otter trawl in the immediately (8 to 10m) adjacent fringing seagrass habitat. The 
density and biomass of fish collected by the 2 gear were greater in the prop root 
habitat than in the adjacent fringing seagrass areas. There also were consistent 
differences in species composition between the 2 habitat types across all 4 geographic 
regions. Analysis of the stomach contents of gray snapper Lutjanus griseus suggested 
that smaller snapper tend to feed in the prop root habitat while larger snapper may 
forage out into adjacent areas to feed. The red mangrove prop root habitat is utilized by 
a wide variety of fish, and greater attention should be given to evaluating its 
contribution to fish production in south Florida and elsewhere. 
1984 - 1985 
Thayer, G. W., and A. J. Chester (1989) Distribution and abundance of fishes among basin 
and channel habitats in Florida Bay. Symp. on Florida Bay: A Subtropical Lagoon. Miami, FL. 
June, 1987. BulL Mar. Sci.. 44(1 ):200-1 9. 
Surface and bottom trawls were used to sample fishes in basins and channels in the 
western half of Florida Bay during 1984 and 1985. These data were evaluated in 
conjunction with information on environmental parameters, including seagrasses, to 
identify fish-habitat associations. Florida Bay is utilized by a diverse fish assemblage 
dominated by juveniles and forage species. The western portion of our sampling area 
within Florida Bay, adjacent to the Gulf of Mexico, and channels within the Bay, 
consistently supported the highest diversity of fish. Channel areas generally displayed 
the highest overall standing crop and density of seagrasses. Basins in the eastern 
portion of the Bay were most diverse in terms of seagrass composition and exhibited 
the highest overall densities of Syringodium filiforme. Cluster analysis revealed two 
major station groups. One, characterized by fish species that occurred frequently and 
in large numbers, occurred primarily in channels and in western Florida Bay where 
mixtures of seagrasses were prevalent; a second, characterized by low fish densities, 
occurred in generally monotypic stands of Thalassia testudinum. Discriminant function 
analysis demonstrated that comparatively higher sediment organic contents, slightly 
shallower water, and abundant Halodule wrightii and Syringodium populations were 
important factors at stations belonging to the typically high density fish cluster. 
1984 - 1985 
Thayer, G. W., W. F. Hettler, A. J. Chester, D. R. Colby, and P. T. McElhaney (1987) 
Distribution and abundance of fish communities among selected estuarine and marine 
habitats in Everglades National Park. Rep. SFRC-87/02. South Florida Research Center, 
Everglades National Park, Homestead, FL. 166 pp. 
The overall objective of this juvenile study was to evaluate relative species abundance 
and size composition of fish communities among selected habitats in estuarine and 
marine waters of Everglades National Park and to provide descriptions of the habitats 
in which these fishes occurred. Particular emphasis was placed on spotted seatrout 
(Cynoscion nebulosus) and gray snapper ( Lutjanus griseus). The study was divided into 
two subobjectives: juvenile fish associated with open water habitats, and fish utilizing 
red mangrove prop root habitats. The study area was subdivided into five sampling 
strata that included Whitewater Bay - Coot Bay, channels in Florida Bay, and three open 
water areas between western and eastern Florida Bay. Random sampling was conducted 
within these strata as well as regular periodic sampling at several selected sites. 
Biological, physical and chemical data, fish, shrimp, crabs, vegetation and sediment 
were collected during 1984 and 1985. Coot Bay and eastern Whitewater Bay are 
characterized by low salinities and sediments with high organic content and generally 
low densities of Ruppia maritima and/or Halodule wrightii. Channel areas in Florida Bay 
generally display the highest overall standing crop and density of seagrasses composed 
of Thalassia testudinum, Syringodium filiforme and Halodule wrightii. The western 
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