6.65
6.49
7.03
6.42
6.60
6.40
5.66
5.35
6.04
5.30
6.40
2-117
-------
Table 2-2$. Mean values of water temperature, salinity, turbidity, pH, chlorophyll a, and
dissolved oxygen at locations sampled by Lapointe and Clark (1990). (continued)
Location
Doctor's Arm Canal
Mariner's Resort
Canal
Boot Key Harbor
Duck Key Canal
Port Antigua Canal
Venetian Shores
Port Largo Canal
Largo Sound Canal
Glades Canal
(C-I11)
Survey
Summer
Winter
'Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Temperature
(°C)
30.02
23.79
27.20
22.31
29.40
25.48
29.51
25.46
30.42
22.00
30.48
24.96
29.90
24.02
31.80
26.14
31.10
24.20
Salinity
(PPO
37.0
38.1
41.0
38.8
37.8
37.9
36.9
38.0
39.7
40.3
40.9
37.8
37.5
32.6
46.8
39.2
33.0
42.2
Turbidity
(MTU)
1.43
1.58
1.85
1.43
2.34
4.59
5.69
8.62
0.74
0.50
0.52
1.38
0.38
3.14
0.42
0.85
2.10
0.69
pH
7.76
7.82
7.94
8.04
8.00
7.60
7.86
7.18
7.76
7.58
7.72
7.56
7.90
Chlorophyll a
0*g/L)
2.374
0.263
0.396
2.350
0.762
0.257
0.295
0.517
0.299
0.675
0.111
15.510
0.324
1.177 .
0.206
0.801
0.415
Dissolved
Oxygen
(mg/L)
3.65
4.41
4.75 .
5.46
5.07
5.84
5.70
6.25
5.38
6.77
4.92
5.57
4.17
5.02
4.41
5.29
2.78
6.20
2-118
-------
Table 2-27. Mean values of nutrient parameters at locations sampled by Lapointe and Clark (1990).
Location
Sand Key
Looe Key National
Marine Sanctuary
Sombrero Reef
Alligator Reef
Molasses Reef
Carysfort Reef
Sawyer Key
^Newfound Harbor
Hens and Chickens
Shark Reef
Pine Channel
Rachael Key
Little Blackwater
Sound
Boca Chica
Submarine Pens
Port Pine Heights
Doctor's Arm
Canal
Surrey
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Wuiter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Summer
Winter
Nitrate
plus
Nitrite
0»M)
0.51
0.17
0.62
0.07
0.51
0.45
0.27
0.11
0.23
0.18
0.25
0.19
0.13
0.17
0.21
0.28
0.30
0.12
0.11
0.05
1.42
0.32
0.25
0.39
0.40
2.59
0.78
0.52
1.86
0.99
0.79
1.52
Ammonium
O.M)
0.09
UD
0.10
UD
0.08
0.09
UD
UD
UD
UD
0.25
0.21
0.13
0.11
0.11
0.11
UD
0.14
0.39
UD
1.61
0.27
0.20
0.19
1.60
2.20
0.17
0.20
0.21
0.64
1.63
2.18
Soluble
Reactive
Phosphorus
(MM)
0.12
0.07
0.08
0.04
0.07
0.04
0.04
0.03
UD
0.03
UD
0.04
0.08
0.06
0.12
0.05
0.06
0.05
0.06
UD
0.10
0.06
0.12
0.06
0.10
0.06
0.18
0.07
0.16
0.09
0.35
0.10
Total
Dissolved
Nitrogen
(MM)
2.66
2.40
2.85
4.19
3.33
2.04
3.00
4.66
2.32
2.14
2.74
3.55
4.77
3.19
4.95
2.88
2.52
2.89
2.21
2.25
4.57
2.97
4.21
3.97
13.30
8.12
5.84
4.18
6.82
4.59
6.93
4.97
Total
Dissolved
Phosphorus
(MM)
0.35
0.28
0.33
0.22
0.26
0.16 .
0.12
0.13
0.13
0.13
0.06
0.22
0.34
4.09
0.37
0.31
0.11
0.13
0.13
0.14
0.36
0.12
0.35
0.38
0.20
0.13
0.42
0.10
0.39
0.14
0.79
0.28
Paniculate
Carbon
(Mg/L)
175.34
146.96
188.40
132.59
203.86
74.60
121.43
73.41
98.88
76.87
81.02
158.63
180.93
225.30
209.53
148.30
129.81
104.41
83.67
71.79'
148.30
113.28
314.56
571.74
236.40
476.91
143.61
145.10
189.03
153.46
415.13
330.34
Paniculate
Nitrogen
(Mg/D
18.95
12.32
18.17
9.63
10.06
11.83
15.76
7.81
13.85
9.12
12.00
22.54
23.09
18.08
23.17
12.68
14.35
9.10
12.32
8.47
20.96
9.50
32.13
22.41
21.50
29.39
20.72
19.67
27.35
14.62
63.30
30.35
Paniculate
Phosphorus
(Mg/L)
3.38
2.80
3.22
2.20
3.43
2.03
3.50
2.10
2.82
1.87
2.85
3.05
3.73
3.67
5.65
2.98
3.12
1.22
2.90
8.47
3.35
2.46
8.30
3.08
3.70
4.82
3.58
2.95
3.67
3.55
13.23
7.33
2-119
-------
Table 2-27. Mean values of nutrient parameters at locations sampled by Lapointe and Clark (1990). (continued)
Location
Surrey Nitrate Ammonium Soluble Total Total Particulate Particular Particu1
plus Reactive Dissolved Dissolved Carbon Nitrogen Phosp
Nitrite Phosphorus Nitrogen Phosphorus
0*M) (MM) (MM) (MM) 0
-------
was 0.36 mg/L. Extremely low concentrations were also observed near the bottom at one Boot Key Harbor
sampling station (0.06 mg/L) and at one near-bottom sampling station at Glades Canal (0.16 mg/L) during the
summer. Reduced DO concentrations also were observed at other canal sampling sites, including Boca Chica
Submarine Pens, Port Pine Heights, Mariner's Resort Canal, Port Antigua Canal, Port Largo Canal, and Largo
Sound Canal. DO concentrations occasionally were reduced (<4 mg/L) at sampling sites that Lapointe and
Clark (1990) designated as seagrass sites (i.e., Pine Channel and Little Blackwater Sound).
Dissolved nutrient concentrations generally were elevated at designated canal sites as compared to designated
bank reef sites, the latter of which were located in offshore waters of the Sanctuary. Mean ammonium levels at
the canal sites ranged from 0.09 to 2.96 and from 0.16 to 2.43 /xM in the summer and winter, respectively. By
comparison, mean ammonium levels at bank reef sites ranged from undetected to 0.25 /tM and undetected to
0.21 /iM (summer and winter, respectively). Mean nitrate plus nitrite levels at the bank reef sites ranged from
0.2S to 0.62 /iM and from 0.07 to 0.47 /iM in the summer and winter, respectively. Mean concentrations of
these nutrients at canal sites were 0.26 to 1.86 and 0.23 to 2.73 /iM at the canal sites (summer and winter,
respectively). Mean soluble reactive phosphorus levels at the canal sites ranged from 0.06 to 0.7S and from
0.06 to 0.28 /tM in the summer and winter, respectively. By comparison, mean soluble reactive phosphorus
levels at the bank reef sites ranged from undetected to 0.16 and 0.03 to 0.07 /iM (summer and winter,
respectively). Lapointe and Clark (1990) suggested that these elevated levels, particularly soluble reactive
phosphorus, were associated with development around the canals. This suggestion was based on the fact that the
soluble-reactive phosphorus concentration at the station located in the Boca Chica submarine pens, where there
has been little development, was similar to the corresponding station located in Outstanding Florida Waters.
These investigators concluded that this indicated no significant enrichment of soluble reactive phosphorus within
this canal.
4.1.6 Szmant - 1991
As part of the first phase of the SEAKEYS Program, Szmant (1991) investigated the water quality at four sites
on the ocean side of the Florida Keys. The objective of the study was to collect data on the distribution of
nitrogen and phosphorus macronutrients and chlorophyll a in the water and sediments of the Florida Reef Tract.
Although the primary emphasis of this Program was to determine select nutrients in the vicinity of the Florida
Reef Tract, the surveys were performed in a manner to provide information from nearshore oceanic waters.
During this phase of the study, Szmant (1991) sampled stations located on seven transects. For purposes of
sampling, Hawk Channel marked the point of separation of inshore areas (where there are few patch reefs) from
the offshore Florida Reef Tract and associated waters.
Transects were oriented inshore/offshore from shore locations where potential sources of nutrients were located.
Sampling at inshore stations was expected to result in elevated nutrient levels, particularly in developed areas or
within inter-Key passes. At offshore stations, oligotrophic (low-nutrient) conditions were expected. Four
stations minimum were located on each transect, with stations located in both inshore and offshore areas.
Transects were located at the following locations (as shown in Figure 2-9)
• Biscayne National Park
6 stations during summer and winter (high and low tide)
• Long Key
13 stations sampled during summer and winter (high and low tide)
• Key Largo
35 stations during summer and 13 stations during winter
• Looe Key
7 stations sampled during spring arid summer
2-121
-------
Water samples were collected with Niskin bottles. Samples were collected 1 m below the sea surface and 1 m
above the seafloor. In the laboratory, total nitrogen and phosphorus concentrations were determined from
unfiltered subsamples. Filtered subsamples were analyzed to determine chlorophyll a, nitrate plus nitrite,
phosphate, and ammonium concentrations.
Szmant (1991) presented the data for the concentrations of the measured parameters as bar graphs. Actual
values will be published later. Inshore/offshore trends and concentrations were examined and interpreted from
Szmant's (1991) graphical presentation.
At the Biscayne National Park sampling site, Szmant (1991) observed that nitrogen in the water column was
primarily organic or particulate. Inshore concentrations at Caesar's Creek ranged from less than 10 to about 40
/xM; offshore concentrations at Pacific Reef ranged from below detection to about 35 /xM. Szmant (1991)
observed that storms had an important impact on total nitrogen levels. During stormy periods, when
particulates were suspended in the water column, total nitrogen concentrations exceeded 40 /xM in some
samples. During calm periods, concentrations of total nitrogen generally were between 8 and 12 xxM.
Ammonium concentrations generally were below detection limits. However, a concentration of approximately
1.25 /xM was observed on one survey at Pacific Reef. Szmant reported that nitrate concentrations were
generally below 0.3 xtM. However, because the methods indicated that water samples were analyzed for nitrate
plus nitrite, it was assumed that this concentration was for nitrate plus nitrite. Phosphate levels were generally
less than about 0.1 xtM. Total phosphorus levels were generally about 0.25 xtM or less, but total phosphorus
did reach concentrations of 1 fiM during storms. Chlorophyll a concentrations were low, typically not
exceeding 0.25 /xg/L.
Szmant (1991) observed that organic and inorganic concentrations of nitrogen and phosphorus were higher in
canals and inshore stations at the Key Largo study site. During the summer survey, total nitrogen and
phosphorus concentrations at the canal stations reached approximately 38 and 4.5 xxM, respectively.
Concentrations at the offshore stations did not exceed approximately 13 and 1.3 /xM for total nitrogen and
phosphorus, respectively. Ammonium reached concentrations exceeding 0.3 iiM at four of seven inshore
stations and was not detected at the seven stations located farthest offshore. Similarly, nitrate plus nitrite
concentrations at six of seven of the inshore stations exceeded 0.5 /xM but did not exceed 0.5 /xM at any of the
seven offshore stations during the summer survey. Chlorophyll a also was elevated at some of the canal and
inshore stations during the summer survey, exceeding 1 /xg/L in one instance. During this survey, chlorophyll a
concentrations at the offshore stations were less than 0.4 xtg/L.
Szmant (1991) observed that the nutrient concentrations observed at Long Key generally were higher than those
observed at the Biscayne National Park and Key Largo study sites and that the nutrient concentrations were
higher at stations located in Florida Bay than at oceanside stations. Total nitrogen, ammonium, and nitrate plus
nitrite concentrations tended to be higher during low tide than high tide, an observation that Szmant (1991)
suggested may indicate that Florida Bay was a source for elevated nitrogen levels observed at some stations
located on the Florida Reef Tract. On one occasion, the ammonium concentration at one Bayside station
reached 2 /xM. During low tide, nitrate plus nitrite concentrations exceeded 1.5 xtM at several bayside, inshore,
and Hawk Channel stations. No obvious differences between Florida Bay, inshore, and offshore waters were
noted for phosphate levels; phosphate concentrations generally were between 0.20 and 0.25 xtM. Total
phosphorus concentrations generally were low (<0.25 /xM), and higher concentrations were sometimes
observed at the offshore stations. Chlorophyll a concentrations were higher than those observed at the Biscayne
National Park and Key Largo study sites, exceeding 0.5 /xg/L on only two occasions.
Szmant (1991) reported water-quality data for only one sampling period at the Looe Key study site. Total
nitrogen concentrations ranged from approximately 10 to 15 xiM and obvious inshore/offshore trends were not
apparent. Higher concentrations of ammonium and nitrate plus nitrite were observed at the station located in
Bahia Honda Channel, reaching or exceeding 0.5 and 1 xiM, respectively. Total phosphorus concentrations
2-122
-------
were consistently less than 0.5 /iM and phosphate concentrations did not exceed 0.15 /xM. With the exception
of a sample collected within a wrack of decaying seagrass, chlorophyll a concentrations were generally less that
0.5 ^g/L.
Szmant (1991) concluded that nutrient and chlorophyll a concentrations were elevated at inshore areas,
particularly marinas and developed canals, in the upper Keys (i.e., Biscayne National Park and Key Largo
sampling sites); however, the water quality improved with increasing distance from shore, approaching
oligotrophic conditions within a few hundred meters of shore. Storms were also found to affect the
concentrations of total nitrogen and phosphorus because sediments are suspended into the water column. In the
middle Keys (Long Key), Szmant (1991) concluded that exchanges through passes between Florida Bay and the
Atlantic Ocean were responsible for the pattern of nutrient distributions. The data supported the contention that
water quality is poorer in developed canals and some adjacent nearshore area than it is farther offshore, but they
do not support assertions that extensive nullification is occurring in offshore areas.
4.1.7 Lapointe et al. — 1992
Lapointe et al. (1992) investigated potential transport of nutrients through channels in the lower Keys to the reef
tract, specifically the reefs in Looe Key National Marine Sanctuary. Data were collected from October 1986 to
October 1988. The objective of the study was to determine the potential for nutrients generated in nearsbore
waters to be transported to the reef tract. This was done by comparing data on water currents and water
column nutrients to water transport and nutrient fluxes.
Sampling occurred at 11 stations. Stations were located in South Pine Channel, Newfound Harbor Channel,
Bahia Honda Channel, and Moser Channel. A single station was located in Hawk Channel, between the keys
and the reef tract. Six stations were located at the reef — Deep Fore Reef, East Back Reef, East Fore Reef,
West Fore Reef, West Back Reef, and Central Back Reef.
Near-bottom current meter data were collected in channels in the lower Keys (Newfound Harbor, Bahia Honda,
and Moser Channels) and at stations located on the fore and back reef in the Looe Key National Marine
Sanctuary. Current data were evaluated as progressive vector diagrams for the stations located at the reef and
net cumulative displacement was determined for the along-channel direction for stations located in the channels.
The net water flow through the channels was found to be predominantly from the Gulf of Mexico into Hawk
Channel. Flow in Hawk Channel was generally westward along the channel but seaward displacement was
observed.
From 3 January to 12 February 1983 at the station in South Pine Channel, water samples were collected at
midday twice per week to evaluate the effects of terrestrial runoff on nutrient concentrations in nearshore waters
of the Keys. Sampling at the other stations was conducted at three-week intervals from 17 October 1986 to 18
January 1988. Water samples were collected with 5-L Niskin bottles, filtered to remove participate material,
and preserved until analysis. Water-quality parameters included temperature, ammonium, nitrate plus nitrite,
soluble reactive phosphorus, chlorophyll a, turbidity and Secchi depth. Ammonium and nitrate plus nitrite were
determined using an autoanalyzer. Soluble reactive phosphorus in samples collected at South Pine Channel was
determined by autoanalyzer and by spectrophotometer for the other stations. Turbidity was determined using a
rurbidimeter. Rainfall data were obtained from the NOAA weather service at the Key West airport.
Ammonium concentrations were positively correlated with rainfall at the South Pine Channel station for the six
week study. Concentrations were generally less than 0.10 /xM during the two weeks before a major rainfall
period, and exceeded 4.5 itM after the last week in January 1983 when 30 cm of rainfall was observed. Soluble
reactive phosphorus was undetected after the period of heavy rainfall.
2-123
-------
For the longer term study, nutrient and chlorophyll a data were pooled into "wet" and "dry" categories based
on the quantity of rainfall for the seven days prior to each sampling. Mean concentrations of ammonium
observed during wet periods were twice those observed during dry periods. Significant ammonium increases
during wet periods were observed at the Newfound Harbor Channel, Bahia Honda Channel, Central Back Reef,
West. Fore Reef, and Deep Reef stations. Ammonium was significantly correlated with the quantity of rainfall.
Ammonium concentrations were also observed to increase relative to the soluble reactive phosphorus
concentrations during wet periods.
The investigators combined the near-bottom current data with the water column nutrient data to calculate
ammonium flux. Flux values ranged from 0.1 to 0.8 moles NH4/m2/d during dry periods to 0.5 to 2.4 moles
NH4/m2/d. Ammonium flux was greater at the nearshore channel stations and decreased with increasing
distance from shore. At all channel stations, the ammonium flux was southward from the Gulf of Mexico to
Hawk Channel. At the reef stations, the flux was primarily west-south westward, along Hawk Channel, but
seaward flux was observed.
Chlorophyll a concentrations were elevated during wet periods at most stations. Chlorophyll a levels were
significantly correlated with ammonium concentrations. Chlorophyll a concentrations ranged from 0.1 to 1.1
/tg/L. The pattern of chlorophyll a flux was similar to that of ammonium.
Turbidity values ranged from 0.1 to 6.0 NTU and were significantly correlated with rainfall and wind speed.
Higher turbidity was generally observed at nearshore stations compared to offshore stations. Highest values of
turbidity were associated with high wind stress such as the passage of Hurricane Floyd (12 October 1987) and
cold fronts during winter.
The investigators concluded that near-bottom transport of nutrients from nearshore waters across Hawk Channel
to the reefs in Looe Key National Marine Sanctuary is a likely nutrient source to sustain long-term nutrient
input. In addition, they argue that nutrients generated by human activities in the Keys have increased the
ammonium flux to nearshore waters, and these nutrients contribute to the nutrient wake from the land masses to
the reef tract. In addition, nutrients from Florida Bay passing through the channels were thought to contribute
to the nutrient wake.
4.2 SUMMARY
The studies summarized previously not only provide an overview of the water quality in the FKNMS, but they
also indicate the relative paucity of data presently available to assess the water quality of the Keys. Available
data were insufficient to demonstrate temporal changes in water quality because no well-designed, long-term
studies have been conducted.
Nearshore/offshore trends were very evident in all of the studies reviewed during this assessment. Artificial
waterways and canals in developed areas are subjected to nutrient loading and the commensurate changes in
increased organic matter and reduced DO concentration. For the most part, nearshore Outstanding Florida
Waters are not subjected to the same level of nutrient loading as are artificial canals and waterways. In areas of
development, however, the data do indicate that there may be some nutrient loading. The studies reviewed do
not indicate that offshore Outstanding Florida Waters are undergoing degradation. However, anecdotal
information suggests that these waters may be undergoing degradation. Overall, the data indicate that well
flushed areas (e.g., by exchange of water with the offshore oceanic region) tend to have good water quality. In
nearshore areas where there is no adequate flushing (i.e., areas subjected to anthropogenic influx of nutrients),
the water quality tends to be poor.
This determination agrees with the water assessment performed by the FDER as part of a 305(b) study (FDER
1990). During this study, water quality was examined through an inventory of their STORET database for the
2-124
-------
period 1980 to 1989. It was determined that water quality in the Florida Keys generally was good in areas that
were well flushed because of exchanges with the Gulf of Mexico and Atlantic Ocean. Reduced flushing,
however, exacerbated water-quality problems in many manmade canals and marinas.
5.0 PROJECTED WATER QUALITY (YEAR 2010)
The future water quality in FKNMS waters depends on the natural and on the anthropogenic pollutant loadings
that take place. The temporal and spatial variability of the loadings will also significantly affect the water
quality. The factors that will probably most affect the anthropogenic loadings will be population growth, spatial
distribution of the population increase and land use, required treatment efficiencies of wastes from the existing
and increased population, and selected disposal mechanisms of the wastes.
5.1 POPULATION AND LAND USE
5.1.1 Population
For the past several years, Monroe County and its municipalities have been preparing local comprehensive plans
in accordance with the requirements of Section 163.3161, Florida Statutes, and Rule 9J-5, Florida
Administrative Code (FAC). The plans serve as the local governments' primary growth management tool.
Once local governments complete drafting their plans, they must submit them to the State planning agency, the
Florida Department of Community Affairs (FDCA), for review and comment. This statutory requirement
directs the FDCA to identify where the local comprehensive plans might conflict with adopted State and regional
policy or provisions of the planning statute or Rule 9J-5 FAC that have gone unaddressed, or where there might
be technical deficiencies. On conclusion of their review, the FDCA issues an Objections, Recommendations
and Comment (ORC) report, and transmits it to the local governments.
Monroe County submitted their Plan to FDCA, which issued an ORC report identifying areas of conflicts and
deficiencies. One area of conflict involved the methodology used to develop population projections. To assist
the County in addressing this and other cited objections, the County contracted with the firm of Wallace Roberts
& Todd and their subcontractors (WRT team).
Monroe County is unique; it is different from every other County in Florida. It does not have a ready supply of
potable water; it contains extensive areas of environmentally sensitive lands; it has severe restrictions relative to
safe hurricane evacuation. Due to the severe constraints to growth, the WRT team concluded that the level of
growth defined in its Comprehensive Plan must be based on a carrying-capacity approach rather than simply on
historical growth patterns (Wallace Roberts & Todd el al. 199la).
On 13 November 1991, the Board of County Commissioners reviewed a WRT team report that evaluated the
impact that various carrying-capacity constraints (i.e., traffic circulation, hurricane evacuation, potable water,
sanitary sewer, drainage, recreation/open space, and solid waste) would have on future growth in Monroe
County. Hurricane evacuation-clearance time was determined to pose the most severe restriction on future
growth. The Board determined to allocate net growth capacity over a 10-year period (1992-2002) and to
allocate approximately 31 % to the three municipalities of Key West, Lay ton, and Key Colony Beach. Thus, the
amount of growth to be allocated by Monroe County in the unincorporated area over the next 10 years was
determined to be some 2552 units or approximately 255 equivalent residential units per year (Wallace Roberts &
Toddetal. 199 Ib).
Further, the WRT team recommended a compact pattern for future residential growth allocation. This will
support "infill" development within existing developed areas. "Because the prospective future allocation of
2-125
-------
residential growth is very small relative to the quantity of development already in place, the impact of this
future growth allocation, regardless of the pattern selected will be relatively small as well" (Wallace Roberts &
Todd«a/. 1991b).
5.1.2 Land Use
The Keys are grouped into three general regions, the upper, middle and lower Keys. The upper Keys comprise
all areas north of the Whale Harbor Bridge. The middle Keys extend from Whale Harbor Bridge on the north
to Seven Mile Bridge on the south. The lower Keys comprise the islands south and/or west of the Seven Mile
Bridge to and including the City of Key West.
Residential activities are the predominant type of activity in the Keys. More than 10,200 acres were in
.residential use in 1986 (Monroe County 1986). Residential acreage reflects more than just the homes of the
permanent, year-around residents. There are more than 20 resorts in the Keys that serve primarily the seasonal
dweller. Roughly 43% (4400 acres) of all residential land is situated in the upper Keys, 9% (940 acres) in the
middle Keys, and 48% or 4865 acres in the lower Keys (Monroe County 1986; Solin 1991; A. Tallerico, South
Florida Regional Planning Council, personal communication, 1992). In the middle and lower Keys, most of the
residential use is situated in the two urban centers, Marathon and Key West.
Commercial activities are closely tied to serving the retail and personal service needs of the permanent
population or activities such as motel, hotels, and restaurants that serve the seasonal population. General
commercial activities, e.g, retail, service-related businesses, are generally concentrated in four areas, Key
Largo, upper Matecumbe Key, Marathon, and Key West (Monroe County 1986; Solin 1991).
Tourist-related uses, especially campgrounds, are scattered throughout the Keys. The presence of major tourist
attractions such as Looe Key National Marine Sanctuary and John Pennekamp Coral Reef State Park, have
produced a tourist-oriented local economy that is based on diving and snorkeling the reefs. There are numerous
dive shops, reef boats and private charters, party boats, and backcountry fishing expeditions (RockJand 1988).
With many military installations in the Keys, it is not surprising that over 6500 acres of land is utilized by the
United States Navy and the United States Coast Guard (Monroe County 1986; Solin 1991). The largest
installation is situated on Boca Chica Key: the Boca Chica Naval Air Station. There are military lands to be
found on Saddlebunch and Cudjoe Keys as well as Marathon.
Another major-use category is conservation. These generally are lands that have been designated by the Fish
and Wildlife Service, the State of Florida, and Monroe County as being either wildlife refuge land or land
acquired for conservation purposes. There are approximately 20,000 acres designated as conservation lands in
the Keys (Monroe County 1986).
The WRT team is in the process of completing a land-use survey of the Keys (G. Garrett, Monroe County,
personal communication, 1991). The firm has also prepared alternative future land-use concepts as part of
Monroe County's 1990-2010 Comprehensive Plan (Wallace Roberts & Todd et al. 199 Ib).
5.2 WATER-QUALITY STANDARDS
The State has a series of administrative rules that impact wastewater effluent. Rule 17-600, Florida
Administrative Code (FAC), titled Domestic Wastewater Facilities, establishes a set of rules for the treatment
and reuse or disposal of domestic wastewater. The rule is to assure that all waters of the State shall be free
from components of domestic wastewater discharges which, alone or in combination with other substances are
(1) acutely toxic; (2) present in concentrations which are carcinogenic, mutagenic, or teratogenic to humans,
animals, or aquatic species; or (3) otherwise pose a serious threat to the public health, safety, and welfare.
2-126
-------
There are a number of minimum secondary treatment effluent standards that apply to facilities discharging via
ocean outfall, as well as standards for treatment facilities discharging via underground injection. Some of the
effluent parameters include biochemical oxygen demand (BOD3), TSS, DO, pH, fecal coliform, and chlorine
residual.
It can be stated generally that there are no adopted comprehensive statewide nutrient limitations placed on the
effluent generated from domestic dischargers. Section 403.086, Florida Statutes, addresses nutrient limits;
however, they apply only to a portion of the State in the vicinity of Tampa Bay. A similar statute sets effluent
requirements for the Indian River Lagoon (B. DeGrove, FDER, personal communication, 1992). The nutrient
limits set for the Tampa Bay area are:
• Total Nitrogen, expressed as N 3 mg/L
• Total Phosphorous, expressed as P 1 mg/L
Rules 17-610.510 FAC and 17.610.560 FAC provide for a 12 mg/L limit on nitrates for rapid rate and
absorption field discharges. Around the State there are golf courses that utilize treated wastewater for irrigation
purposes. The public golf course on Stock Island is considering implementing such a system (J. Bottone,
FDER, personal communication, 1992; K. Williams, CH2M Hill, personal communication, 1992).
Monroe County has not addressed nutrient standards in its Comprehensive Plan, but the proposed Sanitary
Wastewater Master Plan will determine the necessary level of treatment throughout Monroe County. The
Wastewater Master Plan will research the feasibility of implementing the adopted policy of 60% nutrient
removal (Wallace Roberts & Todd et al. 1991a).
For the past year and a half, the City of Key West has been monitoring the effluent from its wastewater
treatment facility. Besides BOD5, TSS, and fecal coliform, the City is monitoring for nitrogen, ammonia, and
phosphorous (Solin 1991).
Further, the City of Key West has addressed nutrient standards in its Comprehensive Plan (Solint 1991). The
Plan states that, if the City is to minimize eutrophication of ocean waters, the following standards for nitrates
and phosphates in effluent discharged into ocean water should be adopted:
• Total nitrogen: 6 mg/L
• Total phosphorus: 4 mg/L
5.3 NUTRIENT LOADINGS
Based on the limited data available for water quality and biotic resource effects (Tasks 3 and 4), it appears that
organic loading/nutrients represent a serious long-term threat to the FKNMS. There may be other potential
threats, but a comprehensive water-quality monitoring program is needed to evaluate these possibilities.
Camp Dresser and McKee, Inc. (1990) summarized nutrient loadings to marine coastal waters in the upper
(Sand Key to south of Plantation Key) Keys for the years 1990 and 2010. The nutrient loadings were used in
conjunction with a model and water-quality data to study the relative contribution of the nutrient sources to
nutrient availability in the vicinity of offshore coral reefs. Scenarios to limit nutrient availability were
investigated. An attempt was made to summarize nutrient inputs from wastewater treatment plants, OSDSs,
stormwater, and boat live-aboards. Literature values were used for levels of nutrients. The values presented
show no nitrate loadings from OSDS; however, conventional OSDS effluent undergoes a moderate degree of
nitrification in the drainfield, and aerobic treatment units discharge a fully nitrified effluent. Tables 2-28(a) and
(b) show the estimated wastewater loadings. Tables 2-29(a) and (b) compare the estimated wastewater and
2-127
-------
Table 2-28. Summary of wastewater pollution loads
discharged to the upper Florida Keys study area.
[From Camp Dresser and McKee 1990]
(a) Winter
Pollutant Package Plants Live-Aboard
Land
SS
BOD
P04
NH3
NO2
Land
SS
BOD
P04
NH3
N02 •
(Ib/day)
Boats
(Ib/day)
On-site
Disposal
Systems
(Ib/day)
Total
(Ib/day)
Use Scenario: Existing (1990)
16
16
6
20
f NO3 140
Use Scenario: Future
19
19
8
24
f NO3 169
32
60
5
13
0
(2010)
36
68
5
15
0
120
224
18
240
0
148
278
22
298
0
168
300
29
273
140
203
365
35
337
169
(b) Summer
Pollutant Package Plants
Land
SS
BOD
P04
NH3
N02
Land
SS
BOD
P04
NH3
NO2
(Ib/day)
Use Scenario: Existing
8
8
3
10
f NO3 70
Live-Aboard
Boats
(Ib/day)
(1990)
0
0
0
0
0
On-site
Disposal
Systems
(Ib/day)
77
144
11
155
0
Total
(Ib/day)
85
152
14
165
70
Use Scenario: Future (2010)
10
10
4
12
f NO3 85
0
0
0
0
0
98
182
14
195
0
108
192
18
207
85
2-128
-------
Table 2-29. Comparison of pollution loads discharged
to the upper Florida Keys study area.
[From Camp Dresser and McKee 1990]
(a) Winter
Pollutant
Wastewater* Effluent
(Ib/day) (%)
Stormwater Runoff Total
Ob/day) (%) (Ib/day)
Land Use Scenario: Existing (1990)
BOD 300 72 114 28 414
PO4 29 91 39 32
NH3 273 99 4 1 277
NO2 + NO, 14 67 7 33 21
Land Use Scenario: Future (2010)
BOD 365 73 138 27 503
PO« 35 90 4 10 39
NH3 337 99 4 1 341
NO2 -I- N03 169 95 85 177
'Includes on-site disposal systems, package plants, and live-aboard boats.
(b) Summer
Pollutant Wastewater* Effluent Stormwater Runoff Total
(Ib/day) (%) (Ib/day) (%) (Ib/day)
Land Use Scenario: Existing (1990)
BOD 152 34 291 66 443
P04 14 61 9 39 23
NH3 165 94 11 6 176
NO2 + N03 70 81 16 19 86
Land Use Scenario: Future (2010)
BOD 192 36 346 64 538
PO, 18 62 11 38 29
NH3 207 95 12 5 219
NO2 + N03 85 82 19 18 104
'Includes on-site disposal systems, package plants, and live-aboard boats.
2-129
-------
stormwater loadings. In the winter, wastewater was estimated to contribute more than 90% of the nutrient loads
and 75% of the BOD5 loads under existing as well as future conditions. In the summer, wastewater production
was assumed to be significantly reduced since only the year-around resident population was considered in
generating the loading estimates. In addition, the seasonal distribution of rainfall within the upper Florida Keys
study area projects increased stormwater source loads in summer relative to winter conditions. As a result,
stormwater pollutant loads contribute nearly 40% of the phosphorus load during summer conditions. The
accuracy of the estimates is unknown because a number of assumptions of unknown validity were made.
Additionally, constituent values from outside the Florida Keys were extensively used. Based on available data,
it is not possible to reliably update these estimates of nutrient loadings for the Florida Keys.
2-130
-------
6.0 REFERENCES
Alleman, R.W. 1990. Surface water quality in the vicinity of Black point, Dade County, Florida: March 1990.
MetroDade DERM Tech. Rep. 90-14. 21 pp.
Anderson, J.S., and K.S. Watson. 1967. "Patterns of household usage." J. Am. Water Works Assoc.
59:1228-1237.
Antonini, G.A., L. Zobler, H. Tupper, and R. Ryder. 1990. Boat live-aboards in the Florida Keys: A new
factor in waterfront development. Fla. Sea Grant Rep. No. 98.
Applied Biology, Inc. 1985. Key Largo water quality assessment and modeling program, chemical and
biological data report. A report to the National Oceanic and Atmospheric Administration Sanctuary
Programs Office.
Applied Biology, Inc., and Camp Dresser & McKee Inc. 1985. Key Largo National Marine Sanctuary water
quality assessment and modeling program: Phase II (NOAA Contract NA 81-GA-C-O0047).
Ayers Associates. 1987. The impact of Florida's growth on the use of onsite sewage disposal systems: Onsite
sewage disposal system research in Florida. A report prepared for the Florida Department of Health
and Rehabilitative Services, Tampa, FL. 59 pp.
Basta, D.J., B.T. Bower, C.N. Ehler, F.D. Arnold, B.P. Chambers, and D.R.G. Farrow. 1985. The National
Coastal Pollutant Discharge Inventory. Department of Commerce, National Oceanic and Atmospheric
Administration, Washington, DC.
Beardsley, G.L., Jr. 1967. Distribution in the water column of migrating juvenile pink shrimp, Penaeus
duorarum (Burkenroad), in Buttonwood Canal, Everglades National Park, Florida. Ph.D. dissertation,
University of Miami, Coral Gables, FL.
Bennett, E.R., and E.K. Linstedt. 1975. Individual home wastewater characterization and treatment.
Completion Rep. Ser. No. 66. Environmental Resources Center, Colorado State University, Fort
Collins, CO.
Bicki, T.J., R.B. Brown, M.E. Collins, and R.S. Mansell. 1984. .Impact of on-site sewage disposal systems
on surface and ground water quality. Institute of Food and Agricultural Sciences, University of
Florida.
Brooks, I.H:, and P.P. Niiler. 1975. "The Florida Current at Key West: Summer 1972." J. Mar. Res.
33(l):83-92.
Burnaman, R. 1991. Letter to Eanix Poole, Chief, Environmental Health Program, Florida Department of
Health and Rehabilitative Services. March 7, 1991.
Camp Dresser and McKee, Inc. 1990. Evaluation of alternatives for the reduction of availability of nutrients to
the reef tracts of the upper Florida Keys. A report to The Nature Conservancy, Florida Keys
Initiative.
Canter, L.W., and R.C. Knox. 1985. Septic Tank System Effects on Groundwater Quality. Lewis Publishers,
Inc., Chelsea, MI.
Cheesman, M.S. 1989. 1986 intensive canal study. Metro-Dade DERM Tech. Rep. 89-2.
2-131
-------
Chin Fatt, J. and J.D. Wang. 1987. Canal discharge impacts on Biscayne Bay salinities. Department of the
Interior, National Park Service. SE Region Atlanta, Res./Resources Rep. SER-89. Dec. 1987. 229
pp.
CH2M Hill. 1979. Monroe County 201 Wastewater Facilities Plan.
CH2M Hill. 1988. Baseline data collection for an environmental and hydraulic assessment of Riviera Canal and
the adjoining Salt Ponds, Key West, Florida. Prepared for the City of Key West.
Clark, S.H. 1971. Factors affecting the distribution of fishes in Whitewater Bay. Florida Sea Grant Tech.
Bull. No. 8. Everglades National Park, Homestead, FL. 97 pp.
Cohen, S., and H. Wallman. 1974. Demonstration of waste flow reduction from households. Environmental
Protection Agency Rep. No. EPA 670/2-74-071. NTIS Rep. No. PB 236 904.
Corcoran, E.F., M.S. Brown, F.R. Baddour, S.A. Chasens, and A.D. Freay. 1983. Biscayne Bay
hydrocarbon study. Final report. University of Miami Rosenstiel School of Marine and Atmospheric
Sciences, Miami, FL.
Corcoran, E.F., M.S. Brown, and A.D. Freay. 1984. The study of trace metals, chlorinated pesticides,
polychlorinated biphenyls and phthalic acid esters in sediments of Biscayne Bay. University of Miami
Rosenstiel School of Marine and Atmospheric Science, Miami, FL. 58 pp.
Dammann, W.P., J.R. Proni, J.F. Craynock, and R. Fergen. 1991. "Oceanic wastewater outfall plume
characteristics measured acoustically." Chem. Ecol. 5:75-84.
Davis, G.E., and J.W. Dodrill. 1980. Marine parks and sanctuaries for spiny lobster fisheries management.
Pp. 194-207 in: Proceedings of the Gulf and Caribbean Fisheries Institute, 32nd Annual Session.
Davis, G.E., and C. Wilsenbeck. 1974. The effects of watershed management on the Shark
Slough/Whitewater Bay Estuary of Everglades National Park, FL. Unpublished manuscript. 16 pp.
DOA. 1989. Soil survey of Monroe County, FL. Unpublished report. Department of Agriculture, Soil
Conservation Service.
DOA. 1991. Soil survey of Monroe County. Unpublished. Department of Agriculture, Soil Conservation
Service.
DOD. 1983. Defense Mapping Agency. Sailing Directions for the North Atlantic Ocean. Department of
Defense. 400 pp.
DOI. 1984. South Atlantic Physical Oceanography Study. Vol. 2: Technical Report. Prepared for MMS by
Science Applications Inc. Department of the Interior, Minerals Management Service. 224 pp.
DOI. 1987a. Southwest Florida Shelf Ecosystem Study. Vol. 2: Data Synthesis Report. Prepared for MMS by
Environmental Science and Engineering, Inc. MMS 87-0023. Department of the Interior, Minerals
Management Service. 348 pp.
DOI. 1987b. Gulf of Mexico Physical Oceanography Program final report: Year 4. Vol. II: Technical report.
Prepared for MMS by Science Applications International Corp. OCS Study, MMS 85-0094.
Department of the Interior, Minerals Management Service. 226 pp.
2-132
-------
Duffy, C.P., et al. 1978. Technical performance of the Wisconsin mound system for on-site wastewater
disposal — an interim evaluation. Preliminary environmental report for three alternative systems
(mounds) for on-site individual wastewater disposal in Wisconsin. Wisconsin Department Health and
Social Services.
Emmel, T.C. 1986. Pesticide effects of the survival of the Schaus Swallowtail Butterfly. Report to the
Elizabeth Ordway Dunn Foundation, Miami, FL.
Enos, P. 1977. "Holocene sediment accumulation of the South Florida shelf margin." In Enos, P., and R.D.
Perkins (Eds.) Quaternary sedimentation in South Florida. Geol. Soc. Am. Mem. No. 147.
EPA. 1981. Effects of Baytex and Malathion on early life stages of Snook, Centropomus undecimalis.
Surveillance and Analysis Division, Ecology Branch, Athens, GA.
EPA. 1983. Results of the National Urban Runoff Program (NURP). Executive Summary. Vol. I: Final
report. Vol. II: Appendices. Vol. Ill: Data appendix. Environmental Protection Agency, Washington,
DC.
EPA. 1991a. Monitoring Discharge Reports. Environmental Protection Agency, Washington, DC.
EPA. 1991b. List of Active NPDES Permits, Monroe County, FL. October 1991. Environmental Protection
Agency, Washington, DC.
Evans, C.C. 1982. Aspects of the depositional and diagenetic history of the Miami Limestone: Control of
primary sedimentary fabric over early cementation and porosity development. Unpublished M.S.
Thesis, Univ. of Miami, Miami, FL.
N
Evans, C.C. 1983. Depositional and diagenetic of Miami Limestone: Proceedings from the Symposium on
South Florida Geology, Miami Geological Society, Miami, FL.
FDER. 1985. Appendix K, Florida Keys water quality study, p. K-l - K-32. In Addendum to Report to the
Environmental Regulation Commission on the Proposed Designation of the Florida Keys as an
Outstanding Florida Waters. Outstanding Florida Waters. Florida Department of Environmental
Regulation.
FDER. 1987. Florida Keys Monitoring Study, Water Quality Assessment of Five Selected Pollutant Sources in
Marathon, Florida Keys. Florida Department of Environmental Regulation. 196 pp.
FDER. 1988. Campbell's Marina Study. Florida Department of Environmental Regulation.
FDER. 1990. Boot Key Harbor study. Preliminary draft manuscript. Florida Department of Environmental
Regulation.
FDER. 1991a. Groundwater Management System. Rep. #70. Florida Department of Environmental
Regulation.
FDER. 1991b. Groundwater Management System. Rep. #25. August 1991. Florida Department of
Environmental Regulation.
FDER. 1991c. Groundwater Management System. Rep. #36. Florida Department of Environmental
Regulation.
2-133
-------
FDER. 1992. Groundwater Management System. Rep. #21. Florida Department of Environmental
Regulation.
FDHRS. 1991. Rule 10D-6, Florida Administrative Code. Florida Department of Health and Rehabilitative
Services.
Finucane, J.H., and A. Dragovich. 19S9. Counts of red tide organisms, Gymnodinium breve and associated
oceanographic data form Florida's west coast, 1954-1957. Fish and Wildlife Service. Special Science
Report on Fisheries, 289:202-295.
•.'*> -
Fourqurean, J.W., J.C. Zieman, and G.V.N. Powell. To be published. "Phosphorus limitation of primary
production in Florida Bay: Evidence from the C:N:P ratios of the dominant seagrass Thalassia
testudinum* Submitted to Limnology and Oceanography.
Fourqurean, J.W. 1992. The roles of resource availability and resource competition in structuring seagrass
communities of Florida Bay. Ph.D. dissertation, Univ. of Virginia, Charlottesville, VA. 280 pp.
Halley, R. B., and C.C. Evans. 1983. The Miami Limestone, A Guide to Selected Outcrops and their
Interpretation: Miami Geological Society. 67 pp.
Harrison, R.S., L.D. Cooper, and M. Coniglio. 1984. Late Pleistocene carbonates of the Florida Keys. In:
Carbonates in Subsurface and Outcrop. Pp. 291-306 in Canadian Society of Petroleum Geologists,
Calgary, Alberta. Canada Core Conference.
Haunert, D. 1988. Memorandum to Walt Dineen, South Florida Water Management District, 22 September
1988.
Heald, E.J. 1971. The production of organic detritus in a south Florida estuary. Florida Sea Grant Tech.
Bull. No. 6. University of Miami, Miami, FL. 110 pp.
Heatwole, D. W. 1987. Water quality assessment of five selected pollutant sources in Marathon, Florida
Keys, Florida Keys Monitoring Study: 1984-1985. FDER South Florida District, Marathon Branch
Office.
Hoffmeister, J. E. 1974. Land from the Sea. University of Miami Press, Miami, FL. 138 pp.
Jaap, W.C. 1984. The ecology of the South Florida coral reefs: A community profile. Fish and Wildlife
Service, Slidell, LA. FWS/OBS-82/08. 138 pp.
Janke, T.E. 1971. Abundance of young sciaenid fishes in Everglades National Park, Florida, in relation to
season and other variables. Sea Grant Tech. Bull. No. 11. University of Miami, Miami, FL. 128 pp.
Jones, J.I., R.E. Ring, M.O. Rinkel, and R.E. Smith (Eds.). 1973. A summary of knowledge of the eastern
Gulf of Mexico. The State University System Institute of Oceanography, St. Petersburg, FL.
Laak, R. 1975. Relative pollution strengths of undiluted waste materials discharged in households and the
dilution waters used for each. Manual of gray water treatment practice. Part II Monogram Industries,
Inc., Santa Monica, CA.
2-134
-------
Lapointe, B.E., N.P. Smith, P.A. Pitts, and M.W. Clark. 1992. Baseline characterization of chemical and
hydrographic processes in the water column of Looe Key National Marine Sanctuary. Final report to
National Oceanic and Atmospheric Administration, Department of Commerce. Contract No. NA86AA-
H-CZ071. 54 pp. + app.
Lapointe, B.E., and M.W. Clark. 1990. Spatial and temporal variability in trophic state of surface waters in
Monroe County during 1989-1990. Final report for the John D. and Catherine T. MacArthur
Foundation and Monroe County.
Lapointe, B.E., and J.D. O'Connell. 1988. The Effects of On-Site Sewage Disposal Systems on Nutrient
Relations of Groundwaters and Nearshore Waters of the Florida Keys. Tech. Rep. Monroe County
Planning Department, FL.
Lee, T.N. 1975. Circulation and exchange process in Southeast Florida's Coastal Lagoons. RSMAS-Univ.
Miami Tech. Rep. TR75-3. 71 pp.
Lee, T.N. 1985. Physics of Shallow Estuaries and Bays. J. van de Kreeke (Ed.), Springer-Verlag, New
York.
Lee, T.N., and C. Rooth. 1972. Exchange processes in shallow estuaries. Univ. Miami Sea Grant Spec. Bull.
No. 4. 33 pp.
Lee, T.N., C. Rooth, E. Williams, A.M. Szmant, and M.E. Clarke. To be published. "Influence of the
Florida Current, gyres and wind-driven circulation on transport of larvae and recruitment in the Florida
Keys coral reefs." Submitted to Continental Shelf Research.
Linaweaver, F.P., Jr., J.C. Gever, and J.B. Wolff. 1967. A study of residential water use. Dept. Environ.
Studies, The John Hopkins University, Baltimore, MD.
Lindall, W.N., J.R. Hall, W.A. Fable, and L.A. Collins. 19731 A survey of fishes and commercial
invertebrates of the nearshore and estuarine zone between Cape Romano and Cape Sable, Florida.
Ecological Report No. SFEP-74-44. South Florida Environmental Project, Gulf Coastal Fisheries
Center. National Marine Fisheries Service, Panama City, FL. 66 pp.
Merchant, R., and J. Haberfeld. 1988. Memorandum: Characterization of secondarily treated domestic sewage
disposed of via Class V injection wells (boreholes) in the Florida Keys, Florida Department of
Environmental Protection, Bureau of Ground Water Protection.
Monroe County. 1986. Monroe County Comprehensive Plan, Vol. I.
Monroe County. 1991. Monroe County Comprehensive Plan, Vol. I.
Odum, W.E. 1971. Pathways of energy flow in a south Florida estuary. Sea Grant Tech. Bull. No. 7.
University of Miami, Miami, FL. 175 pp.
Otis, R.J. 1978. An alternative public wastewater facility for a small rural community. Small scale Waste
Management Project. University of Wisconsin, Madison, WI.
Parker, G.G., G.E. Ferguson, S.K. Love. 1955. Water resources of southeastern Florida, with special
reference to the geology and groundwater of the Miami Area. Geological Survey Water Supply Paper
1255. 965pp.
2-135
-------
Perkins, R.D. 1977. Depositional framework of Pleistocene rocks in south Florida. Pp. 131-198 in: P. Enos
and R.D. Perkins (eds.), Quaternary Sedimentation in South Florida, Part II: Geological Society of
America Memoir 147.
Pfeuffer, R.J. 1991. Pesticide Residue Monitoring in Sediment and Surface Water within the South Florida
Water Management District: Vol. 2. South Florida Water Management District, Tech. Pub. 91-01.
West Palm Beach, FL. 61 pp.
Pierce, R.H., R.C. Brown, M.S. Henry, K.R. Hardman, and C.L.P. Palmer. 1988a. Fate and toxicity of
ABATE applied to an estuarine environment. Final report to the Lee County Mosquito Control
District. Fort Myers, FL.
Pierce, R.H., R.C. Brown, K.R. Hardman, and M.S. Henry. 1988b. Fate and toxicity of Temephos applied
to an intertidal mangrove community. Report to the Lee County Mosquito Control District. Ft.
Myers, FL.
Pierce, R.H., M.S. Henry, L.S. Proffitt, R.K. Evans, and J.L. Lincer. 1989. Impact assessment of mosquito
larvicides on nontarget organisms in coastal wetlands. Final report to the Lee County Mosquito
Control District. Ft. Myers, FL.
Rios, G. 1990. Boot Key Harbor Study. Florida Department of Environmental Regulation, Marathon Office,
Marathon, FL.
Rockland, D.B. 1988. The Economic Impact of the Sport and Commercial Fisheries of Florida Keys. Report
to the Everglades Protection Association, Florida Conservation Association, and Monroe County
Industrial Development Authority, Sport Fishing Institute.
Roessler, M.A. 1970. "Checklist of fishes in Buttonwood Canal, Everglades National Park, Florida, and
observations on the seasonal occurrence and life histories of selected species." Bull. Mar. Sci. 20:860-
893.
Saarinen, A.W., Jr. 1989. "The use of septic systems and their effects on the freshwater resources on Big
Pine Key." Pp. 59-99 in Robertson, M.L., and J.M. Young (Eds.), Freshwater and Surface Water
Resources of Big Pine Key, Monroe County, FL. The Nature Conservancy.
Scheldt, D.J., and M.D. Flora. 1983. Mowry Canal (C-103): Water quality and discharge into Biscayne Bay
Florida, 1975-1981. National Park Service. SFRC-83/06.
Schmidt, V.W., and G.E. Davis. 1978. A summary of estuarine and marine water quality information
collected in Everglades National Park, Biscayne National Monument in adjacent estuaries from 1879 to
1977. Rep. No. T-519, National Park Service, South Florida Research Center. Homestead, FL. 79
pp.
Schomer, N.S., and R.D. Drew. 1982. An ecological characterization on the lower Everglades, Florida Bay,
and the Florida Keys. FWS/OBS-82/58.1. United States Fish and Wildlife Service, Office of
Biological Services, Washington, DC. 246 pp.
Schroeder P.B. 1987. Review of live-aboard vessels in the Florida Keys. A report by Biosystems Research,
Inc., Miami, FL.
SFWMD. 1989. Surface water improvement and management plan for Biscayne Bay. South Florida Water
Management District, West Palm Beach, FL. 118 pp.
2-136
-------
SFWMD. 1990. Monitoring and Operating Plan for C-l 11, Interim Construction Project. Final draft report.
South Florida Water Management District, West Palm Beach, FL. SO pp. + App.
SFWMD. 1991. Draft Surface Water Improvement and Management Plan for the Everglades. Tech. Inform.
Doc., September 24, 1991. South Florida Water Management District, West Palm Beach, FL. 465
pp.
Shinn, E.A., and E. Corcoran. 1988. Contamination by landfill leachate South Biscayne Bay Florida. Final
report to Sea Grant, University of Miami, Miami, FL. 11 pp.
Shinn, E.A., B.H. Lidz, and C.W. Holmes. 1990. High-energy carbonate-sand accumulation, the Quicksands,
southwest Florida Keys. J. Sed. Petr. 60(6):9S2-967.
Shinn, E.A., B.H. Lidz, J.L. Kindinger, J.H. Hudson, and R.B. Halley. 1989. Reefs of Florida and the Dry
Tortugas. A Guide to the Modem Carbonate Environments of the Florida Keys and the Dry Tortugas.
A report by the Geological Survey, 600 4th St. South, St. Petersburg, FL 33701. 53 pp.
Siegrist, R., M. Witt, and W.C. Boyle. 1976. "Characteristics of rural household wastewater." J. Environ.
Eng. Div. Am. Soc. Agric. Eng. 102:533-548.
Snedaker, S.C. 1990. Water quality problems and issues in the Florida Keys. A report for The Nature
Conservancy (Florida Keys Office).
Solin. 1991. City of Key West Comprehensive Plan: Data and Inventory and Analysis. Solin and Associates,
Inc.
Swakon, E.A., and J.D. Wang. 1977. Modeling of tide- and wind-induced flow in South Biscayne Bay and
Card Sound. Univ. of Miami Sea Grant Bull. No. 37.
Szmant, A.M. 1991. Inshore-offshore patterns of nutrient and chlorophyll concentration along the Florida Reef
Tract. Pp. 42-62 in SEAKEYS Phase I, Sustained Ecological Research Related to Management of the
Florida Keys Seascape. A final report to the John D. and Catherine T. MacArthur Foundation World
Environment and Resources Program from the Florida Institute of Oceanography, St. Petersburg, FL.
Tabb, D.C., B. Drummond, and N. Kenny. 1974. Coastal marshes or southern Florida as habitat for fishes
and effects of changes in water supply on these habitats. Final report to Bureau Sport Fish Wildlife,
Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL. Contract No.
14-16-004-56.
Tucker, J.W., C.Q. Thompson, T.C. Wang, and R.A. Lenahan. 1986. Effects of organophosphorus mosquito
adulticides on hatching fish larvae, other estuarine zooplankton and juvenile fish. Report to the
Department of Entomology, State of Florida. Harbor Branch Oceanographic Institution, Ft. Pierce,
FL.
USACE. 1986. Draft Feasibility Report: Miami River Dade County Florida. United States Army Corps of
Engineers.
van de Kreeke, J., and J.D. Wang. 1984. Hydrography of North Biscayne Bay. Part I: Results of Field
Measurements. University of Miami Rosenstiel School of Marine and Atmospheric Sciences, Miami,
FL.
2-137
-------
Wallace Roberts & Todd et al. 1991a. Monroe County Year 2010 Comprehensive Plan, Working Paper 2.
Inventory and analysis, proposed levels of service, measures of carrying capacity. Prepared for
Monroe County Board of County Commissioners by Wallace Roberts & Todd; Barton Aschman &
Associates, Inc.; Haben, Culpepper, Dunbar & French, P.A.; Heoigar & Ray; Keith and Schnars,
P.A.; and Price Waterhouse.
Wallace Roberts & Todd et al. 1991b. Monroe County Year 2010 Comprehensive Plan, Working Paper 3.
Alternative concepts. Prepared for Monroe County Board of County Commissioners by Wallace
Roberts & Todd; Barton Aschman & Associates, Inc.; Haben, Culpepper, Dunbar & French, P.A.;
Henigar & Ray; Keith and Schnars, P.A.; and Price Waterhouse.
Watson, K.S., R.P. Farrell, and J.S. Anderson. 1967. "The contribution from the individual home to the
sewer system." J. Water Pollut. Control Fed. 39:2039-2054.
Weber, A.H., and J.O. Blanton. 1980. "Monthly mean wind fields for the South Atlantic Bight. J. Phys.
Oceanogr." 10:1256-1263.
Wennekens, M.P. 1959. "Water mass properties of the Straits of Florida and related waters." Bull. Mar. Sci.
