Florida Bay

By Margaret O. Hall,1 Kevin Madley,1 Michael J. Durako,2 Joseph C. Zieman,3 and Michael B. Robblee4

1

Florida Fish and Wildlife Conservation Commission, Florida Fish and 

Wildlife Research Institute.

2

University of North Carolina at Wilmington, Center for Marine Science.

3

University of Virginia, Department of Environmental Sciences.

4

U.S. Geological Survey, Center for Water and Restoration Studies.

Background

Florida Bay is a shallow, triangular lagoon with an 

average depth of less than 1.5 m (5 ft), located at the southern 

tip of the Florida peninsula (fig. 1). Florida Bay ranks among 

the world’s largest estuarine systems with an overall area 

of 220,000 ha (543,620 acres), and seagrass communities, 

principally turtle grass (Thalassia testudinum), cover 95% 

of the bottom (Fourqurean and Robblee, 1999). Florida Bay 

seagrasses are critically important to the economy and ecology 

of the southeastern Gulf of Mexico, providing food and 

shelter to numerous fish and invertebrate species, including 

the economically important pink shrimp (Farfantepenaeus 

duorarum), stone crab (Menippe mercenaria), and spiny 

lobster (Panuliris argus) (Da­vis and Dodrill, 1989; Holmquist 

and others, 1989a; Thayer and Chester, 1989; Tilmant, 

1989; Robblee and others, 1991). Various wading birds, as 

well as endangered species such as bald eagles (Haliaeetus 

leucocephalus), manatees (Trichechus manatus), American 

crocodiles (Crocodylus acutus), and sea turtles (Chelonia 

mydas) also depend, in part, on seagrass communities 

(Holmquist and others, 1989b; Mazzotti, 1989; Boesch and 

others, 1993).

Florida Bay is divided into numerous, discrete basins 

(locally called “lakes”) by a series of interconnected, 

carbonate mudbanks. These mudbanks function as barriers to 

water circulation, leading to large spatial differences in water 

temperature, salinity, and turbidity within the region. Tidal 

energy is rapidly attenuated by the mudbanks so that there is 

essentially no lunar tide over most of central and northeastern 

Florida Bay. This extensive network of mudbanks covers 

more than 25% of the area and occurs atop an almost planar 

surface of limestone bedrock that slopes from the Florida 

mainland downward to the southwest (Perkins, 1977; Wanless 

and Tagett, 1989). Physical and chemical characteristics of 

both banks and basins vary along this gradient. For example, 

narrow banks separate relatively large basins in the northeast, 

while banks are wider and basins smaller in the southwestern 

portion of bay. Sediment accumulation, water depth, and 

phosphorus availability, which is the limiting plant nutrient 

in much of Florida Bay, also increase from northeast to 

southwest (Zieman and others, 1989; Fourqurean and 

Robblee, 1999).

Florida Bay is typically a negative estuary, with 

evaporation exceeding freshwater input during most of the 

year. Hypersaline conditions (i.e., salinities greater than 

38 ppt) are thus common, especially in central Florida Bay 

where water circulation is most limited. Factors that influence 

salinity levels include proximity to the Gulf of Mexico or 

Atlantic Ocean, groundwater seepage, and local precipitation 

and runoff; however, the single most important factor affecting 

both seasonal and annual variation in salinity patterns 

throughout the system is the amount of rainfall. Salinities are 

usually highest during the late spring, which is the end of the 

dry season, and lowest during the peak rainy season in late 

summer. During extended drought periods, salinities greater 

than 70 ppt are not uncommon in central Florida Bay.

Florida Bay historically received large quantities of 

fresh water via The Everglades watershed. Unfortunately, 

substantial alteration of The Everglades during the past 100 yr 

to accommodate the rapidly growing south Florida population 

has resulted in greatly reduced freshwater inflow to the region 

when compared to historical levels. Most of the reduction 

in freshwater inflow is the result of an extensive series of 

drainage channels constructed to regulate flow through The 

Everglades for agriculture and flood control (i.e., the Central 

and Southern Florida Project). Fresh water that once might 

have flowed into Florida Bay has been diverted east into 

Biscayne Bay and the Atlantic Ocean via the canal system. 

