recreation of the past, a massive 

 cleanup program will be necessary. 

 Even if influxes of pollutants were 

 reduced, the residual levels of con- 

 tamination in the sediments might be 

 sufficient to affect the estuarine 

 biota for several decades. Action 

 programs to clean up these rivers 

 have been resisted because of their 

 costs. Although estuarine systems 

 are capable of treating some organic 

 wastes, they are not capable of hand- 

 ling unlimited volumes as the Raritan 

 Bay case exhibits. 



Chesapeake Bay is the largest 

 estuary on the east coast and is sur- 

 rounded by a population of about 8 

 million people. The principal 

 stresses on the system are sedimen- 

 tation, nutrient enrichment and in- 

 flux of toxic substances. There have 

 been widespread changes in the bay 

 biota in recent years and the most 

 critical are the loss of rooted 

 aquatic vegetation and the decline in 

 oyster production. Dredging of navi- 

 gation channels, construction of 

 harbor facilities, erosion of the 

 shoreline and the watershed, accumu- 

 lation of toxic materials and heavy 

 metals in the sediments and biota 

 have been primary problems. 



The Environmental Protection 

 Agency, U.S. Army Corps of Engineers, 

 Fish and Wildlife Service, universi- 

 ties, states, and other groups are 

 conducting studies on Chesapeake Bay 

 and there is strong support for pru- 

 dent baywide management decisions. 

 The FWS is working actively to pre- 

 vent further deterioration of this 

 valuable ecosystem. 



The State of Florida has serious 

 freshwater inflow problems in Florida 

 Bay and along the southwest coast. 

 These problems began in 1882 when a 

 small canal was constructed which 

 diverted the southerly flowing water 



of the Kissimmee-Okeechobee-Ever- 

 glades system into the Caloosahatchee 

 River and then into the Gulf of Mexi- 

 co. Substantial canal and water di- 

 version efforts by private groups, 

 the State of Florida, and the Federal 

 Government have continued to redirect 

 water that historically flowed south- 

 ward through the Everglades into the 

 south Florida estuaries. Most of the 

 diversion has been for flood control, 

 urban development and agriculture. 

 The reduction of water flow through 

 the Everglades and Big Cypress drain- 

 ages into the estuaries has had the 

 following consequences: 



The area of the south Florida 

 Everglades has been reduced 

 by 50 percent. 



Water levels in the Everglades 

 have been reduced by 5 feet. 



The average period of overland 

 flow in Everglades National Park 

 has been reduced from 8 months 

 to 4 months . 



Wading bird populations in 

 freshwater wetlands have de- 

 creased from about 1.5 million 

 in 1935 to 300,000 today. 



There has been a catastrophic 

 reduction in nursery habitat 

 for estuarine finfish and shell- 

 fish. 



Discharges of fresh water from 

 canals into estuaries are often 

 confined to short time periods 

 and the sudden surges result in 

 fish and shellfish mortalities 

 in estuaries. 



Florida Bay has developed into 

 a hypersaline area. It has es- 

 sentially ceased to function as 

 an estuary. 



25 