9:1-52.
Whalen, P.J., and M.G. Cullum. 1988. An assessment of urban land use/stormwater runoff quality
relationships and treatment efficiencies of selected stormwater management systems. South Florida
Water Management District Tech. Pub. 88-9.
2-138
-------
CORAL COMMUNITY ASSESSMENT
Task 3
CONTENTS
1.0 INTRODUCTION 3-1
2.0 CORAL COMMUNITY TRENDS 3-1
2.1 CORAL COMMUNITY DISTRIBUTION 3-1
2.2 CORAL BIOLOGY 3-4
2.3 CORAL ZOOXANTHELLAE 3-4
Relationship between Zooxanthellae and Coral Polyps > . . 3-4
3.0 FACTORS OR PROCESSES STRESSFUL TO CORAL COMMUNITIES 3-9
3.1 BIOLOGICAL INTERACTIONS 3-9
3.2 DISEASES 3-10
3.2.1 Black-Band Disease . 3-10
3.2.2 White-Band Disease 3-11
3.3 TEMPERATURE 3-11
3.4 WATER TRANSPARENCY AND SEDIMENTATION 3-13
3.5 NUTRIENTS 3-14
3.5.1 Nutrient Cycling 3-14
3.5.2 Response to Increased Nutrients 3-15
3.5.3 Effects of Phosphorus 3-15
3.5.4 Sources and Effects of Nitrogen 3-15
3.5.5 Nutrient Flux and Availability 3-16
3.5.6 Groundwater Flow 3-16
3.5.7 Impacts of Nutrients at Specific Sites 3-17
3.6 OIL AND ASSOCIATED CONTAMINANTS 3-20
3.7 PESTICIDES, HERBICIDES, AND ORGANIC CHEMICALS 3-21
3.8 TRACE ELEMENTS AND HEAVY METALS 3-21
3.9 FRESHWATER 3-23
4.0 SUMMARY 3-23
5.0 STATEMENTS OF PROBLEMS 3-25
5.1 PROBLEMS IDENTIFIED DURING THE LITERATURE REVIEW 3-25
5.2 , PROBLEMS IDENTIFIED AT THE CORAL COMMUNITY
ASSESSMENT WORKSHOP 3-27
6.0 REFERENCES 3-29
LIST OF FIGURES
3-1. Major reefs of the Florida Reef Tract 3-2
-------
LIST OF TABLES
3-1. Southeast Florida reef Scleractinia 3-5
3-2. Octocoral fauna in shallow southeast Florida reef communities 3-7
3-3. Growth rates of scleractinian species from Florida and the Bahamas 3-8
3-4. Corals observed to contract black-band or white-band disease in the Caribbean 3-12
3-5. Pesticide compounds within sediments and biota from the Florida Reef Tract 3-22
3-6. Mean concentrations and ranges of selected trace metals in sediment and biota from the
Florida Reef Tract 3-24
-------
TASK 3 - CORAL COMMUNITY ASSESSMENT
1.0 INTRODUCTION
Coral reef communities are an assemblage of tropical and subtropical marine plants and animals growing
together creating complex shallow-water limestone structures. These structures provide the physical framework
and habitat for large numbers of other plants, invertebrates, and fishes. There are many factors limiting the
distribution of coral reefs, including temperature, salinity, light, nutrient availability, and ocean circulation
patterns. These factors define the predominant plant and animal communities, based upon the optimal
requirements of each community.
The greatest accumulation of hard, reef-forming corals, and other associated biota occurs on coral reefs.
However, these biota are also present elsewhere at a number of other density levels. These densities range
from isolated individuals to more extensive accumulations. Hard bottom, hard grounds, live bottom, coralgal
banks, and patch reefs are some of the terms used to describe these accumulations. The term coral communities
is used in this Section to describe these various density levels.
The purpose of this Section is to provide a brief description of the Florida Keys National Marine Sanctuary
(FKNMS) coral communities. Both natural and human-induced factors affecting the vitality of coral
communities in the FKNMS are described, based upon a review of the available scientific data and literature as
well as conversations with acknowledged coral community experts.
2.0 CORAL COMMUNITY TRENDS
2.1 CORAL COMMUNITY DISTRIBUTION
Hard-bottom areas, patch reefs, and bank reefs in the Florida Keys are found from almost intertidal habitats to
13 km offshore, in depths ranging from less than 1 to 41 m. They extend from Cape Florida south and west to
the Dry Tortugas (Figure 3-1), due in part to the warm Florida Current and its role in moderating winter
temperatures, bringing plankton to the reefs, and providing recruitment to the area (Jaap 1984). The
distribution of coral communities in the Florida Keys is directly related to regional water quality. Extensive
reefs occur where barriers to the transport of potentially lower-quality waters (i.e., Florida Bay, Biscayne Bay)
are in place. These barriers are formed by the large islands in the upper and lower Keys. In the middle Keys,
only limited reef development has taken place because of the many channels connecting Florida Bay to the
Straits of Florida. These Bay waters may have temperature and salinity ranges, turbidity levels, and quantities
of nutrients that are incompatible with coral reef development or survival (Ginsburg and Shinn 1964; Lidz and
Shinn 1991).
The reefs of the FKNMS are high-latitude coral reefs. In high latitude reefs, corals exist at the maximum limits
of their range. Under these conditions, many temperate and subtropical algal species may be found at near
optimal conditions and minor shifts in water temperature, nutrient level, or grazing activity allow the subtropical
algae to out-compete the corals (Johannes et al. 1983b; Crossland et al. 1984; Smith 1988).
Within the FKNMS, there are an estimated 19,420 ha of reef and 110,635 ha of low-relief hard-bottom (BLM
and FDNR 1979; FWS and MMS 1983; CSA and GMI 1991). The reef habitat includes coral patch reefs and
the interspersed sediments and seagrass, bank reefs, and coral reef flats. The low-relief hard-bottom designation
comprises sparse though dense hard-bottom communities as well as areas of finger corals, octocorals, and
coralline algae. The total estimated area of the seagrass and algal bottom habitat is 591,045 ha; the remaining
unmapped bottom area of the newly designated FKNMS is 260,000 ha (H. Norris, Florida Marine Research
Institute, personal communication, 1991).
3-1
-------
K>
1=Fowey Rocks
2=Triumph Reel
3=Pacilic Reel
4=Caryslort Reel
5=The Elbow
6=Key Largo Dry Rocks
7=Grecian Rocks
8=French Reel
9=Molasses Reel
10=Conch Keel
11=Davis Reel
12=Hens and Chicken
Reel
13*Alligator Reel
14=Tennessee Reel
15=Delta Shoal
16=Sombrero Key
17=LooeKey
18=Maryland Shoal
19=»Pelican Shoal
20=Eastern Sambo
21=Middle Sambo
22=Western Sambo
23=Eastern Dry Rocks
24=Rock Key
25=Sand Key
26=Western Dry Rocks
27=Satan Shoal
28=Vestal Shoal
29=Coalbin Rock
30=Marqiiesas Keys
3t=Cosgrove Shoal
32=Marquesas Rock
33=Rebecca Shoal
34-Dry Tortugas
FLORIDA KEYS NATIONAL
MARINE SANCTUARY
ATLANTIC
OCEAN
» STATUTE M.ES
30 KfcOMETERS
Figure 3-1. Major reefs of the Florida Reef Tract.
-------
Hard-bottom or live-bottom communities are found closest to shore, in depths that range from less than 1 m to
greater than 30 m. These areas are composed of exposed rock substrate colonized by algae, sponges,
hydrozoans, octocorals, small hard corals, bryozoans, and ascidians. The hard corals found in these
communities are generally small and are not actively building reef structures.
Patch reefs typically are found offshore of Hawk Channel and inside the bank reefs in water depths of up to 9
m, although a few may be found in nearshore areas (Jaap and Hallock 1990). Patch reefs are relatively
randomly distributed among the seagrass and hard-bottom areas, and thereby they provide structure and increase
the complexity of the habitats. The massive star and brain corals form the bulk of the reef; algae, sponges,
octocorals, and bryozoans fill in the framework.
Bank reefs are found seaward of Hawk Channel and the patch reefs, and are situated parallel to shore. As
mentioned previously, most bank reefs are found in the upper and lower Keys where land masses shield them
from Florida Bay waters. Bank reefs typically consist of spur-and-groove formations that extend offshore,
perpendicular to the coastline or depth contours. The spurs are long reef structures that are covered with
corals, sponges, and other reef biota. The grooves run parallel to and between the spurs and contain coralline
rubble and sand.
Dustan and Halas (1987) documented significant changes between 1974 and 1982 in the hard-coral community
of Carysfort Reef. They used repetitive line transects to measure the individual colonies along the transects to
determine changes in the mean colony size, abundance, and cover. They found that the community had changed
significantly over 8 years, with the corals having increased in abundance in the shallow reef areas and decreased
in abundance on the deeper fore reef. The increased abundance in the shallow reef areas appears to have
resulted from the fragmentation of larger colonies of Acropora palmata into smaller colonies by vessel
groundings, anchor damage, and diver activities.
Porter (manuscript in preparation), during surveys of permanent monitoring quadrats on reefs at Looe Key and
Key Largo, detected a 4% loss in coral cover per year between 1984 and 1986. Unpublished data indicate that
this loss in coral cover may have increased since 1986. The causes for the decline appear to be a higher
incidence of coral disease during the most recent survey and coral bleaching (J. Porter, University of Georgia,
personal communication, 1991). Additional quantitative surveys are currently being undertaken by Porter at
specific locations in the Biscayne National Park.
Sullivan et al. (1992) summarized data collected for two hard-bottom communities in sites off Long Key. These
sites, Fiesta Key on the Florida Bay side of Long Key and Craig Key on the ocean side of Channel 5, represent
inshore and nearshore hard-bottom communities, respectively. These sites can be characterized as follows:
Craig Key Fiesta Key
Total area 810,900m2 100,763m2
% Sand 8.6% 4.1%
% Hard bottom 54.6% 16.7%
% Seagrass 36.8% 74.4%
% Land 0% 4.8%
The results of this work showed that Fiesta Key has experienced a greater rate of change in community
structure than Craig Key. On Fiesta Key, the largest change in structure occurred between the Fall 1989 and
Fall 1990 sampling when the Fiesta Key site showed a decrease in octocoral and sponge abundance. A second
result of this work was that although both reefs fall into the same general community designation, they are very
different; Fiesta Key is an algal-dominated reef and Craig Key is an octocoral/sponge-dominated reef.
3-3
-------
2.2 CORAL BIOLOGY
The corals present in the Florida Keys are composed of hydrozoan corals, including Millepora (fire coral),
octocorals (sea whips and fans), and scleractinian corals (hard or stony corals). Tables 3-1 and 3-2 list the
scleractinian and shallow-water octocoral species found on the reefs of southeast Florida and the Florida Keys,
as noted by Jaap (1984).
The fire corals Millepora alcicornis and M. complanata are common to western Atlantic tropical reefs. These
species have very high concentrations of zooxanthellae in their tissues, giving them a golden brown color.
Although growth-rate data for these two species are limited, upward growth is estimated by Jaap (1984) to
approach 10 cm annually.
Octocorals are generally the most common coral observed on Florida Keys reefs, with documented densities of
up to 27 colonies per square meter (Opresko 1973); unpublished data indicate densities as high as 73 colonies
per square meter (Wheaton and Jaap 1988). Life history information on most octocoral species is scarce; the
taxonomy and systematics of this group are also confusing. As noted by Bayer (1961), a single species may
have different growth forms and variations in the shape of its skeletal spicules, based upon the conditions of its
immediate environment (e.g., water depth, turbulence, light intensity, etc.). Growth rates of 10 to 40 mm per
year for Plexaura homomalla have been reported by Kinzie (1974), whereas Gary (1918) reported most reef-
dwelling species of octocorals from the Dry Tortugas region reached a medium size in 3 to 5 years, with slower
growth rates evident with increasing coral age.
Scleractinian corals are the major reef builders. They have life spans ranging from just a few years for the
small finger corals up to hundreds of years for the more massive star corals and brain corals (Jaap and Hallock
1990). Growth rates for a number of hard-coral species from Florida and the Bahamas are presented in Table
3-3. These rates ranged from 3.5 mm/year for the plate coral Agaricia agaricites to greater than 100 mm/year
for the rapid growing branching coral Acropora cervicornis. Growth rates for the massive, head-forming corals
are relatively slow, with Montastrea annularis averaging approximately 8 mm/year on the nearshore reefs of the
Key Largo National Marine Sanctuary (Hudson 1981). Jaap (1984) gives a more detailed description of some
of the other basic components of the coral reef ecosystem, including algae, sponges, reef fishes, and plankton,
along with a discussion of coral reef ecology.
2.3 CORAL ZOOXANTHELLAE
Hard corals and octocorals are hosts to symbiotic algae. These algae, collectively called zooxanthellae, are
dinoflagellates that naturally exist in both the free-living and symbiotic state. These algae were once assigned
by systematise to the genera Symbiodinium and Gymnodinium (Darley 1982), but have most recently been
proposed for reclassification based upon the genetic relationship in small ribosomal subunit RNA nuclear genes
(Rowan and Powers 1991).
The exact size of a population of zooxanthellae within a coral polyp cannot be measured in situ, but can be
estimated by using techniques such as the average mitotic index (Muscatine 1990). This method assumes a
constant algal division rate and estimates the number of algae, based on the number of dividing cells.
Relationship between Zooxanthellae and Coral Polyps
There is a complex relationship between the zooxanthellae symbiont and its cnidarian host, the coral (animal).
Many components of this relationship and its physical and physiological benefits have been examined and
3-4
-------
Table 3-1. Southeast Florida reef Scleractinia. [From Jaap 1984]
ORDER SCLERACTINIA
SUBORDER ASTROCOENDNA Vaughan and
Wells 1943
Family Astrocoeniidae Koby
Stephanocoenia michelini (Milne
Edwards and Haime)
Family Pocilloporidae Gray
Madracis decaais (Lyman)
M. formosa Wells
M, mirabilis (sensu Wells)
Family Acroporidae Verrill
Acropora palmata (Lamarck)
A. cervicornis (Lamarck)
A. prolifera (Lamarck)
SUBORDER FUNGHNA Verrill
Superfamily Agariciicae Gray
Family Agariciidae Gray
Agaricia agaricites (Linn6)
A. agaricites agaricites (Linn£)
A. agaricites danai Milne Edwards and
Haime
A. agaricites carinata Wells
A. agaricites purpurea (LeSueur)
A. lamarcki Mime Edwards and Haime
A. undata (Ellis and Solander)
A. fragilis (Dana)
Helioseris cucullata (Ellis and Solander)
Family Siderastreidae Vaughan and Wells
Siderastrea radians (Pallas)
5. siderea (Ellis and Solander)
Superfamily Poriticae Gray
Family Poritidae Gray
Forties astreoides (Lamarck)
P. parties (Pallas)
P. parties divaricata LeSueur
P. parties furcata Lamarck
P. parties clavaria Lamarck
P. branneri Rathbun
SUBORDER FAVUNA
Superfamily Faviicae Gregory
Family Faviidae Gregory
Faviafragum (Esper)
F. gravida (Verrill)
D. clivosa (Ellis and Solander)
Diploria labyrinthiformis (Linne1)
D. strigosa (Dana)
Manicina areolata (Linn6)
M. areolata mayori (Wells)
C. amdranthus (Muller)
C. breviseralis Milne Edwards and
Haime
Colpophyllia natans (Houttyn)
Cladocora arbuscula (LeSueur)
M. annularis (Ellis and Solander)
Montastraea cavernosa (Linne")
S. bournoni Milne Edwards and Haime
Solenastrea hyades (Dana)
Family Rhizangiidae d'Orbigny
Astrangia astreiformis (Milne Edwards
and Haime)
A. solitaria (LeSueur)
Phyllangia americana Milne Edwards
and Haime
Family Oculinidae Gray
Oculina diffusa Lamarck
O. varicosa LeSueur
O. robusta Pourtales
Family Meandrinidae Gray
Meandrina meandrties (Linne')
M. meandrties braziUensis Milne
Edwards and Haime
Dichocoenia stellaris Milne Edwards
and Haime
D. stokesii Milne Edwards and Haime
Dendrogyra cylindrus Ehrenberg
3-5
-------
Table 3-1. Southeast Florida reef Scleractinia. [From Jaap 1984] (continued)
Family Mussidae Ortmann
Mussa angulosa (Pallas)
Scotymia lacera (Pallas)
S. cubensis Milne Edwards and Haime
hophyllia sinuosa (Ellis and Solander)
/. multiflora Verrill
hophyllastraea rigida (Dana)
Mycetophyllia lamarddana Milne
Edwards and Haime
M. danaana Milne Edwards and Haime
M. ferox Wells
M. aliciae Wells
SUBORDER CARYOPHYLLI1NA Vaughan
and Wells 1943
Superfamily Caryophylliicae Gray
Family Caryophylliidae Gray
Eusmiliafastigiata (Pallas)
Paracyathus pulchellus (Philippi)
SUBORDER DENDROPHYLLIINA Vaughan
and Wells 1943
Family Dendrophylliidae Gray
Balanophyllia floridana Pourtales
3-6
-------
Table 3-2. Octocoral fauna in shallow southeast Florida reef
communities. [From Jaap 1984; Wheaton 1987; Wheaton and Jaap 1988;
Dustan et al. 1991]
Species
Briareum asbestinum
Ellisella barbadensis
E. elongate
Erythropodium caribaeorum
Eunicea palmeri
E. pinta
E. mammosa
E. succinea
E. fusca
E. laciniata
E. tourneforti
E. asperula
E. clavigera
E. knighti
E. cafyculata
Gorgonia ventalina
Iciligorgia schrammi
Lophogorgia hebes
Muricea muricata
M. atlantica
M. laxa
M. elongata
Muriceopsis flavida
M. petila
Nicella schmitti
Plexaura homomalla
P. flexuosa
Pseudoplexaura porosa
P. Jlagellosa
P. wagenaari
P. crucis
Plexaurella dichotoma
P. nutans
P. grisea
P. fusifera
Pseudopterogorgia bipinnata
P. hallos
P. rigida
P. acerosa
P. americana
P. elisabethae
P. navia
Pterogorgia citrina
P. anceps
P. guadalupensis
Swiftia exserta
Patch Reef
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Bank Reef
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
3-7
-------
Table 3-3. Growth rates of scleractinian species from Florida and the Bahamas*. [From Jaap 1984]
Species
Growth rateb Location
(mm/year)
Source
Acropora cervicornis
A. palmata
A. prolifera
Agaricia agaricites
Dendrogyra cylindrus
Dichocoenia stokesii
Diploria labyrinthiformis
D. clivosa
D. strigosa
Eusmilia fastigiata
Faviafragum
Isophyllia sinuosa
Manicina areolata
M. areolata mayor!
Montastraea cavernosa
M. annularis
Oculina diffusa
Parties parties
P. astreoides
Siderastrea radians
S. siderea
40.0 H
109.0 H
115.0 H
39.5 H
105.0 B
37.2 H
3.5 H
10.4 H
6.7 D
7.8 D
17.3 D
6.9 H
5.0 H
5.8 H
4.9 D
5.1 D
8.2 D
14.0 D
4.4 H
9.0 H
5.0 - 6.8 H
10.7 H
8.4 H
8.0- 9.7 H
14.3 H
17.9 H
17.6 D
4.3 D
6.3 D
Dry Tortugas
Key Largo Dry Rocks
Eastern Sambo
Goulding Cay, Bahamas
Eastern Sambo
Goulding Cay, Bahamas
Dry Tortugas
Dry Tortugas
Dry Tortugas
Dry Tortugas
Dry Tortugas
Dry Tortugas
Carysfort
Dry Tortugas
Dry Tortugas
Goulding Cay, Bahamas
Dry Tortugas
Dry Tortugas
Dry Tortugas
Key West
Dry Tortugas
Carysfort
Carysfort
Key Largo area
Dry Tortugas
Dry Tortugas
Dry Tortugas
Dry Tortugas
Dry Tortugas
Vaughan and Shaw 1916°
Shinn 1966
Jaap 1974
Vaughan and Shaw 1916
Jaap 1974
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Shinn 1975
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Agassiz 1890
Vaughan and Shaw 1916
Hoffmeister and Multer 1964
Shinn 1975
Hudson 1981
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Vaughan and Shaw 1916
Moulding Cay, Bahamas data were used only when Tortugas information was unavailable.
bB: Increase in branch length. D: Increase in diameter. H: Increase in height.
'Multiple values from Vaughan and Shaw (1916) were averaged.
3-8
-------
characterized. Direct benefits to the algal symbiont and its coral host, along with the exact mechanisms of
nutrient transfer, are less well understood (Miller and Veron 1990; Muscatine 1990). Possession of algae.are
believed to benefit corals by supplying nutritional requirements when they cannot be met heterotrophically
(Cook and D'Elia 1987; Muller-Parker et al. 1988). The coral can obtain nutrition heterotrophically by
capturing prey with its tentacles or autotrophically through its symbiont algae, the latter of which translocate
photosynthetically fixed material (Porter 1976; Muscatine and Porter 1977). Zooxanthellae photosynthesis also
aids in the coral's production of its carbonate skeleton by providing the coral with energy for calcification
(Goreau and Goreau 1959a,b).
Debate in the literature has traditionally centered on the percentage of energy supplied to the coral by capturing
prey versus energy from photosynthetically fixed carbon, the mechanism of transfer, and the nature of control
exerted between the coral and its symbiont algae (D'Elia and Cook 1988; Miller and Yellowlees 1989).
Hallock (1981) estimated that the energy available to the host for growth and respiration is 1 to 2 orders of
magnitude above that available to a heterotroph that does not have a symbiont. However, values for
photosynthetic and respiratory quotients for reefs have not been empirically established (Muscatine 1990).
Research using stable isotopic ratios indicates that corals living at depths down to 50 m use carbon from
photosynthesis by zooxanthellae, but that carbon from direct feeding by coral becomes increasingly important
with increasing depth (Muscatine et al. 1989).
3.0 FACTORS OR PROCESSES STRESSFUL TO CORAL COMMUNITIES
A number of factors, both natural and human-induced, affect the vitality of coral reefs, including reefs in the
Florida Keys. These include biological competition, predation, disease, stress from various types of pollution,
algal fouling and smothering, sedimentation, temperature extremes, salinity variations, decreases in water
clarity, and physical damage. Many of these factors are interrelated and synergistic in their effects on the coral
community (e.g., warm or cold water stressing coral colonies and making them more susceptible to disease).
This Section attempts to cover most of these factors, with the exception of physical damage, but concentrates on
potential and known detrimental effects due to water-quality deterioration.
3.1 BIOLOGICAL INTERACTIONS
There are numerous ways in which corals are adversely affected by other members of the community in which
they live. Competition among and between hard-coral species has been documented extensively and includes
chemical defenses (Cameron 1974; Sullivan et al. 1983), digestion of competing species tissues by the extension
of mesenterial filaments (Lang 1971, 1973), and actual overgrowth and shading of slower growing species by
those with a more rapid growth rate (Shinn 197S, 1989).
Hard corals are also killed by damselfish, which will destroy the coral tissue and then farm the algae that
colonize the dead coral skeleton (Kaufman 1977). Parrotfish (Scaridae), butterflyfish (Chaetodontidae), and
other damselfish (Pomacentridae) are also known to feed upon hard corals (Glynn 1973). The polychaete worm
Hermodice carunculata is also known to feed on coral species (Marsden 1962; Ebbs 1966; Lizama and Blanquet
1975). The long-spined sea urchin, Diadema antillarum, although primarily an herbivore that rasps algae off
the limestone reef providing coral larvae with new attachment sites, may also remove these newly settled larvae
while feeding (Sammarco 1980).
Boring sponges have been shown to rapidly erode hard-coral skeletons by dissolving any organic matter and
etching away the carbonate rock with acid (Rutzler and Rieger 1973; Pomponi 1977). In work done in Belize
by HighsmJth et al. (1983), boring sponges had caused 85% to 94% of the erosion of cavities in the massive
corals studied. Hein and Risk (1975) analyzed eight heads of several species of reef corals from Hens and
3-9
-------
Chickens Reef near Tavemier, FloricL
boriog sponges, spionid polychaetes, ar.
Montastrea annularis heads was initk
erosion by parrotfish (Scaridae) and t!
included bacteria, fungi, boring algae,
molluscs as important reef bioeroders.
Octocorals are not immune to the ef"
(1980) that colonies of the fire coral
toward, and then overgrow the imm
common predator upon certain octocon'
ral skeletal structure reworked by
und that surface bioerosion of dead
ag sponges followed by increased
.-urn. Risk and MacGeachy (1978)
jipunculids, barnacles, and bivalve
: has been documented by Wahle
rby colonies of octocorals, grow
xi molluscs Cyphoma spp. are a
A variety of diseases can cause coral
Gladfelter 1982; Peters 1984). They
polluted areas. These include variou=
band disease being the most well-kiK
Strake et al. 1988); calicoblastic neop!
at. 1981). Black-band disease and
suspected of decimating the long-spir
during 1983-1984. The urchins have st
la,b, 1985; Bak and Criens 1981;
i pristine as well as from heavily
(or black-line) disease and white-
weakened corals (Jaap 1985; Te
;ous green algal tumors (Morse et
ow. Bacterial disease was also
.'.aliens throughout the Caribbean
'evels.
Black-band disease was described one:
Oscillatoria submembranacea. Subsec
cyanobacteria Phormidium corallyticu/
composed of cyanobacteria and decomp
the disease spreads. Hard corals have
suffering from white-band disease, afte.
filamentous green algae occurs along
digestion of competing species tissues '
exposing the coral's endoderm to infe.
coral margin causes a chafing of the cc
coral tissue to infection. Once infectev
daylight hours, although the rate dimini.-'
Black-band disease seems to be more
strigosa and Montastrea annularis are •
corals that are less frequently obs<
labyrinthiformls, M. cavernosa, Colp.
Florida Keys, Montastrea annularis is '
having been killed from 1978 to 1985
disease was seriously infecting corals >
black-band disease — the octocorals C
Pseudopterogorgia acerosa have also
including penicillin, erythromycin, am'
1981b).
id by the common blue-green alga
Bribed the causative agent as the
•om the characteristic black band,
across the surface of the coral as
i black-band disease either while
species, or when a dense band of
The white-band disease and the
'iving tissue in the affected coral,
'ous green algae buildup along a
ater movement, also exposing the
.1 head at up to 1 cm/day during
nian corals. Of these, Diploria
Species of western Atlantic hard
i>ease include D. clivosa, D.
,-,J Siderastrea siderea. In the
large colonies at Carysfort Reef
i also reported that Ha k u : J
• not alone in being z
ra homomalla, P.
(Antonius 19? 5
-! black band ci
-------
3.2.2 White-Band Disease
White-band disease is similar to black-band disease in the way that it progresses across the coral surface in an
observable line, although the line in this case is approximately 1 cm wide and white. The zooxanthellae-
containing coral tissue and mucus slough off the coral as the disease spreads. Unlike black-band disease, white-
band disease is not affected by antibiotics and the speed of advance does not diminish at night (Antonius 1981b).
On branching forms of coral, the disease starts at the base and proceeds out to the branch tips. On lobate
forms, the disease typically begins in a shady area or crack where there is some type of algal growth (Antonius
1981b). Peters (1984) suggests that an unusual gram-negative bacteria that is resistant to antibiotics may be
responsible for some of the cases of white-band disease; in other cases in which microorganisms cannot be seen,
the disease may be due to physiological stress caused by high nutrient levels or excessive sedimentation. White-
band disease shows a distinct seasonality in Bermuda and Florida waters, with occurrences peaking during the
wannest months of the year and disappearing in late fall. Black-band disease also shows this seasonality, but
lags slightly behind the white-band disease (Antonius 1981a,b).
Dustan (1977) described this disease as a plague in work that he had performed at Carysfort Reef off Key Largo
in 1975. He observed the disease in Mycetophyllia ferox, M. lamarckiana, and Colpophyllia natans and found
M. ferox to be extremely susceptible to the disease, with death usually occurring within 4 months. Other
Caribbean corals known to commonly contract the disease include Acropora cervicornis, A. palmata, A.
prolifera, Diploria strigosa, and Montastrea annularis (Antonius 198 Ib). The disease appears to affect various
species with differing frequencies, depending upon geographic location. Acropora palmata is the most affected
coral species in the Virgin Islands, with the disease starting at the base of the coral and progressing to the tips
of the branches (Gladfelter 1982). On 44 of 45 colonies studied by Gladfelter (1982) in St. Croix, Virgin
Islands, the disease destroyed the entire colony. In Florida and Belize populations of A. palmata, the, disease is
seldom observed (Antonius 198Ib). Table 3-4 lists hard-coral species from the Caribbean Sea found to have
white-band disease, black-band disease, or both, as observed in the field.
3.3 TEMPERATURE
Thermal stress can adversely affect a coral reef system and, because of the Florida Keys' location on the
northern edge of the sub tropics, both heat and cold stress are frequently experienced. Annual mean seawater
temperatures in the Florida Keys range from 18 to 30 °C (Jaap 1984). Cold-water stress occurs in the Keys
when a winter cold front extends into south Florida and cools the shallow waters of Florida Bay and nearshore
water of the Keys. As this cool, dense water moves south out of Florida Bay through the passes, it sinks under
the warmer surrounding waters, hugging the bottom, and exposing the reefs to cold temperatures. Numerous
occurrences of coral mortality have been reported for the Florida Keys in recent years. During a January 1977
cold front, temperatures dropped below 16 °C for 8 days. This caused the death of 91% of the shallow-water
Acropora cervicornis at Loggerhead Key in the Dry Tortugas (Roberts et al. 1983). The same cold front also
caused the death of 96% of the living corals in depths less than 2 m at Dry Tortugas reefs (Porter et al. 1982).
A cold-water mass was implicated in the death of as many as 90% of the corals at Hens and Chickens Reef off
Plantation Key in the winter of 1969-1970 (Hudson et al. 1976). In January 1981, record low temperatures
were the cause of cold-water mortalities of hard corals near Elliot Key in the upper Keys and at Looe Key
(Walker et al. 1982).
Elevated water temperatures can also stress corals, principally causing zooxanthellae expulsion (or coral
bleaching). In more severe cases, disease and death have been reported. High water temperatures may be
more localized than are cold-water events and typically occur during periods when seas are calm and when low
tides coincide with high midday temperatures. Since 1973, there have been four major zooxanthellae expulsions
in the Florida Keys and South Florida that were caused by increased water temperatures. Corals at Middle
3-11
-------
Table 3-4. Corals observed to contract black-band or white-band disease
in the Caribbean. [From Antonius 1981b]
Species
Acropora palmata
A. prolifera
A. cervicornis
Agaricia agaricites
A. tenuifolia
Siderastrea siderea
S. radians
Forties astreoides
Faviafragum
Diploria clivosa
D. labyrinthiformis
D. strigosa
Colopophyllia natans
Montastrea annularis
M. cavernosa
Dichocoenia stokesi
Dendrogyra cylindrus
Mycetophyllia lamardd
M. ferox
Millepora sp.
Gorgonia ventalina
G. flabellum
Frequent
W
W
W
W
W
W
W
WB
WB
W
Occurrence
Seldom
WB
W
B
B
B
B
WB
B
W
B
B
Never
B
B
B
B
B
B
B
B
W
WB
B
B
WB
W
W
W: White-band disease
B: Black-band disease
WB: Both white- and black-band diseases.
3-12
-------
Sambo Reef, near Boca Chica Key, expelled their zooxanthellae in late September but most regained their
zooxanthellae within 6 weeks (Jaap 1979). During September 1983, there was extensive coral bleaching from
Key Largo to the Dry Tortugas owing to high water temperatures (Jaap 1985). A very extensive zooxanthellae
expulsion began in July 1987, and lasted for 6 months. It extended from Palm Beach to the Dry Tortugas and
was reported throughout the Caribbean and into the northern Gulf of Mexico as well (Jaap 1988). The most
recent coral bleaching occurred in 1990 and 1991 and was likely caused by elevated seawater temperatures and
potentially increased exposure to ultraviolet illumination (W. Jaap, Florida Marine Research Institute, personal
communication, 1992). The 1983 and 1987 bleaching events were also experienced in the eastern, central, and
western Pacific (Glynn 1984; Williams and Williams 1988). The 1982-1983 El Nino Southern/Oscillation
apparently caused the first documented case of species extinction from a warming event. An undescribed
species of Millepora that was endemic to the Gulf of Chiriqui off the west coast of Panama apparently did not
survive the severe bleaching of early 1983 and is therefore presumed to be extinct (Glynn and De Weerdt 1991).
Although coral bleaching is discussed relative to elevated water temperatures, this stress response also manifests
itself because of other factors. These can include low water temperatures, low light conditions, exposure to air,
low salinities, increased levels of sedimentation, and various pollutants (D'EIia el al. 1991).
3.4 WATER TRANSPARENCY AND SEDIMENTATION
Coral development and growth is dependent upon water clarity because the zooxanthellae need sunlight to
photosynthesize. In the waters of high clarity that are typical on coral reefs, phytoplankton efficiently absorb
available nutrients and increase their division rates to outcompete larger organisms (Geider el al. 1986; Smith et
al. 1981). An increase in water-column phytoplankton densities that can be caused by higher levels of nutrients
in the-water results in a decrease in light penetration and, in turn, may stress the corals (Hallock et al. 1988).
Increases in waterborne particulate matter also cause decreased light penetration through the water column.
Water clarity over the Florida Keys reefs varies from extremely clear (following extensive periods of calm
weather) to virtually opaque.(after sustained storms and hurricanes when fine sediments become resuspended)
(Jaap 1984). Decreased light penetration caused by sediment suspension is only one of the problems that beset
corals living near dredging activities (Rogers 1990).
Sedimentation adversely affects corals because it causes the corals to increase mucus production. For example,
corals increase mucus production to slough away materials that settle out on the colonies, thereby diverting
energy that would normally be utilized for growth (Lasker 1980; Marszalek 1981; Rogers 1983; Kendall and
Powell 1988). Increased mucus production due to sedimentation has also been implicated as a cause of
increased incidence of disease in corals. The higher output of mucus provides a substrate for bacterial and other
pathogenic growth (Mitchell and Chet 1975; Loya 1976a,b; Loya and Rinkevich 1980). Sedimentation causes
the burial of hard substrates, reducing the available hard substrate for coral settlement and recruitment.
Sedimentation also adversely affects hard corals when the coral margin is covered with tufts of filamentous
algae. These algae tufts tend to trap fine sediments and form a dense mat that eventually overgrows the coral
margin (Dustan 1977; Gittings 1988).
Dredging for beach nourishment is now the major type of dredging activity taking place in southeast Florida
(Rogers 1990). In many cases, the constant resuspension of sediments finer than those originally on the beach
causes recurring damage more severe than any initial impacts (Marszalek 1981; Rogers 1990). In the Florida
Keys, treasure hunting activities, utilizing "mail-box blowers" which divert propeller wash to the bottom,
suspend large amounts of sediment thereby increasing turbidity (W. Jaap, Florida Marine Research Institute,
personal communication, 1992).
3-13
-------
3.5 NUTRIENTS
Many factors control the development and survival of a coral reef. Of these factors, climate and nutrient
availability are thought to be the dominant influences. Climate determines the broad distribution of organisms.
Nutrient availability influences the species composition of a reef (D'Elia and Wiebe 1990). Coral reefs
classically are located in oligotrophic environments where the water is clear, warm, and has low or undetectable
nutrient levels.
A coral reef system is especially adapted to utilize nutrients from the water column when these compounds are
at very low concentrations. Coral reefs can also utilize nitrogen fixed from the atmosphere and taken up from
groundwater. The balance of species in a reef community can be altered by a change in concentration and
availability of nutrients to that system. The effects of nutrients on a reef ecosystem can be modified by other
physical factors, including biozoogeography (the relative distribution of organisms), geographic location
(physical factors associated with the geographic location), competition between species, the type of nutrients
available, the zone of the reef being examined, and the relative abundance of these nutrients.
Nutrients affect corals by interfering with calcification, providing an environment suitable to increased levels of
phytoplankton, macroalgae, blue green algae, bacteria, and bioerosion (Mitchell and Chet 1975; Dustan 1977;
Kinsey and Davies 1979; Antonius 198Ib; Highsmith 1980; Te Strake et al. 1988; Hallock 1988; Hallock and
Schlager 1986). Each of these factors potentially causes the decline of coral species and a shift in ecosystem
biomass to one that is less dominated by coral.
3.5.1 Nutrient Cycling
Organisms exist in an elemental equilibrium that is defined by the interbalance of carbon, nitrogen, and
phosphorus, or the C:N:P ratio. This value, 106:16:1, which was defined for marine phytoplankton by Redfield
(1958), is known as the Redfield ratio. He concluded that nitrogen and phosphorus are available in amounts
that are limiting to plant growth, depending upon their sources, as cited by Smith (1984). However, it has
recently been observed that the Redfield ratio does not apply generally to all systems; it may be misleading
when applied to coral systems (Kinsey 1991). In marine systems, elements and compounds (such as iron,
silicon, and trace elements) that occur in small, often trace, amounts are known as micronutrients. Elements
(such as nitrogen and phosphorus) that occur in larger amounts are known as macronutrients. Nitrogen and
phosphorus are generally the nutrients of concern when eutrophication has overtaken a system. Depending on
the part of the coastal area being examined, the primary limiting nutrient may be either nitrogen or phosphorus.
In carbonate environments, the limiting macronutrient is primarily phosphorus because it chemically binds to
calcium carbonate (CaCO,; R. Jones, Florida International University, personal communication, 1991).
Nitrogen fixation is the process converting atmospheric nitrogen gas into compounds that can be utilized by
organisms. The reverse process by which these compounds are changed back into the gaseous state is
denitrification. Many organisms on the reef tract have symbiotic bacterial associations that fix nitrogen and
make it available to other organisms in biologically utilizable forms. Phosphorus, the other macronutrient of
interest, is available only from the breakdown of natural components, including the recycling of organic matter.
Because phosphorus is found in organisms in a relatively lower ratio, it was once assumed that it was needed in
small quantities and so would be less likely to be limiting for plant growth. It is now known that the
determination of the limiting macronutrient (nitrogen or phosphorus) depends upon the location and component
of the system being examined (Smith 1988). Reef systems represent an integrated relationship among many
diverse parts that move nutrients among components, with productivity depending upon the component being
examined (Kinsey 1991).
3-14
-------
3.5.2 Response to Increased Nutrients
A community response to increased nutrients is to shift toward systems that are less light-limited, because they
can rapidly take up available nutrients (Birkeland 1977; Hallock and Schlager 1986; Hallock 1987, 1988;
Hallock et al. 1988). Factors influencing ecological shifts that result from nutrient increase are growth rate,
ability to utilize increased nutrients, ability to respond to rapidly increased nutrients, competition, larval
recruitment, larval survival, and larval competition (Birkeland 1977; Hallock and Schlager 1986; Hallock 1987,
1988). Successful coral recruitment is inversely correlated with nutrient availability (Birkeland 1977), and high
eutrophication can eliminate corals from a benthic community (Smith et al. 1981). Geologically, reefs are
believed to have drowned in response to changes in circulation patterns and the increase in nutrient-laden water,
essentially natural eutrophication (Hallock and Schlager 1986; Hallock et al. 1988; Hallock 1988).
3.5.3 Effects of Phosphorus
Calcium carbonate chemically binds phosphorus to form the mineral apatite, which is the dominant sink for
soluble reactive phosphorus (Berner 1981). Due to this phenomenon, phosphorus is often the limiting nutrient
in calcium carbonate sediments (R. Jones, Florida International University, personal communication, 1991).
Available information for Florida Bay indicates that it is a phosphorus-limited system, a possibility that may also
extend to the reef tract [Lapointe 1989; Powell et al. 1989, 1991; Fourqurean et al. to be published)].
Phosphorus, as an element in the reef nutrient cycle, is generally tightly coupled and not found in the water
column (Pilson and Betzer 1973; Webb et al. 1975; D'Elia and Wiebe 1990). Carbonate sediments also recycle
phosphorus very slowly (Mines and Lyons 1982). For these reasons, healthy systems of corals with
zooxanthellae have adapted to remove phosphorus from waters with naturally low phosphorus concentrations
(Pomeroy et al. 1974; D'Elia 1977; D'Elia and Wiebe 1990). Recycling of phosphorus and nitrogen is,
therefore, tied to the regeneration of these components, principally at the sediment/water interface (Andrews and
Muller 1983).
Phosphate pollution was recognized as a factor in the decline of reefs in Eilat, Red Sea (Loya 1975, 1976a,b;
D'Elia and Wiebe 1990). It has been suggested that nutrient enrichment, together with algal competition and
reduced temperatures, was responsible for reduction of growth rates of reefs adjacent to upwelling areas and
during the Holocene transgression (Kinsey and Davies 1979). Evidence suggests that calcification may be
affected by large increases in the phosphorus level in surrounding wafers (Kinsey and Davies 1979).
Water-column dissolved inorganic phosphorus (DIP, also called soluble reactive phosphorus) concentrations of
less than 0.4 /tM to below detection level (0.03 /xM) are common in reefs around the world (D'Elia and Wiebe
1990). Historic DIP concentrations were undetectable (less than 0.03 /tM) from Biscayne Bay to Triumph Reef
in an early south Florida survey (Smith et al. 1950). Historic values can be taken from Jones (1963), for an
area at Margot Fish Shoal off Elliot Key, from the period November 1961 to May 1962, who reported total
phosphorus values from 0.15 to 0.3 itg atoms/L and inorganic phosphorus values that ranged from undetectable
to 0.1 /jg atoms/L. Inorganic phosphorus levels along the Florida Reef Tract in 1990 .generally ranged below
0.4 /iM (Szmant 1991). Because of the small size of this data set, conclusions should not be drawn until large
scale sampling over meaningful time frames can be conducted.
3.5.4 Sources and Effects of Nitrogen
Nitrogen is available to reefs from the atmosphere (i.e., fixed by organisms on the reef), the reef flat, terrestrial
input, sediment regeneration, sediment pore waters, coral interstices, and groundwater [Kinsey and Domm
1974; Webb et al. 1975; Johannes 1980; D'Elia et al. 1981; Andrews and Muller 1983; Johannes et al.
3-15
-------
1983a,b; Szmant-Froelich 1983; Corredor and Morell 1985; Hallock 1988; Hallock and Schlager 1986; Lee et
al. (to be published)]. Nutrients are available to reef systems at low levels from the water column and from
components of the reef capable of fixing nitrogen (Kinsey 1991). Nitrogen-fixing blue-green algae
(cyanobacteria) are found in various components of the reef and include Microcoleus fyngbyaceus, Schizothrix
calcicola, Calothrix Crustacea, Hormothamnion enteromorphoides, and Rivularia sp. (Webb et al. 1975; Jaap
1984). In addition to this source of nitrogen, nitrogen and phosphorus compounds have both been found to be
sequestered in cavities within corals and beneath the reef (Andrews and Muller 1983; Risk and Muller 1983;
Szmant-Froelich 1983). Corredor and Morell (1985) reviewed sources of nitrogen in reef sediments and
reported levels of dissolved inorganic nitrogen (DIN) found in interstitial pore waters of reefs.
Different components of the reef release various forms of nitrogen. Corredor et al. (1988) found that two
sponges, Chondrilla nucula and Anthosigmella variant, released large amounts of nitrate — 600 nmol N/g (dry
weight) and 19 nmol N/g (dry weight), respectively. Based upon aerial calculations, these sponges could
together supply 50%-120% of the nitrogen required to sustain reef productivity. Ammonium was the dominant
form of nitrogen available on Mona Island reefs, with concentrations ranging up to 40 pM (Corredor and
Morell 1985). Nitrate was present at lower concentrations, and nitrite was present in only trace amounts.
Computed flux rates of nitrogenous species ranged between 0.75 and 1.37 /tM m'1 h"1 and represented a
significant source of recycled nitrogen on the reef tract. Bythell (1988) measured nitrogen and carbon budgets
for Acropora palmata in the Virgin Islands on a back-reef zone and determined that 50% of the total nitrogen
requirements were excreted as mucus.
3.5.5 Nutrient Flux and Availability
Reef productivity, nutrient uptake, and nutrient flux are related directly to the section of the reef being
examined (Kinsey 1977; Kinsey and Davies 1979; Kinsey 1985; D'Elia and Wiebe 1990). Kinsey (1991)
divides reefs based upon the productivity rates (determined from 11 worldwide reefs):
• Active reef parameters,
where gross production (F) = 7 (±1) C m"2 year1, and the net production of carbonates (G) = 4 (±0.5)
C m'2 year1.
• Sand and rubble,
where P = 1 (±0.3) C m'2 year1 and C = 0.5 (±0.2) C m'2 year1.
Highest primary production is found to be associated with the seaward areas of a reef (Kinsey 1991). Due to
the differences between sites on a specific reef, nutrient levels found at a given reef site are not necessarily
applicable to all sites on that reef or to reefs in general (D'Elia and Wiebe 1990). D'Elia and Wiebe (1990)
reviewed the biogeochemical nutrient cycles in coral reef ecosystems and their relationship to the portion of the
reef being examined.
Productivity measurements made by Kanwisher and Wainwright (1968) on Scleractinian corals taken from reefs
of Plantation Key (Hens and Chickens and the Rocks) show gross photosynthesis values that range between 4.0
C m"2 day'1 (for Siderastrea siderea) and 10.2 C m"2 day"1 (for Forties divaricata). This places the corals from
these areas, at that-time, near the values defined for active reef parameters by Kinsey (1991).
3.5.6 Groundwater Flow
Ground water and water within the reef structure have been implicated as a source of nutrients by several
investigators (Simmons et al. 1985; Simmons and Netherton 1987; Sansone et al. 1988). Much of this work
3-16
-------
was stimulated by the apparent coupling of septic systems, sewage ponds, and groundwater adjacent to reef
areas (D'Elia et al 1981; Lapointe et al. 1990). Carbonate platforms derived geologically from living coral
reefs are extremely porous in structure. Potentially, there are interconnections that allow movement of
groundwater great distances through these formations. Work has been done in Bermuda, Jamaica, and the
Florida Keys on these phenomena (D'Elia et al. 1981; Simmons et al. 1985; Simmons and Netherton 1987;
Lapointe et al. 1990; E. Shinn, Geological Survey, personal communication, 1991).
Bermuda, Jamaica, and the Florida Keys have shown elevated nutrient levels in adjacent marine waters.
Municipal practices in these areas include the disposal of sewage waste in septic systems, septic ponds, and
shallow injection wells, practices that are postulated to contaminate marine waters through fresh groundwater
connection to the marine environment (D'Elia et al. 1981; Lapointe et al. 1990; Simmons and Netherton 1987;
Jickells 1981). In Discovery Bay, Jamaica, seeps along the reef showed an inverse relationship (correlation
coefficient, r = -0.97) between salinity and nitrogen concentration (D'Elia et al. 1981). In Key Largo, along
the Florida Reef Tract, Simmons and Love (1984) report anthropogenic chemicals in lower salinity seeps into
the marine environment. Although direct connections between the aquifer underlying the Florida Keys and the
mainland portion of the Biscayne Aquifer have not been mapped, historic up well ing of freshwater is well-
documented in Biscayne Bay and along portions of the ocean side of Key Largo (Kohout and Kolipinski 1967;
Harlem 1979; VanAnnan et al. 1989). Based on these observations, shallow injection wells could be point
sources for nutrients to enter the marine environment and the reef tract. Recently, a large sinkhole,
approximately 300 m in diameter, was discovered off Key Largo near a reef that is experiencing a blue-green
algae bloom (E. Shinn, United States Geological Survey, personal communication, 1991). Although the
sinkhole is completely filled with marine sediments, it is thought that it may provide a pathway for groundwater
with elevated nutrient levels to reach the reef. Monitoring wells were drilled around the sinkhole to test for
elevated nutrient levels. To date, no elevated nutrient levels or unusual salinity readings have been detected
from these monitoring wells.
Shallow injection wells in the Keys with depths of 30 to 90 ft inject freshwater sewage into a saltwater-intruded
aquifer. The sewage is then a lens of freshwater overlying the more saline aquifer. Movement of this lens
should be controlled by the hydraulic head of the Everglades/Dade County region acting on the Biscayne
Aquifer. The lens of sewage would then be available to outwell wherever the Biscayne Aquifer connected to
surface waters in the marine environment.
3.5.7 Impacts of Nutrients at Specific Sites
Large-scale eutrophication impacts on coral reef areas have been documented and closely monitored in a
restricted number of sites worldwide. Nutrient enrichment and/or eutrophication effects have been reported
many places, but are well-documented for only a few locations. That information is available for Kaneohe Bay
in Hawaii. Other locations with research documenting nutrient effects include the Gulf of Aqaba and Bermuda.
3.5.7.1 KANEOHE BAY
Detailed examinations of the problem in Kaneohe Bay are given in Smith et al. (1973), Banner (1974), and
Smith et al. (1981). Kaneohe Bay is the largest enclosed embayment in the Hawaiian Archipelago and is
approximately 12.7 km long and 4.3 km wide (Banner 1974). This embayment received rainwater runoff from
the Kaneohe watershed and primary and secondary sewage for a total peak flow of 1.9 X 10* mVday until
approximately 1977-1978, when it was diverted offshore (Smith et al. 1981).
Changes in Kaneohe Bay were the result of si I tat ion, freshwater runoff, and high sewage loads to the Bay
(Smith et al. 1981). Areas in the southern basin nearest the outfall were the most devastated. These areas had
3-17
-------
been dredged and received sewage. They showed little live coral and massive growths of the algae
Acanthophora, Graciliara, and Hydroclathrus (Banner 1974). Overgrowth of coral by the alga Dictyosphaeria
cavernosa occurred throughout other portions of the Bay. Other community changes included increased water-
column phytoplankton, shifts in the community structure of benthic macroalgae, decline in coral cover, and
increased proportions of heterotrophic filter feeders (Banner 1974; Smith el at. 1981).
Toxicity to benthic organisms adjacent to the outfall was believed to be due to hydrogen sulfide in the sediments
(Banner 1974). Benthic community metabolism was believed to be controlled primarily by particulate loading,
but the limiting nutrient was found to be nitrogen (Smith et al. 1981). Due to the responses of rapid
incorporation and recycling of nutrients, measurement of the limiting nutrient (nitrogen in this case) was not a
good indicator of eutrophication (Smith et al. 1981); Response of the system relative to proximity of the outfall
and changes observed after diversion of the outfall indicated that circulation and water movement were
important to the impacts upon the system. The Kaneohe Bay situation was summarized by Marszalek (1987, p.
82), including the following points.
"Phytoplankton and zooplankton grazers increased dramatically, especially in the southeast sector
"Populations of benthic filter-feeders (e.g., sponges and zooanthids, the latter of which is a type of
encrusting soft coral) increased in response to increased food supply (i.e., plankton and organic detritus)
"The sediment-feeding sea cucumber Ophiodesoma spectabilis appeared in large numbers on organic-rich
sediments in the southeast sector
"The growth of benthic algae, especially the 'bubble algae' Dictospharea cavernosa, was greatly
stimulated
"Corals decreased in abundance. . ."
Upon cessation of sewage flow, the ecosystem slowly began to shift back to presewage conditions (Smith et al.
1981; Marszalek 1987).
3.5.7.2 REEFS OF THE FLORIDA KEYS
In the reef waters of the Florida Keys, either nitrogen and/or phosphorus can be limiting, depending upon
conditions. In Florida Bay, however, there is an abundance of nitrogen that may be available to the reefs,
depending upon transport mechanisms (R. Jones, Florida International University, personal communication,
1991; Smith 1991; Szmant 1991). Very few nutrient data are available for the Florida Reef Tract. Historical
data are summarized by Jaap (1984). Nutrient levels in the water column in Looe Key at control sites sampled
during enrichment showed normal oligotrophic values. Littler et al. (1986) indicated the following nutrient
ranges: N03: 0.51-2.44 /iM; NH4: 0.10-0.20 /iM; P0«: 0.10-0.38 /xM.
Samples for nutrient analysis were taken under the SEAKEYS Program managed by the Florida Institute of
Oceanography during 1990. Szmant (1991) and Lee et al. (to be published) sampled along seven
inshore/offshore transects from Biscayne National Park to Looe Key National Marine Sanctuary and offshore in
the Florida Current. Concentrations of total nitrogen were found to be within the range typical for oligotrophic
reef waters (i.e., 8- to 12-/iM range), except during windy days when sediments had been resuspended into the
water column (Szmant 1991). Reactive and organic phosphorus concentrations were also low for this area.
This pattern was generally mirrored in the entire sampling set from Key Largo to Looe Key, with some
exceptions.
3-18
-------
Major exceptions to oligotrophic conditions in the Keys coastal area were seen in samples taken off inshore
canals, the Ocean Reef Club development, Algae Reef, and Long Key. Samples taken near inshore canals and
marinas showed elevated levels of NH<, NO,, and PO4. Samples taken from near the Ocean Reef Club
development showed elevated organic and inorganic phosphorus levels (Szmant 1991). Samples taken off Long
Key generally were higher than those taken elsewhere along the Keys. Results of sampling suggested that high
nitrogen values for samples taken offshore indicate that Florida Bay may be a source of nitrogen on outgoing
tides. Chlorophyll a values, a measure of phytoplankton productivity, were twice as high for the Long Key
area as for the other sample areas.
Nutrient transport from nearshore waters in the lower Florida Keys to reefs in the Looe Key National Marine
Sanctuary has been examined (Lapointe et al. 1992). Current meter data indicate a long-term net flow from the
Gulf of Mexico through three tidal channels (Newfound Harbor Channel, Bahia Honda Channel, and Moser
Channel) to the Atlantic Ocean. Water flow in Hawk Channel was predominantly westward along-channel with
some seaward deflection. Elevated ammonium concentrations, at times exceeding 4.5 /iM, were observed after
rainfall events, and ammonium concentrations were elevated during wet periods compared to dry periods.
Soluble reactive phosphorus concentrations were low to undetectable and did not vary between wet and dry
periods. Lapointe et al. (1992) suggested that this was due to rapid uptake of soluble reactive phosphorus by
microbes and plants. Chlorophyll-a concentrations were elevated at most stations during wet periods compared
to dry periods.
Lapointe et al. (1992) concluded that a broad "island mass effect" transports nutrients seaward from the lower
Florida Keys. They suggested that anthropogenic sources, such as sewage disposal into septic tanks, increase
nutrient concentrations in groundwater, which is flushed into nearshore waters during rainfall events. These
anthropogenic nutrients were thought to be major contributors to the "wake" of nutrients existing between land
mass and the reefs. The investigators believe that nutrients entering the nearshore waters of the Florida Keys
are transported across Hawk Channel in near-bottom layers toward the reefs in Looe Key National Marine
Sanctuary, and that this nutrient flux contributes to eutrophication and reef coral stress.
An unidentified species of the blue-green alga Lyngbya sp., with filaments up to 46 cm long, has caused severe
damage to the octocoral community of a reef off Key Largo, Florida, for the past 2 years. The algae, which
are most prevalent from May through the end of October, have killed an estimated 95 % of the octocorals on
Algae Reef (L. Richardson, Florida International University, personal communication, 1991). The algal fouling
had been confined to Algae Reef, but there is now evidence that it is spreading to nearby Horseshoe Reef.