In addition, construction of the Flagler Railway (1905–12) 

connecting Key West to the Florida mainland greatly changed 

circulation patterns within the region, essentially eliminating 

waterflow between Florida Bay, the Atlantic Ocean, and the 

Gulf of Mexico.

The majority of fresh water flowing directly into Florida 

Bay enters from the northeast through the Taylor River (fig. 

2). Fresh water also enters the northeastern portion of the 

bay as overflow from the C-111 Canal, part of the South 

Florida Water Management District’s canal system, and as 

sheet flow from The Everglades. Shark River Slough, the 

principal freshwater flowway of The Everglades, empties 
75 

95 

4

275 

St. Petersburg

Tampa 

Orlando 

Port Saint Lucie

West Palm Beach

Fort Lauderdale 

Miami 

Gulf of Mexico

Taylor R iver

Florida Bay

Fort Myers 

20 0 km 40 60 80 

30 20 10 0 mi 40 50 

N

Florida Bay 

Watershed boundary 

City 

Interstate highway 

River 

Gulf Intracoastal 

Waterway 

County line 

Figure 1. Watershed for Florida Bay.

244 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
into Whitewater Bay and the mangrove estuaries of the 

southwestern Florida coast. Fresh water from Shark River 

Slough enters Florida Bay from the west after mixing with 

near shore waters of the Gulf of Mexico. Inflows from both 

the Taylor River and Shark River Sloughs are significantly 

lower than historical volumes because of current water 

management practices.

Recent paleoecological investigations have provided 

evidence that salinities in Florida Bay have increased over 

the last century, and the temporal patterns of change coincide 

with human activities in the south (Swart and others, 1996; 

Brewster-Wingard and Ishman, 1999; Halley and Roulier, 

1999). For example, increases in salinity in Florida Bay 

between 1910 and 1920 have been attributed to construction 

of the Flagler Railroad causeway. Salinity elevations observed 

after 1940 are most likely related to the canal system that 

diverts fresh water away from The Everglades before it can 

reach Florida Bay. Although the effects of increased salinity 

on the Florida Bay ecosystem are difficult to quantify given 

the lack of historical data, it is widely recognized that salinity 

greatly influences the distribution and abundance of 

estuarine organisms.

Scope of Area

Florida Bay is bordered to the north by the Florida 

mainland, to the southeast by the Florida Keys, and to the 

west by the Gulf of Mexico (fig. 1). The exact geographical 

boundaries of Florida Bay are difficult to establish given the 

open connection with the Gulf of Mexico. Florida Bay is 

generally considered to be the shallow, less than 3 m (10 ft), 

mudbank-dominated region located east of The Everglades 

National Park boundary (Fourqurean and Robblee, 1999).

Methodology Employed To Analyze 

Historical Trends

Aerial Photography and Interpretation

Three reports have provided acreage estimates for Florida 

Bay seagrasses that were based primarily on the interpretation 

of aerial photography. The first acreage estimates in 1972 were 

included in a natural resource inventory of estuaries along the 

Florida Gulf of Mexico coast found in McNulty and others 

(1972) (table 1). The authors collected photography from 

county offices, described as mostly 1:400-scale imagery, that 

was acquired within 5 yr before the study. The document does 

not specifically state the scale or source of the Florida Bay 

photography. Submerged vegetation was mapped by freehand 

on navigation charts while consulting the aerial photography, 

and field checks were performed to determine accuracy of 

the photointerpretation. Seagrasses were classified in a single 

category called “submerged vegetation.”

The second mapping report that included Florida Bay 

seagrasses was prepared by Continental Shelf Associates, 

Inc. (1989) under contract with the U.S. Department of the 

Interior’s Minerals Management Service (table 1; fig. 3). For 

this project, 1:40,000-scale, natural-color aerial photography 

was collected for a large area of southwestern Florida, 

including Florida Bay. The classification system consisted 

of 26 categories describing a variety of benthic habitat types 

(e.g., seagrasses, algae, live bottom, coral, sand), of which 14 

contained a seagrass component. Extensive groundtruthing 

data were gathered to facilitate photointerpretation. In addition 

to seagrass acreage, the report included information on the 

characteristics of the seagrass community that included 

seagrass biomass and short-shoot density.

