Distribution and Abundance of Fish Communities Among Selected Estuarine and Marine Habitats in Everglades National Park

Thayer, Gordon; Hettler, William; Chester, Alexander; Colby, David; Mcelhany, Patti

The overall objective of this 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 (Everglades National Park) and to provide descriptions of the habitats in which these fishes occurred. Emphasis was placed on spotted seatrout (Cynoscion nebulous) and Gray snapper (Lutjanus griseus). Subobjectives included studies on juvenile fish associated with open water habitats and fish utilizing red mangrove prop root habitats. The study area was divided into five sampling strata that included Whitewater-Coot Bay, channels in Florida Bay, and three open water areas between eastern and western Florida Bay. Habitat and vegetative characteristics, and environmental conditions, are given for each sampling area. Western Florida Bay and channels in Florida Bay supported fish communities that were highest in fish density when compared to other areas. Cluster analysis demonstrated two major station groups occurring in channels and in northwestern Florida Bay. Juvenile gray snapper were most abundant in eastern Florida Bay while seatrout were collected mostly in the northwestern portion of the Bay. Data are also presented on the food habitats of these species and on the distribution of selected crustaceans. Discriminant function analysis were employed to identify those environmental characteristics most important in determining snapper and seatrout habitat. It was concluded from the prop root study that red mangrove habitat is utilized by a wide variety of fish and that greater attention should be given to evaluating its contribution as a refuge and a source of food resources for fishes in Everglades National Park. Study Period: May 1984-Sept 1985; Study Type: Qualitative, quantitative; Habitat: Open water (bay/basin), channel, red mangrove prop root; Biological Component: Fish (sportfish/nonfishery sp), crustaceans, benthic vegetation; Gear Type: Trawls (surface/bottom), 100 cm2 quadrats; Number of Stations: Juvenile fish studies- 262, mangrove studies-16; Number of Replicates/Stations; Fish- 1 per trawl type, vegetation and sediment-1-3; Temporal Frequency: Monthly, irregular; Abiotic Parameters Measured: Salinity, water temperature and depth, sediment characteristics and thickness; Dominant Taxon/Taxa Studied: Silver jenny (Eucinostomus gula), pinfish (Lagodon rhomboides), rainwater killifish (Lucania parva), halfbeak (Hyporhamphus unifasciatus), hardhead catfish (Arius felis).