Since the algal growth is fairly localized, elevated nutrient levels in groundwater leaching out from the reef
substrate are theorized to be involved. Dr. Richardson has also observed increased incidence of black-band
disease in hard corals on this reef.
An algal outbreak has also been occurring during the summer months off the southeast coast of Broward and
Palm Beach Counties for at least 3 years, although the alga is not a blue-green form. Large concentrations of
the green alga Codium isthmocladum have been fouling the reefs from depths of greater than 100 ft inshore to
the nearshore reefs (W. Parks, tropical fish collector, personal communication, 1991). The algae are brought in
from deeper water by currents during the summer and pile up on the downcurrent sides of reefs and ledges to a
depth of approximately 1 m. This has resulted in the temporary burial and subsequent death of significant
numbers of sponges, hard corals, octocorals, and other attached organisms.
There was also a reported heavy bloom of the brown algae Dictyota sp. in the summer of 1989 at Sand Key in
the Key West area (B. LaPointe, Florida Keys Land and Sea Trust, personal communication, 1991).
3-19
-------
3.5.7.3 OTHER REEF LOCATIONS
Reefs in the northern Gulf of Aqaba on both the Sinai and Arabian Peninsulas have been subjected to a variety
of human-related impacts, including oil spills, dredging, sewage, and phosphate dust (Mergner 1981).
Phosphorus levels were five times higher in the area of a phosphate loading platform near Eilat than in the area
south of Eilat. In the area near Aqaba, where phosphate is loaded for export, there was an increase in water
turbidity, extensive new algal areas, and an increase in herbivorous fish and sea urchin populations. The
changes noted by Mergner (1981) conspicuously mirror those seen in Kaneohe Bay.
Bermuda is located on the edge of the oligotrophic Sargasso Sea. Sewage on the island has been disposed of via
septic systems and cesspits that are connected through the porous limestone formation with groundwater. This
groundwater, in turn, is connected to local marine waters (Simmons et at. 1985); Lapointe and O'Connell
(1989) reported an increase of Cladophora prolifera in Harrington Sound and attributed this increase to
underground seepage of nitrogen-enriched groundwater. Concentrations of NH4 ranged from 23 to 40 /xM;
concentrations of PO4 ranged from 0.3 to 0.49 /tM in pore waters under the Cladophora mats. Analysis of
nutrient concentrations in Bermuda inshore waters has shown that enclosed waters, specifically Harrington
Sound, are more affected by potential eutrophication problems (Jickells 1981). In this case, eutrophication
resulted in algae blooms in an enclosed body of water.
3.6 OIL AND ASSOCIATED CONTAMINANTS
There is a very small body of information on the effects of oil (primarily various forms of refined oil and crude
oil treated with dispersants) on corals and coral communities. Available information indicates detrimental
effects of oil pollution on coral reproduction, growth, colonization, and behavior (Loya and Rinkevich 1980).
Data show that areas with chronic oil pollution in the Red Sea near Eilat have much lower recruitment than do
oil-free areas (Loya and Rinkevich 1979) although these same areas are also impacted by airborne phosphate
from a fertilizer plant as noted by Mergner (1981), and the low recruitment could be a synergistic effect. Loya
and Rinkovich (1979) report abortion effects in corals induced by oil pollution. Diploria strigosa was found to
accumulate high levels of phenanthrene, a polycyclic aromatic hydrocarbon (PAH), from the water column.
This species exhibited slow elimination rates when compared to elimination rates for these compounds in other
invertebrates (Knap et al. 1982). Twenty-four-hour exposure of Diploria strigosa to oil/water mixtures and oil-
dispersant/water mixtures showed sublethal effects on the corals (Wyers et al. 1986). It should be pointed out
that more severe effects were seen at longer doses. Long-term followup examinations to determine chronic
secondary disease effects or impacts on reproduction remain to be completed.
A 1986 oil spill on the Caribbean coast of Panama caused extensive damage to subtidal corals. Coral cover had
decreased by up to 76% on heavily oiled shallow reefs 1 year after the spill. The still-living corals showed
signs of stress, including zooxanthellae expulsion, excess mucus production, and bacterial infections (Jackson et
al. 1989; Guzman et al. 1991). This spill was treated with oil dispersants which may have increased its toxicity
to corals by putting the crude oil into solution.
In 1964, a 500 gallon spill in the Dry Tortugas was reported to cause widespread damage to shallow water
corals (DOI 1987). Following a 1975 spill of heavy oil in the Florida Keys, Jaap (1984) reported little evidence
of damage to the reefs or individual corals. Minimal information on the effects of oil and other hydrocarbons is
available for the FKNMS region. There is, however, heavy tanker traffic close to the reef line (see Task 6) and
frequent reports of floating oil or tar balls on the reef tract (H. Hudson, Key Largo National Marine Sanctuary,
personal communication, 1991). The relative magnitude and impact of these conditions are not known.
3-20
-------
Shinn (1989) immersed colonies of staghom and star coral in crude oil-seawater solutions for over one hour in
1970 with no obvious detrimental effects to the colonies after 14 days of observation. The staghorn coral was
also reported to survive a one-half hour total immersion in Louisiana crude oil; however, processed oils or
crude oil treated with dispersants killed the corals.
3.7 PESTICIDES, HERBICIDES, AND ORGANIC CHEMICALS
Analyses for pesticides, herbicides, and organic chemicals have been performed on various components of coral
communities. Organisms on a reef comprise a broad cross section of feeding strategies, including a large
number of filter feeders. These organisms would be susceptible to biofiltration and bioconcentration effects.
Due to the extreme dilution effects, such accumulations would be most possible for those organisms that have
had long periods of time (e.g., 10s to 100s of years) to accumulate and biomagnify these compounds. To date,
analyses for these compounds have been performed only on the Florida Reef Tract by a small number of
researchers, and there have been no substantial data to either support or reject this theory to date.
Researchers who have analyzed and published pesticide, herbicide, or organic chemical data for sediments,
organisms, or water samples from the Florida Reef Tract include Simmons and Love (1984), Braman et at.
(1989), Glynn et al. (1989), and Skinner and Corcoran (1989). Simmons and Love (1984) analyzed a
submarine groundwater discharge into the reef tract off Key Largo and found it to have several chlorinated
pesticide peaks that could not be positively identified. The only positively identified compound was a
nematocide, O-Ethyl S, S-dipropyl phosphorodithioate, at 0.061 jxg/L. The other compounds were assumed to
be organophosphates, phthalates, and/or phenoxyherbicides; however, positive identification could not be made.
Braman et al. (1989) analyzed sediment and organisms (producers and consumers) from the entire Florida Reef
Tract out to the Dry Tortugas. The producers included the seagrasses Syringodium filiforme and Thalassia
testudinum and the algae Dictyota spp., Halimeda spp., and Sargassum spp. Consumers consisted of the
sponges Haliclona rubens, Spheciospongia vesparium, and Xestospongia muta. and the colonial mat anemone
Palythoa caribaeorum. They reported chlorinated pesticide levels to be below detection limits (
-------
Table 3-5. Pesticide compounds within sediments and biota from
the Florida Reef Tract, as analyzed by Braman et al. (1989), and
hard corals and octocorals, as analyzed by Glynn et al. (1989).
Braman et al. 1989
Sediments Biota
(/ig/kg) (/xg/kg)
Compound
Glvnn et al. 1989
Hard Corals* Octocoralsb
(ng/g (ng/g
wet weight) wet weight)
A i
4,4' ODD
4,4' DDE
4,4' DDT
Aldrin
Dieldrin
SLPHA-BHC
B-BHC
Endosulfan I
Endosulfan II
Endosulfan Sulfate
< 5 each < 500 each Endrin
Endrin Aldehyde
Gamma-BHC
Heptachlor
Heptachlor Epoxide
Methoxychlor
PCB 1016
PCB 1221
PCB 1232
PCB 1242
PCB 1248
PCB 1254
PCB 1260
T T Toxaphene
ND ND Lindane
ND ND a and y chlordane
ND ND Mirex
1
} 10.08
J
} 0.37
} 0.00
99.51
] 4.18
0.00
23.60
177.64
4.19
321.05
41.05
88.95
0.00
546.57
0.00°
314.40
2415.83
0.00
ND: No data.
'30 specimens.
bll specimens.
cOne speciman had a concentration of 768.64 ng/g.
3-22
-------
7.9-8.5, lead 0.2-0.8, uranium 1.3-5.8, vanadium 0.05-8.5, and yttrium 0.04-0.16. This work shows growth
rates to be significantly lower in more polluted sites with declines first appearing in shallow communities and
grading out to deeper, more distant sites.
Trace and heavy metals from the Florida Reef Tract have been analyzed by Manker (1975), Simmons and Love
(1984), Braman el al. (1989), Skinner and Corcoran (1989), Glynn et al. (1989), and Strom et al. (1991).
Manker (1975) examined the Keys Reef Tract for metals in the sediments and reported elevated levels of
mercury, zinc, lead, and cobalt. Braman et al. (1989) and Strom et al. (1991) report results for the same data
set collected from Biscayne National Park to the Dry Tortugas. Ranges for these data are given in Table 3-6.
Glynn et al. (1989) also analyzed hard corals and octocorals from Biscayne National Park for heavy metals.
They found the following ranges of concentrations within the organisms' tissues: arsenic <0.5 to 40 ppm;
cadmium <0.2 to 0.3 ppm; copper 2.5 to 90 ppm; iron < 10 to 117 ppm; mercury <0.1 to 2.7 ppm; and lead
< 1 to 11.5 ppm (Table 3-6). Skinner and Corcoran (1989) measured the concentration of metals in water from
John Pennekamp Coral Reef State Park. Concentrations of samples were arsenic < 10 ng/L; copper < 1 jig/L;
lead < 10 jig/L; mercury <0.5 /xg/L; cadmium <5 ftg/L; iron <30 /xg/L; and zinc <30 jtg/L.
3.9 FRESHWATER
Freshwater affects coral reef growth because corals have restricted salinity requirements. In a study on Atlantic
and Pacific corals, Marcus and Thorhaug (1981) found the salinity range for Florida Keys Porites ponies to be
between 15 and 45 ppt whereas, Hawaiian corals in this study exhibited a much narrower range of salinity
tolerance (between 20 and 40 ppt). Isdale (1984) has used the natural incorporation of fluorescence into corals
as a tracer of the history of freshwater input to coral. Smith et al. (1989) and Hudson et al. (1989) showed a
correlation between freshwater discharge and fluorescent banding in an isolated head of Solenastrea bournoni in
the Peterson Keys in Florida Bay. Hudson et al. (1989) compared the core taken by Smith et al. (1989) to
another core taken on the Hens and Chickens patch reef on the Atlantic side of the Keys. They found that
fluorescent banding, as a measure of freshwater discharge, may not be a good record of hurricane activity but
may show a possible cause-and-effect relationship between human-induced perturbations (such as development
and the resulting large-scale changes in water management) and long-term coral growth rates.
Discharge of freshwater from canals in south Biscayne Bay tends to remain as a cohesive water mass and move
unmixed out over an area adjacent to the canal (Lee and Rooth 1972; Chin Fatt and Wang 1987). Water
moving in this manner from the extreme southern canals of Dade County should mix before it reaches the ocean
through Angel fish or Caesars Creeks owing to the extended residence time for water in this area (Lee 1975; Lee
and Rooth 1972). Since water mass movement in this area is wind- and tide-driven, mixing would depend upon
meteorological conditions. It is also possible that water could move north of Key Largo through Buttonwood
Sound and out through the Adams Waterway to the ocean. The required time and distance, however, reduce the
likelihood that this water would remain as a coherent, freshwater mass (S. Baig, NOAA, National Hurricane
Center, personal communication, 1991).
4.0 SUMMARY
Factors that influence the health of the Florida Keys reefs can be separated into two categories: natural and
man-induced. Natural parameters include biological competition and predation, disease, light, temperature,
salinity, and storms. Man-induced parameters are nutrient enrichment, sedimentation, turbidity, pesticides and
PCBs, hydrocarbons, heavy metals, and freshwater. Despite being able to identify most of these factors,
understanding the mechanisms is difficult because of the many different interactions between various parameters
and the diverse ways in which they affect specific areas. Further confounding the problem is the fact that the
3-23
-------
Table 3-6. Mean-concentrations and ranges of selected trace metals in sediment and biota from the
Florida Reef Tract. [From Braman et al. 1989 and Glynn et al. 1989]
Trace Metals Braman et al. 1989
Sediments Producers
Mean Mean
(Range) (Range)
(ppm dry weight)
Arsenic
Cadmium
Copper
Iron
Lead
Mercury
Tin
0.071
(0.000-0.315)
0.52
(0.13-1.2)
1.58
(0.65-4.7)
ND
2.08
(0.81-4.5)
0.061
(0.002-0.242)
0.034
(0.002-0.208)
0.94
(0.00-9.73)
0.54
(0-1.8)
1.71
(0.4-3.5)
ND
2.54
(1-5.1)
0.64
(0.00-7.00)
0.10
(0.00-0.60)
Consumers
Mean
(Range)
0.71
(0.03-6.6)
5.48
(0.7-22)
9.01
(1.5-38)
ND
11.08
(1.3-60)
0.09
(0.002-0.434)
1.77
(0.1-13.1)
Glvnn et
Hard Corals
Mean
(Range)
(/ig/g wet
4.16
(< 0.5-40)
0.18
(<0.2-0.3)
10.93
(2.5-90)
39.03
(< 10-63)
2.62
(< 1-11.5)
0.21
(< 0.1-2.7)
ND
al. 1989
Octocorals
Mean
(Range)
weight)
6.54
(3-9)
0.20
(<0.3)«
9.0
(6-12)
74.55
(23-117)
0.091
(<1)
0.07
(0-0.1)
ND
ND: No data
'No range provided
3-24
-------
Florida Reef Tract is already living at the climatic threshold for a coral reef and any additional changes in the
environment could cause major impacts on the community.
There is a general consensus among researchers that both natural and anthropogenic factors are affecting the
coral community of the FKNMS. Although there appears to be a severe problem, there are not sufficient
baseline and research data available from most locations to scientifically document the extent of the problem.
Since what constitutes natural conditions is in many cases unknown, discerning natural changes from
anthropogenic perturbations is extremely difficult. The workshop on Coral Bleaching, Coral Reef Ecosystems,
and Global Climate Change was held June 1991 in Miami (D'Elia et al. 1991). A major conclusion of the
workshop was that "much subjective evidence exists to indicate that there is a worldwide decline in the overall
'health' of coral reefs and related ecosystems, but there are not adequate baseline and survey data to provide a
vigorous scientific assessment of the nature and extent of the problem."
5.0 STATEMENTS OF PROBLEMS
A key part of Phase I of the Water Quality Protection Program is the identification of water quality problem
areas to be addressed during Phase II. A two-step approach was used to identify and obtain agreement among
members of the scientific community on known, suspected, or potential water-quality problems affecting the
natural resources of the Sanctuary. Initially, information gathered during the literature review was used to
derive a series of statements describing potential water-quality related problems (presented in Section 5.1).
These problem statements were then refined through discussions with EPA Region IV Coastal Programs staff
and State of Florida environmental staff and delivered to workshop participants to provide focal points for
discussions at technical workshops. The participants in each workshop were charged with coming to a
consensus, where possible, on the problem statements developed for each workshop resource area. A matrix
analysis of each workshop resource area (Appendix B) was the tool used to develop consensus on the problem
statements. Specific descriptive terms were used to complete the matrix based on the discussions with the
expert panels assembled for each workshop (Appendix B). Public comments were also heard during the course
of each workshop. To assist EPA Region IV and the State of Florida to direct their limited resources, each
expert panel was asked to rank the overall significance of the water-quality related problems at the end of each
daily workshop. The consensuses developed at the workshops are summarized in Section 5.2 and presented in
more detail in Appendix B.
5.1 PROBLEMS IDENTIFIED DURING THE LITERATURE REVIEW
The following lists either known, suspected, or potential problems, exclusive of mechanical destruction (not
addressed in this document), related to coral reef communities in the FKNMS. However, to state a problem
does not of itself mean or imply that the stated problem actually exists. There is a divergence of views on what
actually constitutes either real or potential problems for the FKNMS.
In many instances, the data are insufficient to assess the true importance or validity of a given problem, so
called. For this reason, there is a "data sufficiency" question posed under each statement of a problem. No
references are supplied for statements made in this Subsection — the statements made here represent an
evaluation of the data and referenced studies presented in the preceding text.
Diseases are making major impacts on the FKNMS coral reef community. — Black-band disease, caused by
the blue-green alga Oscillatoria submembranacea, is widespread within the FKNMS. It has been reported as
occurring extensively in the Key Largo and north Key Largo areas and as a significant feature in the Looe Key
area. There is some debate whether white-band disease, which may result from bacterial infection or may
represent a response by the coral to physiological stress, occurs in the FKNMS. Data are sufficient to say that
3-25
-------
disease is a very significant problem for the coral reef community in the FKNMS and suggest that infections of
black-band disease may have increased over the past 20 years. Additionally, research on other potential coral
diseases is minimal. The relationship of coral disease to water quality is not known.
Water-temperature fluctuations are a major cause of impacts on the FKNMS coral communities. — The
effects of cold stress, which occurs when cold fronts chill the waters of Florida Bay and the shallow, nearshore
waters of the Keys, are more pronounced in the middle Keys and along channels because reefs along the upper
Keys are shielded from the cooled waters of Florida Bay by Key Largo. Heat stress, resulting from elevated
water temperatures occurring during calm, low-tide periods of the summer, causes corals to expel their
zooxanthellae. This coral bleaching can occur at virtually any reef area in the FKNMS. Data indicate that the
effects of temperature fluctuations are moderately significant in the Keys — cold-water stress may be the
mechanism controlling reef distribution along the Florida Keys and coral bleaching may result in colony death.
Temperature stress is water-quality related, but is not usually anthropogenic. The draining of so much of south
Florida has resulted in reduced water flow to the Everglades, affecting the thermal buffer that may have
previously protected the waters of Florida Bay from cold fronts.
Reduced water transparency and sedimentation may be affecting the FKNMS coral reef communities. —
Reduced light availability in the water column because of increased phytoplankton abundance as a result of
increased nutrient concentrations or increased participate matter may be widespread in the Keys, although its
specific extent is unknown. Although data are sufficient to say that this phenomenon does cause problems for
coral reef communities, they are insufficient to establish long-term, water-clarity trends in the FKNMS. Also,
there are no well-established links between decreased water clarity and specific coral community deterioration at
any sites in the FKNMS. This problem is potentially very significant and is related to water quality.
Anthropogenic sources are suggested for the increasing levels of nutrients and for contributing to the suspended
sediments in the FKNMS waters.
Anthropogenically increased nutrient levels in the water column may be adversely affecting the FKNMS coral
reef communities. — Contamination of ground water in some areas by septic tank and shallow well injection of
sewage may result in increased nutrient levels. Increased nutrient levels can cause increases in abundance of
phytoplankton, macroalgae, blue-green algae, and bacteria. Increased nutrient levels may also interfere with
calcification in hard corals. Increased nutrient levels in groundwater have been demonstrated, and the results of
one study suggest that the anthropogenic nutrients may be transported offshore to the reefs. Massive blue-green
algal blooms on a specific reef off Key Largo are being studied in relation to possible seasonal fluxes in nutrient
levels from groundwater flow. There are very few data on nutrient levels within the Florida Reef Tract and
there is no historical water quality database with which to assess nutrient trends along the offshore reefs. What
data have been collected do not, as a general rule, show alarmingly high nutrient values along the reef tract.
The possibility of seasonal fluxes in nutrient levels from groundwater flow has not been fully investigated, nor
can the currently available nutrient database be considered conclusive. This problem is related to water quality
and is potentially very significant.
Contamination from spilled oil and petroleum products may be adversely affecting the FKNMS coral reef
communities. — Small-scale or chronic impact of hydrocarbon pollution, resulting from chronic small spills and
"tar balls" in the environment, may be widespread throughout the FKNMS. Short-term, major impacts from a
catastrophic oil spill would be localized to the area impacted by such a spill. The effects of petroleum spills
include reduced recruitment, accumulation of hydrocarbon contaminants in some species, and other sublethal
effects. Minimal information on the effects of oil and other hydrocarbons within the FKNMS area is available.
During the one major spill of heavy oil in the Florida Keys, there was little evidence of damage to reefs or
individual corals. The problem of chronic hydrocarbon contamination to the FKNMS coral community has not
been investigated. The significance of this water-quality related problem is not known.
Pesticides, herbicides, and organic chemicals may be adversely affecting the FKNMS coral communities. —
There is little evidence of pesticide, herbicide, or organic chemical contamination in reef sediments from the
FKNMS. Elevated levels of organochlorine pesticides have been reported from Biscayne National Monument,
3-26
-------
and there is one report of elevated pesticide and polychlorinated biphenyls (PCB) from the water column of John
Pennekamp Coral Reef State Park. Potential sources of such contamination include sewage outfalls, terrestrial
runoff, agricultural runoff transported by water-mass movement, groundwater seepage, upwelling, and ocean
currents transporting contaminants from remote areas. The mosquito control programs conducted by Monroe,
Dade, and Collier Counties are also potential sources of pesticides. The data are insufficient to determine if a
problem exists with pesticide contamination in the FKNMS coral communities. The significance of this water-
quality related problem is not known.
Trace element and heavy metals may be adversely affecting the FKNMS coral communities. — No impacts
from trace elements or heavy metals have been reported in the FKNMS coral communities. Some studies have
reported elevated levels of mercury, zinc, lead, and cobalt from the sediments adjacent to the FKNMS Reef
Tract, but no connection with any observable impact has been made. Sources of such contamination may
include sewage outfalls, terrestrial runoff, agricultural runoff transported by water-mass movement, groundwater
seepage, upwelling, ocean currents transporting contaminants from long distances away, airborne contamination
from solid waste incinerators, and boat traffic and the local marine industry. Although studies to date are not
comprehensive, they suggest that trace-element or heavy-metal contamination is not a significant problem along
the outer reefs of the FKNMS. This -problem is related to water quality.
Freshwater discharges and changes in freshwater flow patterns may be having an adverse effect on the
FKNMS reefs. — Reduced salinities, caused by freshwater input, impact coral communities by reducing colony
growth rates and, if low salinity conditions persist, by causing colony death. Freshwater input in the FKNMS
may originate from the discharge of freshwater from canals into lower Biscayne Bay and the Card Sound/Barnes
Sound area of the FKNMS. A possible future source may result from restored freshwater flow through the
Everglades and its subsequent discharge into Florida Bay. No impacts, other than possible increased coral
growth in Florida Bay, as a result of reductions of freshwater input, have been attributed to freshwater along the
FKNMS outer reef tract. Massive freshwater discharges from canals in the Card and Barnes Sounds portions of
the FKNMS have caused community disruption in the benthic communities seen there, but these are not coral-
dominated communities. Data indicate that freshwater input does not presently appear to present a significant
problem for the FKNMS coral community. This problem is related to water quality.
Long-term climate changes may be adversely affecting the FKNMS coral reef communities. — All FKNMS
coral reef communities are vulnerable to large-scale environmental disruptions resulting from global wanning
(increased air and water temperatures, sea-level rise) and ozone depletion (increased shorter wavelength
irradiance reaching the Earth's surface). Large-scale evaluations of potential community changes due to global
climate change are being conducted by a number of United States and international research agencies. There
are studies in progress, although not mentioned in this report, that are assessing possible community shifts in
tropical marine ecosystems resulting from global climate change. None of these studies has specifically targeted
the FKNMS, but their results should be indicative of the potential problems faced here. Possible indirect effects
on water quality may result from changes in precipitation patterns. While this problem is real, its specific
impact on the FKNMS coral reef communities has not been assessed. From a FKNMS management point of
view, this problem is too large-scale and long-term to be of immediate significance in the FKNMS planning
process. The possibility of synergistic effects between global climate change and local near-term stresses in the
environment should be considered in any long-term monitoring plan developed for the Sanctuary.
5.2 PROBLEMS IDENTIFIED AT THE CORAL COMMUNITY ASSESSMENT WORKSHOP
Eight problems identified and discussed by the workshop panel Were coral disease, coral bleaching, problematic
algal growth, Lyngbya growth, lack of recruitment, growth rate (individual), decline in coral abundance, and
decline in species diversity (abundance and richness). The parameters for analysis and the matrix used for the
discussion are included in Appendix B.
3-27
-------
Coral disease and problematic algal growth are the problems most directly related to water quality. Therefore
they should also have a high priority in the Water Quality Protection Program. In addition, the lack of
information regarding the decline in biodiversity indicates that additional work needs to be done regarding this
problem. Generally, there is a lack of data regarding all of the above problems; more research and data are
needed to determine how the water quality parameters affect each of the problems.
Coral disease is widespread with patchy occurrences, and its severity is increasing in the Keys. — The cause
of coral disease is possibly water-quality related. Temperature (significantly) and salinity (slightly) affect coral
disease. Parameters that require more investigation regarding their effects on this problem are nutrients,
turbidity, toxics/pesticides, bacteria, and viruses. In addition, more data are needed to determine the cause of
coral diseases (epidemiology) and there is a need to determine whether there is a global influence on coral
disease. The overall significance of coral disease from a water-quality perspective is high.
Coral bleaching is species-dependent and known to occur in the Keys. — The trend for bleaching events is
known to be increasing, but the events vary in their severity. This problem is water-quality related; temperature
significantly affects bleaching of coral communities and salinity is also thought to be a contributor to the
bleaching. More data are needed on the effects of nutrients, turbidity, and toxics/pesticides on the bleaching of
coral communities. The overall significance of coral bleaching from a water-quality perspective is high.
Temporally, problematic algal growth is known to occur in localized "hot spots" and this trend is increasing.
— The potential exists for problematic algal growth to be water-quality related, however it is not yet seen as a
problem. Temperature and nutrients significantly affect this problem. More data are needed on the effects of
toxics/pesticides and bacteria on problematic algal growth. The overall significance of problematic algal growth
from a water-quality perspective is moderate.
Occurrence of the Lyngbya bloom is localized, spreading, and increasing. — The recent (fall 1988 bloom) and
rapid increase in Lyngbya occurrence could potentially occur with other species within the algal community.
The severity of this problem is high in the Keys and is definitely water-quality related. Temperature and
nutrients significantly affect Lyngbya growth; however, more data are needed on the effects of .toxics/pesticides
and bacteria on Lyngbya growth. The overall significance of Lyngbya growth from a water-quality perspective
is high.
Areas exhibiting a lack of recruitment are patchy in the Keys. — Recruitment is species-dependent and driven
by the reproductive cycle of the organism. The trend of this problem is unknown, however, the severity of the
problem is high in the Keys. It is possible that this problem is water-quality related. All of the water-quality
parameters discussed have an unknown effect on the problem; more research is needed. The overall
significance of the lack of coral recruitment from a water-quality perspective is high.
Cases of impaired growth rates of individual corals are known and isolated. — The trend of this problem is
variable and the severity is localized in the Keys. This problem is known to be water-quality related;
temperature and turbidity significantly affect individual growth rates. More data are needed to determine if
nutrients, toxics/pesticides, bacteria, and viruses affect individual growth rates. Additionally, physical damage
to corals is a concern and coral diseases are known to affect growth rates. The overall significance of growth
rates of individual corals from a water-quality perspective is high.
The decline in coral abundance is known to be a seasonal, long-term problem (geographically). — The
severity of the decline is high and the rate of the decline over time is unknown; there is a lack of data. It is
probable, in the historical sense, that this problem is water-quality related. Water-quality parameters that
significantly affect this problem are temperature and turbidity. Salinity has been an historically significant
problem; however, it is currently insignificant. More data are needed on the effects of nutrients,
toxics/pesticides, bacteria, and viruses on the decline in coral abundance. Additionally, cyanobacteria diseases
are known to affect coral abundance. The overall significance of the decline in coral abundance from a water-
quality perspective is high.
3-28
-------
Temporally, the decline in species diversity (abundance and richness) for species other than coral is extremely
variable (from hours to years) and widespread for the width of the Keys. — Species diversity is declining
particularly because of the commercial harvest of several species, although the available data relate to harvested
species and few data exist for other species. It is probable that the decline in species diversity is water-quality
related for the nearshore breeding species and possibly water-quality related for offshore breeding species.
Temperature significantly contributes to the decline while the effects of nutrients on this problem are slight to
moderate. Salinity is a slight contributor to this problem, and toxics/pesticides are a slight contributor offshore.
It is unknown if turbidity, bacteria, viruses, and dissolved oxygen (DO) affect the problem; more data are
needed. The overall significance of the decline in species diversity from a water-quality perspective is
unknown.
6.0 REFERENCES
Agassiz, A. 1890. "On the rate of growth of corals." Bull. Mus. Comp. Zool. 20(2):61-64.
Andrews, J.C., and H. Muller. 1983. "Space-time variability of nutrients in a lagoonal patch reef." Limnol.
Oceanogr. 28(2):21-27.
Antonius, A. 1973. "New observations on coral destruction in reefs." Assoc. Isl. Mar. Lab. Caribb. Univ.
Puerto Rico, Mayaquez, Abstr. 10:3.
Antonius, A. 1981a. Coral reef pathology: A review. Proc. Int. Coral Reef Symp. 4th, 1981. 2:3-6.
Antonius, A. 1981b. The band disease in coral reefs. Proc. Int. Coral Reef Symp. 4th, 1981. 2:7-14.
Antonius, A. 1985. Black band disease infection experiments on hexacorals and octocorals. Proc. Int. Coral
Reef Cong. 5th, 1985:155-160.
Bak, R.P.M., and S.R. Criens. 1981. Survival after fragmentation of colonies of Madracis mirabilis,
Acropora palmata, and A. cervicornis (Scleractinia) and the subsequent impact of a coral disease. Proc.
Int. Coral Reef Symp. 4th, 1981. 2:221-227.
Banner, A.H. 1974. Kaneohe Bay, Hawaii: Urban pollution and a coral reef ecosystem. Proc. Int. Coral Reef
Symp. 2nd, 1974:685-702.
Bayer, F. 1961. The shallow-water octocorallia of the West Indian region. Martin Nijhoff, The Hague, The
Netherlands. 373 pp.
Berner, R.A. 1981. "Autogenic mineral formation resulting from organic matter decomposition in modem
sediments." Fortschr. Miner. 59:117-135.
Birkeland, C.E. 1977. The importance of rate of biomass accumulation in early successional stages of benthic
communities to the survival of coral recruits. Proc. Int. Coral Reef Symp. 3rd, 1977. 1:15-21.
BLM and FDNR. 1979. Florida Reef Tract Marine Habitats and Ecosystems. Bureau of Land Management
and Florida Department of Natural Resources.
Braman, R.S., D.F. Martin, and R.N. Strom. 1989. Environmental contamination of coral reef areas.
Unpublished contract report, from the Institute for Environmental Studies, University of South Florida, to
the Florida Marine Research Institute, Florida Department of Natural Resources, St. Petersburg, FL,
USF Contract No. 27-05-199-LO. 54pp.
3-29
-------
Bythell, J.C. 1988. A total nitrogen and carbon budget for the elkhorn coral Acropora palmata (Lamarck).
Proc. Int. Coral Reef Symp. 6th, 1988. 2:535-540.
Cameron, A. 1974. Toxicity phenomena in coral reef waters. Proc. Int. Coral Reef Symp. 2nd, 1974.
1:513-518.
Gary, L. 1918. "The Gorgonacea as a factor in the formation of coral reefs." Carnegie Inst. Wash. Publ.
213:341-362.
Chalker, B.E., and D.L. Taylor. 1978. "Rhythmic variations in calcification and photosynthesis associated
with the coral Acropora cervicornis." Proceedings of the Royal Society of London B(201): 179-189.
Chin Fatt, J., and J.D. Wang. 1987. Canal Discharge Impacts on Biscayne Bay Salinities. Department of the
Interior, National Park Service. SE Region Atlanta, Res./Resources Rep., SER-89. Dec. 1987. 229 pp.
t
Cook, C.B., and C.F. D'Elia. 1987. "Are natural populations of zooxanthellae ever nutrient-limited?"
Symbiosis 4:199-212.
Cook, C.B., G. Muller-Parker, and C.F. D'Elia. 1992. •Ammonium enhancement of dark carbon fixation and
nitrogen limitation in symbiotic zooxanthellae: Effects of feeding and starvation of the sea anemone
Aiptasia pallida." Limnol. Oceanogr. 37(1): 131-139.
Corredor, I.E., and J. Morell. 1985. "Inorganic nitrogen in coral reef sediments." Mar. Chem. 16:379-384.
Corredor, I.E., C.R. Wilkinson, V.P. Vicente, J.M. Morell, and E. Otero. 1988. "Nitrate release by
Caribbean reef sponges." Limnol. Oceanogr. 33(1): 114-120.
Grassland, C.J., B.G. Hatcher, M.J. Atkinson, and S.V. Smith. 1984. "Dissolved nutrients of a high-latitude
coral reef, Houtmac Abrolhos Islands, Western Australia." Mar. Ecol. Prog. Ser. 14:159-163.
CSA and GMI. 1991. The southwest Florida nearshore benthic habitat study. MMS Rep. 89-0080. Final
report prepared by Continental Shelf Associates, Inc., and Geonix Martel, Inc., for the Department of the
Interior Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. 55 pp.
D'Elia, C.F. 1977. "The uptake and release of dissolved phosphorus by coral reefs." Limnol. Oceanogr.
22:301-315.
D'Elia, C.F., and C.B. Cook. 1988. "Methylamine uptake by zooxanthellae-invertebrate symbioses: Insights
into host ammonium environment and nutrition." Limnol. Oceanogr. 33(5): 1153-1165.
D'Elia, C.F., and W.J. Wiebe. 1990. Biogeochemical nutrient cycles in coral reef ecosystems. Pp. 49-74 in
Dubinsky, Z. (Ed.), Ecosystems of the world, coral reefs. Elsevier, New York, NY.
D'Elia, C.F., K.L. Webb, and J.W. Porter. 1981. "Nitrate-rich groundwater inputs into Discovery Bay,
Jamaica: A significant source of N to local coral reefs?" Bull. Mar. Sci. 31(4):903-910.
D'Elia, C.F., R.W. Buddemeier, and S.V. Smith. 1991. Workshop on Coral Bleaching, Coral Reef
Ecosystems, and Global Climate Change. Miami, FL.
Darley, W.M. 1982. Algal Biology: A Physiological Approach. In Wilkinson, J.F. (Ed.), Basic Microbiology
Series Vol. 9. Blackwell Scientific Publications. Boston (Stoneham), MA. 168 pp.
3-30
-------
DOI. 1987. Final environmental impact statement. Proposed oil and gas lease sales 113, 115, and 116. Gulf
of Mexico OCS Region, New Orleans, Louisiana. Department of the Interior, Minerals Management
Service. OCS EIS/MMS 87-0077.
Dustan, P. 1977. "Vitality of reef coral populations off Key Largo, Florida: Recruitment and mortality."
Environ. Geol. 2:51-58.
Dustan, P., and J.C. Halas. 1987. "Changes in the reef-coral community of Carysfort Reef, Key Largo,
Florida: 1974 to 1982." Coral Reefs 6:91-106.
Dustan, P., B.H. Lidz, and E.A. Shinn. 1991. "Impact of exploratory wells, offshore Florida: A biological
assessment." Bull. Mar. Sci. 48(1):94-124.
Ebbs, N.K., Jr. 1966. "The coral-inhibiting polychaetes of the northern Florida reef tract, Part I." Bull. Mar.
Sci. 16(3):455-485.
Fourqurean, J.W., J.C. Zieman, and G.V.N. Powell, (to be published). "Phosphorus limitation of primary
production in Florida Bay: Evidence from C:N:P ratios of the dominant seagrass Thalassia testudinum."
Submitted to Limnology and Oceanography.
FWS and MMS. 1983. Florida Ecological Atlas Biological Series. Department of the Interior, Fish and
Wildlife Service and Minerals Management Service.
Geider, R.J., T. Platt, and J.A. Raven. 1986. "Size dependence of growth and photosynthesis in diatoms: A
synthesis." Mar. Ecol. Progr. Ser. 30:93-104.
Ginsburg, R.N., and E.A. Shinn. 1964. "Distribution of the reef building community in Florida and the
Bahamas (abst)." Am. Assoc. Petrol. Geol. Bull. 48:527.
Gittings, S.R. 1988. The recovery process in a mechanically damaged coral reef community. Diss. Abstr. Int.
49/06-8:2023.
Gladfelter, W.B. 1982. "White-band disease in Acropora palmata: Implications for the structure and growth
of shallow reefs." Bull. Mar. Sci. 32(2):639-643.
Glynn, P.W. 1973. "Aspects of the ecology of coral reefs in the western Atlantic region." Pp. 271-324 in
O.A. Jones and R. Endean (Eds.), Biology and geology of coral reefs, Vol. 2, Biology 1. Academic
Press, New York.
Glynn, P.W. 1984. "Widespread coral mortality and the 1982-83 El Nino warming event." Environ.
Conserv. 11(2): 133-146.
Glynn, P.W., and W.H. De Weerdt. 1991. "Elimination of two reef-building hydrocorals following the
1982-83 El Nino warming event." Science 253:69-71.
Glynn, P.W., A.M. Szmant, E.F. Corcoran, and S.V. Cofer-Shabica. 1989. "Condition of Coral Reef
Cnidarians from the northern Florida reef tract: Pesticides, heavy metals, and histopathological
examination." Mar. Pollut. Bull. 20(ll):568-576.
Goreau, T.F., and N. Goreau. 1959a. "The physiology of skeleton formation in corals. I. A method for
measuring the rate of calcium deposition by corals under different conditions." Biol. Bull. 116:59-75.
3-31
-------
Goreau, T.F., and N. Goreau. 1959b. "The physiology of skeleton formation in corals. II. Calcium deposition
by hermatypic corals under various conditions in the reef." Biol. Bull. 117:239-250.
Guzman, H.M., J.B.C. Jackson, and E. Weil. 1991. "Short-term ecological consequences of a major oil spill
on Panamanian subtidal reef corals." Coral Reefs 10:1-12.
Hallock, P. 1981. "Algal symbiosis: A mathematical analysis." Mar. Biol. 62:249-255.
Hallock, P. 1987. "Fluctuations in the trophic resource continuum: A factor in global diversity cycles?"
Paleooceanography 2:457-471.
Hallock, P. 1988. "The role of nutrient availability in bioerosion: Consequences to carbonate buildups."
Palaeogeogr. Palaeoclimatol. Palaeoecol. 63:275-291.
Hallock, P., and W. Schlager. 1986. "Nutrient excess and the demise of coral reefs and carbonate platforms."
Palaios 1:389-398.
Hallock, P., A.C. Hine, G.A. Vargo, J.A. Elrod, and W.C. Jaap. 1988. "Platforms of the Nicaraguan Rise:
Examples of the sensitivity of carbonate sedimentation to excess trophic resources." Geology
16:1104-1107.
Harlem, P.W. 1979. Aerial photographic interpretations of the historical changes in Northern Biscayne Bay,
Florida: 1925-1976. University of Miami: Sea Grant Tech. Bull. No. 40.
Hein, F.J., and M.J. Risk. 1975. "Bioerosion of coral heads: Inner patch reefs, Florida reef tract." Bull.
Mar. Sci. 25(1): 133-138.
Highsmith, R.C. 1980. "Geographic patterns of coral bioerosion: A productivity hypothesis." J. Exp. Mar.
Biol. Ecol. 46:177-196.
Highsmith, R.C., R.L. Lueptow, and S.C. Schonberg. 1983. "Growth and bioerosion of three massive corals
on the Belize barrier reef." Mar. Ecol. Prog. Ser. 13:261-271.
Mines, M.E., and W.B. Lyons. 1982. "Biogeochemistry of nearshore Bermuda sediments. I. Sulfate reduction
rates and nutrients generation." Mar. Ecol. Prog. Ser. 8:87-94.
Hoffmeister, J.E., and H.G. Multer. 1964. "Growth rate estimates of a Pleistocene coral reef of Florida."
Geol. Soc. Am. Bull. 75:353-358.
Hudson, J.H. 1977. "Long-term bioerosion rates on a Florida reef: A new method." Proc. Int. Coral Reef
Symp. 3rd, 1977:491-497.
Hudson, J.H. 1981. "Growth rates in Montastrea annular is: A record of environmental change in Key Largo
Coral Reef Marine Sanctuary, Florida, USA." Bull. Mar. Sci. 31(2):444-459.
Hudson, J.H., E.A. Shinn, R.B. Halley, and B. Lidz. 1976. "Sclerochronology — a tool for interpreting past
environments." Geol. 4:361-364.
Isdale, P.J. 1984. "Fluorescent bands in massive corals record centuries of coastal rainfall." Nature
310:578-579.
Jaap, W.C. 1974. Scleractinian growth rate studies. Pp. 17 in Proceedings of the Florida Keys Coral Reef
Workshop. Florida Department of Natural Resources, Coastal Coordinating Council. (Abstract).
3-32
-------
Jaap, W.C. 1979. "Observations on zooxanthellae expulsion at Middle Sambo Reef, Florida Keys, USA."
Bull. Mar. Sci. 29(3):414-422.
Jaap, W.C. 1984. The ecology of the South Florida coral reefs: A community profile. Fish and Wildlife
Service, SHdell, LA. FWS/OBS-82/08. 138 pp.
Jaap, W.C. 1985. "An epidemic zooxanthellae expulsion during 1983 in the lower Florida Keys coral reefs:
Hyperthermic etiology." Proc. Int. Coral Reef Cong. 5th, 1985. 6:143-148.
Jaap, W.C. 1988. "The 1987 zooxanthellae expulsion event at Florida reefs." Pp. 24-29 in Ogden, J., and R.
Wicklund (Eds.), Mass bleaching of coral reefs in the Caribbean: A research strategy. National
Undersea Research Program Research Rep. 88-2, National Oceanic and Atmospheric Administration,
Washington, DC.
Jaap, W.C., and P. Hallock. 1990. "Coral reefs." Pp. 574-616 in Myers, R.L., and J.J. Ewel (Eds.),
Ecosystems of Florida. University of Central Florida Press, Orlando, FL.
Jackson, J.B.C, J.D. Cubit, B.D. Keller, V. Batista, K. Bums, H.M. Coffey, R.L. Caldwell, S.D. Garrity,
C.D. Getter, C. Gonzalez, H.M. Guzman, K.W. Kaufmann, A.H. Knap, S.C. Levings, M.J. Marshall,
R. Steger, R.C. Thompson, and E. Weil. 1989. "Ecological effects of a major oil spill on Panamanian
coastal marine communities." Science 243:37-44.
Jickells, T. 1981. "Nutrients and trace metals in the inshore waters of Bermuda." Proc. Assoc. Is. Mar.
Labs. Caribb. 16:10.
Johannes, R.E. 1980. "The ecological significance of submarine discharge of groundwater." Mar. Ecol.
Progr. Ser. 3:365-373.
Johannes, R.E., W.J. Wiebe, and C.J. Grassland. 1983a. "Three patterns of nutrient flux in a coral reef
community." Mar. Ecol. Progr. Ser. 12:131-136.
Johannes, R.E., W.J. Wiebe, C.J. Grassland, D.W. Rimmer, and S.V. Smith. 1983b. "Latitudinal limits of
coral reef growth." Mar. Ecol. Progr. Ser. 11:105-111.
Jones, J.A. 1963. "Ecological studies of the southeastern Florida patch reefs. I: Diurnal and seasonal changes
in the environment." Bull. Mar. Sci. Gulf Caribb. 13: 282-307.
Kanwisher, J.W., and S.A. Wainwright. 1968. "Oxygen balance in some reef corals." Biol. Bull.
133(2): 378-390.
Kaufman, L. 1977. "The three-spot damselfish: Effects on benthic biota of Caribbean coral reefs." Proc.
Int. Coral Reef Symp. 3rd, 1:559-564.
Kendall, J.J., and E.N. Powell. 1988. "An in situ incubation procedure for examining the metabolic
parameters of corals exposed to various stressing agents." Texas A&M University, Ad van. Underwater
Sci. 88:77-88.
Kinsey, D.W. 1977. "Seasonally and zonation in coral reef productivity and calcification." Proc. Int. Coral
Reef Symp. 3rd, 1977. 2:383-388.
Kinsey, D.W. 1985. "Metabolism, calcification and carbon production. I. Systems level studies." Proc. Int.
Coral Reef Congr. 5th, 1985. 4:505-526.
3-33
-------
Kinsey, D.W. 1991. "The Coral Reef: An owner-built, high-density, fully-serviced, self-sufficient housing
estate in the desert — Or is it?" Symbiosis (10)1-22.
Kinsey, D.W., and P.J. Davies. 1979. "Effects of elevated nitrogen and phosphorus on coral reef growth."
Limnol. Oceanogr. 24(5):935-940.
Kinsey, D.W., and A. Domm. 1974. "Effects of fertilization on a coral reef environment — primary
production studies." Proc. Int. Coral Reef Symp. 2nd, 1974:49-66.
Kinzie, R.A. 1974. u Plexaura homomalld: The biology and ecology of a harvestable marine resource." In
Bayer, P.M., and A.J. Weinheimer (Eds.), Prostaglandins in Plexaura homomalla, A symposium. Stud.
Trop. Oceanogr. 12:22-38.
Knap, A.H., J.E. Solbakken, R.E. Dodge, T.D. Sleeter, S.J. Wyers, and K.H. Palmork. 1982.
"Accumulation and elimination of (9-14C) phenanthrene in the reef-building coral (Diploria strigosd)."
Bull. Environ. Contam. Toxicol. 28:281-284.
Kohout, F.A., and M.C. Kolipinski. 1967. "Biological zonation related to groundwater discharge along the
shore of Biscayne Bay, Miami, Florida." Pp. 488-499 in Lauff, G. (Ed.), Estuaries. A.A.A.S. Publ.
No. 83, Washington, D.C.
Lang, J.C. 1971. "Interspecific aggression by scleractinian corals. 1. The rediscovery of Scolymia cubensis
(Milne Edwards and Haime)." Bull. Mar. Sci. 21(4):952-959.
Lang, J.C. 1973. "Interspecific aggression by scleractinian corals. 2. Why the race is not to the swift." Bull.
Mar. Sci. 23(2):260-279.
Lapointe, B.E. 1989. "Macroalgal production and nutrient relations in oligotrophic areas of Florida Bay."
Bull. Mar. Sci. 44(l):312-323.
Lapointe, B.E., and J. O'Connell. 1989. "Nutrient-enhanced growth of Cladophora prolifera in Harrington
Sound, Bermuda: Eutrophication of a confined, phosphorus-limited marine ecosystem." Estuarine Coast.
Shelf Sci. 28:347-360. «
Lapointe, B.E., J.D. O'Connell, and G.S. Garrett. 1990. "Nutrient couplings between on-site sewage disposal
systems, groundwaters, and nearshore surface waters of the Florida Keys." Biochemistry 10:289-307.
Lasker, H.R. 1980. "Sediment rejection by reef corals: the roles of behavior and morphology in Montastrea
cavernosa (Linnaeus)." J. Exp. Mar. Biol. Ecol. 47:77-87.
Lee, T.N., and C. Rooth. 1972. "Exchange processes in shallow estuaries." Univ. Miami Sea Grant Spec.
Bull. No. 4. 33 pp.
Lee, T.N., C. Rooth, E. Williams, A.M. Szmant, and M.E. Clarke. To be published. "Influence of the
Florida Current, gyres and wind-driven circulation on transport of larvae and recruitment in the Florida
Keys coral reefs." Submitted to Continental Shelf Research.
Lee, T.N. 1975. Circulation and exchange process in southeast Florida's coastal lagoons. RSMAS Univ.
Miami Tech. Rep. TR75-3. 71 pp.
Lidz, B.H., and E.A. Shinn. 1991. "Paleoshorelines, reefs, and a rising sea: South Florida, U.S.A." J.
Coast. Res. 7(l):203-229.
3-34
-------
Littler, M.M., D.S. Litter, and B.E. Lapointe. 1986. Baseline studies of herbivory and eutrophication on
dominant reef communities of Looe Key National Marine .Sanctuary. NOAA Tech. Mem. NOS MEMO.
1, Sep. 1986.
Lizama, J., and R. Blanquet. 1975. "Predation on sea anemones by the amphinomid polychaete Hermodice
carunculata." Bull. Mar. Sci. 25(3):442-443.
Loya, Y. 1975; "Possible effects of water pollution on the community structure of Red Sea corals." Mar.
Biol. 29:177-185.
Loya, Y. 1976a. "Effects of water turbidity and sedimentation on the community structure of Puerto Rican
corals." Bull. Mar. Sci. 26:450-466.
Loya, Y. 1976b. "Recolonization of Red Sea corals affected by natural catastrophes and man-made
perturbations." Ecology 57:278-289.
Loya, Y., and B. Rinkevich. 1979. "Abortion effects in corals induced by oil pollution." Mar. Ecol. Prog.
Ser. 1:77-80.
Loya, Y., and B. Rinkevich. 1980. "Effects of oil pollution on coral reef communities." Mar. Ecol. Prog.
Ser. 3:167-180.
Manker, J.P. 1975. "Distribution and concentration of mercury, lead, cobalt, zinc, and chromium in
suspended participates and bottom sediments-upper Florida Keys, Florida Bay, and Biscayne Bay." PhD
dissertation, Rice University, Houston, TX.
Marcus, J., and A. Thorhaug. 1981. "Pacific versus Atlantic responses of the subtropical hermatypic coral
Ponies spp. to temperature and salinity effects." Proc. Int. Coral Reef Symp. 4th, 1981. 2:15-20.
Marsden, J.R. 1962. "A coral-eating polychaete." Nature 193(4815):598.
«
Marszalek, D.S. 1981. "Impact of dredging on a subtropical reef community, southeast Florida, U.S.A."
Proc. Int. Coral Reef Symp. 4th, 1981. 1:147-153.
Marszalek, D.S. 1987. "Sewage and Eutrophication." Pp. 77-90 in Salvat, B. (Ed.), Human Impacts on
Coral Reefs: Facts and Recommendations. Antenne Museum E.P.H.E., French Polynesia.
Mergner, H. 1981. "Man-made influences on and natural changes in the settlement of the Aqaba reefs (Red
Sea)". Proc. Intl. Coral Reef Symp. 4th, 1981. 1:193-207.
Miller, D.J., and C. Veron. 1990. Biochemistry of a special relationship. New Scientist 1990(2):44-49.
Miller, D.J., and D. Yellowlees. 1989. "Inorganic nitrogen uptake by symbiotic marine cnidarians: A critical
review." Proc. R. Soc. London 8237:109-125.
Mitchell, R., and I. Chet. 1975. "Bacterial attack of corals in polluted seawater." Microb. Ecol. 2:227-233.
(Red Sea).
Morse, D.E., A. Morse, H. Duncan, and R.K. Trench. 1981. "Algal tumors in the Caribbean octocorallian
Gorgonia venialina: II. Biochemical characterization of the algae and first epidemiological observations."
Bull. Mar. Sci. 31(2):399-409.
3-35
-------
Muller-Parker, G., C.F. D'Elia, and C.B. Cook. 1988. "Nutrient limitation of zooxanthellae: Effects of host
feeding history on nutrient uptake by isolated algae." Proc. Intl. Coral Reef Symp. 6th, 1989. 3:15-20.
Muscatine, L. 1990. "The role of symbiotic algae in carbon and energy flux in reef corals." Pp. 75-87 in
Dubinsky, Z. (Ed.), Ecosystems of the world, coral reefs. Elsevier, New York, NY.
Muscatine, L., and J.W. Porter. 1977. "Reef corals: mutualistic symbiosis adapted to nutrient-poor
environments." Bioscience 27:454-460.
Muscatine, L., J.W. Porter, and I.R. Kaplin. 1989. "Resource partitioning by reef corals as determined from
stable isotope composition. I. 13C of zooxanthellae and animal tissue vs. depth." Mar. Biol. 100:185-
193.
Opresko, D. 1973. "Abundance and distribution of shallow-water gorgonians in the area of Miami, Florida."
Bull. Mar. Sci. 23(3):535-558.
Peters, E.C. 1984. "A survey of cellular reactions to environmental stress and disease in Caribbean
scleractinian corals." Helgol. Meeresunters. 37:1-4.
Peters, E.C., J.C. Halas, and H.B. McCarty. 1986. "Calicoblastic neoplasms in Acropora palmata, with a
review of reports on anomalies of growth and form in corals." J. Natl. Cancer Inst. 76(5):895-912.
Pilson, M.E.Q., and S.B. Betzer. 1973. "Phosphorus flux across a coral reef." Ecology 54(3):581-588.
Pomeroy, L.R., M.E.Q. Pilson, and W.J. Wiebe. 1974. "Tracer studies of the exchange of phosphorus
between reef water and organisms of the windward reef of Eniwetok Atoll." Proc. Int. Coral Reef
Symp. 2nd, 1974:87-96.
Pomponi, S.A. 1977. "Etching cells of boring sponges: an ultrastructural analysis." Proc. Int. Coral Reef
Symp. 3rd, 1977. 2:485-490.
Porter, J.W. 1976. "Autotrophy, heterotrophy, and resource partitioning in Caribbean* reef corals." Am. Nat.
110:731-742.
«
Porter, J., J. Battey, and G. Smith. 1982. "Perturbation and change in coral reef communities." Proc. Natl.
Acad. Sci. 79:1678-1681.
Powell, G.V.N., J.W. Fourqurean, W.J. Ken worthy, and J.C. Zieman. 1991. "Bird colonies cause seagrass
enrichment in a subtropical estuary: Observational and experimental evidence." Estuarine Coast. Shelf
Sci. 32:567-579.
Powell, G.V.N., W.J. Kenworthy, and J.W. Fourqurean. 1989. "Experimental evidence for nutrient limitation
of seagrass growth in a tropical estuary with restricted circulation." Bull. Mar. Sci. 44(1):324-340.
Redfield, A.C. 1958. "The biological control of chemical factors in the environment." Am. Sci. 46:205-221.
Risk, M.J., and J.K. MacGeachy. 1978. "Aspects of bioerosion of modem Caribbean reefs." Rev. Biol.
Trop. 26(Supl. 1):85-105.
Risk, M.J. and H.R. Muller. 1983. "Porewater in coral heads evidence for nutrient regeneration." Limnol.
Oceanogr. 28:1004-1008.
3-36
-------
Roberts, H.H., L.J. Rouse, Jr., and N.D. Walker. 1983. "Evolution of cold water stress conditions in high
latitude reef systems: Florida, USA reef tract and the Bahama Banks, West Indies." Caribb. J. Sci.
19(l-2):55-60.
Rogers, C.S. 1983. "Sublethal and lethal effects of sediments applied to common Caribbean reef corals in the
field." Mar. Pollut. Bull. 14:378-382.
Rogers, C.S. 1990. "Responses of coral reefs and reef organisms to sedimentation." Mar. Ecol. Prog. Ser.
62:185-202.
Rowan, R., and D.A. Powers. 1991. "A molecular genetic classification of zooxanthellae and the evolution of
animal-algal symbioses." Science 251:1348-1351.