The third Florida Bay seagrass mapping effort was a 

joint venture between the Florida Marine Research Institute 

and the National Oceanic and Atmospheric Administration’s 

Coastal Services Center (table 1; fig. 4). At two different times 

between 1991 and 1995, 1:48,000-scale aerial photography 

was collected for the Florida Bay region. The imagery was 

interpreted for benthic habitats, including seagrasses. Of the 

30 classification categories used in the interpretation process, 

9 contained a seagrass component. 

Differences in the quality of the photography, delineation 

techniques, classification systems and geographic extents of 

the study areas preclude using these datasets for determining 

trends in Florida Bay seagrass distribution and abundance. 

For this document, the Continental Shelf Associates, Inc. 

(1989) and the Florida Marine Research Institute and National 

Oceanic and Atmospheric Administration (1995) data 

were analyzed within the same extent boundary by using a 

geographic information system (GIS) software clip command. 

The data reported in McNulty and others (1972) were not 

available in digital form, so a similar GIS clip function was 

not possible. 

Table 1. Historical coverage in hectares (acres) of submerged 

vegetation in Florida Bay. 

Year of 

Photography

Seagrass 

Coverage Source

1970 103,848 

(256,608)

McNulty and others, 1972 

1987 166,030 

(410,270)

Continental Shelf 

Associates, Inc., 1989

1991–95 147,612 

(364,602)

Florida Marine 

Research Institute/

National Oceanic 

and Atmospheric 

Administration, 1995

Methodology Employed To Analyze Historical Trends 245
1

1

Segment

Gulf Intracoastal Waterway

Florida Bay

Florida Bay

Whitewater Bay

Ta lo y Rr iv r e Slou hg C 111 Canal

Florida Keys Long Key

Cape Sable

EvergladesNational Park

Shark River Slough

Gulf of Mexico

km

mi 5

5 0

0 10

15 10

Study area

N

Florida

Figure 2. Scope of area for the Florida Bay seagrass vignette.

246 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
Field Investigations

The first quantitative seagrass survey in Florida Bay 

was conducted during the summer of 1984. Zieman and 

others (1989) were contracted by the National Park Service to 

characterize the status of seagrass habitats in the Everglades 

National Park. Seagrass species composition and abundance 

were determined at more than 100 stations distributed 

throughout the bay. Seagrass beds dominated by turtle grass 

covered more than 80% of the subtidal mudbanks and basins 

in Florida Bay.

Since the late 1980s, many components of the Florida 

Bay ecosystem have changed substantially, and changes in 

the seagrass community have been particularly conspicuous. 

Extensive areas of turtle grass began dying in summer 1987, 

particularly in central and western Florida Bay (Robblee and 

others, 1991). This die-off expanded rapidly, and by summer 

of 1988, 30% of the dense seagrass beds in western Florida 

Bay were affected. By 1990, more than 4,000 ha (9,884 

acres) of seagrass had been completely lost, and an additional 

23,000 ha (56,833 acres) were damaged. Although the rate has 

slowed, turtle grass die-off continues to occur in the bay.

The patchy mortality characteristic of die-off is very 

different from the gradual thinning and loss of seagrasses 

typically resulting from decreased water clarity. In turtle 

grass meadows affected by die-off, there is often a very 

sharp transition between die-off patches and visually healthy 

seagrasses. Factors that may contribute to turtle grass die-off 

are physiological stressors such as elevated water temperature 

and prolonged hypersalinity, excessive seagrass biomass 

leading to increased respiratory demands, hypoxia and sulfide 

toxicity, and disease; however, the causative mechanism 

behind die-off remains poorly understood (Robblee and others, 

1991; Carlson and others, 1994; Durako, 1994; Durako and 

Kuss, 1994; Fourqurean and Robblee, 1999).

