IV-517 



into coastal marshes is in a secondary stage in the larger estuarine 

 systems, with sand spits and barrier islands forming. 



Chesapeake Bay Estuarine Region : All of the Chesapeake Bay system 

 from Cape Charles and Cape Henry Island. 



Isolation from direct oceanic effects in much of the greatly branched 

 system, the many subsystems with major river flows, and the reduced 

 concentration of the ocean salt throughout the Bay and its tributaries 

 make tnis a unique estuarine system. This is a drowned river valley 

 with numerous similar tributary systems in various stages of evolution, 



South Atlantic Estuarine Region : Cape Hatteras to Fort Lauderdale, 

 Florida, (about 26° North Latitude). 



The generally wide continental shelf is brushed by the warm waters 

 of the well-defined Gulf Stream. The low-lying coastal plain 

 terminates in barrier islands and marshes in which large amounts of 

 sediments are being continually deposited by moderate-sized rivers 

 fed by heavy summer rainfall. Many of the drowned river valley 

 estuaries have evolved all the way to coastal marshes. Tidal ranges 

 are small to moderate, depending on local conditions. 



Carribean Estuarine Region : Fort Lauderdale to Cape Romano (the 

 Florida peninsula south of 26° North Latitude), plus Puerto Rico 

 and the Virgin Islands. 



High temperatures, heavy rainfall, and warm ocean currents along 

 practically nonexistent continental shelves result in tropical 