Rutzler, K., and G. Rieger. 1973. "Sponge burrowing: fine structure of Cliona lampa penetrating calcareous
substrate." Mar. Biol. 21:144-162.
Rutzler, K., and D.L. Santavy. 1983. "The black band disease of Atlantic reef corals. I. Description of the
cyanophyte pathogen." Mar. Ecol. 4(4):301-319.
Sammarco, P.W. 1980. "Diadema and its relationship to coral spat mortality: Grazing, competition, and
biological disturbance." J. Exp. Biol. Ecol. 45:245-272.
Sansone, F.J., C.C. Andrews, R.W. Buddemeier, and G.W. Tribble. 1988. "Coral reefs." Vol. 7(1): 19-22
in Well point sampling of reefs interstitial water.
Scott, P.J.B. 1990. "Chronic pollution recorded in coral skeletons in Hong Kong." J. Exp. Mar. Biol. Ecol.
139:51-64.
Shinn, E.A. 1966. "Coral growth-rate an environmental indicator." J. Paleontol. 40(2):233-240.
Shinn, E.A. 1975. "Coral reef recovery in Florida and the Persian Gulf." Environ. Geol. 1(4):241-.
Shinn, E.A. 1989. "What is really killing the corals?" Sea Frontiers 35(2):72-81.
Shinn, E.A., B.H. Lidz, J.L. Kindinger, J.H. Hudson, and R.B. Halley. 1989. Reefs of Florida and the Dry
Tortugas. A Guide to the Modem Carbonate Environments of the Florida Keys and the Dry Tortugas.
A report by the Geological Survey, 600 4th St. South, St. Petersburg, FL 33701. 53 pp.
Simmons, G.M., and F.G. Love. 1984. Water quality of newly discovered submarine groundwater discharge
into a deep coral reef habitat. Final report to Sanctuary Program Division, Office of Ocean and Coastal
Resource Management, National Oceanic and Atmospheric Administration under Contract No.
NA83AAA02762. August 30, 1984.
Simmons, G.M., and J. Netherton. 1987. "Groundwater discharge in a deep coral reef habitat: Evidence for a
new geochemical cycle?" In Mitchell, C.T. (Ed), Proc. Am. Acad. Underwater Sci. Ann. Scientif.
Diving Symp. 6th, 1987.
Simmons, G.M., G.B. Hall, A.T. Mikell, and F.G. Love. 1985. "A comparison of biogeological properties
of a deep-water stromatolite analog with those from ice-covered antarctic freshwater lakes."
Geomicrobiol. J. 4:269-283.
Skinner, R.H., and E.F. Corcoran. 1989. "Assessment of water quality data from five stations." John
Pennekamp Coral Reef State Park Water Quality Monitoring Program. Vol. 1, Nov. 1982-Dec. 1984.
3-37
-------
Smith, F.G., R.H. Williams, and C.C. Davis. 1950. "An ecology survey of the subtropical inshore waters
adjacent to Miami." Ecology 31:119-146.
Smith, N.P. 1991. "Physical oceanography." Pp. 16-22 in SEAKEYS Phase I, Sustained Ecological Research
Related to Management of the Florida Keys Seascape. A final report to the John D. and Catherine T.
MacArthur Foundation World Environment and Resources Program from the Florida Institute of
Oceanography, St. Petersburg, FL.
Smith, S.V. 1984. "Phosphorus versus nitrogen limitation in the marine environment." Limnol. Oceanogr.
29(6): 1149-1 160.
Smith, S.V. 1988. "Mass balance in coral reef-dominated areas." In Jansson, B.O. (Ed.), Coastal offshore
ecosystem interactions. Lect. Notes Coastal Estuarine Stud. 22:209-226.
Smith, S.V., K.E. Chave, and D.T.O. Kam. 1973. "Atlas of Kaneohe Bay: A Reef Ecosystem Under Stress."
Univ. Hawaii Sea Grant Program. UNHI- SEAGRANT-TR-72-01. 128 pp.
Smith, S.V., W.J. Kimmerer, E.A. Laws, R.E. Brock, and T.W. Walsh. 1981. "Kaneohe Bay Sewage
Diversion Experiment: Perspectives on Ecosystem Responses to Nutritional Perturbation." Pac. Sci. 35
(4): 1-402.
Smith, T.J., III, J.H. Hudson, M.B. Robblee, G.V.N. Powell, and P.J. Isdale. 1989. "Freshwater How from
the everglades to Florida Bay: A historical reconstruction based on fluorescent banding in the coral
Solenastrea bournoni." Bull. Mar. Sci. 44(l):274-282.
Strom, R.N., R.S. Braman, W.C. Jaap, P. Dolan, K.B. Donnelly, and D.F. Martin. 1992. "Analysis of
selected trace metals and pesticides offshore of the Florida Keys." Fla. Sci. 55(1): 1-13.
Sullivan, K., M. Chiappone and J. Levy. 1992. Long Key Monitoring Project Fall 1991 Summary. A report
produced by K.M. Sullivan, Sea and Sky Foundation, 1027 Andalusia Avenue, Coral Gables, Florida
33134. 147pp.
Sullivan, B., D. Faulkner, and L. Webb. 1983. "Siphonodictidine: A metabolite of the burrowing sponge
Siphonodictyon sp. that inhibits coral growth." Science 221:1175-1176.
Szmant, A.M. 1991. "Inshore-offshore patterns of nutrient and chlorophyll concentration along the Florida
reef tract." Pp. 42-62 in Sustained Ecological Research Related to Management of the florida Keys
Seascape. SEAKEYS Phase I. Final report to the John D. and Catherine T. MacArthur Foundation World
Environment and Resources Program from the Florida Institute of Oceanography, 830 First St. South, St.
Petersburg, FL. September 1991.
Szmant-Froelich, A. 1983. "Functional aspects of nutrient cycling on coral reefs." Symposia Series for
Undersea Research: The Ecology of Deep and Shallow Coral Reefs. NOAA Undersea Res. Prog.
Te Strake, D., W.C. Jaap, E. Truby, and R. Reese. 1988. "Fungal filaments in Millepora complanata
Lamarck, 1816 (Cnidaria: Hydrozoa) after mass expulsion of zooxanthellae." Fla. Sci. 51(3/4): 184-188.
VanArman, J., S. Bellmund, and L. Gulick. 1989. Surface Water Improvement and Management Plan for
Biscayne Bay. Publication by South Florida Water Management District, 3301 Gun Club Rd., West
Palm Beach, FL. 118 pp.
3-38
-------
Vaughan, T.W., and E.W. Shaw. 1916. "Geologic investigations of the Florida coral reef tract." Year Book
Carnegie lost. Washington. 14:232.
Vaughan, T.W., and J.W. Wells. 1943. "Revision of the suborders, families, and genera of the Scleractinia."
Geol. Soc. Am. Spec. Pap. 44. 363 pp.
Wahle, C.M. 1980. "Detection, pursuit, and overgrowth of tropical gorgonians by milleporid hydrocorals,
Perseus and Medusa revisited." Science 209(4457):689-691.
Walker, N.D., H.H. Roberts, L.J. Rouse, Jr., and O.K. Huh. 1982. "Thermal history of reef-associated
environments during a record cold-air outbreak event." Coral Reefs 1:83-87.
Webb, K.L., W.D. DuPaul, W. Wiebe, W. Sottile, and R.E. Johannes. 1975. "Enewetak (Eniwetok) Atoll:
Aspects of the nitrogen cycle on a coral reef." Limnol. Oceanogr. 20(2): 198-210.
Wheaton, J.L. 1987. "Observations on the octocoral fauna of southeast Florida's outer slope and fore reef
zones." Caribb. J. Sci. 23(2):306-312.
Wheaton, J.L., and W.C. Jaap. 1988. "Corals and other prominent benthic cnidaria of Looe Key National
Marine Sanctuary, Florida." Fla. Mar. Res. Publ. No. 43. 25 pp.
Williams, E.H., Jr., and L.B. Williams. 1988. "Bleaching of coral reef arrivals in 1987-1988: An updated
summary." In Ogden and WickJund (Eds.), Mass Bleaching of Coral Reefs in the Caribbean: A Research
Strategy. Department of Commerce, Natl. Undersea Res. Prog. Res. Rep. 88-2.
Wyers, S.C., H.R. Frith, R.E. Dodge, S.R. Smith, A. H. Knap, and T.D. Sleeter. 1986. "Behavioral effects
of chemically dispersed oil and subsequent recovery in Diploria strigosa." Mar. Ecol. 7(l):23-42.
3-39
-------
SUBMERGED AND EMERGENT
AQUATIC VEGETATION ASSESSMENT
Task 4
CONTENTS
1.0 INTRODUCTION 4-1
2.0 BACKGROUND AND CURRENT CONDITIONS 4-1
2.1 HISTORY 4-1
2.2 ESTIMATED EXISTING ACREAGES OF SUBMERGED AND
EMERGENT VEGETATION IN THE
FLORIDA KEYS NATIONAL MARINE SANCTUARY 4-2
3.0 KNOWN WATER-QUALITY CAUSES OF ADVERSE IMPACTS ON
SUBMERGED AND EMERGENT AQUATIC VEGETATION 4-5
3.1 MAGNITUDE AND GEOGRAPHICAL EXTENT OF
WATER-QUALITY-RELATED DECLINES IN SEAGRASS BEDS 4-6
3.1.1 Europe 4-6
3.1.2 Australia 4-6
3.1.3 Florida 4-7
3.2 WATER-QUALITY FACTORS THAT HAVE BEEN IMPLICATED IN
DECLINES IN SUBMERGED AND EMERGENT VEGETATION 4-7
3.2.1 Temperature 4-7
3.2.2 Salinity 4-8
3.2.3 Sediment Stability 4-8
3.2.4 Toxic Substances 4-8
3.2.5 Light Attenuation 4-9
3.3 RECENT DIE OFF OF SEAGRASSES IN FLORIDA BAY 4-11
3.4 EMERGENT VEGETATION 4-13
4.0 COMMUNITY TRENDS AND WATER-QUALITY-RELATED IMPACTS SEEN
IN THE FLORIDA KEYS NATIONAL MARINE SANCTUARY 4-13
5.0 STATEMENTS OF PROBLEMS 4-14
5.1 PROBLEMS IDENTIFIED DURING THE LITERATURE REVIEW 4-14
5.2 PROBLEMS IDENTIFIED AT THE SUBMERGED AND EMERGENT AQUATIC
VEGETATION ASSESSMENT WORKSHOP 4-17
6.0 REFERENCES 4-20
LIST OF FIGURES
4-1. Geographic subdivisions of the Florida Keys National Marine Sanctuary 4-3
4-2. Distribution of Thalassia testudinum die off in Florida 4-15
-------
LIST OF TABLES
4-1. Estimated Hectares (Acres) of submerged and emergent vegetation in the Florida Keys National
Marine Sanctuary, in existing proximal marine reserves, and in critical adjacent areas 4-4
-------
TASK 4 - SUBMERGED AND EMERGENT AQUATIC VEGETATION ASSESSMENT
1.0 INTRODUCTION
Seagrass meadows and emergent mangrove forest represent two critical communities within the boundaries of
the Florida Keys National Marine Sanctuary (FKNMS). As applied here, the term community refers to a
complex structure of interacting plant and animal assemblages. The exact composition of these communities
may vary from place to place, but seagrass and mangrove plant species always form the matrix around which
the communities develop. Without these framework species, these respective communities cease to exist. This
Section represents a compilation and summarization of information on these submerged and emergent vegetative
species in relation to the ambient and projected water quality in the Florida Keys. The potential effects of
water-quality deterioration are discussed, and the current status and trends within each community are assessed
based on the available scientific data. Data evaluated include published scientific literature, unpublished data
sets, and interviews with acknowledged experts. In many instances, scientific opinion varies as to the extent of
impact or the specific mechanisms causing impact. In such circumstances, available data have been objectively
evaluated; respective interpretations have also been presented.
2.0 BACKGROUND AND CURRENT CONDITIONS
2.1 HISTORY
Submerged vegetation within the boundaries of the FKNMS consists mainly of the vascular seagrass species
Thalassia testudinum (turtle grass), Syringodium filiforme (manatee grass), and Halodule wrightii (shoal grass).
Occasionally, sprigs or clumps of Halophila decipiens (paddle grass) or H. engelmannii (star grass) are seen
growing in and around the fringes of the major bed-forming species, but both these species are diminutive and
their biomass is minuscule as compared to the three major species. Also, a large number of macroscopic algal
species are associated with the seagrass beds and sand bottom areas of the Florida Keys.
For the purposes of this analysis, emergent vegetation consists entirely of the mangroves and dwarf mangroves
seen along the island chain. Mangrove forests once stretched along almost the entire coastline of the Florida
Keys. Coastal development has reduced their abundance, but there are still significant stands present in certain
areas. Of particular significance in the FKNMS Program are the mangrove islands of the Marquesas, the
smaller mangrove-covered islands along the Gulf side of the lower Florida Keys, and the extensive mangrove
coastlines of Rodriquez Key and John Pennekamp Coral Reef State Park off Key Largo. In addition, there are
many acres of mangrove swamp still in private ownership. Large tracts in many areas also exist adjacent to the
FKNMS in Everglades and Biscayne National Parks.
The Florida Keys have been undergoing development since the time of the Calusa Indians, 500 years before the
arrival of Columbus. The City of Key West was founded in the early 1800s, and had a population of only
12,927 in 1940 (Wallace, Roberts, & Todd et al. 1991). In 1912, the Florida East Coast Railway was extended
to Key West, prompting the first large-scale destruction of seagrass beds and emergent vegetation associated
with development.
In Key West, large areas of bottom were dredged to create anchorage. This same dredged material was used to
fill other areas of shallow bottom. Today, over one-third of Key West is built on manmade land. Dredging and
land filling have had significant impact on nearshore submerged and emergent vegetative communities
throughout the Florida Keys.
In addition to man's activities, both the submerged and the emergent vegetative communities in the Florida Keys
are impacted by storms and hurricanes. While seagrass communities appear quite resilient to these periodic
4-1
-------
disturbances, a major hurricane such as Hurricane Donna (1960), can produce long-term changes in the
emergent vegetation community (Tabb and Jones 1962).
2.2 ESTIMATED EXISTING ACREAGES OF SUBMERGED AND EMERGENT
VEGETATION IN THE FLORIDA KEYS NATIONAL MARINE SANCTUARY
At present, there are an estimated 565,094 ha (1,396,345 acres) of seagrass and 22,560 ha (55,744 acres) of
mangrove within the designated boundaries of the FKNMS (BLM and FDNR 1979; FWS and MMS 1983; CSA
and GMI 1991).
To facilitate comparison of different areas within the FKNMS, five subdivisions are designated based on
geographic parameters and resource utilization patterns (Figure 4-1).
. 1. Western Extension
Extending from Dry Tortugas Bank eastward to just west of Key West
2. Lower Keys
Extending from Key West to the middle of the Seven Mile Bridge
3. Middle Keys
Extending from the middle of the Seven Mile Bridge to Craig Key
4. Upper Keys
Extending from the Long Key/Lower Matecumbe Channel to North Key Largo (Broad Creek)
5. Northern Extension
Encompassing the small extent of the reef tract north of Broad Creek that lies outside Biscayne
National Park and extends northward to just off the southern end of Key Biscayne.
Table 4-1 presents the estimated acreages of submerged and emergent vegetation within each of these individual
subdivisions of the Sanctuary. There are several State- and Federally designated marine preserves within the
boundaries of the FKNMS. These include Fort Jefferson National Monument in the Western Extension, Looe
Key National Marine Sanctuary (in the lower keys), and John Pennekamp Coral Reef State Park, and the Key
Largo National Marine Sanctuary (in the upper keys). In addition to these marine reserves actually contained
within the boundaries of the FKNMS, both the Everglades National Park and the Biscayne National Park border
the Sanctuary and both are considered critical adjacent habitats (Table 4-1). Submerged and emergent
vegetative habitats have been presented separately in Table 4-1 for all marine preserves completely contained
within the Sanctuary. For the portions of the Biscayne and Everglades National Parks that border the
Sanctuary, only the submerged vegetative community figures are presented. Emergent vegetation in these parks
is located too far beyond the borders of the Sanctuary to be significant in this discussion.
Because of the nature of the mapped data sources (e.g., from which information in Table 4-1 is taken), it is not
possible to differentiate among individual plant species. Further subdivision of the habitat categories submerged
and emergent is not possible on a regional basis.
The three species of perennial seagrasses, Thalassia testudinum, Syringodium filiforme, and Halodule wrightii,
persist from year to year in the same general location and form large, complex, and extremely significant
biological habitats. The seagrass beds formed by these species are one of the most, if not the most, biologically
productive habitats within the FKNMS.
4-2
-------
Everglades National Park
Forl Jcllceson
National Monument
Biscayne National Park
Northern
Extension
John Pennekamp Coral
Reef Slate Park
Key Largo National
Marine Sanctuary
'pper
Keys
Western
Extension
Lower
Keys
Middle
Keys
Lone Key National
Marine Sanctuary
Florida Keys National Marine Sanctuary
Figure 4-1. Geographic subdivisions of the Florida Keys National Marine Sanctuary.
-------
Table 4-1. Estimated Hectares (Acres) of submerged and emergent vegetation in the Florida Keys National Marine
Sanctuary, in existing proximal marine reserves, and in critical adjacent areas*.
Subdivision or Area
Submerged Vegetation Emergent Vegetation Size of Total Area
Hectares Coverage Hectares Coverage Hectares
(Acres) (%) (Acres) (%) (Acres)
Florida Keys National Marine Sanctuary
Western Extension
(Dry Tortugas Bank eastward to just west
of Key West)
Lower Keys
(Key West to the middle of the Seven Mile
Bridge)
Middle Keys
(The middle of the Seven Mile Bridge to
the Long Key/Lower Matecumbe Channel)
Upper Keys
(The Long Key/Lower Matecumbe Channel to
North Key Largo at Broad Creek)
Northern Extension
(The reef tract north of Broad Creek that
lies outside Biscayne National Park, and
extends northward to just off the southern
end of Key Biscayne)
Totals:
Existing Marine Reserves
Fort Jefferson National Monument
Looe Key National Marine Sanctuary
John Pennekamp Coral Reef State Park
Key Largo National Marine Sanctuary
Critkal Adjacent Areas
Everglades National Park
Biscayne National Park
326,041 69
(805,648)
117,851 48
(291,207)
79,238 64
(195,797)
67,914 43
(167,814)
0 0
565,094 56
(1,396,345)
20,959 80
(51,790)
237 13
(584)
18,375 78
(45,405)
7,574 21
(18,716)
222,585 -
(550,000)
36,154 -
(89,334)
1,257 0.3
(3,105)
12,664 5
(31,293)
1,215 1
(3,003)
7,423 5
(18,343)
0 0
22,560 2
(55,744)
6 0.02
(16)
0 0.00
1,242 5
(3,068)
0 0
— —
— —
473,281
(1,169,476)
246,241
(608,438)
124,613
(307,914)
(158,280)
(391,101)
10,667
(26,357)
1,013,082
(2,503,286)
26,048
(64,330)
1,818
(4,493)
23,581
(58,286)
35,772
(88,268)
NC
NC
'Submerged habitat data were provided by the Florida Department of Natural Resources (FDNR) and were compiled from maps
published by BLM and FDNR (1979) and by CSA and GMI (1991). These map sets have been digitized by the FDNR and
submerged habitat area calculations were made electronically. Emergent habitat estimates were derived by planimetry from the maps
published by FWS and MMS (1983).
4-4
-------
The two annual, vascular plant species reported from the Sanctuary area, Halophila decipiens and H.
engelmannii, are much smaller than the perennial bed-forming species. They are propagated by seed dispersion,
and do not form permanent seagrass beds. Because they are capable of surviving at reduced light levels, they
are generally seen in deeper water than the major, bed-forming species. They may, however, occasionally be
found growing in and around the bases of the larger seagrass species. Zieman (1982), quoting from an earlier
but unidentified source, reports H. engelmannii occurring in the Dry Tortugas area. Extensive field surveys by
Continental Shelf Associates, Inc., in that area in 1988 (CSA and GMI 1991), failed to identify any H.
engelmannii. However, due to the ephemeral nature of this species growth patterns, it is difficult to say whether
or not its absence in 1988 is significant.
It is estimated, based on data from Zieman and Fourqurean (1985) and CSA and GMI (1991), that the seagrass
species of Thalassia testudinum, Syringodium filiforme, and Halodule wrightii comprise 75% to 85% of the
submerged vegetation acreage estimates presented in Table 4-1. These species also provide approximately 95%
of the submerged vegetative biomass within the entire FKNMS (Zieman 1991).
Benthic macroalgae making a significant contribution to the submerged vegetation habitat component of the
FKNMS include various species of Batophora, Caulerpa, Acetabularia, Penicillus, Halimeda, Udotea,
Rhipocephelus, Dasya, Gracilaria, and Laurencia (Tabb et al. 1962; Zieman and Fourqurean 1985; Merriam
1989; and Montague et al. 1989). Geologically, the calcareous algae such as Halimeda, Udotea, and Penicillus
have been of importance in creating the calcareous sediments seen throughout the Sanctuary (Ginsburg et al.
1971; Merriam 1989). Biologically, such temporally transient species as Laurencia make up an important and
poorly studied component of the FKNMS ecosystem. Drift algal clumps of Laurencia and other algal species
may provide various habitats for colonization by many small molluscan and arthropod species. There is evidence
to suggest the presence of these seasonal drift algal mats provides a settling cue for post larvae Panulirus argus,
thus forming critical habitat for the Florida lobster.
Three mangrove species are present in the Sanctuary: red mangrove (Rhizophora mangle), white mangrove
(Laguncularia racemosa), and black mangrove (Avicennia germinans). These three species form six recognized
vegetative communities: overwash, fringe, riverine, basin, hammock, and scrub or dwarf (Odum et al. 1982).
Overwash mangrove forests dominated by red mangrove are seen on islands such as the Marquesas, the smaller
keys on the Gulf side of the lower Keys, in Florida Bay, and the islands and sounds on the Atlantic side of the
upper Keys off Key Largo. Fringing mangrove forests are typically seen along rather narrow stretches of the
coastline. Fringing mangrove stands may contain all three species in specific zones defined by tidal inundation.
Riverine mangrove forest within the FKNMS are limited primarily to red mangrove stands in the tidal creeks of
the lower and upper Keys. Basin mangroves and hammock forest mangroves within the Sanctuary are limited
almost exclusively to the depressions and sink holes seen in the interior of some of the lower Keys. These
communities usually are dominated by black and white mangroves. Hammock mangrove communities are found
in the same general areas, but they occur on slightly higher elevations, and all three mangrove species may be
present. The scrub or dwarf mangrove communities are seen in the hard, limestone substrates on both sides of
the Florida Keys. They are more common in the upper and lower Keys than in the middle Keys.
3.0 KNOWN WATER-QUALITY CAUSES OF ADVERSE IMPACTS ON
SUBMERGED AND EMERGENT AQUATIC VEGETATION
The seagrass beds of south Florida, including those in Florida Bay and along the Florida Keys reef tract, cover
an estimated 5500 km2 (Iverson and Bittaker 1986), making them among the most extensive areas of seagrass in
the world. In spite of their extent, there is very little documented information on man's impact on this system.
Almost all of the information concerning declines in the seagrass beds of this region is anecdotal and
speculative. In a recent review of anthropogenic impacts on seagrass beds in Florida, Livingston (1987) found
4-5 -
-------
very few data from the Florida Keys. Because of this general lack of information, it is necessary to analyze
information from other parts of the world to assess the possible adverse impact of degradation in water quality
on submerged vegetation within the boundaries of the FKNMS.
In this Section, the magnitude and extent of worldwide declines in seagrass beds are presented by briefly
reviewing some of the literature on historical changes in seagrass beds. The specific water-quality-related
mechanisms most often implicated in the declines of seagrasses and mangroves are then addressed.
3.1 MAGNITUDE AND GEOGRAPHICAL EXTENT OF WATER-QUALITY-RELATED
DECLINES IN SEAGRASS BEDS
In many places around the world, increases in human development in the coastal zone during the past SO years
have coincided with loss of seagrass beds. These losses are well documented for many areas of Europe,
Australia, and North America. In the following Sections, a few examples of studies examining the extent and
causes of declines from these geographic areas are presented. Special emphasis is placed on Florida seagrass
beds.
3.1.1 Europe
Prior to the 1930s, the eelgrass (Zostera marina) beds were large enough to support an important industry based
on the harvest of seagrass in the northwestern part on the Netherlands. In 1932, an epidemic known as the
wasting disease reached the Netherlands and wiped out the sublittoral Z marina beds (Den Hartog and
Polderman 1975). At the same time, the Dutch government completed the enclosure of the Zuyder Zee,
severely changing the hydrological conditions in areas that had supported Z, marina beds prior to the wasting
disease. Elsewhere in Europe, Z marina beds that had been lost to the epidemic began to slowly recover, but
the sublittoral beds in the Waddenzee never recovered. Littoral beds did recover, however. Beginning in 1965,
these littoral beds started to decline anew, and a 30% to 60% decline in the remaining beds was recorded
between 1971 and 1973 (Den Hartog and Polderman 1975). It has been argued (Den Hartog and Polderman
1975; Giesen et al. 1990) that both the failure of the sublittoral beds to recover and the more recent declines in
the littoral populations were due to progressively increasing turbidity throughout the century. Increases in
turbidity have been caused by eutrophication, mining, and dredging activities (Giesen et al. 1990).
Other areas in Europe have also experienced marked seagrass declines. In the Gulf of Marseilles on the French
Mediterranean coast, an impressive decrease in seagrass beds dominated by Posidonia australis was reported
(Peres and Picard 1975). General eutrophication of the area caused the loss of the deeper beds between 1948
and 1955. Engineering the Rhdne River for hydroelectric power has also contributed to this decline by
changing the flood frequency and strength, and therefore sediment characteristics, of the Gulf.
3.1.2 Australia
There have been widespread and extensive declines in seagrasses reported from many areas of Australia (see
Shepherd et al. 1989 for review). The losses were recorded from both temperate and subtropical areas in
Australia. Diverse seagrass communities were affected, with major losses of at least nine seagrass species,
including Amphibolis antarctica, Halophila avails, Heterozostera tasmanica, Posidonia angustifolia, P.
australis, P. sinuosa, Ruppia megacarpa, Zostera capricorni, and Z muelleri. A variety of proximal
mechanisms have been postulated to explain these losses, but all of these are a direct result of human activities
in the coastal zone.
4-6
-------
3.1.3 Florida
Seagrass beds in Florida have been particularly hard hit by the rapid population growth and industrialization that
has occurred over the past SO years. In two embayments on the west coast of Florida, Pensacola Bay and
Tampa Bay, the problem is most severe. Seagrass beds have been substantially reduced in Pensacola Bay over
the period from 1949 to 1979, concurrent with the urbanization and industrialization of the watershed for the
Bay, and the resulting eutrophication, industrial waste discharge, and dredging and filling (Livingston 1987).
The same causes have been suggested as the reason for the 81 % reduction of the seagrass beds of Tampa Bay,
where total coverage has been reduced from 30,970 ha to 5750 ha in the period from 1948 to 1980 (Lewis et al
.1985). Significant loss of seagrasses has also occurred over the last 20 to 40 years in Choctawahatchee Bay,
Apalachee Bay, Charlotte Harbor, Biscayne Bay, and the Indian River (reviewed in Livingston 1987). While all
of these losses are well-documented, exact mechanisms for the declines are not known, but they all occurred as
the watersheds of the embayments were progressively developed.
3.2 WATER-QUALITY FACTORS THAT HAVE BEEN IMPLICATED IN DECLINES IN
SUBMERGED AND EMERGENT VEGETATION
Most documented losses of seagrasses have been attributed to the general development of the watershed and
coastline that influence the beds. The primary reason that exact mechanisms often can not be identified is that
human activities tend to alter many water-quality characteristics simultaneously. In some instances, alterations
in the physical parameters of temperature, salinity, and sediment stability have been documented to affect
seagrass beds. The effects of toxic materials (such as herbicides, detergents, and petroleum products) have also
been blamed for losses of seagrass beds. Most often, however, the reduction of the quantity and quality of light
that reaches the seagrasses is cited as the reason for the destruction of seagrass beds. Two primary factors are
responsible for increases in light attenuation: increases in suspended sediments in the water and water-column
eutrophication from nutrient input.
3.2.1 Temperature
Abnormally high temperatures have been implicated in the decline of seagrass beds. In the temperate zone,
Rasmussen (1973) reported a correlation between high summer temperatures and the disappearance of Zostera
marina beds in Danish coastal waters during the 1930s. High temperatures may also cause problems in tropical
and subtropical areas, because the upper thermal limit of tropical organisms is often no greater than that of
organisms from warm temperate regions (Zieman 1975a). Glynn (1968) observed that leaves of Thalassia
testudinum were killed when temperatures exceeded 35 °C on a reef flat in Puerto Rico, but that the rhizomes of
these seagrasses were apparently unaffected by virtue of being insulated in the sediment. Under prolonged
temperature stress, the roots and rhizomes of seagrasses may also be affected (Wood and Zieman 1969).
Higher than normal late summer and autumn temperatures may have a role in the recent die off of seagrasses
from Florida Bay, as discussed in greater detail in Section 4.3.3.
High-temperature stress to seagrass beds may result from human activity, primarily from the use of ambient
water for cooling systems of power plants (Zieman 1982). Prior to the construction of a 270-km network of
cooling canals, the effluent from the nuclear power plant at Turkey Point caused decreased productivity of
Thalassia testudinum beds and extirpation of 40 ha of seagrass beds from Biscayne Bay (Zieman and Wood
1975). Relatively small (4 °C) temperature increases were responsible for these impacts (Roessler and Zieman
1969).
4-7
-------
3.2.2 Salinity
While most seagrasses can tolerate some variation in salinity, most experience reduced pbotosynthetic rate and
growth at salinities that are much higher or lower than normal. The degree to which salinity affects
photosynthesis and growth varies among species, however. For the species that dominate seagrass beds of
South Florida, Thalassia testudinum and Syringodium filiforme are more susceptible to salinity deviations than is
Halodule wrightii (McMillan and Moseley 1967). Salinity levels near normal (35 ppt) may support lusher and
more productive seagrass beds than do mesohaline conditions (Zieman and Zieman 1989).
Seagrasses can survive in salinities far outside of their normal range, but only for short periods. Even after
short exposures to low or high salinity, extensive leaf loss is common (Zieman 1982). In the aftermath of
Hurricane Donna in 1960, it has been speculated that more damage was done to Thalassia testudinum beds in
Biscayne Bay by lowered salinity than by wind and wave action from the storm (Thomas el al. 1961).
Human activity can alter the salinity regime of seagrass beds, and thereby cause changes to the beds. It has
been speculated that the diversion of freshwater and the changing of hydroperiod of the Everglades drainage has
changed the historic salinity regime in Florida Bay from a variable, mesohaline system to a more stable,
polyhaline to hypersaline system. These changes may be responsible for the observed shift in Florida Bay
seagrass communities from Halodule wrightii dominance to Thalassia testudinum dominance (Zieman 1982).
3.2.3 Sediment Stability
Dredging activity can be deleterious to seagrass beds in many ways. Not only are beds removed or buried by
dredging, but the resulting change in the amount of current and wave energy reaching surrounding seagrass beds
may be changed. In Botany Bay, Australia, dredging of a ship channel increased wave energy to the point that
even minor storms caused damage to established seagrass beds. This storm damage is thought to be one of the
primary factors behind a 5896 reduction in the Posidonia australis beds of Botany Bay (Larlcum and West
1990). Increased currents and tidal fluctuations brought on by the enclosure of the Waddenzee are thought to
have altered the bottom-sediment characteristics so severely that Zostera marina was unable to recolonize
following its demise caused by the wasting disease (Den Hartog and Polderman 1975).
3.2.4 Toxic Substances
Anionic detergents are a common component of domestic sewage. Detergents carried into seagrass beds
adsorbed to clay particles have been implicated in the decline of Posidonia oceanica beds of the French
Mediterranean (Peres and Picard 1975). Den Hartog and Polderman (1975) hypothesize that toxic effects of
detergents may also have played a role in the modern decline of intertidal seagrass beds in the Dutch
Waddenzee.
Seagrasses are susceptible to some herbicides (see Thayer el al. 1984 for review). The decline in submerged
aquatic vegetation in the upper and middle Chesapeake Bay has been correlated with the use of the herbicide
atrazine (Correl and Wu 1982). The toxicity of the breakdown products of common herbicides to seagrasses is
not known.
Little is known about heavy metal toxicity to seagrasses, but at least some seagrasses concentrate heavy metals
in their tissues (Drifmeyer et al. 1980). The possible effects of bioaccumulation of heavy metals in the animals
occurring in seagrass beds are unknown.
4-8
-------
Seagrasses are generally not strongly affected by acute contact with petroleum products (see Zieman 1982;
Phillips 1984 for reviews), but Thayer et al. (1984) point out that the effects of long-term, chronic exposure to
petroleum and related products are not known. The animals in seagrass beds are highly susceptible to poisoning
by oil and related compounds (Zieman 1982).
3.2.5 Light Attenuation
In areas where physical and sedimentary characteristics are amenable to seagrass growth, light availability is
considered one of the primary physical factors limiting seagrass distribution (see Dennison 1987 for review).
The availability of light limits seagrass distribution by controlling the maximum depth at which seagrasses can
survive. Shoreward, or minimum depth limits, of seagrass beds are often set by the ability of seagrasses to
survive exposure to low-tide conditions (e.g., Bridges and McMillan 1986). The offshore extent of seagrass
beds often occurs where the water depth reaches the maximum depth at which the seagrasses receives enough
light to survive.
The relationship between maximum depth of seagrass beds and light availability is illustrated by the relationship
between maximum depth and measures of water clarity. For example, the maximum depth of Thalassia
testudinum in Puerto Rico (Vicente and Rivera 1982) and Zostera marina near Woods Hole, Massachusetts
(Dennison 1987), are both closely correlated with the mean annual Secchi disk depth. On the western Florida
shelf, the depth limits of seagrass beds dominated by T. testudinum, Syringodium filiforme, and Halodule
wrightii correspond to the depth to which approximately 10% of the incident surface irradiance penetrates
(Iverson and Bittaker 1986). The depth to which 10% of surface irradiance penetrates is a good general rule of
thumb to predict maximum depth distribution of seagrasses: in a review of published depth limits of seagrasses
from around the world, Duarte (1991) found that seagrass depth limits, on average, were at the depth to which
10.8% of the surface irradiance penetrated.
Many factors act to attenuate light in the water column that overlies seagrass beds (Gallegos et al. 1991). The
total absorption of light in the water column may be partitioned into the contributions of the absorption by pure
water and the absorption of material dissolved and suspended in the water. Dissolved organic matter can
contribute substantially to the attenuation of light in the water column. Suspended materials that may play a
major role in absorbing light include mineral matter, organic detritus, and phytoplankton.
Due to the importance of light availability in determining seagrass distributions, any factor that decreases the
amount of light penetrating the water column may have a significant impact on seagrass beds. Not all factors
that decrease light penetration will have the same effect on the seagrasses, however (Gallegos et al. 1991). The
dissolved organic matter that results from the decomposition of mangroves and salt-marsh plants can lead to tea-
colored water that appears very dark, yet the specific wavelengths of light that are directly utilized by seagrasses
for photosynthesis are not as strongly attenuated as total visible light. Since phytoplankton and seagrasses utilize
similar specific wavelengths of light for photosynthesis, the portion of the total light spectrum that is absorbed
by phytoplankton has a much greater effect on the growth of seagrasses than does a similar amount of light
absorbed by suspended mineral matter.
3.2.5.1 SEDIMENT LOAD AND TURBIDITY
Increased suspended sediment loads are harmful to seagrasses in three ways: (1) suspended sediments decrease
the light penetration of the water column, (2) sediments can coat seagrass blades and block light, and (3) settling
of the suspended load can bury seagrass beds.
4-9
-------
Any process that affects the sediment load of the water column overlying seagrasses may have negative impacts
on seagrasses. The cultivation of land for agriculture is correlated with increases in turbidity in nearby coastal
waters, and has been shown to result in decreased growth of seagrasses (Thayer et al. 1975). Turbidity and
increased sedimentation rates caused by the construction of the Julia Tuttle Causeway may have been
responsible for the reduction in seagrass beds in Biscayne Bay, even after the diversion of a domestic sewage
outfall from the Bay (McNulty 1961).
Suspended solids in the water may have been responsible for the loss of seagrasses in Western Port, Australia,
not while in suspension, but after settling on leaf surfaces (Shepherd et al. 1989). A fine mud coating on the
leaves may have blocked light from reaching the leaves. The problem was especially severe in intertidal
seagrasses because fine muds became permanently adhered to leaf surfaces upon exposure to the air.
A positive feedback exists in the effects of turbidity on seagrasses. The ability of seagrasses to trap and bind
sediments is well known. When seagrasses are killed, they no longer hold the sediments out of the water
column. In this way, the death of seagrasses due to shading can lead to greater turbidity in the overlying water
column, causing even greater attenuation of light. After the loss of Zostera marina to the wasting disease in the
1930s, sediments in the Waddenzee were no longer stabilized, and turbidity increased dramatically, thereby
precluding the recolonization of the former seagrass beds (Giesen et al. 1990).
Heavy suspended loads of fine, flocculent material can kill mangroves by clogging the lenticels and
pneumatophores on the roots, thereby preventing aeration of the roots. Untreated sugar cane wastes, pulp mill
effluent, and ground bauxite and other ore particles all have been implicated as deleterious sources of fine,
flocculent sediments (Odum and Johannes 1975).
3.2.5.2 NUTRIENTS
Seagrasses are faced with a paradox in their environmental requirements. As with all autotrophs, seagrasses
need light to survive, but they are rooted underwater, a medium that attenuates light much more strongly than
air. In addition to light, they require mineral nutrients to photosynthesize and build tissue. The density of
many seagrass beds is limited by the nutrient supply. Experimental additions of nutrients to both sediments and
the water column of seagrass beds can greatly increase seagrass biomass and growth rate (e.g., Orth 1977;
Harlin and Thome-Miller 1981; Powell et al. 1989). In south Florida, nutrient additions can influence the
species composition of seagrass beds, with Halodule wrightii replacing Thalassia testudinum after 3 years of
nutrient addition (Powell et al. 1991). It is important to note that all these nutrient addition experiments were
all conducted on temporal and spatial scales.
Unfortunately for seagrasses, long-term increases in nutrients in the overlying water column of large geographic
areas cause the attenuation of light to increase dramatically, often leading to extirpation of seagrass beds
(Zieman 1975b; Orth and Moore 1983; Cambridge and McComb 1984; Giesen et al. 1990; Larkum and West
1990). Seagrasses are, therefore, usually found in areas with relatively low nutrient concentrations in the
surface water. Nutrients can be brought into nearshore waters that support seagrasses by either surface runoff
or groundwater discharge (Valiela et al. 1990). Two distinct phenomena contribute to the deleterious effects of
elevated water-column nutrients on seagrasses: (1) nutrient-induced phytoplankton blooms that reduce the
amount of light that penetrates to the seagrass beds and (2) enhanced growth of epiphytes that directly shade
seagrasses.
4-10
-------
3.2.5.2.1. Nutrient-Induced Phytoplankton Blooms
The increased growth of phytoplankton and the concomitant increase of light attenuation in eutrophic bodies of
water is a well-known phenomenon. This reduction in light is a problem for seagrasses growing in deeper areas
of affected coastal areas, but it has relatively little effect on seagrasses in shallow areas (Cambridge et al.
1986). In numerous estuaries in New South Wales, Australia, seagrass beds dominated by Zostera capricorni
have been reduced by 50%, apparently due to the reduction of light penetration owing to eutrophication
(Shepherd et al. 1989). Increases in nutrient concentrations due to pollution of the Rhine River have
exacerbated the attenuation of light in the Dutch Waddenzee, and contributed to the continuing decline of local
Z marina populations (Giesen et al. 1990). In at least one instance, (Cockburn Sound, Australia) the reduction
of anthropogenic nutrient loads has led to a decrease in phytoplankton biomass and an arresting of the loss of
seagrass beds (Shepherd et al. 1989). In this case, the anthropogenic nutrient source was a domestic sewage
outfall into a bay with limited circulation. Although no identical situations to this Australian experience exist in
the FKNMS, there are several locations where seagrasses growing in nearshore areas with restricted flushing
may be undergoing stress as a result of anthropogenic nutrient-induced eutrophication.
3.2.5.2.2 Nutrient-Induced Epiphyte Growth
Significant losses of seagrasses occur in coastal waters that receive anthropogenic nutrient loads, despite the
minimal decrease in water clarity in some of these areas (e.g., Silberstein et al. 1986). Obviously, nutrient
loading produces responses other than increases in phytoplankton biomass that affect seagrasses. One such
phenomenon is the increase in epiphytization of seagrasses in areas of high-nutrient availability. Increased
water-column nutrients have been shown to increase epiphyte loads in seagrass beds from many areas of the
world (Sand-Jensen 1977; Kemp et al. 1985; Borum 1985; Silberstein et al. 1986; Dunton 1990; Tomasko and
Lapointe 1991). Epiphytes directly shade seagrass leaves; the light attenuation through epiphytes is an
exponential function of epiphyte biomass (e.g., Bulthuis and Woelkerling 1983, Silberstein et al. 1986). This.
reduction in light can greatly reduce photosynthesis and growth of seagrasses (Bulthuis and Woelkerling 1983;
Silberstein et al. 1986; Tomasko and Lapointe 1991).
Increased epiphytism may be the primary mechanism through which human-induced eutrophication destroys
seagrass beds. Increased nutrients from bird colonies and human sewage can lead to an increase in epiphyte
loads, and therefore a decrease in biomass and shoot density. This phenomenon has been noted in Thalassia
testudinum beds in the Florida Keys and the Caribbean (Tomasko and Lapointe 1991). Increased epiphytes have
been identified as the primary factor contributing to the loss of seagrasses in Cockburn Sound (Cambridge et al.
1986) and in other estuaries in Australia (Shepherd et al. 1989). It has also been implicated in the loss of
submerged aquatic vegetation from Chesapeake Bay (Kemp et al. 1985) and other coastal waters (Valiela et al.
1990).
3.3 RECENT DIE OFF OF SEAGRASSES IN FLORIDA BAY
Seagrasses dominate the bottom of Florida Bay (Zieman et al. 1989a), a critically important area adjacent to the
FKNMS. Beginning in 1987, there has been a massive and unprecedented mortality of seagrasses in Florida
Bay, mostly within the boundaries of Everglades National Park (Robblee et al. 1991). Since 1987, 4000 ha of
seagrass beds have been completely denuded, and another 23,000 ha have been impacted to a lesser extent.
This die off occurred in dense seagrass communities that were dominated by Thalassia testudinum, and at first
spread very rapidly. Over the past 2 years, die off of seagrasses has continued at a slower pace, and the
denuded areas that were previously covered with dense stand of T. testudinum have been recolonized by
Halodule wrightii. It has been speculated in the popular press that water-quality degradation, and particularly
enhanced nutrient loading, due to human activities has caused this seagrass mortality. Three years of intensive
4-11
-------
investigation by a team of researchers from the Florida Department of Natural Resources (FDNR), Everglades
National Park, Florida International University, University of Georgia, and University of Virginia has all but
ruled out anthropogenic pollution including nutrients as the cause of this die off (Robblee et al. 1991; J.
Zieman, University of Virginia, personal communication, 1991; R. Jones, Florida International University,
personal communication, 1991). The locations of the most severe die off are distant from surface-water
pollution sources. Degradation in water quality, including increases in total nutrient concentrations and
decreases in light penetration, have been observed in the water column overlying areas of this seagrass die off.
These decreases have, in all cases studied, followed the beginning of mortality of the seagrass community and
have not preceded it. At present, two potential causes of the mortality are under investigation: (1) a pathogenic
marine slime mold and (2) imbalances in the respiration/photosynthesis balance within the plants themselves.
Muehlstein and Porter have isolated a pathogenic slime mold (Labyrinthula sp.) from Thalassia testudinum
leaves from dying areas of Florida Bay (Robblee et al, 1991). This organism is closely related to the pathogen
thought to be responsible for the Zostera marina wasting disease (Short et al. 1987; Muehlstein 1989) that
devastated North Atlantic Z marina eelgrass beds in the 1930s and has been recently recurring in New England
(Short et al. 1987). No mortality has been induced in apparently healthy Thalassia testudinum stands by
exposing them to this pathogen (D. Porter, University of Georgia, personal communication, 1991), indicating
that, although this disease may contribute to the ultimate demise of the seagrasses, it is not the ultimate cause of
the observed mortality.
Zieman et al. (1989b) proposed a conceptual model for the Florida Bay seagrass die off. It invokes two
potential ultimate causes of the die off: (1) a long-term modification of the freshwater inputs into Florida Bay
from the Everglades due to the diversion of freshwater for agricultural, industrial, and domestic use and (2) an
abnormally long interval between major hurricane impacts on Florida Bay. Salinities in Florida Bay have been
very hypersaline over the past few years, reaching year-average highs of over 55 ppt in central Florida Bay
[Fourqurean et al.-(to be published)]. Draining of the Everglades caused the diversion of runoff, which has
been curtailed by as much as 59% from historical levels (Smith et al. 1989). Salinities of this magnitude can be
fatal to seagrasses (McMillan and Moseley 1967). Reduction of freshwater would also allow Thalassia
testudinum to invade areas that historically were too fresh or too variable for colonization by this species
(Zieman 1982).
Hurricanes may function to remove accumulated organic matter and sediments from Florida Bay. There has
been an abnormally long period since that last major hurricane affected Florida Bay, perhaps allowing
accumulations of sediments and organic matter beyond historic levels. This may have allowed the overly dense
beds of Thalassia testudinum to develop in portions of Florida Bay. These overly dense beds may now be
experiencing the consequences of overdevelopment, and may be succumbing to the effects of
respiration/photosynthesis balance or disease. Very hot summers and falls in 1987, 1988, and 1989 may be
responsible for the beginning of the die off. High temperatures, especially in the fall, would enhance
respiration rates more than photosynthetic rates would, and cause a decrease in the net production of the grass
beds. Also, direct mortality of large amounts of shallow-water beds of T. testudinum occurred during the
summers and falls of 1987 and 1988 (J. Fourqurean and G. Powell, unpublished data), which supplied large
amounts of decomposing leaves to the basins that were subsequently affected by die off. The decomposition of
these leaves may have led to hypoxic stress in the seagrass beds in deeper water, causing more seagrass
mortality.
Even though the ultimate cause of the present seagrass die off has yet to be proven conclusively, it seems clear
that anthropogenic nutrient input to the surface water is not responsible. Ground water sources of nutrients have
also been shown to affect seagrass beds (Lapointe et al. 1990; Valiela et al. 1990). While a definitive study of
the potential for this type of input to Florida Bay has not been completed, there is no evidence for increased
nutrient loadings of any kind to Florida Bay being responsible for the die off.
4-12
-------
3.4 EMERGENT VEGETATION
The main anthropogenic threats to mangrove swamps are diking, flooding, impounding, and outright destruction.
by dredging and filling. In south Florida, the most significant impacts to mangrove communities, other than
outright destruction, have resulted from alteration of the freshwater runoff and drainage patterns. Reductions
and shifts in freshwater drainage patterns have had extensive effects in the estuarine mangrove community
(Odum 1970). While many estuarine mangrove communities have shrunk as a result of increased freshwater
input, the mangrove communities of Florida Bay and Everglades National Park have expanded due to the
reduced freshwater discharge (Odum and Mclvor 1990).
Mangroves are extremely susceptible to herbicides (Odum et al. 1974). At least 100,000 ha of mangroves were
defoliated and killed by herbicides applied by the U.S. Army in Southeast Asia during the Vietnam War (Walsh
et al. 1973). Not all mangrove species are affected equally by herbicides. In Florida, the red mangrove
(Rhizophora mangle) is much more susceptible to herbicide damage than the black mangrove (Avicennia
germinans) (Teas and Kelly 1975).
Petroleum and petroleum products have a number of deleterious effects on mangroves (see Lewis 1980; de la
Cruz 1982; Zieman et al. 1984 for reviews). Damage to mangroves by oil results in the clogging of lenticels
and pneumatophores on mangrove roots. As a result, disruption of oxygen transport within the plants and
impacts from the toxic effects of the petroleum products occur. Odum and Johannes (1975) have suggested that
the critical concentration of crude oil which may cause extensive damage in mangrove communities is between
100 and 200 ml/m2. As with other intertidal communities, many of the fish, invertebrates, and macroalgal
species associated with the mangrove community are severely impacted by spilled oil products.
In the FKNMS, all documented mangrove community loss has resulted from mechanical destruction (i.e.,
dredging and filling, cutting, channeling, and general clearing). There are some areas where surface runoff
from cleared areas may have adversely impacted adjacent mangrove communities by clogging aerial root
pneumatophores, but these areas have not been well studied. Continued land development represents the
greatest current threat to the mangrove community of the FKNMS.
Mangrove systems provide shoreline stabilization and act as natural filters for terrestrial runoff entering the
marine environment. The loss of these communities in highly developed areas of the FKNMS has contributed
to problems associated with surface water runoff in these areas. It is important to remember that the nearshore
mangroves, the seagrass beds, and the coral reefs are all part of one large ecosystem in the FKNMS. Loss of
mangrove habitat to development contributes to loss of seagrass via increased nutrient loading and terrestrial
runoff, which in turn contributes to loss of reef fish species and species diversity on the offshore coral reefs.
4.0 COMMUNITY TRENDS AND WATER-QUALITY-RELATED IMPACTS
SEEN IN THE FLORIDA KEYS NATIONAL MARINE SANCTUARY
Historically there have been localized losses within both the submerged and emergent aquatic vegetation
communities of the FKNMS. The most significant habitat losses in terms of acreage have been in emergent
vegetation, but there have been localized losses in the seagrass community as well. Up through the 1990s these
habitat losses resulted almost exclusively from the physical destruction of these communities by activities
associated with development (e.g., land clearing, dredging and filling, highway construction, channel dredging,
etc.). With increasing regulation of wetland habitat development, the pace of emergent vegetative community
loss has slowed over the past few years. Many other activities associated with land development are now also
coming under increasing regulation, and this is also expected to further slow wetland habitat loss in the Florida
Keys.
4-13
-------
The area encompassed by the FKNMS has never suffered, at least during recorded history, a loss of submerged
vegetative habitat similar to that of the eel grass (Zostera marina) wasting disease of the 1930s. Similarly, a
seagrass die-off event on the scale of the continuing die off of the turtle grass (Thalassia testudinum) beds seen
in Florida Bay (Robblee et al. 1991) has not been realized. Originally there was considerable concern that this
Florida Bay die off might spread to seagrasses throughout Florida, but it now appears that the die off in Florida
Bay results from specific localized conditions. While there is the possibility that, if it continues unabated, it
may eventually impact some seagrass communities within the Sanctuary, this phenomenon is not considered the
threat that it once was. Currently, the only seagrass beds within the FKNMS to be affected by this die off are
the bank-fringing Thalassia beds near Steamboat Channel on the Florida Bay side of upper Matecumbe Key
(Figure 4-2).
The loss of historic seagrass habitat within the Sanctuary has resulted almost entirely from mechanical
destruction. Over the entire estimated number of hectares lost since the turn of the century, approximately 2000
ha represents only 0.35% of the total seagrass acreage within the Sanctuary (565,094 ha).
5.0 STATEMENTS OF PROBLEMS
A key part of Phase I of the Water Quality Protection Program is the identification of water quality problem
areas to be addressed during Phase II. A two-step approach was used to identify and obtain agreement among
members of the scientific community on known, suspected, or potential water-quality problems affecting the
natural resources of the Sanctuary. Initially, information gathered during the literature review was used to
derive a series of statements describing potential water-quality related problems (presented in Section 5.1).
These problem statements were then refined through discussions with EPA Region IV Coastal Programs staff
and State of Florida environmental staff and delivered to workshop participants to provide focal points for
discussions at technical workshops. The participants in each workshop were charged with coming to a
consensus, where possible, on the problem statements developed for each workshop resource area. A matrix
analysis of each workshop resource area (Appendix B) was the tool used to develop consensus on the problem
statements. Specific descriptive terms were used to complete the matrix based on the discussions with the
expert panels assembled for each workshop (Appendix B). Public comments were also heard during the course
of each workshop. To assist EPA Region IV and the State of Florida to direct their limited resources, each
expert panel was asked to rank the overall significance of the water-quality related problems at the end of each
daily workshop. The consensuses developed at the workshops are summarized in Section 5.2 and presented in
more detail in Appendix B.
5.1 PROBLEMS IDENTIFIED DURING THE LITERATURE REVIEW
The following lists either known, suspected, or potential problems, exclusive of mechanical destruction (not
addressed in this document), related to submerged and emergent vegetative communities in the FKNMS.
However, to state a problem does not of itself mean or imply that the stated problem actually exists. There is a
divergence of views on what actually constitutes real or potential problems for the FKNMS.
In many instances, the data are insufficient to assess the true importance or validity of a given problem, so
called. For this reason, there is a "data sufficiency" question posed under each statement of a problem. No
references are given for statements made in this Subsection — the statements made here represent an evaluation
of the data and referenced studies in the preceding text.
4-14
-------
'••' .'.'.'..•.,.-..:' Flamingo:
•'- -ji^^iiJiii^: :• i :>>*^^^r^
300 600 Nautical Miles
0 300 600 900 Kilometers
= Thalassia lestudinum die o(l
Figure 4-2. Distribution of Thalassia testudinum die off in Florida. [From Robblee et al. 1991]
-------
Degraded water quality may be adversely affecting emergent vegetation in the FKNMS. — Because mangroves
in general have been shown to be relatively resistant to problems caused by degraded water quality, and there
are no reported areas where such habitat losses have occurred in the FKNMS, the data are considered sufficient
to indicate that this water-quality related problem is not significant at this time.
Toxic substances may be adversely affecting submerged and emergent vegetative communities. — There are no
reported cases of significant community impact from toxic substances — anionic detergents and heavy metals
from domestic and industrial waste, herbicides from lawn and agricultural run off, and hydrocarbon
contamination from spills of petroleum products — on either the submerged or the emergent vegetative
community in the FKNMS. Critical areas where impacts from these sources might be seen are Card and Barnes
Sounds (mainland agricultural runoff and canal discharge), in and adjacent to marinas with a large live-aboard
.population and/or bottom-scraping and painting operations, and adjacent to large point-source discharges. There
are no specific data to evaluate the effects of anionic detergents, which have been suggested as causative agents
for seagrass declines in some parts of the world, or heavy metals, which may be concentrated in the tissues of
some seagrasses on vegetation communities within the FKNMS. Although emergent mangrove vegetative
communities are extremely susceptible to certain types of herbicides, there has never been a major loss of
mangrove habitat in the FKNMS because of a herbicide accident. Petroleum and petroleum products have been
shown to have deleterious effects on mangroves and on the animal components of seagrass-bed communities
which are highly susceptible to poisoning by oil and oil-related compounds. Significant oil spills have come
ashore in the FKNMS in the past. This problem is related to water quality and is potentially very significant,
particularly in nearshore areas.