As the die-off subsided in 1991, a widespread decline 

in water clarity began that persisted in some parts of the 

bay until 1997 (Boyer and others, 1999; Stumpf and others, 

1999). Before this event, most of the water in Florida Bay was 

exceptionally clear and often described as “gin” clear. Usually, 

the only turbid areas were in northeastern Florida Bay, where 

carbonate sediments are easily resuspended by wind and 

waves. This increased light attenuation was principally the 

result of microalgal blooms and resuspended sediments and 

was most severe in western and central Florida Bay (Phlips 

and others, 1995; Phlips and Badylak, 1996). Environmental 

changes that lead to reduced light availability have been 

implicated in seagrass declines worldwide (Peres and Picard, 

1975; Cambridge and McComb, 1984; Orth and Moore, 1984; 

Giesen and others, 1990; Dennison and others, 1993; Onuf, 

1994), raising concerns that Florida Bay seagrasses would 

suffer even further damage.

In response to the substantial ecosystem changes and 

probable negative impacts on seagrasses, Hall and others 

(1999) conducted a study to determine the current status 

of Florida Bay seagrass communities. During the summer 

of 1994, seagrass species composition, distribution, and 

abundance were measured at the same stations visited 10 yr 

earlier by Zieman and others (1989) to assess changes that had 

taken place since 1984, a time which preceded the seagrass 

die-off and microalgal blooms.

Despite seagrass die-off and persistent declines in light 

availability, turtle grass remained the dominant seagrass 

species in Florida Bay, and its distribution changed little 

between 1984 and 1994. On a bay-wide basis, however, turtle 

grass abundance declined significantly between surveys; mean 

short-shoot density dropped by 22% over the 10-yr interval. 

Turtle grass decline was not homogeneous throughout Florida 

Bay; largest reductions in shoot density occurred principally 

in the central and western regions. Both the distribution and 

abundance of two other seagrasses, shoal grass (Halodule 

wrightii) and manatee grass (Syringodium filiforme), declined 

substantially between 1984 and 1994. Bay-wide, shoal grass 

and manatee grass shoot densities declined by 92% and 93% 

between surveys, respectively. The spatial patterns of seagrass 

loss in Florida Bay between 1984 and 1994 suggested that 

chronic light reduction and die-off were the most likely causes 

for decline.

Current Seagrass Change—Florida Bay 

Fisheries Habitat Assessment Program

The Florida Bay Fisheries Habitat Assessment Program 

(FHAP) was initiated during spring 1995 in response to 

continuing concerns over environmental changes and seagrass 

loss within the region. The goal of FHAP is to provide 

spatially explicit information on the distribution, abundance, 

species composition, and population dynamics of Florida Bay 

seagrasses. The Miami-Dade Department of Environmental 

Resource Management (DERM) employs FHAP protocols 

in Biscayne Bay and northeastern Florida Bay, and the 

Florida Keys National Marine Sanctuary (FKNMS) also uses 

FHAP protocols in its seagrass monitoring program. The 

establishment of compatible sampling protocols among these 

three large-scale programs has provided a mechanism for the 

establishment of a regional management-oriented database 

of unprecedented geographic scope (Fourqurean and 

others, 2002).

 Methods

Sampling for FHAP is conducted twice a year, during 

spring (May–June) and fall (October–November). Each of 

10 basins representing a range of conditions and gradients 

in Florida Bay are partitioned into approximately 30 to 35 

tessellated, hexagonal grid cells. Sampling-station locations 

are randomly chosen from within each cell, for a total of about 

330 stations per sample period. Sampling grids and station 

locations were generated by using algorithms developed by the 

Current Seagrass Change—Florida Bay Fisheries Habitat Assessment Program 247
Gulf of Mexico

LandSeagrass, presentWater

129630km

8 0 2 4 6 mi

N

Figure 3. Seagrass distribution in Florida Bay, 1987.

