and municipal growth on the other hand. Agree- 

 ment was reached that the best way to offset 

 such influences was to develop realistic compar- 

 able appraisals of estuarine resources along the 

 entire coast. The planners envisioned a broad 

 study that would include physical descriptions 

 of the estuarine basins and the waters within 

 them plus comprehensive biological studies of 

 plant and animal life. Funding was provided 

 through the Commercial Fisheries Research and 

 Development Act (Public Law 88-309, as amend- 

 ed) with which studies in Alabama, Mississippi, 

 and Louisiana were financed in part. This Lab- 

 oratory and the National Marine Fisheries Ser- 

 vice Biological Laboratory, Galveston, Texas, 

 undertook the Florida and Texas portions of the 

 study largely because other uses were made of 

 P.L. 88-309 funds in those states. Members of 

 the ETCC developed work outlines, which all 

 participants agreed to follow so that methods 

 of study w r ould be the same and results would be 

 comparable. J. Y. Christmas chaired the Com- 

 mittee meetings. Work outlines for four phases 

 of the Inventory were developed — Area Descrip- 

 tion, Hydrology, Sedimentology, and Biology. 

 The approved Area Description outline was the 

 basis for material presented in this paper. 



THE COAST 



The length and biological diversity of the 

 Florida Gulf coast exceed those of any other Gulf 

 state. Its length, some 770 statute miles (1,240 

 km) measured headland to headland on the main- 

 land, exceeds the airline distance from New York 

 to Chicago. Its climate varies from subtropical 

 to temperate. The 17-year minimum air tem- 

 perature of 47 °F (8°C) at Key West contrasts 

 strongly with 9°F (— 13°C) atPensacola. These 

 and other air temperatures, which follow, were 

 provided by James T. Bradley, NOAA Clima- 

 tologist for Florida, National Weather Service, 

 Lakeland, Fla.: 



Air Temperature (°F)* 

 Locality January July 



Mean Extremes Mean Extremes 

 Key West (17 yr) 70 47-85 83 69-95 



St. Petersburg (56 yr) 63 28-85 83 63-97 

 Cedar Key (30 yr) 58 19-88 82 65-102 



Pensacola (39 yr) 53 9-76 82 61-99 



*°C = 5/9 (°F - 32). 



Tidal swamps and marshes fringe the entire 

 coast and submerged vegetation blankets most 



of the shallow-water bottom. The dense man- 

 grove swamps of the south and central coasts 

 are gradually replaced by tidal marshes north of 

 Cedar Key because hard frosts kill the mangroves 

 (Fig. 1) ; Davis (1904) concluded that air tem- 

 peratures below 25°F (— 4°C) are lethal. Al- 

 though sea grasses flourish in shallow water on 

 the entire coast, the northern limit of some trop- 

 ical algae and the southern limit of some tem- 

 perate algae is in the vicinity of Tampa Bay. 



Four basic coastal types are characteristic 

 (Fig. 1). The southernmost, from Florida Bay 

 to Cape Romano, consists of mangrove swamps, 

 tidal marshes, and mangrove-covered islands in- 

 terspersed with open-water estuarine areas. 

 Florida Bay consists of a series of circular 

 drowned lake basins (hence the term "lacu- 

 strine," Fig. 1) that are divided by shallow flats 

 and interconnected by tidal channels set in a com- 

 plex of mangrove-rimmed Keys. On the main- 

 land coast the mangroves extend inland 0.5 to 5 

 nautical miles (0.9 to 9 km) except along rivers 

 where penetration may be up to 10 or 12 nau- 

 tical miles (19-22 km). Tidal marshes have de- 

 veloped on the relatively high ground between 

 rivers and landward of the mangrove swamps. 

 Underwater vegetation is extensive in Florida 

 Bay, where it consists of predominantly turtle 

 grass (Thalassium testudinum) mixed with a 

 rich variety of tropical algae. In shallow water 

 from Cape Sable northward algae are abundant 

 locally in many places, but grass beds are sparse, 

 possibly because of turbidity from suspended 

 materials and discoloration of the water by tan- 

 nins from the mangroves. 



Barrier islands with sandy beaches on the Gulf 

 characterize most of the second type of coast, 

 which extends from about Cape Romano to An- 

 clote Key. The islands separate the Gulf from 

 a series of bays and lagoons that are lined with 

 mangrove swamps except where land elevations 

 preclude their development. The mangroves 

 merge into tidal marshes that are less extensive 

 here than in the two more southerly segments 

 of the coast. Sea grasses and algae are abundant 

 to about 6 feet (2 m) in the bays and lagoons. 



The irregular coastline of the third coastal 

 type, from Anclote Key to Lighthouse Point, is 

 the result of rock outcroppings, clusters of is- 

 lands, and oyster reefs. Beaches and semi-en- 

 closed bays are rare. Salt marshes line its 

 shores and penetrate inland several miles in 