Reduced light levels resulting from anthropogenic increases in sediment load and turbidity may be adversely
affecting submerged vegetative communities. — Increased and more rapid terrestrial runoff resulting from land
clearing and paving, direct turbidity resulting from coastal construction, and resuspension of sediments by boat
traffic and normal wind/wave activity are the primary factors causing increased sediment loads and turbidity in
Sanctuary waters. The impact resulting from these phenomena may be occurring throughout the FKNMS, but is
potentially more significant in nearshore areas. Data are insufficient to evaluate long-term trends in turbidity
levels throughout the FKNMS or the relationship between turbidity and seagrass health in the Sanctuary. This
problem is related to water quality and is potentially significant.
Anthropogenic nutrients entering the FKNMS may be adversely affecting submerged vegetative communities.
— Nutrient enrichment, resulting from lawn fertilizer runoff, live-aboard boaters sewage discharges, septic-tank
leachate, municipal sewage-plant and package-plant discharges, and shallow- and deep-well injection of
domestic sewage may be a problem throughout the FKNMS. However, the impacts of nutrient enrichment,
which causes phytoplankton blooms and increased epiphyte growth would be expected to be most severe in
nearshore and confined waters in the Sanctuary. Sufficient water-quality data from the FKNMS are not
available for long-term trend analysis of nutrient levels or to effectively evaluate the impact of nutrient
enrichment on the submerged vegetative community. Several studies have indicated that nutrient levels remain
low along the outer reef line, whereas others have shown that nutrient levels may be rising in confined waters
adjacent to developed areas. This problem is related to water quality and is potentially significant.
Disease may be a threat to the FKNMS submerged vegetative community. — Potentially, any seagrass bed in
the FKNMS may be at risk from disease-causing agents such as slime molds (similar to those linked with the
great European Zostera die off of the 1930s) and unknown viral, bacterial, or algal agents. The recent die off
of Thalassia beds in Florida Bay is not thought to be disease-induced and there is no evidence of disease in the
seagrass beds of the FKNMS. Nevertheless, a disease-related die off of submerged vegetation such as the
Zostera event is always a possibility. The risk of a disease-related die off affecting the submerged vegetative
community of the FKNMS is unknown, but considered slight because of the lack of reported disease in
Thalassia beds worldwide. This problem is not water-quality related and is not considered significant.
4-16
-------
Long-term climate changes may be adversely affecting the submerged and emergent vegetative communities in
the FKNMS. — All submerged and emergent vegetative communities within the FKNMS are vulnerable to such
large-scale environmental disruptions resulting from global warming (increased air and water temperatures, sea-
level rise) and ozone depletion (increased shorter wavelength irradiance reaching the Earth's surface). Large-
scale evaluations of potential community changes from global climate change are being conducted by a number
of United States and international research agencies. Studies are in progress, although not mentioned in this
report, that are assessing possible community shifts in tropical marine seagrass beds due to global climate
change. None of these studies has specifically targeted the FKNMS, but their results should be indicative of the
potential problems faced here. Possible indirect effects on water quality may result from changes in
precipitation. While this problem is real, its specific impact on the submerged and emergent vegetative
communities of the FKNMS has not been assessed. From a FKNMS management point of view, this problem
is too large-scale and long-term to be of immediate significance in the FKNMS planning process. The
possibility of synergistic effects between global climate change and local near-term stresses in the environment
should be considered in any long-term monitoring plan developed for the Sanctuary.
5.2 PROBLEMS IDENTIFIED AT THE SUBMERGED AND EMERGENT
AQUATIC VEGETATION ASSESSMENT WORKSHOP
The problems discussed at this workshop were divided into four areas — Seagrasses, Macroalgae,
Mangroves/Buttonwoods, and Freshwater Influence. Problems regarding seagrass communities were increased.
epiphyte growth, seagrass historic growth rates (individual), declines in community diversity (other than
seagrasses), decreased geographical extent, decreased recruitment of seagrasses, and hypoxia. Problems
regarding macroalgae communities were increased epiphyte growth, macroalgae historic growth rates
(individual), decreased community diversity (other than seagrasses), hypoxia, and diversity of algae. Problems
regarding mangrove/buttonwood communities were decreased tree productivity (individual), decreased
geographical extent, and functional value of habitat. Problems regarding freshwater influence were decreased
productivity, decreased geographical extent, and functional value of the habitat. The parameters for analysis
and the matrices used for discussion during the workshop are presented in Appendix B.
Currently, extremely saline waters from Florida Bay are believed to be causing reef damage (coral die-off).
This extremely saline water is the result of the reduction of the historic and sporadic freshwater flow by canals
such as the C-lll canal. This is the only anthropogenic effect on Florida Bay. The natural system in Florida
Bay (SO years ago) would be better for more species of fish and vegetation than the present-day environment.
The panel members commented that this freshwater flow to Florida Bay needs to be restored and that EPA
should determine the extent of the previous coral community. In addition, it was suggested that a historical
description of the area describing the communities that existed prior to the reduction of freshwater flow to
Florida Bay is needed to determine how much the area has changed. The Florida Bay water quality issue must
be included in the management of the FKNMS.
Seagrasses
Priority problems identified for the seagrass communities are epiphyte growth and anthropogenic nutrient
loading; control measures are needed.
The problem of increased epiphyte growth on seagrasses is known to occur primarily in hot spots throughout
the Keys and the trend is worsening. — This problem is definitely water-quality related in the hot spots and
possibly water-quality related elsewhere in the Keys; more data are needed. Turbidity, and anthropogenic
nutrients and dissolved oxygen (DO) significantly affect increased epiphyte growth in seagrass communities.
The overall significance of this problem from a water-quality perspective is high.
4-17
-------
Seagrass historic growth rates (individual) have decreased recently and the reductions are known to occur In
hot spots associated with human activity throughout the Keys. — This problem is unknown yet suspected to
occur elsewhere in the Keys. This problem is water-quality related in the hot spots and possibly water-quality
related elsewhere; more data are needed. Temperature, salinity, anthropogenic nutrients and DO, and turbidity
significantly affect growth rates of seagrasses. The overall significance of this problem from a water-quality
perspective is high in the hot spots and slight elsewhere in the Keys.
Areas of declines in community diversity are isolated to hot spots and the trend is worsening; declines are
unknown elsewhere. — This problem is water-quality related in the hot spots and probably water-quality related
elsewhere in the Keys; more data are needed. Temperature, salinity, and anthropogenic DO significantly affect
community diversity. The overall significance of this problem from a water-quality perspective is high in the
hot spots and possible but unknown elsewhere in the Keys. Overfishing effects have an impact on community
diversity. [Note: The problem was considered regarding anthropogenic changes.]
Decreased geographical extent (i.e., anthropogenic losses) is known to be isolated to hot spots and this trend
is worsening. — Outside the hot spot areas, changes are taking place naturally; human effects here are slight.
Temperature, anthropogenic nutrients and DO, salinity, and turbidity significantly affect this problem. The
overall significance of this problem from a water-quality perspective is high in the hot spots and slight elsewhere
in the Keys.
Decreased recruitment of seagrasses is isolated to hot spots and is worsening. — There is a general lack of
data and information regarding this problem and because of the lack of data, no accurate assessment can be
made. The problem is possibly water-quality related. Parameters thought to have a significant affect on the
problem are temperature, salinity, turbidity, and anthropogenic DO. The overall significance of this problem
from a water-quality perspective is unknown.
The problem of hypoxia depends on circulation patterns, flushing of an area, and climate effects and
influence (drought, wet). — Hypoxia is definitely water-quality related and usually occurs in hot spots where it
has the potential to be severe. Temperature and anthropogenic nutrients and DO significantly affect the
problem. The overall significance of. the problem from a water-quality perspective cannot be determined
because it depends on circulation.
Macroalgae
Priority problems identified for the macroalgae communities are epiphyte growth and anthropogenic nutrient
loading; control measures are needed.
The problem of increased epiphyte growth on macroalgae is known to occur primarily in hot spots throughout
the Keys and the trend is worsening. — This problem is definitely water-quality related in the hot spots and
possibly water-quality related elsewhere in the Keys; more data are needed. Turbidity and anthropogenic
nutrients and DO significantly affect increased epiphyte growth in macroalgae communities. The overall
significance of this problem from a water-quality perspective is high.
Macroalgae historic growth rates (individual) have increased over the last decade, are known to occur in hot
spots throughout the Keys, and are widespread elsewhere. — This problem is water-quality related in the hot
spots and possibly water-quality related elsewhere in the Keys. Temperature, turbidity, salinity, and
anthropogenic nutrients and DO significantly affect growth rates of macroalgae. The overall significance of this
problem from a water-quality perspective is high in the hot spots and slight elsewhere in the Keys. More data
are'needed regarding this problem.
4-18
-------
Areas of decreased community diversity are isolated to anthropogenic hot spots and the trend is worsening. —
Declines were unknown elsewhere; more data are needed. This problem is water-quality related in the hot spots
and probably water-quality related elsewhere in the Keys. Temperature, salinity, and anthropogenic DO
significantly affect community diversity. The overall significance of this problem from a water-quality
perspective is high in the hot spots and possible but unknown elsewhere in the Keys. Overfishing effects have a
negative impact on community diversity. [Note: This problem was considered regarding anthropogenic changes.]
The problem of hypoxia depends on circulation patterns, flushing of an area, climate effects and influence
(drought, wet). — Hypoxia is definitely water-quality related and usually occurs in hot spots where it has the
potential to be severe. Temperature and anthropogenic nutrients and DO significantly affect the problem. The
overall significance of hypoxia from a water-quality perspective cannot be determined because it depends on
circulation.
Diversity of the algae has decreased within the last decade. — This problem is isolated to hot spots, is
worsening in the hot spots, and is widespread elsewhere in the Keys. Decreasing algal diversity is water-quality
related; temperature, anthropogenic nutrients and DO, salinity, and turbidity significantly affect the problem.
The overall significance of the problem from a water-quality perspective is high. Overfishing and grazing have
an impact on this problem.
Mangroves/Buttonwoods
Priority concerns identified for the mangrove/buttonwood communities are preserving geographical extent and
the functional value of the habitat.
. The extent, trend, and severity of decreased tree productivity (individual) are unknown. — This problem is
water-quality related. Temperature, salinity, turbidity and anthropogenic nutrients and DO significantly affect
tree productivity. The overall significance of this problem from a water-quality perspective is unknown. A
consequence of decreased tree productivity is increased flood sensitivity. Dredge and fill operations can cause
changes in the community. Impoundment effects should be considered.
Decreased geographical extent is widespread and the continuing decline is characterized by large losses of
mangroves and buttonwoods. — The severity of the problem, decreased geographical extent, is high. This
problem is probably related to water quality. Parameters that have a significant effect on the problem are
salinity, turbidity, and anthropogenic nutrients and DO. The overall significance of decreased geographical
extent from a water-quality perspective is slight; however, this problem is a highly significant one.
The functional value of the habitat is affected by seasonal and episodic flooding and the trend of this problem
is unknown but thought to be declining. — This problem is probably related to water quality. Toxics/
pesticides and anthropogenic nutrients and DO significantly affect the functional value of the habitat. The
overall significance of the problem from a water-quality perspective is high. .Fragmentation is a critical
component of the problem. >
Freshwater Influence
For freshwater influence, the priority concern is preserving the geographical extent so that there is no further
loss of mangrove/buttonwoods and coastal wetlands.
The spatial consideration, trend, severity, and certainty of the problem, decreased productivity, are unknown;
however, the problem is probably related to water quality. — Temperature highs and lows, anthropogenic
nutrients, and salinity significantly affect productivity; toxics/pesticides possibly affect productivity. The overall
4-19
-------
significance of the problem from a water-quality perspective is moderate to high. A climatic effect associated
with decreased productivity is the lowering of the water table.
The problem of decreased geographical extent is continuing; losses have been high and the severity of the
problem is high. — This problem is definitely water-quality related and impacted by nutrient additions and
septic system runoff. The overall significance of how water quality affects this problem is high. Dredge and
fill operations cause a direct loss of habitat due to development activities. Septic tanks and cesspools also
contribute to the problem.
The functional value of the habitat continues to worsen and the problem is widespread in the Keys. — This
problem is water-quality related (in part) and anthropogenic nutrients, salinity, turbidity, and toxics/pesticides
significantly affect the problem. The overall significance of the problem from a water-quality perspective is
high. Fragmentation is a critical component of the problem.
(.0 REFERENCES
BLM and FDNR. 1979. Florida Reef Tract marine habitats and ecosystems. Department of Interior Bureau of
Land Management, Washington, DC, and Florida Department of Natural Resources, Tallahassee, FL.
Borum, J. 1985. "Development of epiphytic communities on eelgrass (Zostera marina) along a nutrient
gradient in a Danish estuary." Mar. Biol. 87:211-218.
Bridges, K.W., and C. McMillan. 1986. "The distribution of seagrasses of Yap, Micronesia, with relation to
low tide conditions." Aquat. Bot. 24:403-407.
Bulthuis, D.A., and W.J. Woelkerling. 1983. "Biomass accumulation and shading effects of epiphytes on
leaves of the seagrass, Heterozosiera tasmanica, in Victoria, Australia." Aquat. Bot. 16:137-148.
Cambridge, M.L., and A.J. McComb. 1984. "The loss of seagrasses in Cockburn Sound, Western Australia.
I. The time course and magnitude of seagrass decline in relation to industrial development." Aquat.
Bot. 20:229-243.
Cambridge, M.L., A.W. Chiffings, C. Brit tan, L. Moore, and A.J. McComb. 1986. "The loss of seagrasses
in Cockbum Sound, Western Australia. II. Possible causes of seagrass decline." Aquat. Bot. 24:269-
285.
CSA and GMI. 1991. The southwest Florida nearshore benthic habitat study. MMS Rep. 89-0080. Final
report prepared by Continental Shelf Associates, Inc., and Geonix Martel, Inc., to the Department of
the Interior Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. 55 pp.
Correl, D.L., and T.L. Wu. 1982. "Atrazine toxicity to submersed vascular plants in simulated estuarine
microcosms." Aquat. Bot. 14:151-158.
de la Cruz, A. A. 1982. The impact of crude oil and oil-related activities on coastal wetlands — A review.
Proc. Int. Wetlands Conf., Delhi, India.
Den Hartog, C., and P.J.G. Polderman. 1975. "Changes of the seagrass populations of the Dutch Wadden
Sea." Aquat. Bot. 1:141-147.
Dennison, W.C. 1987. "Effects of light on seagrass photosynthesis, growth and depth distribution." Aquat.
Bot. 27:15-26.
4-20
-------
Driftneyer, J.E., G.W. Thayer, F.A. Cross, and J.C. Zieman. 1980. "Cycling of Mn, Fe, Cu and Zn by
eelgrass Zostera marina L." Am. J. Bot. 67(7): 1089-1096.
Duarte, C.M. 1991. "Seagrass depth limits." Aquat. Bot. 40:363-377.
Dunton, K.H. 1990. "Production ecology of Ruppia maritima L. s.l. and Halodule wrightii Aschers. in two
subtropical estuaries." J. Exp. Mar. Biol. Ecol. 9:123-130.
EPA. 1975. Finger-fill Canal Studies, Florida and North Carolina. EPA Contract No..904/9-76-017. 180 pp.
Fourqurean, J.W., J.C. Zieman, and G.V.N. Powell. To be published. "Phosphorus limitation of primary
production in Florida Bay: Evidence from the C:N:P ratios of the dominant seagrass Thalassia
testudinum." Submitted to Limnology and Oceanography.
FWS and MMS. 1983. Florida Ecological Atlas Biological Series. Department of the Interior Fish and
Wildlife Service and Minerals Management Service, Washington, DC.
Gallegos, C.L., D.L. Correll, and J. Pierce. 1991. "Modelling spectral light available to submerged aquatic
vegetation." Pp. 114-126 in Kenworthy, W.J., and D.E. Haunert (Eds.), The light requirements of
seagrasses: Proceedings of a workshop to examine the capabilities of water quality criteria standards
and monitoring programs to protect seagrasses. NOAA Tech. Mem. NMFS-SEFC-287.
Giesen, W.B.J.T., M.M. van Katwijk, and C. den Hartog. 1990. "Eelgrass condition and turbidity in the
Dutch Wadden Sea." Aquat. Bot. 37:71-85.
Ginsburg, R., R. Rezak, and J.L. Wray. 1971. Geology of calcareous algae. Comparative Sedimentology
Laboratory, Division of Marine Geology and Geophysics, University of Miami Rosenstiel School of
Marine and Atmospheric Science, Miami, FL.
Glynn, P.W. 1968. "Mass mortalities of echinoids and other reef flat organisms coincedent with midday, low
water exposure in Puerto Rico." Mar. Biol. l(3):226-243.
Harlin, M.M., and B. Thome-Miller. 1981. "Nutrient enrichment of seagrass beds in a Rhode Island coastal
lagoon." Mar. Biol. 65:221-229.
Iverson, R.L., and H.F. Bittaker. 1986. "Seagrass distribution and abundance in eastern Gulf of Mexico
coastal waters." Estuarine Coast. Shelf Sci. 22:577-602.
Kemp, W.M., W.R. Boynton, R.R. Twilley, J.C. Stevenson, and J.C. Means. 1985. "The decline of
submerged vascular plants in upper Chesapeake Bay: a summary of results concerning possible
causes." Mar. Tech. Soc. J. 17:78-89.
Lapointe, B.E., and J.D. O'Connell. 1988. The effects of on-site sewage disposal systems on nutrient relations
of groundwater and nearshore waters of the Florida Keys. Unpublished report to the National Oceanic
and Atmospheric Administration, Office of Coastal Zone Management; Florida Department of
Environmental Regulation; and Monroe County, FL.
Lapointe, B.E., J.D. O'Connell, and G.S. Garrett. 1990. "Effects of on-site sewage disposal systems on
nutrient relations of groundwater and nearshore surface waters of the Florida Keys." Biogeochem.
10:289-307.
4-21
-------
Lapointe, B.P., and M.W. Clark. 1990. Interim Report 2: Ambient water quality assessment in nearshore
waters of Monroe County during winter 1990. Florida Keys Land and Sea Trust, Marathon, FL.
18 pp.
Larkum, A.W.D., and R.J. West. 1990. "Long-term changes of seagrass meadows in Botany Bay, Australia."
Aquat. Bot. 37:55-70.
Lewis, R.R., III. 1980. "Impact of oil spills on mangrove forests." P. 36 in 2nd Int. Symp. Biol. Manage.
Mangroves Trop. Shallow Water Communities, Port Moresby, Madang, Papua, New Guinea.
Lewis, R.R., III, M.J. Durako, M.D. Moffler, and R.C. Phillips. 1985. "Seagrass meadows of Tampa Bay —
A review." In Treat, S.E., J.L. Simon, R.R. Lewis, and L.L. Whitman (Eds.), Proceedings, Tampa
Bay Area Scientific Information Symposium. Fla. SeaGrant Publ. 65:210-246.
Livingston, R.J. 1987. Historic trends of human impacts on seagrass meadows in Florida. In Durako, M.J.,
R.C. Phillips, and R.R. Lewis, III (Eds.), Proceedings of the symposium on subtropical-tropical
seagrasses of the southeastern United States. Fla. Mar. Res. Publ. No. 42. 209 pp.
McMillan, C., and F.N. Moseley. 1967. "Salinity tolerances of five marine Spermatophytes of Redfish Bay,
TX." Ecology 48:503-506.
McNulty, J.K. 1961. Effects of abatement of domestic sewage pollution on the benthos volumes of
zooplankton and the fouling organisms of Biscayne Bay, Florida. Studies in Tropical Oceanography
#9. Institute of Marine and Atmospheric Sciences, University of Miami, Coral Gables, FL. 107 pp.
Merriam, D.F. 1989. "Overview of the geology of Florida Bay, review of recent developments." Bull. Mar.
Sci. 44(1):519(A).
Montague, C.L., R.D. Bartleson, J.F. Gottgens, J.A. Ley, and R.M. Ruble. 1989. "The distribution and
dynamics of submerged vegetation along gradients of salinity in northeast Florida Bay." Bull. Mar.
Sci. 44(1):521(A).
Muehlstein, L.K. 1989. "Perspectives on the wasting disease of eelgrass Zostera marina.'" Dis. Aquat. Org.
7:211-221.
Odum, H.T., M. Sell, M. Brown, J. Zucchetto, C. Swallows, J. Browder, T. Ahlstom, and L. Peterson.
1974. The effects of herbicides in South Vietnam: models of herbicide, mangroves, and war in
Vietnam. U.S. National Academy of Sciences, National Research Council. Washington, D.C.
Odum, W.E. 1970. Pathways of energy flow in a south Florida estuary. Ph.D. Dissertation. Univ. of
Miami, Fla. 162pp.
Odum, W.E., and R.E. Johannes. 1975. "The response of mangroves to man-induced environmental stress."
Pp. 52-62 in Wood, E.J.F., and R.E. Johannes (Eds.), Tropical Marine Pollution. Oceanog. Ser. 12.
Elsevier Press, New York, NY, and Amsterdam, The Netherlands.
Odum, W.E., and C.C. Mclvor. 1990. "Mangroves." Pp. 517-548 in Myers, R.L., and J. J. Ewel (Eds.),
Ecosystems of Florida. University of Central Florida Press, Orlando, FL.
Odum, W.E., C.C. Mclvor, and T.J. Smith, III. 1982. The ecology of the mangroves of South Florida: A
community profile. Fish and Wildlife Service, Slidell, LA.. FWS/OBS-81/24. 144pp.
4-22
-------
Orth, R.J. 1977. "Effect of nutrient enrichment on the growth of the eelgrass Zostera marina in the
Chesapeake Bay, VA." Mar. Biol. 44:184-197.
Orth, R.J., and KJ. Moore. 1983. "Chesapeake Bay: An unprecedented decline in submerged aquatic
vegetation." Science 222:51-53.
Peres, J.M., and J. Pickard. 1975. "Causes of the decrease and disappearance Posidonia oceanica on the
French Mediterranean coast." Aquat. Bot. 1:133-139.
Phillips, R.C. 1984. The ecology of eelgrass meadows in the Pacific Northwest: A community profile. Fish
and Wildlife Service, Slidell, LA. FWS/OBS-84/24. 85 pp.
Powell, G.V.N., J.W. Fourqurean, W.J. Kenworthy, and J.C. Zieman. 1991. Bird colonies cause seagrass
enrichment in a subtropical estuary: Observational and experimental evidence. Estuarine Coast. Shelf
Sci. 32:567-579.
Powell, G.V.N., W.J. Kenworthy, and J.W. Fourqurean. 1989. "Experimental evidence for nutrient limitation
of seagrass growth in a tropical estuary with restricted circulation." Bull. Mar. Sci. 44:324-340.
Rasmussen, E. 1973. "Systematics and ecology of the Isefjord marine fauna (Denmark)." Ophelia 11:1-430.
Robblee, M.B., T.R. Barber, P.R. Carlson, MJ. Durako, J.W. Fourqurean, L.K. Muehlstein, D. Porter,
L.A. Yarbro, R.T. Zieman, and J.C. Zieman. 1991. "Mass mortality of the tropical seagrass
Thalassia testudinum in Florida Bay (USA)." Mar. Ecol. Prog. Ser. 71:297-299.
Roessler, M.A., and J.C. Zieman. 1969. "The effects of thermal additions on the biota in southern Biscayne
Bay, Florida." Gulf Caribb. Fish. Inst. Proc. 22nd:136-145.
Sand-Jensen, K. 1977. "Effect of epiphytes on eelgrass photosynthesis." Aquat. Bot. 3:55-63.
Shepherd, S.A., A. McComb, D. Bulthuis, V. Neverauskus, D.A. Steffensen, and R. West. 1989. "Decline
of seagrasses." Pp. 346-393 in Larkum, A.W.D., A.J. McComb, and S.A. Shepherd (Eds.), Seagrass
Biology — An Australian Perspective. Elsevier Press, Amsterdam, The Netherlands.
Short, F.T., L.K. Muehlstein, and D. Porter. 1987. "Eelgrass wasting disease: cause and recurrence of a
marine epidemic." Biol. Bull. Mar. Biol. Lab. Woods Hole 173:557-562.
Silberstein, K., A.W. Chiffings, and A.J. McComb. 1986. "The loss of seagrasses in Cockburn Sound,
Western Australia. III. The effect of epiphyte on productivity of Posidonia australis Hook. F."
Aquat. Bot. 24:355-371.
Smith, T.J., III, J.H. Hudson, M.B. Robblee, G.V.N. Powell, and P.J. Isdale. 1989. "Freshwater flow from
the Everglades to Florida Bay: Reconstruction based on fluorescent banding in the coral Solenastrea
bournoni." Bull. Mar. Sci. 44(l):274-282.
Tabb, D.C., D.L. Dubrow, and R.B. Manning. 1962. "The ecology of northern Florida Bay and adjacent
estuaries." Tech. Ser. Fla. Bd. Conserv. 39:1-79.
Tabb, D.C., and A.C. Jones. 1962. "Effect of hurricane Donna on the aquatic fauna of North Florida Bay."
Trans. Amer. Fish. Soc. 91:375-378.
4-23
-------
Teas, H., and J. Kelly. 1975. "Effects of herbicides on mangroves of S. Vietnam and Florida." Pp. 719-728
in Walsh, G., S. Snedaker, and H. Teas (Eds.), Proc. Int. Symp. Biol. Manage. Mangroves,
University of Florida, Gainesville, FL.
Thayer, G.W., W.J. Kenworthy, and M.S. Fonseca. 1984. The ecology of eelgrass meadows of the Atlantic
coast: A community profile. Fish and Wildlife Service, Washington, DC. FWS/OBS-84/02. 147 pp.
Thayer, G.W., D.A. Wolfe, and R.B. Williams. 1975. "The impact of man on seagrass systems." Am.
Scientist 63:288-296.
Thomas, L.P., D.R. Moore, and R.C. Work. 1961. "Effects of Hurricane Donna on the turtle grass beds of
Biscayne Bay, FL." Bull. Mar. Sci. Gulf Caribb. 11(2): 191-197.
Tomasko, D.A., and B.E. Lapointe. 1991. "Productivity and biomass of Thalassia testudinum as related to
water column nutrient availability and epiphyte levels: Field observations and experimental studies."
Mar. Ecol. Prog. Ser. 75:9-17.
Valiela, I., J. Costa, K. Foreman, J.M. Teal, B. Howes, and D. Aubrey. 1990. "Transport of groundwater-
bourne nutrients from watersheds and their effects on coastal waters." Biogeochemistry 10:177-197.
Vicente, V.P., and J.A. Rivera. 1982. "Depth limits of the seagrass Thalassia testudinum (Konig) in Jobos
and Guayanilla Bays, Puerto Rico." Caribb. J. Sci. 17(l-4):73-77.
Wallace, Roberts, & Todd, Barton Aschman and Associates, Inc., Haben, Culpepper, Dunbar and French,
P.A., Henigar and Ray, Keith and Schnars, P.A., and Price Waterhouse. 1991. Monroe County Year
2010 Comprehensive Plan Working Paper 2: Inventory and analysis of proposed levels of service
measures of carrying capacity. Monroe County Board of County Commissioners. 192 pp.
Walsh, G.E., R. Barrett, G.H. Cook, and T.A. Hollister. 1973. "Effects of herbicides on seedlings of the red
mangrove, Rhizophora mangle L." BioScience 232:361-364.
Wood, E.J.F., and J.C. Zieman. 1969. "The effects of temperature on estuarine plant communities."
Chesapeake Sci. 10(3&4): 172-174.
Zieman, J.C. 1975a. "Seasonal variation in turtle grass, Thalassia testudinum Konig., with reference to
temperature and salinity effects." Aquat. Bot. 1:107-123.
Zieman, J.C. 1975b. "Tropical sea grass ecosystems and pollution." Pp. 63-74 in Wood, E.J.F., and R.E.
Johannes (Eds.), Tropical Marine Pollution. Oceanogr. Ser. 12. Elsevier Press, New York, NY, and
Amsterdam, The Netherlands.
Zieman, J.C. 1982. The ecology of seagrasses of south Florida: A community profile. Fish and Wildlife
Service, Slidell, LA. USFWS/OBS-82/25. 158 pp.
Zieman, J.C. 1991. "Seagrass habitats." Pp. 36-57 in Balcom, B.J. (Ed.), A comparison of marine
productivity among outer continental shelf planning areas. Supplement — An evaluation of benthic
habitat primary productivity. Department of the Interior Minerals Management Service, Herndon, VA.
MMS Rep. 91-0001.
Zieman, J.C., and E.J.F. Wood. 1975. "Effects of thermal pollution on tropical-type estuaries, with emphasis
on Biscayne Bay, Florida." Pp. 75-98 in Wood, E.J.F., and R.E. Johannes (Eds.), Tropical Marine
Pollution. Oceanogr. Ser. 12. Elsevier Press, New York, NY, and Amsterdam, The Netherlands.
4-24
-------
Zieman, J.C., R. Orth, R.C. Phillips, G. Thayer, and A. Thorhaug. 1984. The effects of oil on seagrass
ecosystems. Pp. 37-64 in Cairns, J. and Buikema, A. (Eds.) Recovery and Restoration of Marine
Ecosystems. Butterworth Publications, Stoneham, MA.
Zieman, J.C., and J.W. Fourqurean. 1985. The distribution and abundance of benthic vegetation in florida
Bay, Everglades National Park. Report to the Everglades National Park, South Florida Research
Center. Contract No. CX5280-2-2204. 63 pp.
Zieman, J.C., and R.T. Zieman. 1989. The ecology of eelgrass meadows of the west coast of Florida: A
community profile. Fish Wildl. Serv. Biol. Rep. 85(7.25). 155 pp.
Zieman, J.C., J.W. Fourqurean, and R.L. Iverson. 1989a. "Distribution, abundance, and productivity of
seagrasses and macroalgae in Florida Bay." Bull. Mar. Sci. 44(1)292-311.
Zieman, J.C., J.W. Fourqurean, and R.T. Zieman. 1989b. The Florida Bay seagrass dieoff: Process changes,
potential causes, and a conceptual model. Tenth International Estuarine Research Conference, 8-12
October 1989, Baltimore, MD. (Abstract only), p. 92.
4-25
-------
NEARSHORE AND CONFINED WATERS ASSESSMENT
TaskS
CONTENTS
1.0 INTRODUCTION 5-1
2.0 STUDIES EXAMINING THE NEARSHORE AND CONFINED WATER
ENVIRONMENT IN THE FLORIDA KEYS NATIONAL MARINE SANCTUARY ... 5-1
2.1 WATER QUALITY 5-1
2.1.1 Environmental Protection Agency — 1975 5-1
2.1.2 Florida Department of Environmental Regulation— 1987b 5-16
2.1.3 Florida Department of Environmental Regulation — 1990 5-17
2.1.4 Lapointe and Clark — 1990 5-18
2.1.5 Szmant - 1991 5-19
2.1.6 Other Studies 5-20
2.2 SEDIMENTS 5-21
3.0 FACTORS AFFECTING THE NEARSHORE AND
CONFINED WATER ENVIRONMENT 5-23
4.0 SUMMARY 5-25
5.0 STATEMENTS OF PROBLEMS 5^2
5.1 PROBLEMS IDENTIFIED DURING THE LITERATURE REVIEW 5-42
5.2 PROBLEMS IDENTIFIED AT THE NEARSHORE AND CONFINED WATERS
ASSESSMENT WORKSHOP 5-43
6.0 REFERENCES 5-45
LIST OF FIGURES
5-1. Locations sampled during ministudies investigating nearshore and confined waters 5-2
5-2. Locations of degraded and potentially degraded water quality in the
Florida Keys National Marine Sanctuary . . . . 5-28
LIST OF TABLES
5-1. Sediment heavy-metal concentrations observed at Marathon, Florida 5-22
5-2. Results of the sediment sampling by Lapointe and Clark (1990) at nearshore sites in
the Florida Keys National Marine Sanctuary 5-24
5-3. Sites of known or potential water quality degradation 5-26
-------
TASK 5 - NEARSHORE AND CONFINED WATERS ASSESSMENT
1.0 INTRODUCTION
The objectives of Task 5 were twofold: (1) to determine the extent and status of nearshore and confined waters
within the Florida Keys National Marine Sanctuary (FKNMS) and (2) to identify and evaluate adverse impacts in
the context of current trends in water and sediment quality and biological resources in the nearshore and confined
waters within the FKNMS. This task was organized into four subtasks.
The first subtask was to map the extent of nearshore and confined waters in the Sanctuary. Maps of the Sanctuary
are presented showing the canals and sounds in the Florida Keys (Figures 5-1-1 through 5-1-13), which are part
of the nearshore and confined waters. The boundary between nearshore and offshore waters was not determined
because there is not a standard definition of confined and nearshore waters. We know of no previous estimates of
the area of confined waters in the Sanctuary, and those types of estimates would be difficult to determine without
a generally agreed-upon definition.
The second subtask was to evaluate water quality, sediment, and biological quality trends in the confined waters of
the Florida Keys. This task was done based on the Sanctuary specific data collected under Task 2 and published
scientific literature on pollution effects from the Sanctuary. Interviews did not prove fruitful in gathering additional
data but were of some value in developing the problem statements. The evaluation of water quality pertained to
measurements of parameters from the water column. Similarly, data for sediments were evaluated. Data were not
available to determine trends in biological quality (e.g., differences in quantified abundances of benthic species over
time or between developed and undeveloped canals) in confined waters such as canals or to evaluate relationships
between changes in water quality parameters and abundances of biota.
The third subtask was to evaluate the information gathered under Task 2 and the two proceeding subtasks to identify
known and probable sources of water-quality impacts. The fourth subtask was to prepare this report.
2.0 STUDIES EXAMINING THE NEARSHORE AND CONFINED WATER ENVIRONMENT
IN THE FLORIDA KEYS NATIONAL MARINE SANCTUARY
2.1 WATER QUALITY
2.1.1 Environmental Protection Agency — 1975
The Environmental Protection Agency (EPA 1975) investigated water quality at a canal near Marathon, Florida,
located on Vaca Key (Figure 5-1-8) in August 1974. Although this canal was located in a subdivision (Sea Air
Estates), housing density was low around the canal during the survey. Five stations were sampled, four of which
were located within the canal and one in Florida Bay. Vertical profiles of dissolved oxygen (DO) indicated that
oxygen levels were low in the canal, particularly deeper in the water column. At one station located at a dead end,
the mean concentrations of DO were below 4.0 mg/L throughout the water column. These lower oxygen
concentrations were thought to be related to the lack of flushing of the canal and possibly to the transfer of anoxic
aquifer water into the canal system as this was a deep canal system. Temperature and salinity data indicated that
the water column was not stratified. Nutrient concentrations at the canal stations were similar to those observed
at the Florida Bay station.
In November 1973, EPA (1975) also investigated water quality in the lower Keys at two canals on Big Pine Key
(Figure 5-1-10). One of the canals had been recently constructed at the time of sampling, and the other had some
dwellings with septic tanks located along it. This permitted a comparison to be made between developed and
undeveloped canals.
5-1
-------
FLORIDA
ATLANTIC
OCEAN
Legend to Study-Site References
CH.M Hill (1988)
Florida Department of Environmental Regulation (1987a)
Rorida Department of Environmental Regulation (1987b)
Florida Department of Environmental Regulation (1990)
Florida Department of Pollution Control (1973)
Lapolnte anc Oarfc (1990)
Szmant (1991)
Environmental Protection Agency (1975)
Environmental Protection Agency (19BOa)
Environmental Protection Agency (I980b)
Environmental Protection Agency (19BOc)
Environmental Protection Agency (198Od)
Figure 5-1. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd.
-------
^ °«at County
Atlantic Ocean
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK
Figure 5-1-1. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-3
-------
/XP'-"/^^..^®
••/A £> '<•:!::•'•-^\t
c,:-V
V'.., LWtl* Btaekwattr
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION
OF THE EVERGLADES NATIONAL PARK.
Figure 5-1-2. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-4
-------
Florida Bay
unit
'<; Bultonwood
':. Sound
Atlantic Oc*an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-1-3. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-5
-------
Florid* Bay
&
Plantation K«y
Atlantic Oc*an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-1-4. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn From maps provided by Wallace Roberts & Todd. (continued)
5-6
-------
Florida Bay
Florida Keys National
Marine Sanctuary
UgnumvttM Bafin
Yellow Star* Channel
T«atabl« K*y
Upp«r Mit»cumb« Kty
Low»r Mat*cumb« K»y
Haw* Cnann*)
Atlantic Ocean
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-1-5. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-7
-------
Gulf of Mexico
Florida Bay
Fl««ta
K.y
Craig K*y
Haw* Ch*rv»l
Atlantic Oc«an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-1-6. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-8
-------
Gult of Mexico
LlttU cnwl
Crawl K«y
K«y
Duck K«y
Atlantic Oc««n
Figure 5-1-7. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-9
-------
Gulf of Mexico
Stirrup
K.y
Hiwfc Cntrml
Atlantic Oc»«n
Figure 5-1-8. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-10
-------
No
.*•*.
Spanish
Hartx>r
K»y«
Bahla Honda K*y
Unit Duck K«y
Atlantic Ocean
Figure 5-1-9. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-11
-------
Atlantic Ocean
Figure 5-1-10. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-12
-------
Gutf of Mexico
Saddl*bunch K«y«
Atlantic Ocean
Figure 5-1-11. Locations sampled during ministudies investigating near-shore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-13
-------
Gulf of (Mexico
©)•
a ffe
Wtnz Key B««in
Atlantic Oc«n
Figure 5-1-12. Locations sampled during ministudies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided hy Wallace Roberts & Todd. (continued)
5-14
-------
GuH of Mexico
Fleming
Key
Atlintle Oc««n
Figure 5-1-13. Locations sampled during minisludies investigating nearshore and confined waters.
Base maps have been redrawn from maps provided by Wallace Roberts & Todd. (continued)
5-15
-------
Three stations were established in the undeveloped canal, five in the developed canal, and one station in Bogie
Channel (well-flushed ambient station located outside the canal system). Average DO concentrations in the
undeveloped and developed canals ranged from 5.9 to 6.1 and from 3.0 to 5.2 mg/L, respectively. The average
DO concentration in Bogie Channel was 6.4 mg/L. Although DO levels in the undeveloped canal appeared to be
somewhat depressed relative to the ambient station, the levels in the developed canal were depressed below those
of either of the other two sites. A similar pattern was observed in November 1973 for biochemical oxygen demand
(BOD). Average concentrations were 0.5 to 0.6 mg/L in the undeveloped canal; <0.5 to 1.3 mg/L in the
developed canal; and 0.6 mg/L in Bogie Channel. Average fecal coliform bacteria concentrations at the
undeveloped and ambient stations were less that 5/100 mL in November 1973, whereas the average concentrations
for the developed canal ranged from less than 5 to 18/100 mL. These differences indicated that the water quality
in the canals was different from ambient conditions in a well-flushed area. However, these data suggested that
development had some effect on water quality. No obvious differences among undeveloped canal, developed canal,
and ambient conditions were indicated by nutrient concentrations for the November 1973 and August 1974 surveys.
2.1.2 Florida Department of Environmental Regulation — 1987b
The Florida Department of Environmental Regulation (FDER; 1987b) examined the water-quality condition at five
nearshore sites in Marathon on Vaca Key (Figure 5-1-8). The five sites were selected to examine the impacts of
potential pollution sources on water quality. To evaluate dispersion of discharges, a primary station was established
near each pollution source at each of the five' monitoring sites, and a secondary station was established at the mouth
of the source canal. The results from the primary and secondary stations at each monitoring site were compared
to corresponding ambient reference stations established in Florida Bay and the Atlantic Ocean. Surveys were
conducted to study the sites for 1 year, beginning in February 1984.
At the first site (Faro Blanco Marina), the primary station was exposed to surface-water discharges from a marina
that also had live-aboard vessels. The type of pollution was raw sewage and other vessel-related discharges. The
investigators found that the levels of several water-quality parameters at this station were different from those
observed at the ambient station, suggesting that discharges into the surface waters were affecting water quality.
Annual mean DO concentrations were lower in the canal (primary station) and at the secondary station. The pH
levels of the water were also lower. The secondary station had annual mean levels for DO and pH that were
intermediate between the primary and ambient stations. Turbidity and the quantity of suspended solids did not
appear to be affected by the discharges. Fecal coliform concentrations were greater at the primary station as
compared to those at the ambient station, presumably because of raw sewage discharges from live-aboard vessels.
There appeared to be a relationship between the number of boats anchored in the marina and the fecal coliform
concentrations. These discharges also appeared to increase the BOD in the marina, probably as a result of the
increase loading of organic matter from the discharges. Discharges appeared to increase total Kjeldahl nitrogen and
total phosphorus levels in the marina. Annual mean chlorophyll a concentrations were similar for the primary,
secondary, and ambient control stations, probably because there did not appear to be differences in inorganic
nutrient concentrations.
The primary station at the second monitoring site on Vaca Key was established near a seafood processor in the boat
basin of City Fish Market. The boat basin is connected to Florida Bay via a canal; the secondary station was
established near the mouth of this canal. Water quality in the boat basin was thought to be affected by surface-water
discharges of fish wastes, wastewater, and waste oil. Mean levels of DO and pH were lower at the primary site
near the fish processor discharge than at the ambient reference station. BOD and fecal coliform concentrations were
greater at the primary station. Levels of these parameters at the secondary station indicated that mixing quickly
dispersed the effects of the pollution in the boat basin. Nutrient parameters increased by discharges from the
seafood processor were total Kjeldahl nitrogen, ammonia, total phosphorus, and orthophosphate. The mean
chlorophyll a concentration at the primary station was higher than at the secondary and ambient stations, possibly
because the discharges increased the quantities of some inorganic nutrients (orthophosphate and ammonia).
5-16
-------
The primary station at the third monitoring site was located in a residential waterway that received discharges from
a stormwater collection system. The stonnwater collection system serviced a parking lot from a nearby shopping
center. The secondary monitoring station associated with this canal was located approximately 100 m from the
opening of the main canal. Mean conductivity at the station located within the residential canal was reduced as
compared to that of the secondary and ambient reference stations, probably as a result of freshwater input from the
stormwater drainage system. DO concentrations were suppressed at the head of the residential canal (primary
station). Monthly means at this station ranged from 3.06 to 4.93 mg/L; in contrast, oxygen levels at the canal
mouth station (secondary station) were observed below 5.0 mg/L only once. pH levels were also suppressed at the
head of the canal, but monthly mean levels did not fall below 7.0. Mean pH levels at the mixing zone (secondary
station) were also reduced as compared to those at the ambient reference station, indicating that impacts from
freshwater input to pH in the canal extended to the mouth of the canal. Freshwater input did not affect the
concentrations of fecal coliform bacteria or biochemical oxygen demand. The only measured nutrient parameters
that were greater at the head of the canal were total phosphorus and orthophosphate. The investigators suggested
that septic tank leachate was partially responsible for decreased pH levels and increased levels of total phosphorus
and orthophosphate at the canal head. Chlorophyll a concentrations did not differ among the primary, secondary,
and ambient reference stations.
The'primary station at the fourth monitoring site was located near the outfall from the Key Colony Beach sewage
treatment plant, which discharged treated wastewater into the surface waters of Bonefish Bay. The secondary station
was located approximately 60 m from the outfall. Discharges from the sewage treatment plant appeared to decrease
the DO levels near the outfall and at the secondary station, where mixing was thought to occur; however, mean DO
concentrations consistently exceeded 4.0 mg/L for the entire study at both stations. Effluent discharges also
decreased pH levels at the outfall and secondary station. Conductivity was reduced in the vicinity of the outfall,
indicating that the fresher effluent was diluting the ambient Bay water; conductivity was not altered at the secondary
station, indicating that impacts on conductivity were localized around the outfall.
The fifth monitoring site was selected to monitor the potential for septic leachate to affect water quality. In contrast
to the other sites where there were discharges to the surface water, potential discharges at this site consisted of
septic leachate entering the canal via groundwater. The primary station at this monitoring site was located at the
dead end of a residential canal that was surrounded by permanently located mobile homes. The secondary station
was located near the mouth of the canal. Mean DO and pH were lower at the primary station than at the ambient
reference station. Mean levels of these parameters at the secondary, mixing-zone station were intermediate between
the extremes observed at the other two stations. Monthly mean DO concentrations at the canal head (primary
station) were consistently 2 to 4 mg/L less than the corresponding monthly mean observed at the canal mouth
(secondary station). Mean fecal coliform concentrations were elevated at the canal head relative to the other two
stations. With a single exception, mean fecal coliform concentrations at the canal head exceeded the mean
concentrations observed at the other two stations for the corresponding month. During the November sampling,
the mean fecal coliform .concentration at the canal head was similar to that observed at the canal mouth. The only
nutrient parameter that appeared to be increased at the canal head was the concentration of orthophosphate.
However, orthophosphate enrichment appeared to be restricted to the canal because levels at the secondary station
were not appreciably different from the ambient reference site. The orthophosphate levels were distinctly elevated
during the March, September, October, and January sampling surveys. Mean chlorophyll a concentrations were
greater at the primary station than at the other two stations, although chlorophyll a concentrations were somewhat
erratic temporally.
2.1.3 Florida Department of Environmental Regulation — 1990
The FDER conducted a study in Boot Key Harbor (Figure 5-1-8) to assess and document the nearshore water
quality and to examine the impacts of various pollution sources on the water quality (FDER 1990). Sampling was
conducted over a period of 1 year (January 1989 to February 1990) at 14 stations. The stations were located in
artificial (manmade) canals and basins, Outstanding Florida Waters within the Harbor, and offshore Outstanding
5-17
-------
Florida Waters. Outstanding Florida Waters is a designated regulatory status that prohibits direct discharges from
lowering ambient water quality and indirect discharges from significantly degrading water quality. A water body
can be Outstanding Florida Waters designated only if it has either exceptional ecological significance or exceptiona
recreational significance (FDER 1985). Sites in artificial waterways included an artificial boat basin marina with
operational pumpout facilities available, an artificial residential canal where septic tank systems were in use,
commercial fishing docks, and an artificial boat basin where water circulation was poor and was exposed to
discharges from charter fishing boats, live-aboard vessels, and septic tanks. Stations in Outstanding Florida Waters
within Boot Key Harbor and near potential pollution sources were located near a marina with seafood processing
facilities; near a live-aboard facility that lacked sewage pumpout facilities; near a condominium with a sewage
treatment plant that discharged into an injection well; and in a dredged area used as main anchorage by live-aboard
vessels. Four other stations were located in Outstanding Florida Waters within the Harbor. These were located
at the edge of a well-flushed tidal channel and potentially exposed to impacts from septic tanks and surface runoff
from a nearby subdivision; near a site where the seafloor substrate had been dredged; and two sites with natural
substrate inhabited by turtle grass. Two ambient reference sites were located in Outstanding Florida Waters outside
the Harbor.
Oxygen concentrations in the artificial waterways were generally lower than those observed at most Outstanding
Florida Waters stations. This was attributed to differences in flushing as the poorly flushed canals serve as sinks
for organic matter. DO levels in the artificial canals and basins were reduced throughout the year. Lower DO
values were observed in the study area during the summer; the reduced solubility of oxygen with increasing
temperature and salinity contributed to these lower DO concentrations.
Higher mean concentrations of coliform bacteria were observed at artificial waterway stations; colifonn bacteria
were practically absent from the ambient reference stations. The presence of coliforms may have indicated
substantial freshwater sewage contamination because these organisms do not survive well at high salinities. Likely
sources of contamination were leakage from septic tanks and discharges from live-aboard vessels at the artificial
waterway stations. Two Outstanding Florida Waters Harbor stations had elevated fecal coliform levels; these were
located in close proximity to live-aboard facilities. The highest fecal coliform counts generally occurred during the
winter months at the stations with live-aboard vessels anchored on a seasonal basis. Highest coliform counts at
stations associated with septic tanks were observed after a heavy rainfall.
As a group, artificial waterway stations exhibited higher mean total Kjeldahl nitrogen and total phosphorus
concentrations as compared to the ambient reference stations, and concentrations at Outstanding Florida Waters
Harbor stations were intermediate between the canal and ambient stations. The investigators attributed this to
nutrients entering the canals from anthropogenic sources (sewage, industrial discharges, and surface runoff) and the
decomposition of wind-blown weed wrack and other organic debris trapped in the canals. Elevated mean
chlorophyll a concentrations were also observed at some of the artificial waterway stations, compared to the ambient
control stations.
2.1.4 Lapointe and Clark — 1990
Lapointe and Clark (1990) investigated water quality in nearshore areas throughout the Florida Keys during a study
conducted from 12 September 1989 to 19 September 1990 (Figures 5-1-2 through 5-1-5, 5-1-7, 5-1-8, 5-1-10, and
5-1-12). Water quality parameters determined during the study included temperature, salinity, DO, turbidity, pH,
and chlorophyll a concentrations. Nutrient water quality parameters included the concentrations of nitrate plus
nitrite, ammonium, soluble reactive phosphorus, total dissolved nitrogen, total dissolved phosphorus, particulate
carbon, particulate nitrogen, and particulate phosphorus.
Monitoring sites were located in canals (Boca Chica submarine pens, Port Pine Heights, Doctors's Arm, Mariner's
Resort, Boot Key, Duck Key, Port Antiqua, Venetian Shores, Ocean Shores, Largo Sound, and Glades Canal),
seagrass beds (Pine Channel, Rachel Key, and Blackwater Sound), patch reefs (Newfound Harbor, Sawyer Key,
5-18
-------
Hens and Chickens, and Shark Reef), and bank reefs (Sand Key, Looe Key National Marine Sanctuary, Sombrero
Reef, Alligator Reef, Molasses Reef, and Carysfort Reef). Sampling at the sites was performed along
onshore/offshore transects, and samples were collected at two depths: 0.5 m below sea surface and 0.5 m above
the seafloor.
Analysis of variance revealed that temperature varied seasonally and there were spatial differences among the sites.
Salinity varied spatially. DO concentrations varied spatially and temporally. The spatial variability of DO was due
primarily to the lower values observed at canal seagrass sites and higher values at the bank reef sites. Hypoxic
conditions were observed in several canal systems, including Glades Canal, Boot Key Harbor, and Doctor's Arm.
Dissolved and particulate nutrients varied spatially. Consistently low concentrations were observed at the bank reef
sites and elevated concentrations were observed in nearshore waters. Higher chlorophyll a concentrations were
observed at the nearshore sites. Over the whole study, chlorophyll a was correlated with ammonium, soluble
reactive phosphorus, total nitrogen and phosphorus, and particulate carbon, nitrogen, and phosphorus. Reduced
oxygen concentrations were related to higher concentrations of ammonium, nitrate plus nitrite, soluble reactive
phosphorus, total nitrogen and phosphorus, chlorophyll a, and particulate nitrogen and phosphorus.
A comparison of developed canal systems (Port Antigua, Port Pine Heights, Doctor's Arm, and Mariner's Resort)
with an undeveloped canal system (Boca Chica submarine pens) revealed that reduced oxygen concentrations were
related to higher soluble reactive phosphorus concentrations. In the developed canals, stations located within the
canal system had lower oxygen levels and higher soluble reactive phosphorus compared to their respective reference
stations located in Outstanding Florida Waters. Levels in the canals measured at dawn were commonly hypoxic.
At the Boca Chica submarine pens, levels of soluble reactive phosphorus at stations within the canal were not
different from reference levels outside the canal; hypoxic conditions were not observed within the Boca Chica
submarine pens canal as oxygen levels at stations located within the canal consistently exceeded 4.0 mg/L.
2.1.5 Szmant — 1991
Szmant (1991) investigated the water quality at five sites on the ocean side of the Florida Keys (Figures 5-1-2, 5-1-
6, and 5-1-10). The primary emphasis of this program was to investigate nutrients (nitrogen and phosphorus) and
chlorophyll a in the vicinity of the Florida Reef Tract. The surveys were performed to provide information from
nearshore to oceanic waters. The sampling sites were Biscayne National Park (six stations sampled during summer
and winter), Long Key (13 stations sampled during summer and winter), Key Largo (35 stations sampled during
summer and 13 stations during winter), and Looe Key (seven stations sampled during spring and summer).
Stations were located on seven transects that were oriented inshore/offshore. A minimum of four stations were
located on each transect; stations were located in both the inshore and offshore areas.
Szmant (1991) found that nutrient and chlorophyll a concentrations were elevated nearshore at the Biscayne National
Park and Key Largo sampling sites. At the Looe Key sampling sites, elevated concentrations were especially
associated with marinas and developed canals. Water quality improved with increasing distance from shore,
approaching oligotrophic conditions within a few hundred meters of shore. Higher total nitrogen and phosphorus
concentrations were observed during the winter because storms suspended sediments into the water column.
Movement of water through passes between Florida Bay and the Atlantic Ocean was thought to control the
distribution of nutrients at the Long Key sampling site. Szmant (1991) concluded that water quality in developed
canals and some adjacent nearshore areas is poorer than farther offshore. The data did not support assertions of
extensive nullification in offshore areas.
5-19
-------
2.1.6 Other Studies
The Florida Department of Pollution Control (FDPC 1973) reported the results of a water-quality investigation in
waterways and canals of the Florida Keys that was performed in conjunction with an evaluation of dredge-and-fill
permitting in the Keys. The field study was conducted in April 1973, and 10 sites were sampled. These sites were
located from Key Largo in the upper Keys to Key West in the lower Keys. Measured water-quality parameters were
temperature, conductivity, DO, pH, and Secchi depth. The results of this study indicated that DO concentrations
are sometimes depressed in canals. DO levels below 4.0 mg/L were observed at some depths in a canal at Big
Coppitt Key. At Doctor's Point on Big Pine Key, DO concentrations at stations located within the canal were
predominantly less than 4.0 mg/L. A number of canals were sampled at Vaca Key, and most of the DO levels were
less than 4.0 mg/L. Depressed levels of oxygen were observed in canals located in Lake Surprise Estates and
Worlds Beyond Marina, Key Largo. Investigators noted that organic material that was imported into an artificial
canal would tend to settle on the canal bottom, increasing the oxygen demand of the overlying waters. Additional
sources of organic material listed by the investigators included urban runoff, effluents from septic tanks and
inadequate sewage treatment plants, and wind blown debris (floating organic debris such as seaweed and dead fish
moved into the canal by wind action).
The FDER (1987a) investigated the quality of the water in Campbell's Marina, which is located on the north side
of the western end of Key Largo (Figure 5-1-3). This study was performed in response to concerns raised about
the live-aboard vessels docked in the marina and suspected to be discharging directly into the marina's water. In
addition, two septic tank systems were operating at the marina. Eight stations, include one reference, were sampled
for fecal coliform concentrations. Comparison of the results from the marina stations with the reference indicated
that surface waters were contaminated with fecal coliform bacteria.
Chesher (1974) reported the results of a water-quality survey conducted from July 1973 to March 1974 on SO canal
systems. Six of the canals were natural mangrove canals and the remainder were manmade. The author found that
the water quality was degraded in only four of the canals and that the manmade canals supported biologically
productive communities. The importance of circulation and flushing to water quality was discussed. The
investigator observed that floating debris entering a dead end, poorly flushed canal increased the demand for oxygen
in the canal. Chesher concluded that septic systems had no affect on water quality and generally ascribed depressed
oxygen levels to movement of anoxic aquifer water into canals.