248 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
Gulf of Mexico

129630km

8 0 2 4 6 mi

N

LandSeagrass, continuousSeagrass, patchyWater

Figure 4. Seagrass distribution in Florida Bay, 1994.

Current Seagrass Change—Florida Bay Fisheries Habitat Assessment Program 249
U.S. Environmental Protection Agency’s (EPA) Environmental 

Monitoring and Assessment Program (EMAP) and were 

provided by Dr. Kevin Summers of the EPA in Gulf Breeze, 

Fla. This type of sampling design results in systematic random 

sampling, scales the sampling effort to the size of the basin, 

and is well-suited for interpolation (i.e., kriging) and mapping 

of the data. Stations are located by using a handheld Global 

Positioning System (GPS) unit.

At each station, seagrass cover is visually quantified 

within each of four randomly located 0.25 m2 (3 ft2) quadrats 

by using a modified Braun-Blanquet frequency abundance 

scale (Mueller-Dombois and Ellenberg, 1974). This 

nondestructive, semiquantitative method requires relatively 

little time per sample (5 to 10 min for four quadrats), can 

be used for most plant communities, and approximates 

quantitative characteristics of shoot density and standing 

crop for seagrasses. Because of the efficiency of the BraunBlanquet approach, information about seagrass abundance can 

be collected on a bay-wide scale; this type of geographical 

scope would be cost prohibitive if time-consuming direct shoot 

counts or biomass measurements from destructive sampling 

were used.

For a particular sample quadrat, the observer first lists all 

seagrass species that are observed. A cover-abundance rating 

is then assigned by using the following scale: 5 is assigned to 

any number with cover of more than 75% of the quadrat; 4 

to any number with 50% to 75% cover; 3 to any number with 

25% to 50% cover; 2 to any number with 5% to 25% cover; 

1 to numerous, but less then 5% cover, or scattered with up 

to 5% cover; 0.5 to few, with small cover; and 0.1 to solitary, 

with small cover. The upper four scale values of 5, 4, 3, and 

2 refer only to cover. The lower three scale values, 1, 0.5, and 

0.1, are primarily estimates of abundance (i.e., number of 

individuals per species). Sampling of replicate (four) quadrats 

at each sample point allows assessment of within-station 

versus among-station variability.

Maps of seagrass distribution and abundance and 

changes in abundance are produced by using a contouring 

and 3-D mapping program (ArcView Spatial Analyst). The 

geostatistical gridding method of kriging is used to express the 

trends in the Braun-Blanquet data.

Status and Trends

Contour plots illustrating turtle grass distribution and 

abundance in spring 1995 and spring 2003 (fig. 5A and B) 

indicate that it continues to be the dominant and most widely 

distributed seagrass species in Florida Bay. In contrast, turtle 

grass abundance declined significantly in basins along the 

western margin of Florida Bay from spring 1995 to spring 

2003 (fig. 5C). Although quantitative data on light availability 

in Florida Bay are limited, it appears that the greatest losses 

of turtle grass occurred from 1995 to 1998 in chronically 

turbid areas. Whether disease (i.e., the parasitic slime mold 

Labyrinthula sp.) also influenced decline of turtle grass is 

difficult to determine; however, spatial coincidence among 

the distributional patterns of Labyrinthula abundance in the 

fall and turtle grass loss in the following spring suggests 

that the slime mold affected turtle grass decline. Turtle grass 

abundance increased as water clarity improved during the 

period from 1997 to 2000 and has remained generally stable 

since that time.

The distribution and abundance of shoal grass increased 

substantially from spring 1995 through spring 2003 (fig. 6A, 

B, and C), most likely the result of improvements in water 

clarity. The very large gains in shoal grass relative to those of 

turtle grass in western Florida Bay may reflect the lower light 

requirement of shoal grass relative to that of turtle grass, as 

the gains may also reflect the ability of shoal grass to rapidly 

colonize areas where the turtle grass canopy has been removed.

Restoration Opportunities

Restoration of Florida Bay and The Everglades watershed 

is a long-term process that has only recently begun. Complex 

environmental, engineering, and management issues must be 

resolved to achieve restoration goals, requiring the cooperation 

of multiple Federal, State, local, and tribal organizations. 

To facilitate the restoration process, Congress established 

the South Florida Ecosystem Restoration Task Force through 

the Water Resources Development Act of 1996. The purpose 

of the task force is to coordinate policies, programs, and 

information exchange among all organizations responsible 

for restoration, preservation, and protection of the south 

Florida ecosystem.

Many significant restoration projects affecting Florida 

Bay will be part of the Comprehensive Everglades Restoration 

Plan (CERP). The Water Resources Development Acts of 

1992 and 1996 gave the U.S. Army Corps of Engineers 

authority to review the Central and Southern Florida (C&SF) 

Project, and to develop a comprehensive plan to restore 

historical water flow in the south Florida region while meeting 

other water resource needs (e.g., flood control, agriculture, 

and urban water supplies). The CERP includes over 60 

water improvement projects and will take more than 20 yr to 

complete at an estimated cost of 7.8 billion dollars. 

Projects addressing Florida Bay restoration under CERP 

are being developed through the Florida Bay and Florida 

Keys Feasibility Study, a joint effort led by the U.S. Army 

Corps of Engineers and the South Florida Water Management 

District. The purpose of the feasibility study is to identify 

the modifications needed to restore the water quality and 

ecological conditions of Florida Bay while maintaining or 

improving conditions in the Florida Keys.

A crucial restoration project affecting Florida Bay but not 

included in CERP is the Modified Deliveries to the Everglades 

National Park (ENP) and C-111 Project. This project will 

modify water flow to the ENP to restore more natural 

250 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
Figure 5. Distribution, abundance, and cover change of turtle grass (Thalassia testudinum) in Florida Bay in springs 1995 and 2003 

(FHAP = the Florida Fish and Wildlife Conservation Commission Fisheries Habitat Assessment Program).

km 5 0 5 

N

Cover change:

No Plants 

< 5% Cover 

6 to 25% Cover 

26 to 50% Cover 

51 to 75% Cover 

> 75% Cover 

FHAP Basins

Shallow Banks

Land

Spring 1995-2003 

Spring 1995 

Spring 2003 

> 75% Increase

No Increase or Decrease

< 5% Increase

6 to 25% Increase

26 to 50% Increase

51 to 75% Increase

< 5% Decrease

6 to 25% Decrease

26 to 50% Decrease

51 to 75% Decrease

> 75% Decrease

A

 B

C

Restoration Opportunities 251
km 5 0 5 

N

Cover change:

No Plants 

< 5% Cover 

6 to 25% Cover 

26 to 50% Cover 

51 to 75% Cover 

> 75% Cover 

FHAP Basins

Shallow Banks

Land

6 to 25% Decrease

26 to 50% Decrease

51 to 75% Decrease

> 75% Decrease

> 75% Increase

< 5% Increase or Decrease

6 to 25% Increase

26 to 50% Increase

51 to 75% Increase

Springs 1995 and 2003

Spring 1995 

Spring 2003 

A

 B

C

Figure 6. Distribution, abundance, and cover change of shoal grass (Halodule wrightii ) in Florida Bay in springs 1995 and 2003 

(FHAP = the Florida Fish and Wildlife Conservation Commission Fisheries Habitat Assessment Program).

252 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
hydrologic conditions to the southern Everglades and 

Florida Bay.

More fresh water alone will not return Florida Bay to 

its pre-1980s, clear water condition. Increasing freshwater 

delivery to the bay could actually result in decreased water 

clarity and further seagrass loss if nutrient loads and algal 

blooms also increase. It will be critical to the restoration 

process to determine proper timing, location, and quality of 

fresh water released to Florida Bay in addition to increasing 

input volume.

References Cited 

Boesch, D.F., Armstrong, N.E., D’Elia, C.F., Maynard, N.G., 

Paerl, H.W., and Williams, S.L., 1993, Deterioration of 

the Florida Bay ecosystem—an evaluation of the scientific 

evidence. Interagency Working Group on Florida Bay 

Report, 20 pp.