CH2M Hill (1988) performed a study in Riviera Canal, Key West, to determine the effect of surface runoff on the
quality of. the water in the canal system (Figures 5-1-12 and 5-1-13). Sampling took place during the wet
(September 1987) and dry (February 1988) seasons, and comparisons were made between the two surveys. Eight
stations were established in the canal system and five were established in salts ponds near the canal. Temperature,
salinity, DO, total dissolved solids, hydrogen sulfide, and fecal and total coliform bacteria concentrations were
determined at each site. Measured nutrient parameters were nitrate plus nitrite nitrogen, ammonia nitrogen, total
KjeldahJ nitrogen, orthophosphate, and total phosphate. DO concentrations near the bottom of the canal system
were depressed during the summer survey as compared to the winter survey. This observation was attributed to
increased temperatures during the summer. Elevated sulfide concentrations were observed at two canal stations
(summer and winter) and one salt pond station (winter); however the exact sources for the sulfides could not be
determined. Total nitrogen concentrations were markedly elevated during the summer at all stations, mainly because
of increased nitrate plus nitrite concentrations. The investigators concluded that this was probably due to increased
runoff during the wet season. Fecal coliform concentrations during the winter indicated some degree of
contamination from leaking sewage lines.
EPA investigated several canal systems in the Florida Keys during April 1980. EPA (1980a) studied the water
quality in two canals on Sugarloaf Key (Figure 5-1-11). Oxygen concentrations in the water column exceeded 5.0
mg/L at all sampling sites during the study. EPA (1980b) reported the results of a study of the Joseph Harrison
canal system in upper Key Largo (Figure 5-1-2). Three canals were connected to Barnes Sound and two canals
were connected to the Atlantic Ocean. DO concentrations in the soundside canals were generally greater than 5.0
mg/L. At the dead end of one of the oceanside canals, all DO concentrations were less than 1.1 mg/L. Nutrient
5-20
-------
data collected in the canal did not provide an explanation for the severely depressed DO levels. The oceanside canal
was relatively deep (3 to 4 m); the investigators concluded that a hydrogen sulfide aquifer was penetrated during
dredging of this canal. This conclusion was supported by observations of atmospheric liberation of hydrogen
sulfide.
EPA (1980c) investigated the J.H.T. Incorporated Canal in Key Largo (Figure 5-1-2). Reduced DO levels (<4.0
mg/L) were observed near the bottom of the canal at a station located near the dead end of the canal. The
investigators noted that the canal was isolated from ambient waters during low tide by a sill near the canal mouth.
The isolation and commensurate reduction of mixing between water in the canal and ambient water contributed to
maintaining reduced oxygen concentrations in the canal; mixing canal water with the more oxygenated ambient water
increased oxygen levels in the canal.
EPA (1980d) reported the results of a water quality study conducted at the Ocean Reef Club, Key Largo (Figure 5-
1-1). As part of the air conditioning system, hydrogen-sulfide-laden groundwater was pumped through the system,
aerated, chlorinated, and then discharged into the basin. The area of the discharge was well-flushed and oxygen
levels did not appear to be reduced at four stations in the vicinity of the discharge.
2.2 SEDIMENTS
Sediments can be an important sink for substances discharged into nearshore waters. Many substances, e.g., heavy
metals, are associated with fine-grained sediment particles. Under certain conditions, sediments can also serve as
a source of material previously scavenged from the water column. Unfortunately, sediment data in the Florida Keys
are few and a complete evaluation is not possible.
The FDER (1987b) sampled the sediments quarterly at the monitoring sites at Marathon (Figure 5-1-8). Their data,
as received in a summary STORET file, are summarized in Table 5-1. At the Faro Blanco Marina, boat-related
activities were thought to be responsible for the contamination — copper and lead from antifouling paint, lead from
fuel additives and battery casings, and iron and zinc from galvanized and other metal parts. High levels of fine-
grained particles were also suggested as a possible reason for the elevated iron levels. The elevated concentrations
at the City Fish Market were also ascribed to boat-related activities. Elevated iron concentrations in the sediment
of the Winn Dixie Shopping Center canal were attributed to effluent pipe, septic tanks, discarded metal parts, and
automobiles in the parking lot. Effluent discharges from the sewage treatment plant in Key Colony Beach were not
thought to be responsible for the increased concentrations of iron, copper, and zinc observed at this site. These
increases were thought to be from a nearby marina/boat storage facility or a charter boat operation in Bonefish Bay.
Levels of these metals that were higher at the mixing-zone station than at the canal station supported this conclusion.
Based on their analysis, the investigators concluded that the sediments in the 90th Street Canal were contaminated
with iron, copper, lead, zinc, and mercury; the ranges of mercury levels overlapped between primary, secondary,
and ambient stations (Table 5-1). The investigators suggested that discharges and leaching from boats in the 90th
Street Canal were responsible for the elevated concentrations of copper, lead, zinc, and mercury at this site. They
believed that leaching from septic systems was responsible for the elevated levels of iron in the sediments.
The FDER (1987b) also reported the results of a study of the distribution of coprostanol at three sites. Coprostanol
is an excellent tracer of sewage, particularly in the marine environment where the viability of fecal coliform bacteria
is reduced. Results were reported for Faro Blanco Marina, 90th Street Canal, and the Key Colony Beach sewage
treatment plant outfall. The highest coprostanol concentrations (> 1000 ng/g) observed in Faro Blanco Marina were
associated with discharges from live-aboard vessels. Concentrations decreased rapidly with increasing distance from
the boat slips. Coprostanol was also observed in the vicinity of the sewage outfall, but the major source of this
material was not from the outfall but from other areas, with the coprostanol being transported into the bay by tidal
currents. The highest coprostanol concentration (2206 ng/g) observed during the study occurred in the 90th Street
5-21
-------
Table 5-1. Sediment heavy-metal concentrations observed at Marathon, Florida, by FDER (1987b).
Sampling
Site
Faro Blanco Marina
Canal
Canal mouth
City Fish Market
Canal
Canal mouth
Winn Dixie Shopping Center
Canal
Canal mouth
Key Colony Beach
Canal
Canal mouth
90th Street Canal
Canal
Canal mouth
Bayside ambient
Oceanside ambient
Copper
(mg/kg)
50
11
9
9
15
7
4
6
37
9
5
4
.2
.1
.8
.2
.6
.7
.8
.7
.2
.5
.2
.5
-100.0
- 18.4
- 223.3
- 15.5
-59.0
- 13.6
-15.4
-19.2
- 205.7
- 14.0
-7.3
-7.0
Lead
(mg/kg)
53.6
50.2
41.2
43.3
39.7
40.4
34.1
37.7
53.8
37.6
36.6
38.6
- 536.0
-58.0
- 131.3
-58.4
-57.1
-52.3
-46.3
-51.8
-95.8
-49.5
-51.3
- 55.0
Zinc
(mg/kg)
45.0
11.8
7.5
6.8
18.1
12.4
4.3
6.8
86.0
6.8
4.8
2.6
-72.7
-21.1
- 173.7
- 14.0
-93.1
- 17.3
- 14.9
- 17.8
- 158.5
- 16.9
-7.0
-3.7
Iron
(mg/kg)
1051 -
341 -
845-
523-
2982-
829-
907-
958-
1217-
1052-
506-
128-
2021
645
3650
830
6838
1058
1539
1394
5975
1469
818
191
Mercury
(mg/kg)
0.8 - 1.
0.2 - 0.
0.2 - 1.
0.2
0.2 - 0.
0.2
0.2 - 0.
0.2 - 3.
5
3
1
4
3
4
0.2 - 0.3
0.2 - 0.
0.2
0.2
3
-------
Canal. The high levels observed at this site were thought to be the result of leakage from septic systems located
along the canal. Concentrations decreased with increasing distance from the canal dead end, probably along a
flushing gradient.
Lapointe and Clark (1990) sampled metal concentrations in the sediments (Figures 5-1-2 through 5-1-5, 5-1-7,
5-1-8,5-1-10, and 5-1-12). Their results for the designated nearshore sites in the Sanctuary are presented in Table
5-2. Metal concentrations were variable among the sampling sites. These investigators noted that concentrations
of copper, iron, lead, zinc, and cadmium appeared to be higher in the developed canal systems and at sites in upper
Florida Bay compared to offshore reef sites. Stormwater runoff was suggested as a potential source for zinc, lead,
iron and copper. In addition, antifouling paints and sacrificial tabs were also suggested as sources for copper and
zinc, respectively.
Szmant (1991) investigated total nitrogen and phosphorus levels in the sediments (Figures 5-1-2,5-1-6, and 5-1-10).
Sediments serve as a reservoir for nutrients and as a means of inshore/offshore transport. Nutrients entering the
nearshore may be assimilated by nearshore plant communities (e.g., mangroves, seaweed, seagrass). Detritus
produced by the plant communities is susceptible to being transported offshore by physical processes. Szmant
(1991) observed a strong trend of decreasing nitrogen concentrations with increasing distance from shore. The
gradient was steep, indicating that most of the nitrogen was remaining in the nearshore sediments. Sources for this
sedimentary nitrogen include detritus from mangroves, seagrass, and seaweeds and input from anthropogenic
sources.
3.0 FACTORS AFFECTING THE NEARSHORE AND CONFINED WATER ENVIRONMENT
A variety of mechanisms probably play a role in controlling the quality of the nearshore and confined waters in the
FKNMS. These include physical and anthropogenic mechanisms. At present, the relative contributions of these
different mechanisms (several of which have not been extensively studied) to the nearshore and confined waters are
not known.
Winds can blow weed wrack and other organic debris into confined waters, as indicated by the FDER (1990).
Oxygen in the canals is used during the decomposition of this organic material, and the DO levels decrease. This
is exacerbated in areas of reduced flushing. Upwelling and exchanges with offshore water probably play a role in
controlling the composition of nearshore waters. Szmant (1991) pointed out the potential role of upwelling in the
Pourtales Gyre in providing nutrients to the Florida Reef Tract. This upwelled water could conceivably be
transported to the nearshore by currents. Smith (1991) described movement of Florida Bay water through inter-Key
passes into Hawk Channel. This water could also be involved in the distribution of nutrients in nearshore areas.
Another physical mechanism that could affect nearshore water quality is atmospheric input of nutrients. Although
atmospheric-input studies have not been performed in the Keys, Willey and Gaboon (1991) demonstrated that nitrates
in rainwater enhanced chlorophyll a production in the surface waters of the Gulf Stream off North Carolina. Paerl
et al. (1990) found that rainwater represented a potentially significant source of nitrogen in estuarine and coastal
waters.
Several anthropogenic sources appear to affect nearshore water quality. Discharges of raw sewage from live-aboard
vessels increase nutrient loads, which in turn may stimulate increased phytoplankton growth (FDER 1987b, 1990).
In addition, DO concentrations are decreased because of the increased organic loading, particularly in confined
waters where flushing is poor. Fecal coliform bacteria concentrations may increase as a result of discharges from
live-aboard vessels. Effects of live-aboard vessels are probably limited to the immediate vicinity of the discharges.
Other boat-related activities also have their effects, such as spills during fueling operations and leaching from
antifouling paints.
5-23
-------
Table 5-2. Results of the sediment sampling by Lapointe and Clark (1990) at nearshore sites
in the Florida Keys National Marine Sanctuary.
Sampling Site
Boca Chica Submarine Pens
Port Pine Heights
Mariners Resort
Doctor's Ann
Boot Key Harbor
Duck Key
Port Antigua
Venetian Shores
Ocean Shores
Largo Sound
Glades Canal
Copper
(mg/kg)
1.85
< 0.246
42.1
35.0
37.20
0.578
9.30
14.9
11.8
9.52
4.86
Iron
(mg/kg)
1,480
1,290
630
656
1,890
234
1,330
1,330
4,860
1,760
4,890
Lead
(mg/kg)
2.70
2.13
5.14
6.39
7.75
1.51
4.34
7.80
7.71
8.94
6.92
Mercury
(mg/kg)
0.075
0.053
0.262
< 0.082
0.118
0.030
0.061
0.262
0.079
0.064
0.102
Zinc
(mg/kg)
41.3
2.54
96.2
42.0
30.5
2.37
11.9
11.8
15.4
13.0
20.4
Cadmium
(mg/kg)
0.350
0.079
3.78
0.486
0.313
0.334
0.158
0.417
0.172
0.991
0.213
-------
Direct discharges from sewage treatment plant outfalls also affect nearshore water quality in their vicinity. Although
not detected at the Key Colony Beach outfall by the FDER (1987b), nutrient enrichment would probably occur in
areas that are not as well-flushed as Bonefish Bay. Stormwater runoff is also an important factor that can affect
water quality in nearshore areas.
Leakage from onsite sewage disposal systems has been indicated as a source of nutrients to nearshore waters. Barada
and Partington (1972) identified septic tanks as a problem around canals. Lapointe et al. (1990) suggested that
nutrients build up in the groundwater during the winter dry season when tourist occupancy in the Keys is greatest.
With the coming of the wet summer season, these nutrients are flushed from the groundwater into nearby marine
waters by the hydraulic head developed from rainfall entering the sediments. The studies discussed above indicated
that nutrient enrichment can occur from the movement of ground water into canals (e.g., 90th Street Canal in
Marathon).
In an assessment of nonpoint sources for Florida, the FDER (1988) determined that most nonpoint-source problems
in the Keys arose in the vicinity of Key West and Marathon. Locations in the Key West area that were identified
as impaired by urbanization, live-aboard vessels, and boat and marina activities included Safety Harbor, Key West
Harbor, Garrison Bight, Riviera Canal, and Cow Key Channel. Urbanization, septic tank seepage, and canals were
identified as contributors to impairment of nearshore waters in the Marathon area. Other areas identified by the
FDER (1988) as impaired from anthropogenic nonpoint sources included Tavemier Creek, Largo Lake, and a
development on Windley Key.
Climate change and sea-level rise potentially may have long-term effects on the water quality in the Sanctuary. This
was examined during the October 1991 Research Planning Workshop for the FKNMS held at the University of
Miami Rosenstiel School of Marine and Atmospheric Science (CIMAS 1991). Increases in temperature were noted
as a potential effect. This effect was not only maximum temperature but also seasonally changes such as warmer
spring and milder winter. Changes in precipitation .may result from climate change; such changes would alter
salinity and groundwater flow. Rising sea level would change the landscape, causing widening of channels,
submergence of islands, and changes in the circulation patterns in the Sanctuary. To adequately examine effects
from climate change and sea-level rise, sophisticated modeling would be necessary because this problem is extremely
complex. Such modeling is beyond the scope of this project and must wait for another expanded effort.
4.0 SUMMARY
The quality of nearshore waters in the FKNMS is critical as this area supports important biological communities
(e.g., seagrass beds and patch reefs). Degradation of nearshore water quality would result in the loss or undesirable
changes in the composition of these communities, leading to losses of fishery resources, impacts on the tourist
industry, and other undesirable changes in the Sanctuary. Thus, it is beneficial to maintain and improve the water
quality in nearshore and confined waters in the Sanctuary.
The results of the studies discussed above indicate that the nearshore water quality in some places in the FKNMS
has been degraded, as indicated by the many occurrences of reduced DO. This degradation occurs primarily in
developed artificial waterways that have received anthropogenic input from various sources. Lack of flushing
contributes to the degradation. The relative contributions of various sources and their delivery mechanisms are not
known (e.g., weed wrack versus septic leachate) and obviously vary according to the location. In addition, the
ultimate fate of nutrients is not well understood.
During this phase of the project, it was important to identify areas where water quality degradation is known or
suspected. Based on the results of discussions held during the Phase I workshop and communications with R. J.
Helbling (FDER, Marathon, Florida), these areas were identified (Table 5-3, Figures 5-2-1 through 5-2-13).
5-25
-------
Table 5-3. Sites of known or potential water quality degradation. Sites based on correspondence with
R.J. Helbling (FDER, Marathon, FL) and the results of the Phase I workshop.
Fig. 5-2
ID#
Site
Location
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Ocean Reef Marina
Phase I and Dispatch Creek
Worlds Beyond
C-lll Canal
Sexton Cove and Lake Surprise Subdivisions
Grass Key Waterways Subdivision
Port Largo
Key Largo Fishery Marina
Marian Park and Rack Harbor Estates
Pirate Cove Subdivision
Winken, Blynken, and Nod
Blue Water Trailer Park
Hammer Point
Campbell's Marina
Tropical Atlantic Shores Subdivision
Plantation Key Colony*
Indian Waterways
Plantation Yacht Harbor
Treasure Harbor
Venetian Shores
Holiday Isle Resort
Port Antigua
White Marlin Beach
Lower Matecumbe Beach
Caloosa Cove Marina*
{Campgrounds of America Marina
Long Key Estates and City of Layton*
Outdoor Resorts of America
Conch Key
Coco Plum Beach*
Bonefish Towers Marina*
City of Key Colony Beach
Sewage Treatment Plant Outfall
Key Colony Subdivision*
Sea-Air Estates
90th Street Canal
Winner Docks
City Fish Market
Faro Blanco Marina
Boot Key Marina
Boot Key Harbor
Marathon Seafood
Knight Key Campground
Sunshine Key Marina
Bahia Shores
Key Largo
Key Largo
Key Largo
South Florida Mainland
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Key Largo
Plantation Key
Plantation Key
Plantation Key
Plantation Key
Plantation Key
Plantation Key
Windley Key
Lower Matecumbe Key
Lower Matecumbe Key
Lower Matecumbe Key
Lower Matecumbe Key
Fiesta Key
Long Key
Long Key
Conch Key
Fat Deer Key
Fat Deer Key
Fat Deer Key
Vaca Key
Vaca Key
Vaca Key
Vaca Key
Vaca Key
Vaca Key
Vaca Key
Vaca Key
Vaca Key
Knight Key
Ohio Key
No Name Key
5-26
-------
Table 5-3. Sites of known or potential water quality degradation. Sites based on correspondence with
R.J. Helbling (FDER, Marathon, FL) and the results of the Phase I workshop, (continued)
Fig. 5-2
n>#
45
46
47
48
49
50
51
52
53
54
55
56 .. ,.
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
Site
Doctors Arm
Tropical Bay
Whispering Pines Subdivision
Sands Subdivision
Eden Pines Colony
Pine Channel Estates
Cahill Pines and Palms
Port Pine Heights
Sea Lamp*
Coral Shores Estates
Jolly Roger Estates
Breezeswept Beach Estates*
Summerland Key Fisheries
Summerland Key Cove
Cudjoe Ocean Shore
Venture Out Trailer Park
Cutthroat Harbor Estates*
Cudjoe Gardens Subdivision*
Orchid Park Subdivision
Sugar Loaf Shore Subdivision
Sugar Loaf Lodge Marina*
Bay Point Subdivision
Porpoise Point*
Seaside Resort
Gulfcrest Park*
Boca Chica Ocean Shores
Tamarac Park
Submarine Pens*
Key Haven Subdivision
Boyd's Trailer Park
Ming Seafood
Oceanside Marina
Safe Harbor
Alex's Junkyard
Key West Landfill
House Boat Row
Garrison Bight Marina
Navy/Coast Guard Marina and
Trumbo Point Fuel Storage Facility
Truman Annex Marina
Key West Sewage Treatment Plant Outfall
Location
Big Pine Key
Big Pine Key
Big Pine Key
Big Pine Key
Big Pine Key
Big Pine Key
Big Pine Key
Big Pine Key
Big Pine Key
Little Torch Key
Little Torch Key
Ramrod Key
Summerland Key
Summerland Key
Cudjoe Key
Cudjoe Key
Cudjoe Key
Cudjoe Key
Lower Sugarloaf Key
Lower Sugarloaf Key
Lower Sugarloaf Key
Saddlebunch Keys
Big Coppitt Key
Big Coppitt Key
Big Coppitt Key
Geiger Key
Geiger Key
Boca Chica Key
Raccoon Key
Stock Island
Cow Key
Cow Key
Cow Key
Cow Key
Key West
Key West
Key West
Key West
Key West
Key West
Site of potential water quality degradation.
5-27
-------
Figure 5-2. Locations of degraded and potentially degraded water quality in the Florida Keys National Marine Sanctuary (shaded areas).
Location based on R.J. Helhlinjj [FDER, Marathon, FL, personal communication, 1992] and results of the Phase I workshop.
Numbers correspond to those in Table 5-3. Base maps redrawn from maps provided by Wallace Roberts & Todd.
-------
— *• — "««.«« '""•CO"* 3
*»">• Coiny""""" """ """ — — — ^ .. ^ ^ ^
NOTE: DASHED LANOMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-2-1. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-29
-------
Florida
^i*&i'^ii&i;:V-V-;^:-V:-''»v''"••'«'•.'••' •" •' •'•.' •: •'.'
^***t^f^JM
Long Sound
tyo/'-'JS /sfcss.s^K
^j^T^'^l
X
X
Atlantic O«*an
NOTE: DASHED LANOMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-2-2. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-30
-------
f?
$&
$
Florida Bay
A
^
&£>'
0
.&:$
•Si
J'
a.
<&
«*:> fi!l$"::.f-:t
t i-.'.y» K--'n..::'
%&&* k
Vjy ^
V'^>^:^,
U;v--'^v.>r
I--*
i.';o* •:
-^'
<-^"
jlT1'-." um«
Bononxoo^ ,'.
Ifc-
^
Sound
/^ Bunenoeod Sotnj
Rodrlgu«z K«y
Atlantic Oc««n
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK
Figure 5-2-3. Locations or degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-31
-------
Florida Bay
•?
e£';i$
'&&''-*'
.•$*• >?W#\1
"«vS &*£•&
Fl°rjd,a
Marine Sanctuary
H^*Ch."~'
Atlantic Oc«an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-2-4. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-32
-------
Florida Bay
F/orlda Key, Nationa
Marine Sanctuary
MINK Chinrwl
Atlantic Oc*an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-2-5. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-33
-------
Gulf of Mexico
/
Craig K»y
Atlantic Oc«an
NOTE: DASHED LANDMASSES FALL WITHIN JURISDICTION OF THE EVERGLADES NATIONAL PARK.
Figure 5-2-6. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-34
-------
Gulf of Mexico
Hawk Ch»nr»l
Atlantic Oc*«n
Figure 5-2-7. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-35
-------
Gulf of Mexico
Atlantic
Figure 5-2-8. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-36
-------
Gulf of Mexico
Spanith
Harbor
K»y«
AUantic Ocean
Figure 5-2-9. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-37
-------
Atlantic Ocean
Figure 5-2-10. Locations or degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-38
-------
Gulf of Mexico
Upper Sug*f1o*t Sound
3
uttonwood
S«ddl«bunch K»y«
AHantks Oc««n
Figure 5-2-11. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-39
-------
Figure 5-2-12. Locations of degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
5-40
-------
GuffofMttxfco
Atlantic Oc*«n
Figure 5-2-13. Locations or degraded and potentially degraded water quality
in the Florida Keys National Marine Sanctuary (shaded areas), (continued)
.5-41
-------
5.0 STATEMENTS OF PROBLEMS
A key part of Phase I of the Water Quality Protection Program is the identification of water quality problem areas
to be addressed during Phase II. A two-step approach was used to identify and obtain agreement among members
of the scientific community on known, suspected, or potential water-quality problems affecting the natural resources
of the Sanctuary. Initially, information gathered during the literature review was used to derive a series of
statements describing potential water-quality related problems (presented in Section 5.1). These problem statements
were then refined through discussions with EPA Region IV Coastal Programs staff and State of Florida
environmental staff and delivered to workshop participants to provide focal points for discussions at technical.
workshops. The participants in each workshop were charged with coming to a consensus, where possible, on the
problem statements developed for each workshop resource area. A matrix analysis of each workshop resource area
(Appendix B) was the tool used to develop consensus on the problem statements. Specific descriptive terms were
used to complete the matrix based on the discussions with the expert panels assembled for each workshop (Appendix
B). Public comments were also heard during the course of each workshop. To assist EPA Region IV and the State
of Florida to direct their limited resources, each expert panel was asked to rank the overall significance of the water-
quality related problems at the end of each daily workshop. The consensuses developed at the workshops are
summarized in Section 5.2 and presented in more detail in Appendix B.
5.1 PROBLEMS IDENTIFIED DURING THE LITERATURE REVIEW
The potential problems for water quality of nearshore and confined waters are presented below. Some changes in
water quality associated with these potential problems include reduced dissolved oxygen (DO) concentrations,
elevated chlorophyll a and nutrient concentrations, and elevated bacterial counts. Sediment contamination may also
be associated with these problems. Each problem is evaluated in light of the reviewed studies to identify information
gaps and stimulate discussions of these problems with regard to potential regulatory steps.
Water quality in confined wafers is deteriorating and is potentially deteriorating in nearshore waters, and this
degradation may be adversely affecting biota inhabiting nearshore areas. — Water quality in confined waters (such
as canals that receive input from anthropogenic sources) appears to have deteriorated. The extent of this
deterioration is unknown, other than in a few areas where data have been collected. If the quantity of the
anthropogenic-source input increases with an increasing population and development of the Florida Keys, the water
quality may reasonably be expected to continue to deteriorate. At present, the spatial extent of the problem is not
well known, but it appears to be limited to areas of development. Nearshore water quality in areas that are well
flushed does not appear to be presently degraded, except where anthropogenic pollutants are being released. The
effect of continued development is not known. Studies directly relating changes in water quality to changes in the
biota have not been performed within the FKNMS. It is reasonable to assume that degrading water quality will
affect biota in the nearshore. The extent and degree of possible effects on the biota are unknown.
Septic leachate from on-site sewage disposal systems (OSDS) is degrading water quality in confined waters and
may be degrading water quality in nearshore waters. — Septic leachate appears to have contributed to degrading
water quality in canals that have housing developments with septic tanks and cesspools around them. Continued
development without proper treatment of wastes may result in degradation beyond the immediate vicinity of affected
canals. The contribution of this pollution source relative to other sources is also unknown and is likely site-specific.
Sewage discharges from live-aboard vessels are degrading water quality in nearshore and confined waters. —
Degraded water quality has been demonstrated in some areas where live-aboard vessels congregate. Degraded water
quality may also be a problem in unstudied areas. If the number of live-aboard vessels increases and untreated
sewage continues to be discharged, the water quality may be degraded further. The contribution of this pollution
source relative to other sources is unknown and is likely site-specific.
5-42
-------
Decomposition of weed wrack and other windblown organic debris may be degrading water quality in canals. —
Deposition of windblown debris in canals has been mentioned in several studies as a reason for reduced water
quality relative to ambient conditions. This has not been well studied, and its contribution to degraded water quality
relative to other sources is unknown. Its contribution would not be expected to increase with increasing population.
Discharges from sewage treatment/package plants into nearshore receiving waters may be degrading nearshore
water quality. — Discharges from the Key Colony Beach outfall affected water quality in the vicinity of the outfall.
Effects of discharges from the Key West Sewage Treatment Plant have not been studied. The degree of changes
in water quality are likely related to the level of waste treatment. The contribution of the pollution source relative
to other sources is unknown and is probably site-specific.
Stormwater runoff is degrading confined water quality and may be degrading nearshore water quality. —
Stormwater runoff has been shown to degrade water quality in some canals. Runoff occurs throughout the Keys,
and the effects on water quality at individual locations are probably related to the substrate over which the runoff
flows prior to reaching the nearshore waters. Changes in land use will therefore affect the nature of the runoff.
Deleterious effects of Stormwater runoff on water quality are probably more prevalent in developed areas.
5.2 PROBLEMS IDENTIFIED AT THE NEARSHORE AND CONFINED WATERS
ASSESSMENT WORKSHOP
This workshop was divided into three areas of interest, Confined Waters, Nearshore Waters, and Back Country
Waters. The problems discussed in relation to confined waters were divided into two areas; eutrophication and
human health. Under eutrophication, increased epiphyte growth, increased chlorophyll (i.e., phytoplankton), and
change in benthic community structure were identified as problems. Under human health, the effects of fish and
shellfish consumption on human health was discussed. Problems discussed in relation to nearshore waters were
increased epiphyte growth and increased chlorophyll (i.e., phytoplankton). Problems discussed in relation to back
country waters were increased epiphyte growth and increased chlorophyll (i.e., phytoplankton). The parameters
for analysis and the matrices used for the discussion are presented in Appendix B.
The consensus of the workshop panel members was that water quality in some confined waters was degraded;
however, there was not a unanimous consensus that water quality in nearshore and back country waters was
degraded. Priority areas in need of more information were new methodologies for using managed aquatic systems
for treatment, hot spots (areas of severe water quality degradation), nutrient loading, nutrient transport/hydrology,
monitoring from a hydrological/biological standpoint (develop a systems monitoring program), back country waters,
hydrology regarding well injection (has the ability to impact nearshore and offshore waters), and hydrological studies
[intensive surveying needed, establish a liaison with the United States Geological Survey (USGS)]. Priority problem
areas are the canal systems adjacent to inappropriate sewage treatment systems; secondary treatment should be
mandated for such areas.
Confined Waters — Eutrophication
[Note: Confined waters are defined as canals, marinas, bays, and lagoons.]
Increased epiphyte growth is a widespread problem and the trend is worsening. — Epiphyte growth has been
increasing over the last decade. This problem is water-quality related and the overall significance of the problem
from a water-quality perspective is high. Parameters that significantly affect increased epiphyte growth are
nutrients, turbidity, and anthropogenic BOD loadings. An increase in epiphyte growth is an indicator of a change
in the community structure and amount. Poor flushing and the lack of circulation in the canals contributes to the
poor water quality in the canals.
5-43
-------
Increased chlorophyll is related to temperature and tight, and is thought to be widespread, chronic, and worsening
(anecdotal evidence). — This problem is water-quality related and the overall significance of the problem from a
water-quality perspective is high. Parameters that significantly affect this problem are nutrients, turbidity, and
anthropogenic BOD loadings. Increased chlorophyll is an indicator of the severity of the nutrient loading.
Change in the benthic community structure is a widespread problem and the trend is worsening. — The problem
is water-quality related and the overall significance' of the problem from a water-quality perspective is high.
Parameters that significantly affect this problem are nutrients, turbidity, and anthropogenic BOD loadings.
Decomposing seagrass wrack can lead to eutrophication.
Confined Waters — Human Health
Human health (fish and shellfish consumption) refers to problems associated with consuming fish/shellfish caught
by an individual, not fish/shellfish purchased from a seafood market. No historical data exist regarding health
problems from personally caught fish/shellfish.
More data are needed regarding the trend, severity, and certainty of the human health problem. —
Toxics/pesticides, human-derived bacteria, turbidity, anthropogenic BOD loading, and viruses significantly affect
the problem. Temperature, nutrients, and salinity affect the problem slightly to significantly depending on the
species. It is possible but unlikely that the problem is water-quality related. The overall significance of this problem
from a water-quality perspective is unknown. In areas with inappropriate sewage treatment systems, the potential
exists for severe health problems.
Nearshore Waters
[Note: Nearshore waters are defined as those that extend from shore to Hawks Channel including the 18 ft depth
contour.]
Increased epiphyte growth is widespread and worsening, and has been increasing over the last decade. — For
increased epiphyte growth, severity is slight, certainty is possible, and overall significance of this problem from a
water-quality perspective is slight. The problem is water-quality related. Parameters that significantly affect this
problem are nutrients, turbidity, and anthropogenic BOD loadings.
Increased chlorophyll is thought to be widespread, chronic, and worsening. — Severity is slight, certainty is
possible, and overall significance of this problem from a water-quality perspective is slight. Increased chlorophyll
is related to temperature and light, and has been reported since 1973. The problem is water-quality related.
Parameters that significantly affect this problem are nutrients, turbidity, and anthropogenic BOD loadings.
Back Country Waters
[Note: Back country waters are defined as nearshore Florida Bay waters within the 8 to 10 ft depth contour.]
Increased epiphyte growth is widespread and worsening, and has been increasing over the last decade (anecdotal
evidence). — For increased epiphyte growth, the severity is slight, certainty is possible, and overall significance
of this problem from a water-quality perspective is slight. The problem is water-quality related. Parameters that
significantly affect this problem are nutrients, turbidity, and anthropogenic BOD loadings.
Increased chlorophyll is thought to be widespread, chronic, and worsening (anecdotal evidence). — Severity is
slight, certainty is possible, and overall significance of this problem from a water-quality perspective is slight.
Increased chlorophyll is related to rainfall, temperature, and light and has been reported since 1973. The problem
5-44
-------
is water-quality related. Parameters that significantly affect this problem are nutrients, turbidity, and anthropogenic
BOD loadings. In addition, no historical data exist regarding the back country waters.
6.0 REFERENCES
Barada, W., and W.P. Partington, Jr. 1972. Report of investigation of the environmental effects of private
waterfront canals. A report to the State of Florida,' Board of Trustees of the Internal Improvement Trust
Fund. 63 pp.
CH2M Hill. 1988. Baseline Data Collection for an Environmental and Hydraulic Assessment of Riviera Canal and
the Adjoining Salt Ponds, Key West, Florida. A report prepared for the City of Key West, Florida.
Chesher, R.H. 1974. Canal Survey, Florida Keys. A report for the Society for Correlation of Progress and
Environment. 172 pp.
CIMAS. 1991. Report on the Research Planning Workshop for the Florida Keys National Marine Sanctuary. A
draft report prepared for the National Oceanic and Atmospheric Administration, Sanctuaries and Reserves
Division. Cooperative Institute for Marine and Atmospheric Studies. 48 pp.
EPA. 197S. Finger-fill canal studies, Florida and North Carolina. Environmental Protection Agency. 427 pp.
EPA. 1980a. Hydrographic, water quality, and biological studies of the Fred Weiszmann canal system. A report
prepared for the United States Army Corps of Engineers and the Department of Justice. Environmental
Protection Agency. 43 pp.
EPA. 1980b. Hydrographic, water quality, and biological studies of the Joseph Harrison canal system.
Environmental Protection Agency. 30 pp.
EPA. 1980c. J.H.T. Incorporated Canal, Key Largo, Florida, April 23, 1980. Environmental Protection Agency.
9pp.
EPA. 1980d. Water quality and hydrological investigations, Ocean Reef Club, Key Largo, Florida, April 1980.
Environmental Protection Agency. 12 pp.
FDER. 1985. Proposed designation of the waters of the Florida Keys as Outstanding Florida Waters. Report to
the Florida Environmental Regulation Commission. Florida Department of Environmental Regulation. 57
pp.
FDER. 1987a. Campbell's Marina Study. Florida Department of Environmental Regulation. 8 pp.
FDER. 1987b. Florida Keys Monitoring Study, Water Quality Assessment of Five Selected Pollutant Sources in
Marathon, Florida Keys. Florida Department of Environmental Regulation. 196 pp.
FDER. 1988. Florida nonpoint source assessment. Vol.1. Report prepared pursuant to Section 319 of the 1987
Federal Clean Water Act. Florida Department of Environmental Regulation. 312 pp.
FDER. 1990. Boot Key Harbor Study. Preliminary draft manuscript. Florida Department of Environmental
Regulation.
FDPC. 1973. Survey of water quality in waterways and canals of the Florida Keys with recommendations.
Florida Department of Pollution Control. Tallahassee, FL. 19 pp. + App.
5-45
-------
Lapointe, B.E., and M.W. Clark. 1990. Final report: Spatial and temporal variability in trophic state of surface
waters in Monroe County during 1989-1990. - A report for the John D. and Catherine T. MacArthur
Foundation and Monroe County.
Lapointe, B.E., J.D. O'Connell, and G.S. Garrett. 1990. "Nutrient couplings between on-site sewage disposal
systems, groundwaters, and nearshore surface waters of the Florida Keys." Biogeochemistry 10:289-307.
Paerl, H.W., J. Rudek, and M.A. Mallin. 1990. "Stimulation of phytoplankton production in coastal waters by
natural rainfall inputs: Nutritional and trophic implications." Mar. Biol. 107:247-254.
Smith, N.P. 1991. Physical oceanography. Pp. 16-22 in SEAKEYS Phase I, Sustained Ecological Research
Related to Management of the Florida Keys Seascape. A final report to the John D. and Catherine T.
MacArthur Foundation World Environment and Resources Program from the Florida Institute of
Oceanography, St. Petersburg, FL.
Szmant, A.M. 1991. Inshore-offshore patterns of nutrient and chlorophyll concentration along the Florida Reef
Tract. Pp. 42-62 in SEAKEYS Phase I, Sustained Ecological Research Related to Management of the
Florida Keys Seascape. A final report to the John D. and Catherine T. MacArthur Foundation World
Environment and Resources Program from the Florida Institute of Oceanography, St. Petersburg, FL.
Willey, J.D., and L.B. Gaboon. 1991. "Enhancement of chlorophyll a production in Gulf Stream surface seawater
by rainwater nitrate." Mar. Chem. 34:63-75.
5-46
-------
SPILLS AND HAZARDOUS-MATERIALS ASSESSMENT
Task 6
CONTENTS
1.0 INTRODUCTION 6-1
2.0 HISTORICAL SPILL DATA AND SITES OF HAZARDOUS-MATERIAL
CONTAMINATION 6-1
2.1 TERRESTRIAL 6-1
2.1.1 Spills 6-1
2.1.2 Hazardous-Materials Generators 6-2
2.1.3 Contaminated Sites 6-3
2.2 MARINE 6^
3.0 POTENTIAL LOCATIONS AND RISK OF FUTURE SPILLS
OR HAZARDOUS-WASTE CONTAMINATION WITHIN
THE FLORIDA KEYS NATIONAL MARINE SANCTUARY 6-7
3.1 TERRESTRIAL 6-7
3.2 MARINE 6-8
4.0 STATEMENT OF PROBLEMS 6-9
4.1 PROBLEMS IDENTIFIED DURING THE LITERATURE REVIEW 6-9
4.2 PROBLEMS IDENTIFIED AT THE SPILLS AND HAZARDOUS-MATERIALS
ASSESSMENT WORKSHOP 6-10
5.0 REFERENCES , 6-11
LIST OF FIGURES
6-1. Percent by volume of reported petroleum spills in the
Florida Keys National Marine Sanctuary 6-5
6-2. Total number of spills and annual volume of oil spilled (from the 98
reported spills for which volume estimates are reported)
into the waters of the Florida Keys National Marine Sanctuary 6-6
-------
TASK 6: SPILLS AND HAZARDOUS-MATERIALS ASSESSMENT
1.0 INTRODUCTION
The purpose of this task report is to identify the sources and causes of toxic or hazardous-material spills within
the Florida Keys National Marine Sanctuary (FKNMS). In this discussion, hazardous material is defined as any
substance that may produce negative environmental impacts or human health problems if spilled or released into
the environment. This definition is specifically selected to include all petroleum products. The causes and types
of materials spilled are reviewed and the likelihood of future spills, as well as their potential for impacts on the
Sanctuary, are assessed. Data reviewed for this report consist of the United States Coast Guard (USCG),
National Response Center summary of reported spills 1987-1991, the National Oceanic and Atmospheric
Administration (NOAA) Strategic Environmental Assessments Division copies of the USCG reported spill
records 1970-1990, the Florida Department of Environmental Regulation (FDER), Ground Water Management
System, and the FDER "Emergency Sampling Response" records.
The USCG reported spill records, the data set from which a large portion of any historical analysis must be
derived, show a number of entry errors and discrepancies in the spill location and cause sections, particularly in
earlier reports (1970s through the earlier 1980s). Many of these problems result from recording methods.
Although standardization has improved with time, there are still significant typographical errors and spill
location accuracy problems in the database. To be used in the most effective manner, extensive ground truthing
and "cleaning" of the digitized database would be required (T. Goodspeed, NOAA Strategic Environmental
Assessments Division, personal communication, 1991). NOAA's Strategic Environmental Assessments Division
has generated draft maps of spill locations and quantity from these data files, but the maps are not suitable for
publication without extensive review by field personnel and verification of the individual electronic data files (T.
Goodspeed, NOAA Strategic Environmental Assessment Office, personal communication, 1991).
The quality of the spill records reported by the National Response Center improved dramatically over time with
the period between 1985 and the present having the most complete spill records available. While the entire data
suite has been reviewed, for the purposes of this text, only the records between 1985 and 1991 are discussed in
detail. Electronic data sets, reduced from the USCG records showing spill types and geographic coordinates
from 1973 through 1990, could be developed and provided to the Florida Department of Natural Resources
(FDNR) for inclusion in the Sanctuary Geographic Information System (GIS), if such inclusion is justified in
view of the ongoing NOAA spill-mapping effort.
2.0 HISTORICAL SPILL DATA AND SITES OF HAZARDOUS-MATERIAL CONTAMINATION
2.1 TERRESTRIAL
2.1.1 Spills
The FDER records indicate that, between January 1987 and June 1991, there were 26 environmental incidents
(e.g., spills and groundings) within the Florida Keys. These were of a sufficient magnitude to initiate
"Emergency Response Sampling." Of these incidents, 12 were spills of various substances at terrestrial
locations. These spills were further categorized as follows.
• Six petroleum products spills: jet fuel, two spills; gasoline, three spills; diesel, one spill
• Three sewage spills: raw sewage, two spills; treated sewage, one spill
• Miscellaneous toxic substances: one case where potassium cyanide was abandoned but not actually
spilled; 1 spill of infectious medical waste; one pesticide spill.
6-1
-------
The National Response Center data files obtained from NOAA show that, between October 1984 through March
of 1990, a total of 81 spills were reported at terrestrial locations within the Florida Keys. Fifty-seven of these
spills were petroleum products, six were chemicals, and 18 were classified as other substances such as "soot
and ash," "foam," garbage, etc. The spills resulted from
Structural failure (12 spills)
Natural seepage (12 spills)
Equipment failure (9 spills)
Intended discharges (5 spills)
Unintended discharges (3 spills)
Tanks spills (3 spills)
Not elsewhere classified (37 spills)
Geographically, the spills were concentrated in accordance with population centers. These were
Key West (26 spills)
Key Largo (18 spills)
Islamorada (7 spills)
Marathon (6 spills)
Tavemier (4 spills)
Big Pine (3 spills)
Other areas of the Keys (17 spills)
Petroleum products are the hazardous material most often spilled in the terrestrial areas within the Florida Keys.
Structural failure and natural seepage were responsible for the largest percentage of the hazardous-materials
spills occurring at specific facilities in the Florida Keys. New FDER regulations pertaining to storage tanks and
underground facilities should reduce the risk of future spills from these facilities (see discussion below).
Equipment failure and human error (intended and unintended discharges and tank spills) accounted for the
remaining classified spills reported. Increased enforcement, more frequent equipment inspections, and tougher
penalties will reduce but not eliminate spills in these categories.
The category "Not elsewhere classified" included an array of miscellaneous spill causes as well as spills
detected after the fact and that occurred for unknown causes. These types of spills were typically isolated
incidences, such as transportation accidents or deliberate dumping by unknown persons. Such spills can not be
allotted to any specific problem or facility, and they are the most difficult to prevent or guard against.
2.1.2 Hazardous-Materials Generators
The Resource Conservation and Recovery Act (RCRA) was enacted to enable Federal, State, and local
authorities to regulate handling of hazardous materials, especially those activities related to the handling,
storage, treatment, disposal, and generation of hazardous substances. The Federal government has delegated to
individual states, such as Florida, the authority to implement rulings and statutes listed under RCRA. Most
states, such as Florida, have gone beyond the minimum guidelines set forth by RCRA in their attempt to deal
more adequately and effectively with responsible parties involved with the use of hazardous materials.
RCRA technically defines hazardous materials as solids, liquids, or gases or combinations thereof, which may
because of its quantity; concentration; or physical, chemical or infectious characteristics be harmful or toxic to
human health. The Environmental Protection Agency (EPA) provides a concise definition, listing all
exemptions and exclusions, as well as constituents considered to be hazardous materials in 40 CFR 261.
6-2
-------
As part of Florida's enforcement program, the FDER has created numerous tracking systems/databases capable
of storing a site's past and current activities, its level of compliance with State statutes, current environmental
status, and other site-specific criteria.
A specific example is the FDER Groundwater Management System (CMS), which is a database system
consisting of several subsections. A subsection of particular interest is the CMS 10 System (small quantity
generators). This database or facility directory includes EPA and CMS operating permit numbers, site
locations, operating status, and treatment processes.
To be registered as a "small quantity generator," no more than 1000 kg can be generated within a 1-month
period. Full generator status is applicable to facilities that exceed 1000 kg/month or generate acutely hazardous
waste in excess of 1 kg/month.
There are currently (FDER CMS 10, dated 8 August 1991) 44 registered hazardous-waste generator sites in the
Florida Keys. Data quantifying the type of hazardous materials generated are not available. Only two sites
were classified as small quantity generators. These two sites are the United States Naval Air Station at Boca
Chica and the United States Naval Facility at Demolition Key. These sites were listed as facilities that
transport, dispose, and store hazardous materials.
2.1.3 Contaminated Sites
Site contamination in the Florida Keys generally is the result of failure of an underground storage tank system
that contains either petroleum products or materials listed under RCRA, Subtitle I. Under RCRA, Subtitle I,
the Regulation of Underground Storage Tanks was enacted in 1984 as part of the Hazardous and Solid Waste
Amendments (HSWA) to RCRA. An underground storage tank is one that stores "regulated substances" and
has at least 10% of its total volume below the surface of the ground, including all piping network. Regulated
substances are hazardous chemical products regulated under the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA). The regulation of petroleum products is covered by CERCLA.
Regulated substances do not include RCRA hazardous wastes. EPA 40 CFR Parts 280 and 281 differentiate
among substances regulated by CERCLA and RCRA.
The State of Florida, specifically the FDER, has been delegated authority by EPA through the development of
internal programs that exceed or meet EPA Federal guidelines, specifically the criteria set in Florida Chapter 1-
761, Florida Administrative Code (FAC), and Chapter 17-762.FAC. These are laws that deal with aboveground
as well as underground storage-tank systems, respectively. These chapters deal exclusively with regulatory
compliance, regulation, retrofitting to meet current "best available technology" criteria. In addition, Florida
developed Chapter 17-770.FAC, which deals exclusively with the assessment and remediation of contaminated
sites.
Of the 395 registered storage-tank systems sites in the Florida Keys, there are currently 64 sites that have
reported a."notice of discharge" with the FDER. A notice of discharge is required under Section 17-761,FAC
when a suspected underground storage-tank leak has contaminated the surrounding soils, surface waters
immediately adjacent to, or groundwaters directly beneath a tank system.
A portion of these sites are a part of either the Florida "Early Detection Incentive Program" (the EDIP) or the
more recently implemented "Abandoned Tank Restoration Program" (ATRP). These programs assist in the
funding of assessing the area! extent of a sites contamination, as well as the remedial activities required to clean
up contaminated sites. While the majority of sites contaminated are locations of major oil/gasoline companies,
marinas, retail facilities, and privately held commercial businesses, the costs from assessment to remediation can
. easily exceed hundreds of thousands of dollars.
6-3
-------
Although approximately 17% of the sites in the Florida Keys have experienced some sort of storage-tank
failure, the immediate nearshore marine environment could be impacted by tank failure, but the timing, location,
and magnitude cannot be predicted. As laws continue to improve the structural integrity of new underground
storage tank systems, the impacts attributed to their inadequacies will significantly decrease. There will still be
problems with older systems until these can be replaced.
2.2 MARINE
Between October 1985 and September 1991, there were 355 reported spills of hazardous materials in the waters
of the present FKNMS. Of these spills, 319 (90%) were petroleum products, 29 were classified as other oils,
.and seven were classified as other materials.
The vast majority of these spills were detected after the fact, consequently their actual cause is not known. For
those spills where causes were reported (84 of the 355), USCG data show the following.
Equipment failure (23 spills)
Intended discharge (15 spills)
Structural failure (13 spills)
Unintended discharge (12 spills)
Other (21 spills)
In 73 of the 355 spills, the type of vessel held responsible was identified. These data show the following.
Fishing boats (27 spills)
Freight barges (12 spills)
Recreational vessels — e.g., yachts (11 spills)
Passenger vessels (9 spills)
Public vessels — e.g., research vessels (4 spills)
Tug/tow boats (3 spills)
Unclassified vessels (3 spills)
Tank barges (2 spills)
Tank ships — e.g., tankers (2 spills)
Geographically, the 355 spills were reported as having taken place in the following areas.
Atlantic Coast — 0 to 3 nmi from shore (156 spills)
Gulf Coast — 0 to 3 nmi from shore (132 spills)
Inland, including canals and harbors (35 spills)
Atlantic contiguous — 3 to 12 nmi offshore (14 spills)
Gulf contiguous — 3 to 12 nmi offshore (9 spills)
Atlantic offshore — 12 to 200 nmi offshore (9 spills)
Petroleum products, primarily gas and diesel fuel, were the hazardous materials most often spilled into
Sanctuary waters. In 98 of the 355 spill records, estimations of the quantity of material spilled are given.
Figure 6-1 illustrates the relative frequencies of petroleum spills in the 0-5, 6-50, 51-100, and 100-1- gal ranges.
The maximum spill for which a volume was given was 755 gal. Obviously, small spills (0-5 gal) make up the
vast majority of reported petroleum spills from the FKNMS.
Applying percent by volume estimates (Figure 6-1) to the total 355 reported spills yields a range from 3852 to
17,785 gal of spilled petroleum products over the last six years. Based on these calculations, between 642 and
2964 gal of oil are spilled annually into the FKNMS. Figure 6-2(a) shows the total reported spills per year
6-4
-------
1004
51-100
6-50
0-5
11%
127%
159%
10
20
30
40
50
60
PERCENT ALL SPILLS
TOTAL NUMBER
OF SPILLS
11
26
58
-H
70
Figure 6-1. Percent by volume of reported petroleum spills in the Florida Keys National Marine Sanctuary
(based on 98 of 355 spills reported from October 1985 through September 1991
for which volume estimates are available).
-------
110
100-
W TK
_i 75-
51
LL
O
CC
111 en
CQ 50-
5
z
25-
0-
1000-
5 75°-
o
CO
O
li 500-!
O
250-
0-
««)
1,6
62
II I
I li
1 i 1 1 1 1
76
(b)
673
380
288
I 1
III
10/1/85 10/1/86 10/1/87 10/1/88 10/1/89 10/1/90
to to to to to to
9/30/86 9/30/87 9/30/88 9/30/89 9/30/90 9/30/91
Figure 6-2. Total number of spills (a) and annuaJ volume of oil spilled (from the 98 reported spills
for which volume estimates are reported) (b) into the waters of the Florida Keys National Marine Sanctuary.
6-6
-------
over the last six years in the FKNMS, and Figure 6-2(b) presents the annual volume of spilled oil from the 98
spills for which volume estimates are reported.
Annual reported volumes of spilled oil fluctuate far too much to reveal any trend. This is primarily because of
the lack of consistent volume estimates accompanying the spill reports, and the fact that large oil spills, while
occurring infrequently, distort the annual picture. No trends were seen in the seasonal data on oil spill
frequency or volume.
The vast majority of spills happen in coastal or nearshore waters and they are rather small in terms of the
quantities discharged. Structural or equipment failure accounted for 43% of the spills whose cause was
reported. Human error accounted for 32%. Commercial boats accounted for 85% of the spills for where actual
vessel type was reported, whereas recreational boats accounted for only 15%. Fishing boats, with 30% of the
boat-specific reported spills, were the vessels that most often spilled oil within the Sanctuary.
It is important to remember that all of the oil spills discussed represent only those spills that were reported or
came to the attention of the authorities. One can assume that a large number, probably the majority of small
spills (0-5 gallons), are never reported. No data exist on the number of these small spills occurring annually in
the FKNMS, but based on the amount of boating activity, such unreported spills may represent a significant
source of petroleum within the Sanctuary.
3.0 POTENTIAL LOCATIONS AND RISK OF FUTURE SPILLS OR HAZARDOUS-WASTE
CONTAMINATION WITHIN THE FLORIDA KEYS NATIONAL MARINE SANCTUARY
3.1 TERRESTRIAL
The causes of storage-tank system releases, which typically result in the discharge of a regulated or hazardous
substance, can be attributed to many sources, which include, the following.
• Spillage of fuels because of overfilling a storage-tank system. Systems that lack overfill protection are
susceptible to continued discharges that infiltrate and/or percolate downward into the soil and eventually
the phreatic or groundwater interface.
• Structural failures because tanks are old and unprotected from direct contact with groundwaters.
Unprotected tanks constructed of steel (which offer little resistance to the effects of rusting) degrade to
the point where they become prone to leakage. The groundwater interface in the Florida Keys makes
this type of failure a common source or cause of pollutants being released into the surrounding
environment. Most underground storage tanks are set directly within the groundwater. Taking
measures such as providing cathodic protection or using polymers or waterproof coatings on the
exterior of an underground storage tank prior to placement help to retard corrosion. However, storage
tanks, as part of a tank management program, should be inventoried monthly or "tightness"-tested
annually to check the structural integrity of the storage tank system.
• Pipe joint and integral pipe fitting failure because of improper installation, corrosion, and degraded
structural integrity. Sealants, epoxies, and similar pipe adhesives tend to decompose over extended
periods, especially in the Florida Keys area, where the combination of solvents, gasoline additives, and
persistent exposure to moisture accelerate decomposition.
• Poor human judgment, lack of training, indifference to impact on the environment and the
consequences thereof are additional causes of spills. Training and education are very important to
decrease spills from these causes.
6-7
-------
Fortunately, Florida is currently putting into law a program requiring that newly installed underground storage
tanks have "dual" containment lining systems to prevent the leakage of hazardous substances into the
environment. Depending on the initial installation date, storage tank systems are subject to either removal or
retrofitting to have as a minimum (1) leak detectors and (2) protection against overfill.
3.2 MARINE
Marine spills are presently not a major source of environmental impact within the FKNMS. The spills that do
occur typically are small and confined to the surface of the Sanctuary waters. The marine communities and
habitats comprising the critical environmental resources of the Sanctuary are relatively resistant to minor
amounts of oil floating on the water surface. There is a potential for long-term, cumulative environmental
effects resulting from frequent small oil spills. This potential is particularly acute in nearshore and confined
waters, but the basic research available on such low level exposures to petroleum products for FKNMS-type
habitats is so limited and equivocal that it is difficult to draw any firm conclusions that could be used to guide a
management strategy.
Mangrove mortality resulting from heavy oiling from a major spill incident is attributed to the oil covering the
gas exchange surfaces of the affected trees causing mechanical suffocation. While this is a logical assumption,
there is no experimental evidence to confirm the theory. There are reports in the oil spill literature indicating
delayed mortalities in oiled mangroves months or years after an oiling incident occurred (Getter et al. 1980).
Based on these reports, it appears that persistent oil or its breakdown products impose a chronic, sublethal stress
that taxes the metabolic resources of the trees. This chronic stress could be the direct result of an accumulation
of toxic materials (e.g., aromatic petrogenic compounds) in the sediments, or an indirect response to the altered
sediment chemistry (Marshall et al. 1990). To date no research has been conducted on the cumulative effects of
low-grade chronic exposure of sublethal amounts of petroleum products to mangroves.
Since 1973, there have been two major tanker-related oil spills in or adjacent to the waters of what is now the
FKNMS. Forty thousand gallons of oil were spilled on 18 July 1975. This slick actually oiled shorelines from
Boca Chica to Little Pine Key, where it came ashore between 21 and 25 July 1975 (Chan 1976). Sixty-nine
thousand gallons of oil were spilled into the Florida Current at a point northwest of Miami on 17 January 1980,
but this spill moved northward and did not impact any U.S. shorelines.
The major risk to the FKNMS from marine spills is the risk of a catastrophic oil spill resulting from a tanker
grounding or other major shipping accident. In 1989, the volume of oil transported through the Straits of
Florida for Florida ports alone was 286.5 million barrels. This volume was carried in 5860 transits along the
coast of Florida. Heavy tanker traffic off the Florida coast was estimated to transport over 12 billion gallons
per year (Najafi et al. 1991). The South Florida Regional Planning Council has identified four "hazard areas"
as having a greater potential for oil spills because of the presence of converging or crossing tanker traffic. One
of these areas is 12 nmi south of the Dry Tortugas, where the traffic from the Gulf of Mexico converges to
enter the Loop Current and travel northeast. The heavy tanker traffic utilizing the Loop Current increases the
possibilities of groundings as well as collisions (Najafi et al. 1991). No catastrophic shipping accident has ever
occurred in the area of the FKNMS, but the risk of such an accident remains. New Federal shipping
regulations (Federal Register 55:19,418-19,419) have moved tanker traffic farther offshore from the Keys.
Although this should reduce the risk of a Valdez-type accident impacting the Sanctuary, that kind of risk will
always remain.
6-8
-------
4.0 STATEMENTS OF PROBLEMS
A key part of Phase I of the Water Quality Protection Program is the identification of water quality problem
areas to be addressed during Phase II. A two-step approach was used to identify and obtain agreement among
members of the scientific community on known, suspected, or potential water-quality problems affecting the
natural resources of the Sanctuary. Initially, information gathered during the literature review was used to
derive a series of statements describing potential water-quality related problems (presented in Section 4.1).
These problem statements were then refined through discussions with EPA Region IV Coastal Programs staff
and State of Florida environmental staff and delivered to workshop participants to provide focal points for
discussions at technical workshops. The participants in each workshop were charged with coming to a
consensus, where possible, on the problem statements developed for each workshop resource area. A matrix
analysis of each workshop resource area (Appendix B) was the tool used to develop consensus on the problem
statements. Specific descriptive terms were used to complete the matrix based on the discussions with the
expert panels assembled for each workshop (Appendix B). Public comments were also heard during the course
of each workshop. To assist EPA Region IV and the State of Florida to direct their limited resources, each
expert panel was asked to rank the overall significance of the water-quality related problems at the end of each
daily workshop. The consensuses developed at the workshops are summarized in Section 4.2 and presented in
more detail in Appendix B.
4.1 PROBLEMS IDENTIFIED DURING THE LITERATURE REVIEW
The following lists either known, suspected, or potential problems related to spilled material impacts on water
quality in the FKNMS. However, to state a problem does not of itself mean or imply that the stated problem
actually exists. There is a divergence of views on what actually constitutes real or potential problems for the
FKNMS.
Chronic, relatively small petroleum and chemical spills may be adversely impacting the water quality of the
FKNMS. — Illegal dumping, where oil or other chemicals are deliberately dumped into marine waters, and
vessel spills could occur throughout the FKNMS, although the latter appear to be concentrated in nearshore
areas. Terrestrial spills involving oil or chemicals may occur at terrestrial facilities or during the transport of
such materials along any and all highways in the Florida Keys. Historically, spills at terrestrial facilities
sometimes reached marine waters, particularly under the old spill containment requirements. Transport spills
occurring on bridges may result in the material entering FKNMS waters. Data are sufficient to state that
chronic, relatively small spills of primarily petroleum products occur frequently in the waters of the FKNMS.
New regulations and stricter enforcement may reduce certain types of oil spills in the FKNMS, but overall the
number of small spills each year is not expected to decrease substantially. Data are insufficient to predict the
cumulative impact of these small spills on the overall water quality of the FKNMS. There are no quantitative
data on the effect of this chronic hydrocarbon pollution in the waters of the FKNMS. The problem is water
quality related and is possibly significant.
Catastrophic oil tanker spills are a risk to the FKNMS biological communities. — A catastrophic oil spill,
resulting from the sinking or grounding of a tanker in or near the FKNMS, could affect the entire FKNMS.
Tanker spills have been rare in the Florida Keys. Only one major spill has come ashore since the United States
Coast Guard began keeping computerized spill records in 1973, and the impacts from that spill were minimal in
marine waters. The data are insufficient to determine the real likelihood or risk of a catastrophic oil spill
impacting the FKNMS at any specific time. The problem is not directly related to water quality, but is
essentially a risk assessment problem. A catastrophic spill is potentially significant, but the extent of its effects
is undetermined.
6-9
-------
4.2 PROBLEMS IDENTIFIED AT THE SPILLS AND HAZARDOUS MATERIALS
ASSESSMENT WORKSHOP
The ten problems discussed at this workshop were small vessel spills (marine), small facility spills (landbased),
illegal dumping (marine and landbased), catastrophic tanker spills, tanker truck spills, effects of dispersant use,
bioremediation, teachable toxics, boat scraping, and ruptured bulk tanks and pipelines. The parameters for
analysis and the matrix used for the discussion are presented in Appendix B. For all of the following problems,
there is little documentation or information generated in the Keys and this information is greatly needed.
Small vessel spills occur year-round, are widespread (nearshore and fueling areas), and the trend is
worsening (with the qualification that there has been an increase in reporting), — Small vessel spills (marine)
•were defined as spills from a vessel with £5000 gallons of fuel and/or cargo. The major constituents of these
spills are diesel fuel, gas, and bilge. The problem is severe locally and unknown overall. The adequacy of
existing contingency plans is low. The water-quality effect is locally toxic and unknown overall. The authority
exists for enforcement, but manpower is low and compliance is also low. The risk (likelihood of an event
occurring) is high. The overall significance of this problem to the Water Quality Protection Program is high.
Small facility spills occur year-round and are widespread (in marinas and fueling areas) and the trend is
worsening (with the qualification that there has been an increase in reporting). — Small facility spills
(landbased) generally are unreported and include those spills from marinas, auto fueling facilities, small
industrial facilities, and residents. Constituents of these spills are diesel fuel, gas, solvents, pesticides, used
motor oil, and paint-related material. The problem is severe locally and unknown overall. Compliance,
enforcement, and the adequacy of existing contingency plans are low. The water-quality effect is locally toxic
and unknown overall. The risk (likelihood of an event occurring) is high. The overall significance of this
problem to the Water Quality Protection Program is moderate.
Illegal dumping (marine and landbased) occurs year-round, is widespread, and the trend is worsening. —
Illegal dumping (marine and landbased) for marine-based sources was defined as spills from a vessel with
^5000 gallons of fuel and/or cargo and materials resulting from the pumping of bilges and cleaning of cargo
holds. Constituents of these marine-based spills are petroleum products. The constituents of land-based spills
are paint and solvents. The quality and quantity of these marine- and land-based substances are unknown. The
problem is severe locally and unknown overall. The water-quality effect would be locally high and unknown
overall. Compliance is very low and enforcement is improving. The risk (likelihood of an event occurring) is
moderate. The overall significance of this problem to the Water Quality Protection Program is high.
Catastrophic tanker spills occur year-round (two have occurred in the last 16 years in the Keys) and the
potential severity of a spill in the FKNMS is high. •— Catastrophic tanker spills were defined as a spill of
> 10,000 gallons inshore and > 100,000 gallons offshore whose major constituents are diesel fuel, blends of
fuel, heavy fuels, hazardous materials, and crude. The likelihood of a catastrophic spill happening is
decreasing. A sanctuary-specific contingency plan is needed and it should include what should be done with the
cleanup waste. Compliance and enforcement are moderate to high and the risk (likelihood of the event
occurring) is low. The water-quality effect is high if the spill reaches the FKNMS. The overall significance of
this problem to the Water Quality Protection Program is high.
Tanker truck spills (including tractor trailers) occur year-round (two have occurred in the last 10 years in the
Keys) and are usually isolated to highways. — The major constituents of this type of spill are gasoline, diesel
fuel, and other hazardous materials. The severity of a spill is high locally and the likelihood of this type of spill
occurring is decreasing. The adequacy of the existing contingency plans is good; however, response time is a
problem. The water-quality effect would be severe locally because of the highly toxic compounds being spilled.
Compliance and enforcement are moderate to high and the risk (likelihood of the event occurring) is moderate.
The overall significance of this problem to the Water Quality Protection Program is moderate.
6-10
-------
The effects of dispersant use would have a seasonal impact on habitats. — Currently in the Keys, dispersants
are considered for every spill but have not been used. The adequacy of contingency plans is low and there is a
need for more work on the plans. The risk of using dispersants is low; the water-quality effect would be
variable. The overall significance of this problem to the Water Quality Protection Program is high. More
information is needed regarding the effects of dispersant use on larvae. There are tradeoffs to consider when
using dispersants. Research is needed regarding the toxicity of spilled oil versus the toxicity of the dispersed oil.
The use of bioremediation is not as constrained as dispersant use. — The potential water-quality effect of
adding nutrients is low. The overall significance of this problem to the Water Quality Protection Program is
unknown but unlikely. Interim guidelines are needed.
The leaching of toxics occurs year-round in isolated areas. — Leachable toxics were defined as substances
originating from Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and
Resource Conservation and Recovery Act (RCRA) sites and underground storage tanks and include a variety of
constituents such as heavy metals, polychlorinated biphenyls (PCB), insecticides, and pesticides. The problem
is moderately severe and improving. Compliance/enforcement and contingency plans are site dependent and are
low to high in adequacy. Risk is unknown. The water-quality effect is unknown but potentially significant.
The overall significance of this problem to the Water Quality Protection Program is moderate.
The problem of hazardous materials resulting from boat scraping (metals) occurs year-round with seasonal
peaks and is isolated to site-specific areas. — Trend, severity, and compliance/enforcement are unknown and
the risk (likelihood of event occurring) is high. The water-quality effect of this problem is high. The overall
significance of this problem to the Water Quality Protection Program is high.
The problem of hazardous materials resulting from ruptured bulk tanks and pipelines occurs year-round in
isolated, site-specific areas. — These hazardous materials consist of jet fuel, diesel, and various other petroleum
products. The severity of the problem is moderate to high. Contingency plan adequacy is moderate.
Compliance/enforcement is moderate to high and risk (likelihood of event occurring) is high. The water-quality
effect is probable. The overall significance of this problem to the Water Quality Protection Program is high.
5.0 REFERENCES
Chan, E.I. 1976. Oil pollution and tropical littoral communities: Biological effects of the 1975 Florida Keys
oil spill. M.S. thesis, University of Miami, Miami, FL.
Getter, C.D., S.C. Snedaker, and M.S. Brown. . 1980. Assessments of biological damages at Howard Star oil
spill site, Hillsborough Bay and Tampa Bay, Florida. Florida Department of Natural Resources,
Tallahassee, FL.
Marshall, M.J., S.C. Snedaker, and C.D. Getter. 1990. The sensitivity of south Florida environments to oil
spills and dispersants. Pp. 559-608 in: N.W. Phillips and K.S. Larson, (Eds.), Synthesis of available
biological, geological, chemical, socioeconomic, and cultural resource information for the south Florida
area. Dept. of the Interior, Minerals Management Service, Atlantic OCS Region, Washington D.C.
Contract No. 14-12-0001-30417.
Najafi, F. T. 1991. Oil spill impact assessments and response capabilities in south Florida. South Florida
Regional Planning Council, Hollywood, FL. Grant No. 90-016. 143 pp.
6-11
-------
SUMMARY AND RECOMMENDATIONS
CONTENTS
1.0 POINT-SOURCE DISCHARGES 7-1
2.0 NONPOINT-SOURCE DISCHARGES 7-1
3.0 EXTERNAL SOURCES 7-2
4.0 EXISTING WATER QUALITY 7-2
5.0 FUTURE WATER QUALITY (YEAR 2010) 7-3
6.0 CORAL COMMUNITIES 7-3
7.0 SUBMERGED AND EMERGENT VEGETATION 7-4
8.0 NEARSHORE AND CONFINED WATERS 7-5
9.0 SPILLS AND HAZARDOUS-MATERIALS ASSESSMENT 7-6
10.0 EFFECTS OF WATER QUALITY PARAMETERS 7-7
11.0 RECOMMENDATIONS 7-7
LIST OF FIGURES
7-1. Effects of water-quality parameters on significant environmental problems in the
Florida Keys National Marine Sanctuary 7-8
-------
SUMMARY AND RECOMMENDATIONS
1.0 POINT-SOURCE DISCHARGES
There were 13 active National Pollutant Discharge Elimination System (NPDES) permitted point-source
dischargers within the Florida Keys National Marine Sanctuary (FKNMS) as of January 1992. There are an
additional four facilities with permits that may have discontinued discharging or discharge only in the event of
an emergency. Several of the active facilities are planning to eliminate their surface water discharge either by
connecting to an existing facility or by discharging into the ground. Only one domestic wastewater facility [Key
West Sewage Treatment Plant (STP)] is considered a major [5.82 million gallons per day (MOD)] discharger.
The second largest domestic wastewater discharger (City of Key Colony Beach STP) discharges an average of
0.17 MGD. The remaining wastewater facilities that are actively discharging and for which data are available
(7) have a total combined flow of 0.93 MGD. Two facilities are industrial dischargers and a third permit is for
stormwater. Key West Utility, a power plant, uses seawater for cooling. The average daily discharge from this
facility was 21.4 MGD for the first 8 months of 1991. The second facility is a desalinization unit at Ocean
Reef Club. The average daily discharge from this facility was 0.39 MGD for the first 6 months of 1991. The
facilities are not required to monitor nutrient levels in their discharges. However, the Key West STP has
initiated monitoring of influent and effluent nutrients. The average effluent values for NH3-N, NO3-N, and
PO4-P for 1991 were 2.0, 1.8, and 2.49 mg/L, respectively.
The C-l 11 and Model Land canals discharge into the FKNMS at Barnes and Card Sounds, respectively. Both
canals are operated by the South Florida Water Management District (SFWMD) for flood control. Flow data
are available for both canals. Nutrient data are available only for C-l 11. Total phosphorus ranged from 0.004
to 0.015 mg/L and inorganic nitrogen from 0 to 0.45 mg/L for the period of 1985 to 1987.
2.0 NONPOINT-SOURCE DISCHARGES
There are 209 Florida Department of Environmental Regulation (FDER) permitted wastewater treatment
facilities within the FKNMS. This includes municipal plants (2) and package plants. One hundred ninety-nine
have a subsurface discharge method, with the majority having injection wells. The FDER regulates facilities
that treat flows exceeding 5000 gallons per day (GPD) for domestic establishments, 3000 GPD for food-service
establishments, and where sewage contains industrial, toxic, or hazardous chemical waste. Marathon,
Islamorada, and Key Largo have significant concentrations of facilities. These discharges are not monitored for
nutrients. However, data on biological oxygen demand and total suspended solids are available. The discharges
are considered to have received secondary treatment.
Onsite disposal systems (OSDS) include septic tanks, cesspools, and aerobic systems. The exact number of
OSDS in the Florida Keys is presently unknown. Monroe County's contractor [Wallace Roberts & Todd
(WRT) team] is inventorying all permitted and unpermitted septic tanks and cesspools in unincorporated Monroe
County as part of the development of the County's Comprehensive Plan. It is estimated that there are
approximately 25,000 permitted septic tanks within the FKNMS. The treatment efficiency of OSDS in the
Florida Keys has been questioned due to the geology of the Keys. No monitoring of flow or constituents is
required.
There is a lack of effluent nutrient data for the FDER-permitted facilities and OSDS units in the Florida Keys
although data from other areas are available. Additionally, there are very few studies that have investigated
nutrient uptake by soils, movement of nutrients within the groundwater, and entry of these nutrients into the
marine waters of the FKNMS. Monroe County, as part of their comprehensive plan, is proposing the
development of a Sanitary Wastewater Master Plan by 1995 that may include data gathering in these areas.
7-1
-------
Landfill sites and mosquito control spraying are additional potential nonpoint sources of pollutants to marine
waters within the FKNMS. The amount of pollutants entering marine waters from these sources is unknown.
The SFWMD is responsible for permitting surface-water management in the Florida Keys. There have been
approximately 50 permits issued by the SFWMD. Stonnwater flow and its constituents have not been directly
studied in the Florida Keys. There has not been a single study involving the sampling of flow constituents in
the Keys. The SFWMD has depended on studies outside Florida to assess land use and runoff quality
relationships. Treatment efficiencies for the Keys were also evaluated. Additional studies (Riviera Canal, Key
West; upper Keys) have calculated stormwater loadings based on land use and literature data. Monroe County,
as part of the development of the comprehensive plan, is preparing an updated land-use map. This is needed to
evaluate pervious/impervious conditions for prediction of seepage versus runoff. Monroe County, as part of
their comprehensive plan, is proposing the development of a Stormwater Management Plan by 1995.
Individuals who live aboard their boats continuously for a period of 2 months or more have been termed live-
aboards. The largest number of live-aboards are found in marinas, but many are also anchored offshore. The
discharge of raw sewage from the live-aboards is a potential problem in the FKNMS. There are over 180
marinas in the Florida Keys, but there are only nine sewage pumpout facilities.
Live-aboards may contribute to water quality degradation in marinas as well as other areas of concentration.
The Florida Department of Natural Resources (FDNR) has initiated rule development to assist in regulating live-
aboard vessels on sovereign submerged lands.
3.0 EXTERNAL SOURCES
Water quality in the FKNMS can be affected by sources of poor water quality located outside the Sanctuary
boundaries. Areas adjacent to the FKNMS include Florida Bay, Biscayne Bay, and the Gulf of Mexico/Atlantic
Ocean. Florida Bay has shown no indications of a prevalent anthropogenic problem with contaminants other
than freshwater. The variance in freshwater input from the Everglades area has affected salinity within the Bay.
The effect of these changes in salinity on the FKNMS has not been documented. The effect of natural
variations in temperature, turbidity, and other parameters within Florida Bay on the FKNMS are also relatively
undocumented, although these same variations are probably also occurring in the FKNMS waters. A relatively
extensive water quality sampling program has been conducted in Biscayne Bay. This program indicates that the
water quality in south Biscayne Bay is relatively good and that it is likely that no significant degradation of
FKNMS waters is directly occurring through exchange with Biscayne Bay. The effect of the waters of the Gulf
of Mexico/Atlantic Ocean on the waters of the FKNMS through upwelling and entrainment of relatively nearby
(e.g., Virginia Key sewage outfall) or distant (e.g., Mississippi River) discharges is very difficult to determine.
This difficulty is based, in part, on the great natural variability of the physical oceanographic system and the
level of entrainment and delivery to the FKNMS waters.
4.0 EXISTING WATER QUALITY
There is a lack of data to evaluate the existing water quality in the FKNMS. The water quality data are
insufficient in terms of long-term studies to evaluate temporal changes. The offshore FKNMS waters do not
appear to be degraded, based on the available scientific data though some anecdotal observations suggest
degradation has occurred. Degraded water quality has been detected in many artificial waterways and canals.
This degradation is in the form of measured increases in nutrients and depressed dissolved oxygen. These areas
and others with documented water quality problems have poor water exchange with nearshore/offshore waters.
This poor flushing combined with increased organic enrichment has led to the poor water quality. The
boundaries between confined, nearsbore, and offshore waters are difficult to define as the boundaries are
7-2
-------
relatively arbitrary. The effects of poor water quality in confined waters on nearshore and offshore waters is
dependent on the level of degradation of the water quality and the delivery (mixing rates) of the water to
nearshore waters. However, this poor water quality of confined waters should be considered a major problem
due to the effect on the biotic resources within those waters and the potential effects of continued degradation on
the biotic resources of the nearshore and offshore waters.
5.0 FUTURE WATER QUALITY (YEAR 2010)
The future water quality in FKNMS waters depends on both the natural and anthropogenic pollutant loadings
that occur. The temporal and spatial variability of the loadings will also significantly affect the water quality.
The factors that will probably most effect the anthropogenic loadings will be population growth, spatial
distribution of the increase and land use, required treatment efficiencies of wastes from the existing and
increased population, and selected disposal mechanisms of the wastes.
Many of these factors will be determined through the Monroe County Comprehensive Plan or the proposed
Sanitary Wastewater and Stormwater Master Plans, and City of Key West Comprehensive Plan. The issue of
population growth in the County has been addressed through measures of carrying capacity based on the ability
to evacuate residents in the event of a hurricane threat.
Based on the limited water quality and biotic resource (Tasks 3 and 4) data, it appears that organic/nutrient
loading may represent a serious long-term threat to the FKNMS. There may be other potential threats (e.g.,
metals in marina basins and insecticide usage), but a comprehensive water-quality monitoring program is needed
to evaluate these possibilities.
Additionally, the relative significance of the different sources contributing to the organic/nutrient loading needs
to be determined. This will also involve a determination of the delivery mechanisms. Stormwater runoff,
groundwater discharge, rainfall, decomposition of concentrations of Sargassum and seagrass, and upwelling are
some of the mechanisms that introduce nutrients into the Sanctuary. The location of the point of introduction is
critical to determining the potential impact on water quality and biotic resources.
The existing data and/or data to be collected may suggest adoption of effluent standards to reduce nutrient
inflow. Presently, there are no standards that apply to either surface water or wastewater discharge in the Keys.
The Monroe County and City of Key West Comprehensive Plans discuss possible nutrient removal limits.
The ability to determine existing nutrient loadings is severely constrained due to a lack of data from the Florida
Keys on measured loadings to the groundwater, transport of groundwater nutrients to marine waters, measured
constituents in Stormwater, and quantity of Stormwater discharge to marine waters via groundwater and
overflow.
6.0 CORAL COMMUNITIES
The high latitude coral reefs of the FKNMS extend from Cape Florida to the Dry Torrugas. Included are an
estimated 19,420 ha of reef and 110,635 ha of low-relief hard bottom. Three types of reef habitats occur from
the shoreline to 13 km offshore at depths ranging from < 1 to 41 m. Hard-bottom areas, which occur close to
shore, are exposed rocky substrates colonized by algae, stony corals, and a variety of other sessile invertebrates.
The corals found here are small and are not actively building reef structures. Patch reefs typically occur
offshore Hawk Channel, but inside the bank reefs occur at depths up to 9 m. The reef framework is formed
primarily by massive star and brain corals (Diploria, Montastrea), filled in with algae, sponges, octocorals, and
bryozoans. Bank reefs, positioned parallel to shore, exist seaward of Hawk Channel and the patch reefs. Most
7-3
-------
bank reefs occur in the upper and lower Keys where island mass shelters the reefs from the waters of Florida
Bay. Bank reef structure is complex, generally characterized by a spur-and-groove system oriented
perpendicular to the shoreline or depth contours.
Reef-dwelling corals include hydrozoan corals, octocorals, and scleractinian corals. The primary hydrozoan
coral found in the FKNMS is the limestone-bearing fire coral, Millepora. Octocorals, sea whips or sea fans,
are usually the most common coral within the FKNMS, one species occurring at reported densities of up to 73
colonies per square meter. Scleractinian, or stony, corals are major contributors to reef structure. Life spans
of stony corals range from a few to hundreds of years.
Significant changes in the coral communities of the FKNMS have been documented in recent years. Included
are increases in coral abundance at Carysfort Reef because of fragmentation and subsequent regeneration of
large colonies of Acropora and losses of coral cover at Looe Key and Key Largo. Other coral community
components, octocorals and sponges, have decreased in abundance at Fiesta Key. Changes such as these may
reflect alterations in the vitality of coral communities in the FKNMS attributable to either natural or
anthropogenic factors.
There is a general consensus among researchers that the coral communities in the FKNMS are undergoing stress
from both natural and anthropogenic factors. The problems associated with such stress appear to be severe, but
there are not sufficient data from most localities in the Keys to document their extent. Furthermore, it is not
always easy to extrapolate from studies of other reef systems because corals in the Keys live at the climatic
threshold for coral reefs which may magnify the effects of relatively small environmental changes.
At the technical workshops, coral disease, zooxanthellae expulsion (bleaching), lack of coral recruitment,
impaired colony growth rates, a decline in coral abundance, and blooms of Lyngbya were seen as significant
problems. Many of these reef-associated "problems" are thought to be related to natural water quality
parameters. Two, coral disease and coral bleaching, occur in the Keys as well as world-wide. Both may be
affected by temperature and/or salinity. Temperature may also have an effect on several of the other problems
mentioned. Though temperature stress is not usually anthropogenic, the draining of much of south Florida may
have affected the thermal buffer that may have protected Florida Bay from cold fronts. Changes in several
coral community parameters have been perceived as problems potentially attributable to water quality. The
impacts of anthropogenic factors — e.g., nutrients, toxics/pesticides,and turbidity — are less clear. Nutrient
levels affect blooms of Lyngbya or other algae, and turbidity affects coral growth rates and abundance.
However, the impacts of the other water quality parameters on coral reefs in the Keys are unknown.
7.0 SUBMERGED AND EMERGENT VEGETATION
The FKNMS presently encloses an estimated 565,094 ha of seagrass beds and 22,560 ha of mangroves.
Macroscopic algae also contribute significantly to submerged vegetation communities within the Sanctuary.
Dredging and land filling associated with development in the Keys have significantly affected these plant
communities. Significant storms and hurricanes may affect submerged and emergent vegetation.
Seagrasses — Submerged vascular plant communities within the FKNMS consist mainly of the perennial
seagrass species Thalassia testudinum (turtle grass), Syringodium filiforme (manatee grass), and Halodule
wrightii (shoal grass). These form large, complex biological habitats persisting from year to year in the same
general locations. Such seagrass beds are possibly the most productive of the biological communities occurring
within the FKNMS and produce about 95% of the submerged vegetative biomass in the FKNMS. Annual
species, Halophila decipiens (paddle grass) and H. engelmannii (star grass) are minor contributors to seagrass
biomass. Because they are able to survive at reduced light levels, these species may occur in relatively deep
water.
7-4
-------
Most documented losses of seagrasses have been attributed to the general development of the watershed and
coastline that influence the beds. Most often the reduction of the quantity and quality of light that reaches the
seagrasses is cited as the reason for the destruction of seagrass beds. Two water quality parameters responsible
for increases in light attenuation are increases in suspended sediments in the water (turbidity) and anthropogenic
nutrient input that may cause phytoplankton blooms and increased growth of epiphytes on seagrasses. These
two factors may also affect the growth rates of individual plants, decreased geographical extent of seagrass
beds, and decreased seagrass recruitment. Also having relatively important impacts on seagrass beds are
temperature, salinity, and dissolved oxygen (DO) levels. Seagrass-related problems are most serious in "hot
spots" — areas of severe water quality degradation.
Macroalgae — Many species of benthic macroscopic algae are important members of submerged vegetation
habitats within the FKNMS. Notable are calcareous taxa such as Halimeda, that become disarticulated upon
.death and thereby contribute significantly to the buildup of carbonate sediments and a transient species,
Laurencia. The latter, along with clumps of other taxa may provide environments for colonization by small
invertebrates. These drift algal mats may stimulate settlement of postlarval spiny lobsters, Panulirus.
Priority problems identified for macroalgae communities were increased epiphyte growth and anthropogenic
nutrient loading. Problems discussed at the technical workshops were thought to be acute in hot spots, but may
occur at various degrees in other areas. Increased epiphyte growth, increased macroalgal growth rates, and
decreased community diversity are affected to some degree by anthropogenic changes in nutrients, turbidity, or
DO.
Mangroves—Once spanning the length of the Keys, mangrove forests have been reduced in extent by coastal
development. Significant stands of forest remain, notably in the Marquesas, Rodriquez Key, and John
Pennekamp Coral Reef State Park. Rhiiophora mangle (red mangrove), Laguncularia racemosa (white
mangrove), and Avicennia germinans (black mangrove) are the three species of mangroves that may be found
among the six types of mangrove forests occurring in the FKNMS — overwash, fringe, riverine, basin,
hammock, and scrub or dwarf. The main anthropogenic threats to mangrove swamps are diking, impounding,
flooding, and outright destruction by dredging and filling activities.
Major concerns are preserving the geographical extent of mangroves and the functional value of the mangrove
habitat. Both concerns are probably related to water quality; salinity, turbidity, nutrients, and DO affect the
former, and anthropogenic DO, nutrients, and toxics/pesticides affect the latter. Decreased productivity of
individual .trees is a water quality problem of unknown significance.
Changes in the patterns of historic freshwater flow to Florida Bay have impacted animal and plant communities
in the Bay in different ways. Reduced flow, and concomitant increased salinity, has allowed expansion of some
mangrove communities. However, technical workshop participants felt that increased salinities are responsible
for damaging coral reefs in the Bay. This increased salinity in the Bay may also be responsible for the shift in
the community dominant from Halodule wrightii to Thalassia testudinum.
8.0 NEARSHORE AND CONFINED WATERS
Technical material that was derived from the interviews and literature review of nearshore and confined waters
is summarized in Sections 4.0 and 5.0 above. The following discussion is derived from the technical workshops
held in Miami, Florida. During the technical workshops confined waters were defined as canals, marinas, bays,
and lagoons; nearshore waters as those extending from shore to Hawk Channel, including the 18 ft depth
contour; and back country waters as nearshore Florida Bay waters within the 8 to 10 ft depth contour. Water
quality of these areas is controlled by a variety of natural and anthropogenic factors. The decomposition of
weed wrack and other organic debris, blown by winds into canals, may significantly lower DO levels especially
in areas having poor water exchange. Nearshore water composition may be determined by upwelling and other
7-5
-------
exchange with offshore water. The introduction of nutrients from the atmosphere could affect the quality of
these waters.
Anthropogenically-derived effects on biological communities may result from increased nutrient loads caused by
sewage discharge from the previously described point and nonpoint sources (Sections 4.0 and 5.0). These
increased nutrient loads may stimulate phytoplankton growth and subsequently lead to reduced DO levels.
Sewage discharges may cause an increase in fecal coliform bacteria concentrations. It has been suggested that
nutrients may build up in the groundwater during the winter dry season and are flushed into marine waters
during the summer wet season. Increased nutrient loads also contribute significantly to increased growth of
epiphytes, a problem that has been increasing over the past 10 years. Problems associated with increased
nutrient loads appear to be more severe in confined waters than in nearshore or back country waters. In the
latter two areas, epiphyte and phytoplankton growth increases are slight.
Concern was expressed at the workshops over human health risks associated with the consumption of personally
caught seafood from confined waters. No data exist regarding the potential problem in the Keys.
9.0 SPILLS AND HAZARDOUS-MATERIALS ASSESSMENT
Terrestrial — FDER records for the Florida Keys showed 12 terrestrial spills between January 1987 and June
1991. These included spills of petroleum products (six), sewage (three), and miscellaneous toxic substances
(three). National Response Center data files showed a total of 81 terrestrial spills between October 1984 and
March 1990. These spills involved petroleum products (57), chemicals (6), and other substances (18). The
principal causes of the spills were structural failures, natural seepage, and equipment failure. New FDER
regulations pertaining to storage tanks and underground facilities along with more frequent inspections and
increased enforcement should reduce spills. There are numerous hazardous-material generators and
contaminated sites located within the Florida Keys.
The potential problem areas for the Sanctuary in terms of upland spills and contamination are the existing sites
where the groundwater is known to be contaminated and the sites where the underground storage tank facilities
have not yet been brought up to the current standard for containment and isolation of spills or contamination.
These facilities are scheduled to be brought into compliance by the year 2010. The transport of petroleum
products and other chemicals has the potential to introduce hazardous materials into Sanctuary waters. The
rupture of pipelines used for the movement of petroleum products, such as jet fuel, or tanker truck spills are the
most likely mechanisms for such spills. Contingency plans for these types of spills are moderately adequate.
Terrestrial spills, unless they spill directly into marine waters, will most likely not significantly contaminate
marine waters. Leaching of toxic materials from Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA) sites and underground storage
tanks is moderately severe, but improving.
Marine — There were 355 reported spills of hazardous materials in the waters of the FKNMS between October
198S and September 1991. Approximately 90% of these spills involved petroleum products. Most spills (76%)
were detected after the fact, so no cause could be identified. Volume was estimated for 98 of the reported
spills, all of which involved petroleum products. Most of these 98 reported spills were less than 5 gal. Most of
the spills for which volume was estimated occurred in coastal or nearshore waters as a result of structural or
equipment failure and human error.
The most significant sources for marine spills of hazardous material within Sanctuary waters are oil spills from
small, locally operated, commercial vessels, primarily fishing and transport vessels. While every effort should
be made to reduce and eliminate these spills through inspection and enforcement, at their present levels these
spills do not appear to pose an immediate threat to the biological resources of the Sanctuary. However, the
overall significance of this problem to the Water Quality Protection Program was judged to be high by the
7-6
-------
workshop participants. The likelihood of the introduction of metals into Sanctuary waters from boat scraping is
high and, although the trend and severity are unknown, such introduction represents a significant problem for
the Water Quality Protection Program.
The lowest risk to the FKNMS is from a large marine petroleum spill. Tanker spills have occurred in the area
of the Florida Keys in 1975 and 1980. Tank vessels and vessels greater than SO m long (except public vessels)
are prohibited from operating in an area ('Area to be Avoided* — Federal Register 55:19,418-19,419)
designated to protect the FKNMS. Mineral and hydrocarbon leasing, exploration, development, and production
activities are also prohibited in the FKNMS.
Dispersants are considered for use in each significant spill of oil or other petroleum product into Sanctuary
waters. The risk of using dispersants is low although more information on the effects of dispersants on larvae is
needed. The toxicity of spilled versus dispersed oil needs to be studied. The introduction of nutrients by
bioremediation efforts is not likely to have an impact on water quality.
10.0 EFFECTS OF WATER QUALITY PARAMETERS
The effects of seven water quality parameters — nutrients, turbidity, temperature, salinity, toxics/pesticides,
bacteria/viruses, and DO — on the living resources of the FKNMS were evaluated by participants at the
technical workshops. The evaluations are summarized in Figure 7-1 for problems deemed significant by
workshop participants. From this figure, one can determine whether or not enough information is available to
determine the relative impact of a parameter on living resources and, if there are enough data, what that relative
impact is. For example, nutrients and turbidity impact seagrasses, macroalgae, mangroves, and confined
waters. They also impact some coral resources, but for the most part, their impact on corals is unknown.
Conversely, the impacts of toxics/pesticides and bacteria/viruses on living resources in the FKNMS are largely
unknown.
11.0 RECOMMENDATIONS
There is a lack of data documenting a decline in water quality in the offshore and nearshore waters of the
FKNMS. There is also no documentation that the general declines in coral communities within the FKNMS are
linked to water quality. Data are also not sufficient to definitively state that seagrass bed deterioration is or is
not occurring in the FKNMS. However, it is well documented that deteriorating water quality will lead to
declines in seagrass beds and coral communities if it is sufficiently severe. This fact, coupled with documented
water quality problems in confined waters of the FKNMS, strongly suggests that the development of a Water
Quality Protection Plan for the FKNMS is critical to the long-term survival of the biotic resources within the
FKNMS. Increasing or continuing the current level of organic inputs could lead to further declines in the water
quality of confined waters that could eventually effect the more nearshore waters and their biotic communities.
The following recommendations are made relative to the development of the Water Quality Protection Plan.
Monitoring Program
• Develop a monitoring plan to characterize the nutrient inputs to the groundwater.
• Develop a monitoring plan to characterize the constituents within stormwater in the Florida Keys
based on land use. Determine what percentage of stormwater results in overland flow to marine
coastal waters.
7-7
-------
CORALS
7 OiMM
7 BlMching
? Recnjltmenl
7 Grow* Rat*
? Abundance
tynco/*
SEAGRASSES
Epiphyl**
GrowtfiRat*
Community Diversity
Geographic Rang*
MACROALGAE
Epiphyte
Gretrtn Rat*
Community Diveraity
Algal Oivereity
MANGROVES
Functional Valu*
CONFINED WATERS
Epiphyl*.
Chlorophyll
Community Sffuctur*
CORALS
7 Die*.-
7 BlMching
7 Recruitment
Grown Ret*
SEAGRASSES
Epiphyut
Community Diwriity
Geographic Rang*
MACROALGAE
Epiphyut
Growrn FUl*
Community Oivtriity
MANGROVES
gneton*! V«lut
CONFINED WATERS
Epiphyi«i
Chlorophyll
Community Strvclura
CORALS
Oiwa»
Bleaching
Recruitment
Grow* R*t*
'Abundance.
SEAGRASSES .
, Epiphyl**
Growot Rat*
Community Diversity
Geographic Range
MACROALGAE
' Epiphyte*
Grow*R*t*
Community Oiv*rvty
Ajg«l Oivvraity
MANGROVES
7 Functional V*lu*
A CONFINED WATERS
> Epiphyl**
^ Chlorophyll
Community Structure
CORALS
Oieua*
Bleaching
7 Recruitment
Growth Rat*
Abund*nc*
l/ngb/a
SEAGRASSES
Epiphyl**
Grown Rat*
Community Diwreity
Geogrtphic Rang*
MACROALGAE
Epiphyu*
Growth Rat*
Community Div*r*ity
Algal Oiveriity
MANGRO\'ES
7 Functional Valu*
CONFINED WATERS
Epiphyl**
Chlorophyll
Community Structure
Figure 7-1. Effects of water-quality parameters on significant environmental problems in the
Florida Keys National Marine Sanctuary. Solid arrow denotes a significant effect; dashed arrow
denotes a possible effect; ? denotes an unknown effect; and no symbol denotes no effect.
7-8
-------
CORALS
7 DiWMt
1 Bl**ching
7 Recruitment
7 Growgi R>t*
1 Abundant*
7 Lyngbrl
SEAGRASSES
? Epiphyte*
7 Growth Raw
Community Diwtity
Geographic Rang*
MACROALCAE
7 Epiphyu*
, Growlh Reu
•^ Community Diveraify
7 Algal Diversity
MANGROVES
Functional Valu*
CONT1NED WATERS
CORALS
7 Oiwai*
j EMMching
$ 1 Rtcruitmani
/ 7
7 Chlorophyll
7 Community Svuetur*
Abundanot
SEAGRASSES
7 Epiphytat
7 Growth Rata
•^^ Communln/ Divertiry
7 Gtographic Ranga
MACROALGAE
7 Epiphytaa
7 Growlh Rat*
^^ Community Div*ratty
7 Algal DivvraJty
MANGROVES
7 Functional Valu*
CONFINED WATERS
7 Epiphyua
1 CIMOrophyll
7 Community Structure
CORALS
Dime*
Bleaching
7 Recrulonent
Growth FUl*
Abundance
SEAGRASSES
Epiphy**
Growth Rat*
Community Oivtraity
Geographic Ranga
MACROALGAE
Epiphyua
GrowV< Raw
Community Divttaity
Algal Divtriity
MANGROVES
Funcoonal Valu*
COSTINTD WATERS
7 Epiphyua
7 Chlorophyll
7 Community Structur*
Figure 7-1. Effects or water-quality parameters on significant environmental problems in the
Florida Keys National Marine Sanctuary. Solid arrow denotes a significant effect; dashed arrow
denotes a possible effect; ? denotes an unknown effect; and no symbol denotes no effect, (continued)
7-9
-------
Develop for confined, nearshore, and offshore waters a water-quality monitoring program that
incorporates water, sediment, and biotic parameters.
Research Program
Develop a research plan to collect data and model the transportation of groundwater nutrients to
marine coastal waters.
Develop a research plan to collect data on "natural" nutrient regeneration due to the decomposition
of floating Sargassum and seagrass within confined water bodies.
Evaluate the relative contributions of point-source discharges, groundwater input, stormwater
overland flow, natural decomposition of organic matter, and other mechanisms (e.g., rainfall) to
nutrient input and the potential of further declines in water quality within the confined waters of the
FKNMS.
Develop a research plan to evaluate the effects of toxic chemicals and pesticides on living
resources, especially corals.
General
• Select representative areas of confined waters that are experiencing poor water quality and develop
potential engineering solutions with cost estimates. The solutions must have application to all of
the Florida Keys.
• Coordinate all of the tasks with other government entities with jurisdiction in the Florida Keys.
Particular coordination should be maintained with Monroe County's development of proposed
Sanitary Wastewater and Stormwater Master Plans as well as the National Oceanic and
Atmospheric Administration (NOAA) plans for research initiatives.
Phase II of the Water Quality Protection Program for the FKNMS was initiated in April 1992. During Phase
II, the problems identified in Phase I will be used to evaluate and recommend priority corrective actions,
strategies, and schedules for implementation to be incorporated into the Program. Management, institutional,
agency, and engineering options as well as funding sources will be addressed in Phase II. The Phase I problem
statements will also be considered in the design and establishment of a comprehensive monitoring program and
research plan. The Water Quality Protection Program will recommend priority corrective actions and
compliance schedules addressing point and nonpoint sources of pollution to restore and maintain the chemical,
physical, and biological integrity of the Sanctuary, including restoration and maintenance of a balanced,
indigenous population of corals, shellfish, fish and wildlife, and recreational activities in and on the water.
7-10
-------
FINAL
FLORIDA KEYS NATIONAL MARINE SANCTUARY
WATER QUALITY PROTECTION PROGRAM
WORKSHOPS SUMMARY
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Wetlands, Oceans, and Watersheds
Contract No. 68-C8-0105
Work Assignment 3-225
March 11, 1992
Prepared by
Battelle Ocean Sciences
397 Washington Street
Duxbury, MA 02332
(617) 934-0571
-------
FLORIDA KEYS NATIONAL MARINE SANCTUARY
WATER QUALITY PROTECTION PROGRAM WORKSHOPS SUMMARY
The Environmental Protection Agency (EPA) and the State of Florida have been directed to develop a
Water Quality Protection Program for the Florida Keys National Marine Sanctuary (FKNMS). The
purpose of this Water Quality Protection Program is to recommend priority corrective action and
compliance schedules addressing point and nonpoint sources of pollution. The first phase of this program
involved a compilation and synthesis of available scientific and technical information on water-quality
related parameters in the Florida Keys. The result of this effort was a Phase I Technical Assessment
Report which related the water quality parameters to Florida Keys resources and identified pressing
problems needing priority attention. This Phase I Technical Assessment Report was made available for
review to a selected list of scientific technical experts currently conducting studies and investigations on
the resources of the Florida Keys. The report was also furnished to (1) the National Oceanic and
Atmospheric Administration (NOAA) Advisory Committee that was established to oversee the
development of the Comprehensive Management Plan for the FKNMS, (2) the FKNMS Steering
Committee that was established by EPA Region IV and the State of Florida to oversee the development
of the Water Quality Protection Program, and (3) the public, environmental groups, and user groups
within the Florida Keys.
On February 4 through 7, 1992, as part of Phase I of the program, four workshops were held in Miami
Springs, Florida; the Coral Community Assessment, Submerged and Emergent Aquatic Vegetation
Assessment, Nearshore and Confined Waters Assessment, and Spills and Hazardous Material Assessment
Workshops. These workshops were the first of a series of three consensus-building activities directed
by EPA Region IV and the State of Florida. The other two activities included presenting the results of
the Phase I Technical Assessment Report and the workshops to the NOAA Advisory Committee, the
FKNMS Steering Committee, and the public attending these committee meetings.
The panel members for each workshop are listed in Appendix A. Each workshop was charged with
coming to a consensus, where possible, on the problem statements described in the Technical Assessment
Report for each of the workshop resource areas. These problem statements were refined through
discussions with EPA Region IV Coastal Programs staff and State of Florida environmental staff. The
tool used to develop consensus on the problem statements involved a matrix analysis of each workshop
resource area (Appendix B). The matrix was designed with problem statement key words across the
horizontal axis and parameters for analysis down the vertical axis. Specific descriptive terms were used
to complete the matrix based on the discussions with the expert panels assembled for each workshop
resource area (Appendix C). Public and expert panel member comments on the discussions, matrices
prepared for each workshop resource area, and the Phase I Technical Assessment Report were accepted
during the course of each workshop. In order to assist EPA Region IV and the State of Florida to direct
their limited resources, each expert panel was asked to rank the overall significance of the water-quality
related problems at the end of each daily workshop.
The following is a summary of the major comments, recommendations, and priorities for EPA and the
State to consider when developing the Water Quality Protection Program.
-------
CORAL COMMUNITY ASSESSMENT WORKSHOP
Technical Panel: Dr. Phillip Dustan (College of Charleston, SC), Dr. Walter Jaap (Department of
Natural Resources (DNR), FL), Dr. Pamela Hallock-Muller (University of South Florida, FL), Dr. James
Porter (University of Georgia, GA), Dr..Laurie Richardson (Florida International University, FL), Dr.
Eugene Shinn (United States Geological Survey (USGS), FL), and Dr. Alina Szmant (Rosenstiel School
of Marine and Atmospheric Science, FL).
Problems/Issues discussed at this workshop were (1) Coral Disease, (2) Bleaching, (3) Problematic Algal
Growth, (4) Lyngbya Growth, (5) Lack of Recruitment, (6) Growth Rate (Individual), (7) Decline in
Coral Abundance, and (8) Decline in Species Diversity (see Appendix B). The parameters for analysis
were temporal consideration (Is the problem related to season, has it been happening recently or in the
past, and are there data?), spatial consideration (What is the geographical range of the problem?), trend
(Is the problem worsening, same, better, or unknown?), severity (How severe is the problem?), certainty
(How certain are we that there is a problem?), water quality related? (Is this problem related to water
quality?), water quality parameters (Do the parameters have an affect on the problem?), and overall
significance (What is the significance of the problem from a water-quality perspective?).
Generally, the panel members agreed that there is a lack of data regarding all of the above problems.
More research and data are needed to determine how the water quality parameters affect each of the
problems discussed.
(1) Coral disease is widespread with patchy occurrences, and its severity is increasing in the Keys. The
panel members agreed that the cause of coral disease is possibly water-quality related. Temperature
(significantly) and salinity (slightly) affect coral disease. Parameters that require more investigation
regarding their effects on this problem are nutrients, turbidity, toxics/pesticides, bacteria, and viruses.
The overall significance of the problem from a water-quality perspective is high. Additional comments
were that more data are needed to determine the cause of coral diseases (epidemiology) and that there is
a need to determine whether there is a global influence on coral disease.
(2) Coral bleaching is species-dependent and known to occur in the Keys. The trend for bleaching events
is known to be increasing, but the events vary in their severity. The panel members agreed that this
problem is water-quality related; temperature significantly affects bleaching of coral communities and
salinity is also thought to be a contributor to the bleaching. The effects of nutrients, turbidity, and
toxics/pesticides on the bleaching of coral communities are unknown; more data are needed. The overall
significance of this problem from a water-quality perspective is high.
(3) Temporally, problematic algal growth is known to occur in localized "hot spots" and this trend is
increasing. The panel members agreed that the potential exists for problematic algal growth to be water-
quality related, however it is not yet a problem. Temperature and nutrients significantly affect this
problem; however, the effects of toxics/pesticides and bacteria on problematic algal growth are unknown.
The overall significance of this problem from a water-quality perspective is moderate.
(4) The panel members felt that Lyngbya growth deserved its own discussion because the recent (fall 1988
bloom) and rapid increase in Lyngbya occurrence could potentially occur to other species within the algal
community. Occurrence of the Lyngbya bloom is localized, spreading, and increasing. The panel
members agreed that the severity of this problem is high in the Keys and that this problem is definitely
-------
water-quality related. Temperature and nutrients significantly affect Lyngbya growth; the effects of
toxics/pesticides and bacteria are unknown. The overall significance of this problem from a water-quality
perspective is high.
(5) The panel members agreed that the discussion regarding the problem of lack of coral recruitment
should be an offshore discussion only. Recruitment is species-dependent and driven by the reproductive
cycle of the organism. Areas exhibiting a lack of recruitment are patchy in the Keys. The trend of this
problem is unknown, however, the severity of the problem is high in the Keys. The panel members
agreed that it is possible that this problem is water-quality related. All of the water-quality parameters
discussed have an unknown effect on the problem; more research is needed. The overall significance of
this problem from a water-quality perspective is high. '
(6) Cases of impaired growth rates of individual corals are known and isolated. The trend of this
problem is variable and the severity is localized in the Keys. The panel members agreed that this
problem is known to be water-quality related; temperature and turbidity significantly affect individual
growth rates. It is unknown if nutrients, toxics/pesticides, bacteria, and viruses affect individual growth
rates. The overall significance of this problem from a water-quality perspective is high. Additionally,
it was commented that physical damage to corals is a concern and that coral diseases are known to affect
growth rates.
(7) The decline in coral abundance is known to be a seasonal, long-term problem (geographically). The
severity of the decline is high and the rate of the decline over time is unknown; there is a lack of data.
The panel members agreed that it is probable, in the historical sense, that this problem is water-quality
related. Water-quality parameters that significantly affect this problem are temperature and turbidity.
Salinity has been an historically significant problem; however, it is currently insignificant. The effects
of nutrients, toxics/pesticides, bacteria, and viruses are unknown and more data are needed. The overall
significance of this problem from a water-quality perspective is high and the panel members agreed that
more research and data are needed. An additional comment made was that cyanobacteria diseases are
known to affect coral abundance.
(8) Temporally, the decline in species diversity (species other than coral) is extremely variable (from
hours to years) and widespread for the width of the Keys. Species diversity is worsening particularly for
commercially harvested species, although the panel members agreed that the available data relate to
harvested species and few data exist for other species. It is probable that the decline in species diversity
is water-quality related for the nearshore breeding species and possibly water-quality related for offshore
breeding species. Temperature significantly contributes to the decline while the effects of nutrients on
this problem are slight to moderate. Salinity is a slight contributor to this problem, and toxics/pesticides
are a slight contributor offshore. It is unknown if turbidity, bacteria, viruses, and dissolved oxygen (DO)
affect the problem; more data are needed. The overall significance of the problem from a water-quality
perspective is unknown.
Review of Overall Significance by the Panel Members
Coral disease and problematic algal growth are the problems most directly related to water quality,
therefore they should also have a high priority in the Water Quality Protection Program. In addition, the
decline in biodiversity was rated as unknown by the panel members, and they felt that the lack of
information indicates that additional work needs to be done regarding this problem.
-------
Additional Comments from the Panel Members and Workshop Attendees
• EPA nutrient test standards are too insensitive to provide meaningful data.
• All of the topics discussed at the workshop are global in nature. EPA must take advantage
of the international network of information; information sharing is crucial.
• Data from all research areas in the Keys must be compared to understand the whole
ecosystem and its patterns.
• It must be realized that human impact to the Keys environment is superimposed on the natural
cycles of the environment.
• More information is needed on recruitment cycles, algal blooms, indicator organisms, soft
corals, and nutrient inputs to areas of the FKNMS.
• Long-term, spatial-scale studies are needed in the Keys.
• Fish and invertebrates were omitted from the report and workshop topics.
• Bioerosion of the coral reefs needs research.
• There is a need for a high quality laboratory in the Florida Keys for archiving data relevant
to the Keys.
• EPA should develop site-specific, water-quality standards for the entire Keys; the Keys cannot
be considered as one area.
-------
SUBMERGED AND EMERGENT AQUATIC VEGETATION ASSESSMENT WORKSHOP
Technical Panel: Dr. Bill Kruczynski (EPA, FL), Dr. Kathleen Sullivan (The Nature Conservancy, FL),
Dr. John Ogden (Florida Institute of Oceanography, FL), Dr. Jay Zieman (University of Virginia, VA),
Dr. Brian Lapointe (Harbor Branch Oceanographic Institute (HBOI), FL), Dr. Jim Fourqurean
(Continental Shelf Associates, Inc., FL), and Mr. Paul Carlson (DNR, FL).
Problems/Issues discussed at this workshop were divided into four areas — Seagrasses, Macroalgae,
Mangroves/Buttonwoods, and Freshwater Influence (see Appendix B). Problems regarding Seagrass
Communities were (1) Increased Epiphyte Growth, (2) Seagrass Historic Growth Rates (Individual), (3)
Declines in Community Diversity (other than seagrass communities), (4) Decreased Geographical Extent,
(5) Decreased Recruitment of Seagrasses, and (6) Hypoxia. Problems regarding Macroalgae Communities
were (1) Increased Epiphyte Growth, (2) Macroalgae Historic Growth Rates (Individual), (3) Decreased
Community Diversity (other than seagrass communities), (4) Hypoxia, and (5) Diversity of Algae.
Problems regarding Mangrove/Buttonwood Communities were (1) Decreased Tree Productivity
(individual), (2) Decreased Geographical Extent, and (3) Functional Value of Habitat. Problems
regarding Freshwater Influence were (1) Decreased Productivity, (2) Decreased Geographical Extent, and
(3) Functional Value of the Habitat.
The parameters for analysis were temporal consideration (Is the problem related to season, has it been
happening recently or in the past, and are there data?), spatial consideration (What is the geographical
range of the problem?), trend (Is the problem worsening, same, better, or unknown?), severity (How
severe is the problem?), certainty (How certain are we that there is a problem?), water quality related?
(Is this problem related to water quality?), water quality parameters (Do the parameters have an affect
on the problem?), and overall significance (What is the significance of the problem from a water-quality
perspective?).
Seagrasses
For this discussion, the panel members qualified several of the water-quality parameters on the matrix.
Nutrients was changed to anthropogenic nutrients, bacteria and viruses were combined into diseases,
and DO was changed to anthropogenic DO (DO caused by external sources).
(1) The problem of increased epiphyte gronth on Seagrasses is known to occur primarily in hot spots
throughout the Keys and the trend is worsening. The panel members agreed that this problem is
definitely water-quality related in the hot spots and possibly water-quality related elsewhere; more data
are needed. Turbidity, and anthropogenic nutrients and DO significantly affect increased epiphyte growth
in seagrass communities. The overall significance of this problem from a water-quality perspective is
high.
(2) Seagrass historic growth rates findividual) have decreased recently and the reductions are known to
occur in hot spots associated with human activity throughout the Keys. They are unknown yet suspected
to occur elsewhere. The panel members agreed that this problem is water-quality related in the hot spots
and possibly water-quality related elsewhere; more data are needed. Temperature, salinity, anthropogenic
nutrients and DO, and turbidity significantly affect growth rates of Seagrasses. The overall significance
of this problem from a water-quality perspective is high in the hot spots and slight elsewhere in the Keys.
-------
(3) The problem, declines in community diversity, was considered regarding anthropogenic changes.
Areas of declines in community diversity are isolated to hot spots and the trend is worsening; declines
• are unknown elsewhere. The panel members agreed that this problem is water-quality related in the hot
spots and probably water-quality related elsewhere; more data are needed. Temperature, salinity, and
anthropogenic DO significantly affect community diversity. The overall significance of this problem from
a water-quality perspective is high in the hot spots and possible but unknown elsewhere in the Keys.
. Overfishing effects were highlighted as having an impact on community diversity.
(4) Decreased geographical extent (i.e., anthropogenic losses) is known to be isolated to hot spots and
this trend is worsening. Outside the hot spot areas, changes are taking place naturally; human effects
here are slight. Temperature, anthropogenic nutrients and DO, salinity, and turbidity significantly affect
this problem. The overall significance of this problem from a water-quality perspective is high in the hot
spots and slight elsewhere.