Boyer, J.N., Fourqurean, J.W., and Jones, R.D., 1999, 

Temporal trends in water quality of Florida Bay (1989–

1997): Estuaries, v. 2, p. 417–430.

Brewster-Wingard, G.L., and Ishman, S.E., 1999, Historical 

trends in salinity and substrate in central Florida Bay: 

Estuaries, v. 22, p. 369–383.

Cambridge, M.L., and McComb, A.J., 1984, The loss of 

seagrasses in Cockburn Sound, Western Australia, The time 

course and magnitude of seagrass decline in relation to 

industrial development: Aquatic Botany, v. 20, p. 229–243.

Carlson, P.R., Yarbro, L.A., and Barber, T.R., 1994, 

Relationship of sediment sulfide to mortality of Thalassia 

testudinum in Florida Bay: Bulletin of Marine Science, v. 

54, p. 733–746.

Continental Shelf Associates, Inc., 1989, Southwest Florida 

near shore benthic habitat study, narrative report: U.S. 

Department of the Interior, OCS Study MMS 89-0080, 

55 p.

Davis, G.E., and Dodrill, J.W., 1989, Recreational fishery and 

population dynamics of spiny lobsters, Panulirus argus, in 

Florida Bay, Everglades National Park, Florida: Bulletin of 

Marine Science, v. 44, p. 78–88.

Dennison, W.C., Orth, R.J., Moore, K.A., Stevenson, J.C., 

Carter, V., Kollar, S., Bergstrom, P.W., and Batiuk, R., 1993, 

Assessing water quality with submerged aquatic vegetation: 

Bioscience, v. 43, p. 86–94.

Durako, M.J., 1994, Seagrass die-off in Florida Bay (USA): 

changes in shoot demographic characteristics and 

population dynamics in Thalassia testudinum: Marine 

Ecology Progress Series, v. 110, p. 59–66.

Durako, M.J., and Kuss, K.M., 1994, Effects of Labyrinthula

infection on the photosynthetic capacity of Thalassia 

testudinum: Bulletin of Marine Science, v. 54, p. 727–732.

Florida Marine Research Institute and National Oceanic and 

Atmospheric Administration, 1995, South Florida Benthic 

Habitats—Fish and Wildlife Research Institute Marine 

Resource Geographic Information System at http://ocean.

floridamarine.org/mrgis.

Fourqurean, J.W., and Robblee, M.B., 1999, Florida Bay—a 

history of recent ecological changes: Estuaries, v. 22, p. 

345–357.

Fourqurean, J.W., Robblee, M.B., Durako, M.J., Hall, M.O., 

and Hefty, L.E., 2002, Seagrass distribution in south 

Florida: A multi-agency coordinated monitoring program, in 

Porter, J.W., and Porter, K.G., eds., The Everglades, Florida 

Bay, and coral reefs of the Florida Keys an ecosystem 

sourcebook, p. 497–522.

Giesen, W.B., van Katwijk, M.M., and den Hartog, C., 1990, 

Eelgrass condition and turbidity in the Dutch Wadden Sea: 

Aquatic Botany, v. 37, p. 71–85.

Hall, M.O., Durako, M.J., Fourqurean, J.W., and Zieman, 

J.C., 1999, Decadal changes in seagrass distribution 

and abundance in Florida Bay: Estuaries, v. 22, no. 2, p. 

445–459.

Halley, R.B., and Roulier, L.M., 1999, Reconstructing the 

history of eastern and central Florida Bay using molluskshell isotope records: Estuaries, v. 22, p. 358–368.

Holmquist, J.G., Powell, G.V.N., and Sogard, S.M., 1989a, 

Decapod and stomatopod communities of seagrasscovered mudbanks in Florida Bay—inter- and intrabank heterogeneity with special reference to isolated 

subenvironments: Bulletin of Marine Science, v. 44, p. 

251–262.

Holmquist, J.G., Powell, G.V.N., and Sogard, S.M., 1989b, 

Sediment, water level and water tem­perature characteristics 

of Florida Bay’s grass covered mud banks: Bulletin of 

Marine Science, v. 44, p. 348–364.