(5) There is a general lack of data and information regarding decreased recruitment ofseagrasses. This
problem is isolated to hot spots and is worsening. Because of the lack of data, no accurate assessment
could be made. The panel members agreed that the problem is possibly water-quality related.
Parameters thought to have a significant affect on the problem are temperature, salinity, turbidity, and
anthropogenic DO. The overall significance of this problem from a water-quality perspective is unknown.
(6) The problem ofhypoxia depends on circulation patterns, flushing of an area, and climate effects and
influence (drought, wet). The panel members agreed that hypoxia is definitely water-quality related and
usually occurs in hot spots where it has the potential to be severe. Temperature and anthropogenic
nutrients and DO significantly affect the problem. The overall significance of the problem from a water-
quality perspective could not be determined because it depends on circulation.
The only anthropogenic effect on Florida Bay is the reduction of the historic and sporadic freshwater flow
by canals such as the C-l 11 canal. The natural system in Florida Bay (50 years ago) would be better for
more species offish and vegetation than the present-day environment. Currently, extremely saline waters
from Florida Bay are believed to be causing reef damage (coral die-off). The panel members commented
that this freshwater flow to Florida Bay needs to be restored and that EPA should determine the extent
of the previous coral community. The Florida Bay water quality issue must be included in the
management of the FKNMS.
Additional Comments from the Panel Members and Workshop Attendees
• Calcareous epiphytes are an indicator of good water quality.
• Hypoxia covaries with epiphyte growth.
• Nutrient loading needs investigation.
• A strong relationship exists between anthropogenic nutrients and turbidity.
Macroalgae
For this discussion macroalgae was defined as all soft and hard-bottom macroalgae. Again, the panel
members qualified several of the water-quality parameters on the matrix. Nutrients was changed to
anthropogenic nutrients, bacteria and viruses were combined into diseases, and DO was changed to
anthropogenic DO (DO caused by external sources).
-------
(1) The problem of increased epiphyte growth on macroalgae is known to occur primarily in hot spots
throughout the Keys and the trend is worsening. The panel members agreed that this problem is
definitely water-quality related in the hot spots and possibly water-quality related elsewhere; more data
are needed. Turbidity and anthropogenic nutrients and DO significantly affect increased epiphyte growth
in macroalgae communities. The overall significance of this problem from a water-quality perspective
is high.
(2) Macroalgae compete with seagrasses for area. Macroalgae historic growth rates (individual) have
increased over the last decade, are known to occur in hot spots throughout the Keys, and are widespread
elsewhere. The panel members agreed that this problem is water-quality related in the hot spots and
possibly water-quality related elsewhere. Temperature,, turbidity, salinity, and anthropogenic nutrients
and DO significantly affect growth rates of macroalgae. The overall significance of this problem from
a water-quality perspective is high in the hot spots and slight elsewhere in the Keys. More data are
needed regarding this problem.
(3) The problem, declines in community diversity, was considered regarding anthropogenic changes.
Areas of decreased community diversity are isolated to anthropogenic hot spots and the trend is
worsening. Declines were unknown elsewhere; more data are needed. The panel members agreed that
this problem is water-quality related in the hot spots and probably water-quality related elsewhere.
Temperature, salinity, and anthropogenic DO significantly affect community diversity. The overall
significance of this problem from a water-quality perspective is high in the hot spots and possible but
unknown elsewhere in the Keys. Overfishing effects were highlighted as having an impact on community
diversity.
(4) The problem of hypoxia depends on circulation patterns, flushing of an area, climate effects and
influence (drought, wet). The panel members agreed that hypoxia is definitely water-quality related and
usually occurs in hot spots where it has the potential to be severe. Temperature and anthropogenic
nutrients and DO significantly affect the problem. The overall significance of this problem from a water-
quality perspective could not be determined because it depends on circulation.
(5) Diversity of the algae has decreased within the last decade. This problem is worsening in and is
isolated to hot spots, and is widespread elsewhere. The panel members agreed that this problem is water-
quality related. Temperature, anthropogenic nutrients and DO, salinity, and turbidity significantly affect
the problem. The overall significance of the problem from a water-quality perspective is high.
Overfishing and grazing were highlighted as having an impact on this problem.
Additional Comments from the Pane! Members and Workshop Attendees
• Positive algal growth for the wrong reason is a problem.
Mangroves/Buttonwoods
For the Mangroves/Buttonwoods problems, three parameters were added for analysis: climatic effects
(What are the climatic effects of the problem?), dredge and fill (What are the effects of dredge and fill
on the community?), and other (Are there other effects?).
-------
(1) The extent, trend, and severity of decreased tree productivity (individual) are unknown. The panel
members agreed that this problem is water-quality related and that temperature, salinity, turbidity and
anthropogenic nutrients and DO significantly affect tree productivity. The overall significance of this
problem from a water-quality perspective is unknown. A consequence of decreased tree productivity is
increased flood sensitivity. Dredge and fill operations can cause changes in the community, and other
effects that should be considered are impoundment effects.
(2) The severity of the problem, decreased geographical extent, is high. Decreased geographical extent
is widespread and the continuing decline is characterized by large losses of mangroves and buttonwoods.
The panel members agreed that this problem is probably related to water quality. Parameters that have
a significant effect on the problem are salinity, turbidity, and anthropogenic nutrients and DO. The
overall significance of this problem from a water-quality perspective is slight; however, the panel
members agreed that this problem is a highly significant one.
(3) The functional value of the habitat is affected by seasonal and episodic flooding. The trend of this
problem is unknown but thought to be declining. The panel members agreed that this problem is
probably related to water quality. Anthropogenic nutrients and toxics/pesticides significantly affect this
problem. The overall significance of the problem from a water-quality perspective is high. One
additional comment made was that fragmentation is a critical component of the problem.
Freshwater Influence
For the Freshwater Influence problems, three parameters were added for analysis: climatic effects (What
are the climatic effects of the problem?), dredge and fill (What are the effects of dredge and fill on
community?), and other (Are there any other effects?).
(1) The spatial consideration, trend, severity, and certainty of the problem as they relate to decreased
productivity are unknown; however, the panel members agreed that the problem is probably related to
water quality. Temperature highs and lows, anthropogenic nutrients, and salinity significantly affect
productivity; toxics/pesticides possibly affect productivity. The overall significance of the problem from
a water-quality perspective is moderate to high. A climatic effect associated with decreased productivity
is the lowering of the water table.
(2) The problem of decreased geographical extent is continuing; losses have been high and the severity
of the problem is high. The panel members agreed that the problem is definitely water-quality related
and impacted by nutrient additions and septic system runoff. The overall significance of how water
quality affects this problem is high. Dredge and fill operations cause a direct loss of habitat due to
development activities. Septic tanks and cesspools also contribute to the problem.
(3) The functional value of the habitat continues to worsen and the problem is widespread in the Keys.
The panel members agreed that this problem is water-quality related (in part) and that anthropogenic
nutrients, salinity, turbidity, and toxics/pesticides significantly affect the problem. The overall
significance of the problem from a water-quality perspective is high. Fragmentation was listed as a
critical component of the problem.
-------
Review of Overall Significance by the Panel Members
Priority problems in the seagrass and macroalgae communities are epiphyte growth and anthropogenic
nutrient loading; control measures are needed. Priority concerns in the mangrove/buttonwood
communities are preserving geographical extent and the functional value of the habitat. For freshwater
influence, the priority concern is preserving the geographical extent so that there is no further loss of
mangrove/buttonwoods and coastal wetlands.
Additional Comments from the Panel Members and Workshop Attendees
• Thalassia communities are the most sensitive communities; they cannot be recolonized.
• It should be recognized that a portion of Florida Bay is located in the FKNMS.
• There is a need to restore the historic freshwater flow to Florida Bay; spiking (allowing the
Bay to become all freshwater) should occur for a period of days every few months.
• A historical description of the FKNMS area should be developed; find out what communities
existed and how much the area has changed.
• Sewage is impacting the nearshore waters of the Keys.
• Hot spots are likely to increase as long as nutrient loading increases.
• Standardized marina siting criteria are needed; seagrasses should be taken into account.
« The public should be educated about the problem of prop dredging.
• Mangroves were underrepresented in the report.
• Each point source may be operating under a valid permit within an overall regulatory
strategy, however the cumulative impacts of all point sources should be investigated and
considered.
-------
NEARSHORE AND CONFINED WATERS ASSESSMENT WORKSHOP
Technical Panel: Mr. R.J. Helbling (Department of Environmental Regulation (DER), FL), Dr. Ron
Jones (Florida International University, FL), Dr. Brian Lapointe (HBOI, FL), Dr. Alina Szmant
(Rosenstiel School of Atmospheric Science, FL), Dr. Ned Smith (HBOI, FL), Dr. Steve Miller (NOAA
National Undersea Research Center, FL), Mr. Del Hicks (EPA, GA), and Dr. Jim Fourqurean
(Continental Shelf Associates, Inc., FL).
This workshop was divided into three areas of interest, Confined Waters, Nearshore Waters, and Back
Country Waters (see Appendix B). Problems/Issues discussed in relation to Confined Waters were
divided into two areas; eutrophication and human health. Under eutrophication, (1) Increased Epiphyte
Growth, (2) Increased Chlorophyll (i.e., phytoplankton), and (3) Change in Benthic Community Structure
were discussed. Under human health, (1) Human Health (Fish and Shellfish Consumption) was
discussed. Problems discussed in relation to Nearshore Waters were (1) Increased Epiphyte Growth and
(2) Increased Chlorophyll (i.e., phytoplankton). Problems discussed in relation to Back Country Waters
were (1) Increased Epiphyte Growth and (2) Increased Chlorophyll (i.e., phytoplankton).
The parameters for analysis were temporal consideration (Is the problem related to season, has it been
happening recently or in the past, and is there data?), spatial consideration (What is the geographical
range of the problem?), trend (Is the problem worsening, same, better, or unknown?), severity (How
severe is the problem?), certainty (How certain are we that there is a problem?), water quality related?
(Is this problem related to water quality?), water quality parameters (Do the parameters have an effect
on the problem?), and overall significance (What is the significance of the problem from a water-quality
perspective?).
Confined Waters — Eutrophication
Confined waters are defined as canals, marinas, bays, and lagoons. The panel members made changes
to two water-quality parameters. Bacteria was changed to human-derived bacteria and DO was changed
to anthropogenic biological oxygen demand (BOD) loadings.
(1) Increased epiphyte growth is a problem that is widespread and the trend is worsening. Epiphyte
growth has been increasing over the last decade. The panel members agreed that the problem is water-
quality related and that the overall significance of the problem from a water-quality perspective is high.
Parameters that significantly affect this problem are nutrients, turbidity, and anthropogenic BOD loadings.
An increase in epiphyte growth is an indicator of a change in the community structure and amount. Poor
flushing and the lack of circulation into the canals contributes to the poor water quality in the canals.
(2) Increased chlorophyll is related to temperature and light, and has been reported since 1973. The
problem is thought to be widespread, chronic, and worsening (anecdotal evidence). The panel members
agreed that the problem is water-quality related and that the overall significance of the problem from a
water-quality perspective is high. Parameters that significantly affect this problem are nutrients, turbidity,
and anthropogenic BOD loadings. Increased chlorophyll is an indicator of the severity of the nutrients.
(3) Change in the benthic community structure is a problem that is widespread and the trend is worsening.
The panel members agreed that the problem is water-quality related and that the overall significance of
10
-------
the problem from a water-quality perspective is high. Parameters that significantly affect this problem
are nutrients, turbidity, and anthropogenic BOD loadings. An additional comment was that recycling
seagrass wrack can lead to eutrophication.
The panel members identified the endpoints of eutrophication as
Loss of biodiversity
Hypoxia
Increasing hydrogen sulfide
Increased epiphyte growth
Decreased benthic producers
Decreased light transparency (increased turbidity)
Change in biogeochemical processes
Increased chlorophyll
Decreased circulation (secondary process)
Increased macroalgae
Decreased seagrasses
Increased odor (esthetics)
Decreased nursery functions
Confined Waters — Human Health
Human health (fish and shellfish consumption) refers to problems associated with consuming fish/shellfish
caught by an individual, not fish/shellfish purchased from a seafood market. No historical data exist
regarding health problems from personally caught fish/shellfish. More data are needed regarding the
trend, severity, and certainty of the problem. Toxics/pesticides, human-derived bacteria, and viruses
significantly affect the problem. Temperature, nutrients, and salinity affect the problem slightly to
significantly depending on the species. The panel members agreed that it was possible but unlikely that
the problem is water-quality related. The overall significance of this problem from a water-quality
perspective is unknown. In areas with inappropriate sewage treatment systems, the potential exists for
severe health problems.
Nearshore Waters
Nearshore waters are defined as those that extend from shore to Hawks Channel including the 18 ft depth
contour. The panel members made changes to two water-quality parameters. Bacteria was changed to
human-derived bacteria and DO was changed to anthropogenic BOD loadings.
(1) For increased epiphyte growth, the panel members agreed that severity was slight, certainty was
possible, and overall significance of this problem from a water-quality perspective was slight. Increased
epiphyte growth is a problem that is widespread and worsening, and has been increasing over the last
decade. The panel members agreed that the problem is water-quality related. Parameters that
significantly affect this problem are nutrients, turbidity, and anthropogenic BOD loadings.
(2) For increased chlorophyll, the panel members agreed that severity was slight, certainty was possible,
and overall significance of this problem from a water-quality perspective was slight. Increased
chlorophyll is related to temperature and light, and has been reported since 1973. The problem is thought
11
-------
to be widespread, chronic, and worsening (anecdotal evidence). The panel members agreed that the
problem is water-quality related. Parameters that significantly affect this problem are nutrients, turbidity,
and anthropogenic BOD loadings.
Back Country Waters
Back country waters are defined as nearshore Florida Bay waters within the 8 to 10 ft depth contour.
The panel members made changes to two water-quality parameters. Bacteria was changed to human-
derived bacteria and DO was changed to anthropogenic BOD loadings.
(1) For increased epiphyte growth, the panel members agreed that severity was slight, certainty was
possible, and overall significance of this problem from a water-quality perspective was slight. Increased
epiphyte growth is a problem that is ,widespread and worsening, and has been increasing over the last
decade. The panel members agreed that the problem is water-quality related. Parameters that
significantly affect this problem are nutrients, turbidity, and anthropogenic BOD loadings.
(2) For increased chlorophyll, the panel members agreed that severity was slight, certainty was possible,
and overall significance of this problem from a water-quality perspective was slight. Increased
chlorophyll is related to rainfall, temperature, and light and has been reported since 1973. The problem
is thought to be widespread, chronic, and worsening (anecdotal evidence). The panel members agreed
that the problem is water-quality related. Parameters that significantly affect this problem are nutrients,
turbidity, and anthropogenic BOD loadings. In addition, no historical data exist regarding the back
country waters; all information in this matrix column is anecdotal or from personal observations.
Review of Overall Significance by the Panel Members
The consensus of the panel members was that water quality in some confined waters was degraded;
however, there was not a unanimous consensus that water quality in nearshore and back country waters
was degraded. Priority areas in need of more information were new methodologies for using managed
aquatic systems for treatment, hot spots, nutrient loading, nutrient transport/hydrology, monitoring from
a hydrological/biological standpoint (develop a systems monitoring program), back country waters,
hydrology regarding well injection (has the ability to impact nearshore and offshore waters), and
hydrological studies (intensive surveying needed, establish a liaison with the USGS). Priority problem
areas are the canal systems adjacent to inappropriate sewage treatment systems. Secondary treatment
should be mandated for such areas.
Additional Comments from the Panel Members and Workshop Attendees
• Anecdotal evidence should be weighed very carefully; some is valuable.
• Need to address impacts of water quality on marine fisheries.
• Pesticide spraying in Monroe County should be banned.
• Pesticide problem is unknown; needs investigation.
Hot Spot Criteria
The panel members discussed what criteria they would use to determine a hot spot. The following is a
list of the criteria identified.
12
-------
Documented fish kills (could be natural)
Documented anaerobic conditions (could be natural)
Potential discharge sources/sources of contamination
High chlorophyll
High macroalgal epiphytes
Population density and type of sewage treatment
Poorly flushed areas
Anecdotal/observational evidence of change
Documented water-quality violations
Evidence of high anthropogenic inputs
Type of land and water use
Some of the above criteria will occur before others. Almost all of these criteria are not indicators of a
problem, necessarily. If a condition is observed, it should be investigated to determine if it is a natural
occurrence or not.
Consensus by the Panel Members on Known and Suspected Hot Spots
Upper Keys (north to south) — Known Hot Spots
Phase 1 Ocean Reef, Carysfort Camp Ground, Alabama Jacks, Card Sound Road, C-lll, Point Laurel,
Lake Surprise, Sexton Cove, Cross Key Waterways, Largo Sound/Shores, Port Largo, Campbell's
Marina, Indian Waterways, Venetian Shores, Lower Matecumbe Key, and all marinas.
Middle Keys (north to south) — Suspected Hot Spots
City of Layton, Fiesta Campground, Duck Key, Grassy Key, and Coco Plum Subdivision/Fat Deer Key.
Middle Keys (north to south) — Known Hot Spots
All marinas, Key Colony beach, Sierra Estates, 90th Street Canal, Winner Docks (Boot Key Harbor),
City Fish Seafood Processing Plant, Marathon, and Faro Blanco Marina.
Lower Keys (north to south) — Suspected Hot Spots
Loggerhead Key and Raccoon Key (monkey droppings).
Lower Keys (north to south) — Known Hot Spots
Big Pine Key dead end canal systems (septic tanks), Dr. Arm, Orchid Park Subdivision, Key Haven
Subdivision (undersized treatment system), Keys Community College, Key West Sewage Plant Outfall,
Stock Island Power Plant Discharge, two Navy outfalls, City of Key West Secondary Plant Discharge
(nearshore outfall), Boca Chica Naval Air Station Discharge, and canals (need advanced treatment for
septic tanks and cesspools).
13
-------
SPILLS AND HAZARDOUS MATERIALS ASSESSMENT WORKSHOP
Technical Panel: Mr. Eric Evans (Coastal Tug and Barge, FL), Dr. Ken Haddad (DNR, FL), Lt. Donna
Kuebler (United States Coast Guard (USCG), FL), Mr. Greg Lee (DER, FL), Dr. Anita Wooldridge
(Marine Spill Response Corporation, FL)i Mr. William Hunt (United States Navy, FL), and Ms. Debbie
Prebble (DNR, FL).
Problems/Issues discussed at this workshop were (1) Small Vessel Spills (Marine), (2) Small Facility
Spills (Landbased), (3) Illegal Dumping Marine-Landbased, (4) Catastrophic Tanker Spills, (5) Tanker
Truck Spills, (6) Effects of Dispersant Use, (7) Bioremediation, (8) Leachable Toxics, (9) Boat Scraping,
and (10) Ruptured Bulk Tanks and Pipelines (see attached matrix).
The parameters for analysis were temporal consideration (Is the problem related to season, has it been
happening recently or in the past, and are there data?), spatial consideration (What is the geographical
range of the problem?), trend (Is the problem worsening, same, better, or unknown?), severity (What
is the seriousness when the event occurs?), contingency plans (Are contingency plans in place?, Has
there been a great deal of work on contingency plans?, Are contingency plans adequate?), water quality
effect? (i.e., biotoxicity, physical damage, bioaccumulation), and overall significance (How significant
is the problem to the Water Quality Protection Program? Note: this is different from the previous
workshops). The panel members added three parameters, compliance/enforcement (evaluation of these
capabilities), major constituents (of a spill), and risk (likelihood of event occurring).
For all of the following problems, the panel members agreed that there is little documentation or
information generated in the Keys and that this information is greatly needed.
(1) Small vessel spills (marine) were defined as spills from a vessel with ^5000 gallons of fuel and/or
cargo. The major constituents of these spills are diesel fuel, gas, and bilge. Small vessel spills occur
year-round, are widespread (nearshore and fueling areas), and the trend is worsening (with the
qualification that there has been an increase in reporting). The problem is severe locally and unknown
overall. The adequacy of existing contingency plans was identified as low. The water-quality effect
would be locally toxic and unknown overall. The authority exists for enforcement, but manpower is low
and compliance is also low. The risk (likelihood of an event occurring) is high. The panel members
agreed that the overall significance of this problem to the Water Quality Protection Program is high.
(2) Small facility spills (landbased) generally are unreported and include those spills from marinas, auto
fueling facilities, small industrial facilities, and residents. Constituents of these spills are diesel fuel, gas,
solvents, pesticides, used motor oil, and paint-related material. This problem occurs year-round and is
widespread (in marinas and fueling areas) and the trend is worsening (with the qualification that there has
been an increase in reporting). The problem is severe locally and unknown overall. The adequacy of
existing contingency plans was identified as low. The water-quality effect would be locally toxic and
unknown overall. Compliance and enforcement were reported as low by the panel members. The risk
(likelihood of an event occurring) is high. The panel members agreed that the overall significance of this
problem to the Water Quality Protection Program is moderate.
(3) Illegal dumping (marine-landbased) for marine-based sources was defined as spills from a vessel with
^5000 gallons of fuel and/or cargo and materials resulting from the pumping of bilges and cleaning of
cargo holds. Constituents of these marine-based spills are petroleum products. The constituents of land-
14
-------
based spills are paint and solvents. The quality and quantity of these marine- and land-based substances
are unknown. This problem occurs year-round, is widespread, and the trend is worsening. The problem
is severe locally and unknown overall. The water-quality effect would be locally high and unknown
overall. Compliance was determined to be very low and enforcement is improving. The risk (likelihood
of an event occurring) is moderate. The panel members agreed that the overall significance of this
problem to the Water Quality Protection Program is high.
(4) Catastrophic tanker spills were defined as a spill of > 10,000 gallons inshore and > 100,000 gallons
offshore whose major constituents are diesel fuel, blends of fuel, heavy fuels, hazardous materials, and
crude. These spills occur year-round (two have occurred in the last 16 years in the Keys) and the
potential severity of a spill in the FKNMS is high. The likelihood of a catastrophic spill happening is
decreasing. The panel members agreed that a sanctuary-specific contingency plan is needed and that it
should include what should be done with the cleanup waste. Compliance and enforcement are moderate
to high and the risk (likelihood of the event occurring) is low. The water-quality effect would be high
if the spill reaches the FKNMS. The panel members agreed that the overall significance of this problem
to the Water Quality Protection Program is high.
(5) Tanker truck spills (including tractor trailers) occur year-round (two have occurred in the last 10 years
in the Keys) and are usually isolated to highways. The major constituents of this type of spill are
gasoline, diesel fuel, and other hazardous materials. The severity of a spill is high locally and the
likelihood of this type of spill occurring is decreasing. The adequacy of the existing contingency plans
were determined to be good; however, response time is a problem. The water-quality effect would be
severe locally because of the highly toxic compounds being spilled. Compliance and enforcement are
moderate to high and the risk (likelihood of the event occurring) is moderate. The panel members agreed
that the overall significance of this problem to the Water Quality Protection Program is moderate.
(6) The effects ofdispersant use would have a seasonal impact on habitats. At this time in the Keys,
dispersants are considered for every spill but have not been used. The adequacy of contingency plans
is low and there is a need for more work on the plans. The risk of using dispersants is low; the water-
quality effect would be variable. The panel members agreed that the overall significance of this problem
to the Water Quality Protection Program is high. More information is needed regarding the effects of
dispersant use on larvae. There are tradeoffs to consider when using dispersants. Research is needed
regarding the toxicity of spilled oil versus the toxicity of the dispersed oil.
(7) The use of bioremediation is not as constrained as dispersant use. The potential water-quality effect
of adding nutrients is low. The panel members agreed that the overall significance of this problem to the
Water Quality Protection Program is unknown but unlikely. Interim guidelines are needed.
(8) Leachable toxics were defined as substances originating from Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act
'(RCRA) sites and underground storage tanks and include a variety of constituents such as heavy metals,
PCBs, insecticides, and pesticides. Leaching occurs year-round in isolated areas. The problem is
moderately severe and improving. Compliance/enforcement and contingency plans are site dependent and
are low to high in adequacy. Risk is unknown. The water-quality effect is unknown but potentially
significant. The panel members agreed that the overall significance of this problem to the Water Quality
Protection Program is moderate.
15
-------
(9) Hazardous materials resulting from boat scraping consist of metals. This problem occurs year-round
with seasonal peaks and is isolated to site-specific areas. Trend, severity, and compliance/enforcement
are unknown and the risk (likelihood of event occurring) ishigh. The water-quality effect of this problem
is high. The panel members agreed that the overall significance of this problem to the Water Quality
Protection Program is high.
(10) Hazardous materials resulting from ruptured bulk tanks and pipelines consist of jet fuel, diesel, and
various other petroleum products. This problem occurs year-round in isolated, site-specific areas. The
severity of the problem is moderate to high. Contingency plan adequacy was determined to be moderate.
Compliance/enforcement is moderate to high and risk (likelihood of event occurring) is high. The water-
quality effect is probable. The panel members agreed that the overall significance of this problem to the
Water Quality Protection Program is high.
Review of Overall Significance by the Panel Members
The panel members agreed that their ratings for risk and severity should be used to determine the relative
significance of each problem to the Water Quality Protection Program. If the severity is high and the
risk is high, then some action needs to be taken. If the severity is unknown and the risk is high, more
research is needed (refer to matrices in Appendix B).
Additional Comments from the Panel Members and Workshop Attendees
• More preplanning strategies with major agencies for spill response (must include resource
managers) are needed. -
• Contingency plans are effective in targeting available resources; however, more resources are
needed.
• Existing contingency plans are inadequate; they are not designed to take into consideration
the goals of the FKNMS (that the spill does not reach the FKNMS).
• Technology is not at the same level as the contingency plans.
• Existing contingency plans do not provide for a no damage scenario.
• The USCG is requiring area plans in addition to general contingency plans; however, the
areas are too large. Areas must be decreased in size and the plans must target each ecosystem
in the area individually.
• Contingency plans must be resource-specific and prioritized because decisions at the time of
a spill must be made quickly.
• Resource managers in the Keys are responsible for a specific area of the Keys; they should
be conferred with regarding contingency plan development.
• There is no spill equipment in the FKNMS; shallow-water spill cleanup equipment is needed
(deep-water spill cleanup equipment is not adequate for the area).
16
-------
CONCLUSIONS
Two themes emerged from the four workshops.
• Generally, the panel members agreed that there is an overwhelming lack of data regarding all
of the resource areas and associated problem areas. More monitoring data and research are
needed to determine how the water quality parameters affect each of the resource areas and
related problems.
• The problem statements presented in the Phase I Technical Assessment Report and discussed
at the workshops are problems that anecdotal studies have shown to be important for the well-
being of the Florida Keys. All of the problems are important but the key problems prioritized
at the end of each workshop are the problems that should be addressed first to efficiently use
the limited resources of the Federal and State governments.
The lack of data highlights the need for a clear and concise water-quality monitoring plan that will
produce data that can be compared in a status and trend manner. Many of the current studies have been
conducted over different temporal and spatial periods using differing sampling and analytical techniques.
Quality assurance and quality control procedures have been applied to differing degrees as well. These
points indicate that a monitoring plan which provides a baseline for follow-on investigations and research
studies is definitively needed in order to describe problems beyond the current effort and help focus long-
range problem solving management plans.
17
-------
APPENDIX A
-------
FLORIDA KEYS NATIONAL MARINE SANCTUARY
WATER QUALITY PROTECTION PROGRAM WORKSHOP
PANEL MEMBERS
Coral Community Assessment Workshop
Dr. Phillip Dustan
Biology Department
College of Charleston
Charleston.SC 29424
(803) 792-8086
Dr. Pamela Hallock-Muller
Department of Marine Science
University of South Florida
140 Seventh Avenue South
St. Petersburg, FL 33701-5016
(813) 893-9567
Dr. Walter Jaap
Florida Marine Research Institute
100 Eighth Avenue SE
St. Petersburg, FL 33701-5905
(813) 896-8626
Dr. James W. Porter
Zoology Department
University of Georgia
Athens, GA 30602
(404) 542-3410
Dr. Laurie R. Richardson
Department of Biological Sciences
and Drinking Water Research Center
Florida International University
Miami, FL 33199
(305) 348-1988
Dr. Eugene Shinn
U.S. Geological Survey
Fisher Island Station
600 Fourth Street South
St. Petersburg, FL 33701
(813) 893-3684
Dr. Alina M. Szmant
Associate Professor, Marine Biology and Fisheries
Rosenstiel School of Marine and
Atmospheric Science
4600 Rickenbacker Causeway
Miami, FL 33149
(305) 361-4609
A-l
-------
Submerged and Emergent Aquatic Vegetation Assessment Workshop
Mr. Paul Carlson
Florida Marine Research Institute
100 Eighth Avenue SE
St. Petersburg, FL 33701-5905
(813) 896-8626
Dr. Jim Fourqurean
Continental Shelf Associates, Inc.
759 Parkway Street
Jupiter, FL 33477-4567
(407) 746-7946
Dr. William Kruczynski
Environmental Research Laboratory/ORD
U.S. Environmental Protection Agency
Sabine Island
Gulf Breeze, FL 32561-5299
(904) 934-9200
Dr. Brian E. Lapointe
Associate Research Scientist
Harbor Branch Oceanographic Institute
Route 3 Box 297 A
Big Pine Key, FL 33043
(305) 872-2247
Dr. John C. Ogden
Director, Florida Institute of Oceanography
MSL-Room 128
830 First Street South
St. Petersburg, FL 33701
(813) 893-9100
Dr. Kathleen M. Sullivan
The Nature Conservancy
SFRC P.O. Box 279
Homestead, FL 33030
(305) 242-7800
Dr. Jay Zieman
Department of Environmental Sciences
Clark Hall
University of Virginia
Charlottesville, VA 22903
(804) 924-0570
A-2
-------
Nearshore and Confined Waters Assessment Workshop
Dr. Jim Fourqurean
Continental Shelf Associates, Inc.
759 Parkway Street
Jupiter, FL 33477-4567
(407) 746-7946
Mr. R.J. Helbling
State of Florida
Department of Environmental Regulation
11400 Overseas Highway, Suite 123
Marathon, FL 33050-3627
(305)289-2310
Mr. Delbert Hicks
U.S. Environmental Protection Agency
Region IV, ESD
960 College Station Road
Athens, GA 30613-0801
(404)546-3136
Dr. Ron Jones
Department of Biology
Florida International University
Miami, FL 33199
(305) 348-3095
Dr. Brian E. Lapointe
Associate Research Scientist
Harbor Branch Oceanographic Institute
Route 3 Box 297A
Big Pine Key, FL 33043
(305) 872-2247
Dr. Steven Miller
NOAA National Undersea Research Center
University of North Carolina
514 Caribbean Drive
Key Largo, FL 33037
(305) 451-0233
Dr. Ned P. Smith
Harbor Branch Oceanographic Institution
5600 Old Dixie Highway
Ft. Pierce, FL 34946
(407) 465-2400
Dr. Alina M. Szmant
Associate Professor, Marine Biology and Fisheries
Rosenstiel School of Marine and
Atmospheric Science
4600 Rickenbacker Causeway
Miami, FL 33149
(305) 361-4609
A-3
-------
Spill and Hazardous Material Assessment Workshop
Mr. Eric Evans
Manager Marine Sales
Coastal Fuels Marketing
Coastal Tug and Barge, Inc.
P.O. Box 025500
Miami, FL 33102-5500
(305) 551-5380
Dr. Kenneth Haddad
Florida Marine Research Institute
100 Eighth Avenue SE
St. Petersburg, FL 33701-5905
(813) 896-8626
Mr. William Hunt
Commanding Officer
Boca Chica Naval Air Station (Code 1883)
Key West, FL 33040-5000
(305) 292-2030
Lt. Donna Kuebler
U.S. Coast Guard MSO Miami
51 SW 1st Avenue
Miami, FL 33130
(305)536-5694
Mr. Greg Lee
Florida Department of Environmental .Regulation
2600 Blair Stone Road
Tallahassee, FL 32399-2400
(904) 488-0190
Ms. Debbie Prebble
Environmental Administrator
Department of Natural Resources
3900 Commonwealth Blvd. Room 753-F (MS-640)
Tallahassee, FL 32399-2400
(904)488-5757
Dr. Anita Wooldridge
Marine Spill Response Corporation
905 South American Way
Miami, FL 33132
(305) 375-8410
A-4
-------
APPENDIX A
-------
ACRONYMS
ADF average daily flow
ATRP Abandoned Tank Restoration Program
BAT Best Available Technologies
BOD biochemical/biological oxygen demand
CDERM (Metro-Dade) County Department of Environmental Resources Management
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CIMAS Cooperative Institute for Marine and Atmospheric Studies (University of Miami)
CWA Clean Water Act
DO dissolved oxygen
DOA Department of Agriculture
DOD Department of Defense
DOI Department of the Interior
EDIP Early Detection Incentive Program
EPA Environmental Protection Agency
FAC Florida Administrative Code
FDCA Florida Department of Community Affairs
FDER Florida Department of Environmental Regulation
FDHRS Florida Department of Health and Rehabilitative Services
FDNR Florida Department of Natural Resources
FDPC Florida Department of Pollution Control
A-l
-------
FIO Florida Institute of Oceanography
FKNMS Florida Keys National Marine Sanctuary
FP&L Florida Power & Light
FWS U.S. Fish and Wildlife Service
CIS Geographic Information System
CMS Groundwater Management System
GPAD gallons per acre per day
GPCD gallons per capita per day
GPD gallons per day
HDPE high-density polyethylene
HSWA Hazardous and Solid Waste Amendments
LPC limiting permissible concentration
MGD million gallons per day
MHP mobile home park
MSD municipal services district
MSDS Material Safety Data Sheets
NAS Naval Air Station
NOAA National Oceanic and Atmospheric Administration
NPDES National Pollutant Discharge Elimination System
NTU nephelometric turbidity unit
NWR National Wildlife Refuge
ORC Objections, Recommendations and Comment (Report)
A-2
-------
OSDS
PAE
PCB
PCU
ppt
pptr
RCRA
RV
SFWMD
STP
TBT
TP
TPD
TSS
USAGE
USCG
uses
USDA
USNAS
WMD
WMI
WRT
on-site sewage disposal system
phthalate acid
ester
polychlorinated biphenyls
platinum-cobalt color unit
parts per thousand
parts per trillion
The Resource
Conservation and Recovery Act
recreational vehicle
South Florida
Water Management District
sewage treatment plant
tributyltin
trailer park
tons per day
total suspended solids
United States
United States
United States
United States
United States
Army Corps of Engineers
Coast Guard
Geological Survey
Drug Administration
Naval Air Station
Water Management District
Waste Management, Inc.
Wallace Roberts & Todd
A-3
-------
APPENDIX B
-------
Coral Comm
Assessment — Task 3
Temporal
Consideration
Seasonal— Historical
Spatial Cotuideratioa
Trend
Severity
Certainty
Water Quality Related?
Temperature
(/, Nutrients
" Salinity
u
•jjj Turbidity
?•
j Toxics/Pesticides
K Bacteria
u
£ Viruses
Dissolved Oxygeai
Overall Significance
Additioaal Comments
PROBLEMS/ISSUES
Coral Disease
Summer. 1970s
Widespread
Widespread
Increasing,
patchy
Known
Possible
Significant
Unknown
Slight
Unknown —
need work
Unknown-
need work
Unknown
Unknown
No
High
Need to
determine the
cause
(epidemiology).
Global
influence?
Bleaching
Summer, Fall.
1911
Variable
Increasing
Variable-
species dependent
Known
Yes
Significant
Unknown
Contributor
Unknown
Unknown
Slight-
secondary
Slight-
secondary
NA
High
Problematic
Algal Growth
Summer, Fall.
Localized*
Increasing
Moderate • + '
Known
Potential exists.
Possible — not
yet a problem.
Significant
Significant
No
No
Unknown
Unknown
NA
NA
Moderate
•Hot spots
(e.g., Lyngbya)
Herbivore
effects.
Lack of Recruitment*
Driven by reproduction
cycle. Species
dependent. No
historical data.
Patchy
Unknown
High
Suspected
Possible
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
High
•Offshore discussion
only. Increase in algae
abundance reduces
•elective coral
recolonization.
Competitors, gnzers,
predators.
Growth Rate
(Individual)
Seasonal differences.
Species dependent
(significant).
Isolated
Variable
Localized
Known
Known
Significant
Unknown
Slight
Significant
Unknown
Unknown
Unknown
NA
High
Physical damage to
coral. Coral diseases
are known to affect
growth rates.
Decline in Coral
Abundance
Seasonal.
Long-term problem
(geologically).
Variable
Decline? No data.
Change in rate
unknown.
High
Known
Probable in the
historical sense.
Highly Significant
Unknown. Need data.
Historically
significant. Currently
insignificant.
Significant
Unknown
Unknown
Unknown
NA
High
Need more data.
Cyanobacteria diseases
are known to affect
this problem.
Decline in Species
Diversity
Extremely variable
(hours to years)
Widespread
(width of Keys)
Worsening*
Moderate
(overwhelming lack
of data)
Unknown
Known*
Probable (for
nearshore breeding
species)
Possible (offshore)
Significant
Slight— Moderate
Slight
Unknown
Slight (offshore)
Unknown
Unknown
Unknown
Unknown
'Particularly
harvested species (for
aquariums, etc.).
Lyngbya
Growth
Fall 1988
bloom.
Summer, Fall
Localized and
spreading
Worsening
High
Known
Yes
Significant
Significant
No
No
Unknown
Unknown
NA
NA
High
-------
Submerged and Emergent Aquatic Vegetation Assessment — Task 4
Temporal
Cons»kter8tion
(Seasonal • Historical)
Spatial Consideration
Trend
Severity
Certainty
Water Quality Related?
Temperature
Anthropogenic
v. Nutrients
u
£ Salinity
< Turbidity
CE
^
t-
5 Toxics/Pesticides
=
* Disease
5
Hypoxia
Anthropogenic
Dissolved Oxygen
Overall SignifVatcp
Additional Comments
PROBLEMS/ISSUES
SEAGRASSES . ||
Increased
Epiphyte
Growth
Summer (belt
time to monitor)
Recent*
Widespread*
Unknown
Worsening,
Increasing
High*
Moderate-
Unknown
elsewhere.
Known*
(for nutrients)
Possible
Certain*
Moderate
Significant
Slight
Significant
Unknown
Unlikely but
unknown
In Hot Spou
Significant*
High
•Hot Spou
Lack of data.
Widespread
cpeciei variation.
Strong
relationship
between
temperature and
nutrients.
Above are
observations.
Seagrass Historic
Growth Rate
(Individual)
Seasonal *
Decreasing
recently.
In Hot Spots**
Unknown
elsewhere.
Worsening*
Unknown
elsewhere.
High*
Slight elsewhere.
Suspected*
Possible elsewhere.
Certain*
Possible elsewhere.
Significant
Significant
Significant
Significant
Unknown
Unlikely but
unknown
Hot Spots
Significant
High*
Slight elsewhere.
•Hot Spou
"Associated with
human activity.
Need data.
Variable.
Strong relationship
between
temperature and
nutrienu.
Hot Spot influence.
Declines in
Community .
Diversity**
Anthropogenic
Hot Spou
Isolated*
Worsening*
Unknown
High*
Unknown
Suspected*
Possible
Certain*
Probable
Significant
Moderate
Significant
Moderate-
Significant
Moderate-
Significant
Moderate
Hot Spou
Significant
High*
Possible but
unknown overall.
•Hex Spou
••Other than
seagrass.
Overfishing
effects. Strong
relationship
between
temperature and
nutrienu.
Loss of habiut.
Decreased
Geographical
Extent
Hot Spot losses.
Historical— natural
gains and losses.
Isolated*
Worsening*
Same— other areas
High*
Known*
Certain
Significant
Significant
Significant
Significant
Unknown but
unlikely
Unknown but
unlikely
Hot Spou
Significant
High*
Slight overall
•Hot Spou
Human effects
slight to nil.
Changes taking
place naturally.
Natural
fluctuations.
Decreased
Recruitment of
Seagrasses
Seasonal
Isolated*
Lack of dau
Worsening*
Lack of dau
Unknown
Possible
Significant
Unknown
Significant
Significant (as
it relates to
light)
Unknown but
unlikely.
Unknown but
unlikely
Hot Spou
Significant
Unknown
•Hot Spou
Lack of dau
and
information.
Hypoxia M
Summer, Fall.
Historically-
unknown.
Depends on
circulation.
Unknown
Potentially high
Known
Definitely
Significant ||
Significant ^1
Possible
Possible
Unknown but
unlikely
Unknown but
unlikely
Hot Spou
Significant
Depends on
circulation.
Circulation,
flushing,
climate effecu
and influence
(drought, wet).
1
B-2
-------
Submerged and Emergent Aquatic Vegetation Assessment — Task 4 (continued)
Temporal
Consideration
(Seasonal - Historical)
Spatial Consideration
Trend
Severity
Certainty
Water Quality Related?
Temperature
Anthropogenic
at Nutrients
bj -Salinity
et Turbidity
t Toxics/Pesticides
<
01 ~
K Disease
B
^ Hypoxia
Anthropogeoic
Dissolved Oxygen
Overall Significance
Additional Comments
PROBLEMS/ISSUES
MAGROALGAE
Increased Epiphyte
Growth
Summer
Recent*
Widespread*
Unknown
Worsening,
Increasing
High*
Moderate— Unknown
Known*
(for nutrients)
Possible
Certain*
Moderate
Significant
Slight
Significant
Unknown
Unknown but unlikely
Hot Spots
Significant*
High
•Hoi Spots
Lack of data
Widespread species
variation
Strong relationship
between temperature
and nutrients. Above
are observations.
Macroalgae Historic
Growth Rates
Seasonal*
Increased over last
decade.
More widespread
Worsening*
Unknown
High*
Slight
Known
Certain*
Possible
Significant
Significant
Significant
Significant
Unknown
Unknown but unlikely
Hot Spots
Significant
High*
Otherwise slight
•Hot Spots
Competes with
seagrasses.
Lack of data.
Strong relationship
between temperature
and nutrients.
Above are observations.
Declines in
Community
Diversity**
Anthropogenic
Hot Spota
Isolated*
Worsening*
Unknown
High*
Unknown
Suspected*
Possible
Certain*
Probable
Significant
Moderate
Significant
Moderate-
Significant
Moderate-
Significant
Moderate
Hot Spots
Significant
High* •
Possible but
unknown.
•Hot Spou
••Other than
macroalgae.
Overfishing effects.
Strong relationship
between temperature
and nutrients.
Loss of habitat.
Hypoxia
Summer, Fall.
Historically —
unknown.
Depends on
circulation
Unknown
Potentially high
Known
Definitely
Significant
Significant
Possible
Possible
Unlikely but
unknown
Unknown but
unlikely
Hot Spots
Significant
Depends on
circulation.
Circulation,
flushing, climate
effects and influence
(drought, wet).
Diversity of
Algae
Diversity has
decreased within
last decade.
totaled*
More
widespread
?
?
Known
Known
Significant
Significant
Significant
Significant
Unknown
Unknown
?
Significant
High
•Hot Spou
Overfishing.
Grazing.
B-3
-------
Submerged and Emergent Aquatic Vegetation Assessment — Task 4 (continued)
Temporal
Consideration
(Seasonal • Historical)
Spatial Consideration
Trend
Severity
Certainty
Water Quality Related?
Temperature
g Anthropogenic
H Nutrients
<5 Salinity
2 Turbidity
j-
fc Toxics/Pesticides
£ Bacteria
. ec
•< Viruses
Aii thro pogeuic
Dissolved Oxygen
Overall S*g"'fir
Climatic Effects
Dredge and Fill
Other
Additional Comments
PROBLEMS/ISSUES ^j
MANGROVES/BUTTONWOODS
Decreased
Tree
Productivity
(Individual)
Seasonal
Historically —
unknown.
Unknown
Unknown
Unknown
Unknown
Possible
Significant
Significant
Significant
Significant
Possible
None
None
Significant
Unknown .
Flood sensitive
Changes in
community
type.
Impoundment
effects.
Decreased
Geographical
Exteut
Not seasonal
Historically—
NA
Widespread.
Decreasing
historically.
Large losses,
declining
High
Known
Possible
Slight
Significant
Significant
Significant
Possible
None
None
Significant
Slight
' —
—
Inverse to water
quality. Highly
significant as a
problem.
—
Functional
Value of the
Habitat
Seasonal and
episodic
flooding
Slight
Unknown,
declining
Moderate
Suspected
Probable
Possible
Significant
Likely
Likely
Significant
Unknown but
unlikely
Unknown but
unlikely
Significant
High
-
—
Fragmentation
is critical
component.
— '
FRESHWATER INFLUENCE . ^0
Decreased
Productivity
Seasonal
Historically-
unknown.
Unknown
Unknown
Unknown
Unknown
Probable
High/Low
Significant
Significant
Significant
None
Possible
None
None
Unknown
Moderate— High
Lowering of the
water table
—
^
—
Decreased
Geographical Extent
Historically— known.
Losses high
Important legally
Decreasing
High
Known
Yes. Nutrient
additives. Septic
system runoff.
None
Significant
Significant
Possible
Possible
None
None
Unknown
High
—
Direct loss of habiut
due to development.
Dredging.
Human activity:
cesspool problem and
septic tanki.
—
Functional
Value of the
Habitat
Seasonal
(wet/dry)
Historic losses
Widespread
Loss continues
High
Known
Yei On part)
Slight-None
Significan ^^1
Significant
Significant
Significant
Possible
Possible
Probable-
Significant
High
Fragmentation
—
—
4
B-4
-------
Confined Waters Assessment — Task 5
Temporal Consideration
(Seasonal — Historical)
Spatial Consideration
Tread
Severity
Certainty
Water Quality Related?
Temperature
tt Nutrients
u
t
5 Salinity
h Turbidity
2 Toxks/Pestkides
<
Ql
g Human-Derived
£ Bacteria
£ Viruses
Anthropogenic
BOD Loadings
OveraO Significance
Additional Comments
PROBLEMS/ISSUES
EUTROPH1CATION
Increased Epiphyte
Growth
Seasonal (summer)
Increased over last
decade
Widespread
Worsening
High
Known
Certain
Slight— Moderate
Significant
Slight
Significant
Unknown
Unknown but unlikely
Unknown but unlikely
Significant
High
Significant afTecl on
hypoxia. Succession-
increased nutrienu.
Dealt mostly with canals.
Indicator of change in
community structure and
amount. Circulation and
prevention of funneling
of organic material into
canals.
Increased Chlorophyll
Seasonal
(severe spikes with rain
events) 1973-1974
Widespread
Chronic
Worsening (anecdotal .
evidence)
High
Known
Certain
Slight— Moderate
Significant
Slight
Significant
Potentially important.
Unknown
Unknown but unlikely
Unknown but unlikely
Significant
High
Related to rain, temp,
light and other variables.
Indicator of severity of
nutrients.
Discussion is regarding
phytoplanklon (no
information on
zooplanktonor
ichlhyoplanklon).
Change in Benthic
Community Structure
Seasonal
Widespread
Worsening
High
Known
Certain
Slight— Moderate
Significant
Slight
Significant
Unknown
Unknown but unlikely
Unknown but unlikely
Significant
High
Recycling seagrass wrack
can lead to
eulrophication.
Human Health
(Fish and Shellfish
Consumption)
Seasonal
No historical data
Potentially widespread
Unknown (need to
look at data).
Unknown
Unknown
Possible but unknown
Slight— Significant*
Slight— Significant*
Slight— Significant*
Significant
Significant
Significant
Significant
Significant
Potential for
problems.
Unknown
'Species specific.
Because no adequate
sewage treatment,
potential exists for
severe health
problems.
B-5
-------
Nearshore and.Back Country Waters Assessment — Task 5 (continued)
Temporal
Consideration
(Seasonal • Historical)
Spatial Consideration
Trend
Severity
Certainty
Water Quality Related?
Temperature
2
u Nutrients
£ Salinity
£ Turbidity
H
3 Toxics/Pesticides
C" Human— Derived
2 Bacteria
£ Viruses
Anthropogenic
BOD Loadings
Overall Significance
Additional Comments
PROBLEMS/ISSUES
NEARSHORE .
Increased Epiphyte
Growth
Seasonal (Summer)
Increased over last
decade
Widespread
Worsening
Slight
Possible
Certain
Slight— Moderate
Significant
Slight
Significant
Unknown
Unknown but unlikely
Unknown but unlikely
Significant
Slight
Significant effect on
hypoxia.
Indicator of change in
community structure and
amount.
Sewage spills.
Increased Chlorophyll
Seasonal
(severe spikes with rain
events)
Widespread
Chronic
Worsening
Slight
Possible
Certain
Slight— Moderate
Significant •
Slight
Significant
Unknown
Unknown but unlikely
Unknown but unlikely
Significant
Slight
Related to rain,
temperature, light, and
other variables.
Indicator of severity of
nutrients.
Discussion is regarding
phytoplankton
(no information on
zooplankton or
ichlhyoplankton).
BACK COUNTRY
Increased Epiphyte
Growth*
Seasonal (Summer)
Increased over last
decade
Widespread
Worsening
Slight
Possible
Certain
Slight— Moderate
Significant
Slight
Significant
Unknown
Unknown but unlikely
Unknown but unlikely
Significant
Slight
•All anecdotal evidence
(no data).
Significant effect on
hypoxia.
Indicator of change in
community structure
and amount.
Increased Chlorophyll*
Seasonal
(severe spikes with rain
events)
Widespread
Chronic
Worsening
Slight
Possible
Certain
Slight— Moderate
Significant
Slight
Significant
Unknown
Unknown but unlikely
Unknown but unlikely
Significant
Slight
•All anecdotal evidence
(no data).
Related to rain, temp,
light and other variables.
Indicator of severity of
nutrients.
Discussion is regarding
phytoplankton (no
information on
zooplankton or
ichthyoplankton).
B-6
-------
Spills and Hazardous-Materials Assessment — Task 6
Temporal
Consideration
Seasonal-Historical
Spatial
Consideration
Trend
Severity
Contingency Plans
Water Quality
Effect*
Overall
Significance
Compliance/
Enforcement
Major Constituents
Risk
Additional
Comments
PROBLEMS/ISSUES
Small Vessel Spills
(Marine)*
Year-round
Past/Current
Widespread
Nearshore, fueling
(More reported)
Worsening
Severe— locally
Overall— unknown
Low— low "-"
Local— toxic
Overall— unknown
High
Low authority
exists, not enough
manpower
Diesel, gas, bilge
High
•£3000 gal fuel or
cargo. A lot of
spills are
unreponed. Need
more information.
Aircraft downings—
source.
Small Facility Spills
(Landbased)*
Year-round (marinas,
auto fueling facilities)
Past/Current
Widespread (Marinas,
fueling facilities)
(More reported)
Worsening
Severe— locally
Overall— unknown
Low " + "
Local— toxic
Overall— unknown
Moderate
Low
Diesel, solvents, gas,
pesticides, used oil,
paint-related material
High
Many spills unreponed.
Runoff from boat yards
and paint scraping.
Need more information
(Keys- related).
Illegal Dumping
Marine- Landbased*
Year-round
Past/current
Widespread
Worsening
Local-High
Ove rail— unknown
NA. Coast Guard and
Stale response high.
Local-High
Overall— unknown
Overall-High
Compliance— very low
Enforcement-
improving with Coast
Guard, State manpower
declining
Marine— petroleum
products
Land— paint solvents
Moderate
•> 5000 gal fuel/cargo,
large vessels.
Quality and quantity of
substances unknown.
Need more information
(Keys-related).
Catastrophic Tanker
Spills*
Year-round
2 in last 16 yean.
Isolated — offshore
Gink to climate
conditions)
Improving— better
(likelihood it
decreasing)
High in FKNMS
Sanctuary-specific. A
contingency plan if
needed.
High, if tpill reaches
FKNMS
High
Moderate— High
Diesel, blends of fuel,
heavy fuels,
hazardous materials,
crude.
Low
•Major spill > 10,000
gal inland > 100.000
gal offshore. Usually
occurs outside
FKNMS but may
reach it. Need
information (Keys-
related).
Tanker Truck
Spills*
Year-round
2 in last 10 year*
Isolated—
highway.
Better
Locally severe
Good. Response
lime a problem.
Severe locally.
Highly toxic
compounds.
Moderate
Moderate— High
Diesel, gas,
hazardous
material.
Moderate
•Includes tractor
trailers.
Need more
information
(Keys-related).
*Bioloxicity, physical damage, bioaccumulalion, other.
B-7
-------
Spills and Hazardous-Materials Assessment — Task 6 (continued)
Temporal
Consideration
Seasonal-Historical
Spatial
Consideration
Trend
Severity
Contingency Plans
Water Quality
Effect1
Overall
Significance
Compliance/
Enforcement
Major Constituents
Risk
Additional
Comments
PROBLEMS AND ISSUES
Effects of
Dispersant Use
Seasonal impact to
habitats
Isolated-offshore
Better understanding
Better offshore.
Slight— tradeoffs
Low. Needs work
Tradeoffs
Various effects
High
NA
Proprietary
Constituents (9527)
Risk of using it is
low.
Larval effects.
Tradeoffs. Need
information.
Need preapproval to
use. Need to
stockpile
dispersants. Planes
available.
Bioremediation
NA
NA
NA
NA
NA
Potential effect of
adding nutrients is
low
Unknown but
unlikely
NA
NA
NA
Interim guidelines.
Use not as time
constrained as with
dispersants.
Leacbable Toxics
(CERCLA + RCRA
Sites, Underground
Storage Tanks)
Year-round
Past
Isolated
Better
Moderate
Site-dependent
Low— High
Unknown, but
significant
Need information on
heavy metal impacts
Low-High
Site dependent
Variety of heavy
metals, PCBs,
insecticides and
pesticides
Unknown
Need information on
heavy metal impacts
on nearshore waters.
Runoff from boat
yards/boat paint
scraping.
Boat Scraping
Year-round with
seasonal peaks.
Past/Current
Isolated
Site-specific
Unknown
Unknown
NA
High
High
Unknown
Metals
High
Ruptured Bulk
Tanks and
Pipelines
Year-round
Isolated
Site-specific
Better
Moderate— High
Moderate
Probable
High
Moderate— High
Jet fuel, diesel,
various petroleum
products
Moderate
TJiotoxicity, physical damage, bioaccumulation, other.
B-8
-------
APPENDIX C
-------
DESCRIPTIVE TERMS FOR MATRIX ANALYSIS
Temporal Consideration
Seasonal
- Winter, Spring, Summer, Fall-Duration
Historical
- Recent, Past (Years), - Duration
. Spacial Consideration
- Widespread, moderate, isolated, unknown - specific
Trend
- Worsening, Same, Better, Unknown
Severity
- High, Moderate, Slight, Unknown
Certainty
- Known, Suspected, Possible, Unknown
Water Quality Related?
- Probable, Possible, Unlikely, Unknown
Temperature. Nutrients. Salinity, Turbidity. Toxics/Pesticides. Bacteria,
Viruses, Dissolved Oxygen
- Significant, Moderate, Slight, Unknown
Overall Significance
- High, Moderate, Slight, Unknown
Contingency Plans
- High, Medium, Low, Adequacy
Compliance/Enforcement
- High, Medium, Low, Adequacy
C-l
------- |