Mazzotti, F.J., 1989, Factors affecting the nesting success of 

the American crocodile, Crocodylus acutus, in Florida Bay: 

Bulletin of Marine Science, v. 44, p. 220–228.

McNulty, J.K., Lindall, W.N., and Sykes, J.E, 1972, 

Cooperative Gulf of Mexico estuarine inventory and study, 

Florida, Phase I, area description: NOAA technical report 

National Marine Fisheries Service Circular 368, 126 p.

Mueller-Dombois, D., and Ellenberg, H., 1974, Aims and 

methods of vegetation ecology: New York, John Wiley 

and Sons.

References Cited 253
Onuf, C.P., 1994, Seagrasses, dredging and light in Laguna 

Madre, Texas, U.S.A.: Estuarine, Coastal and Shelf Science, 

v. 39, p. 75–91.

Orth, R.J., and Moore, K.A., 1984, Distribution and abundance 

of submerged aquatic vegetation in the Chesapeake Bay: an 

historical perspective: Estuaries, v. 7, p. 531–540.

Peres, J.M., and Picard, J., 1975, Causes of decrease and 

disappearance of the seagrass Posidonia oceanica on 

the French Mediterranean coast: Aquatic Botany, v. 1, p. 

133–139.

Perkins, R. D., 1977, Depositional framework of Pleistocene 

rocks in South Florida, in Enos, P., and Perkins, R.D., eds., 

Quaternary sedimentation in South Florida: Geological 

Society of America Memoir 147, p. 131–198.

Phlips, E.J., and Badylak, S., 1996, Spatial variability in 

phytoplankton standing crop and composition in a shallow 

inner-shelf lagoon, Florida Bay, Florida: Bulletin of Marine 

Science, v. 58, p. 203–216.

Phlips, E.J., Lynch, T.C., and Badylak, S., 1995, Chlorophyll 

a, tripton, color, and light availability in a shallow tropical 

inner-shelf lagoon, Florida Bay, U.S.A: Marine Ecology 

Progress Series, v. 127, p. 223–234.

Robblee, M.B., Barber, T.R., Carlson, P.R., Durako, M.J., 

Fourqurean, J.W., Muehlstein, L.K., Porter, D., Yarbro, 

L.A., Zieman, R.T., and Zieman, J.C., 1991, Mass mortality 

of the tropical seagrass Thalassia testudinum in Florida 

Bay: Marine Ecology Progress Series, v. 71, p. 297–299.

Stumpf, R.P., Frayer, M.L., Durako, M.J., and Brock, J.C., 

1999, Variations in water clarity and bottom albedo in 

Florida Bay from 1985 to 1997: Estuaries, v. 22, p. 431–

444.

Swart, P.K., Healy, G.F., Dodge, R.E., Kramer, P., 

Hudson, J.H., Halley, R.B., and Robblee, M.B., 1996, 

The stable carbon and oxygen isotopic record from a 

coral growing in Florida Bay—a 160 year record of 

climactic and anthropogenic influence: Paleogeography, 

Palaeoclimatology, Paleoecology, v. 123, p. 219–282.

Thayer, G.W. and Chester, A.J., 1989, Distribution and 

abundance of fishes among basin and channel habitats in 

Florida Bay: Bulletin of Marine Science, v. 44, p. 200–219.

Tilmant, J.T., 1989, A history and overview of recent trends in 

fisheries of Florida Bay: Bulletin of Marine Science, v. 44, 

p. 3–22.

Wanless, H.R., and Tagett, M.G., 1989, Origin, growth and 

evolution of carbonate mudbanks in Florida Bay: Bulletin of 

Marine Science, v. 44, p. 454–489.

Zieman, J.C., Fourqurean, J.W., and Iverson, R.L., 1989, 

Distribution, abundance and productivity of seagrasses and 

macroalgae in Florida Bay: Bulletin of Marine Science, v. 

44, p. 292–311.

254 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002