40 



once prime waterfowl feeding area Inave virtually disap- 

 peared since 197 1 . Other areas have experienced declines 

 in the numbers of plant species present. Since 1978, sub- 

 merged aquatic vegetation appears to have stabilized, 

 with a few areas even showing a slight increase (Orth and 

 Moore 1981). Reductions in submerged vegetation have 

 probably been the most important wintering habitat 

 change which have led to declines in local populations of 

 canvasbacks and redheads (Perry, et al. 1981). These 

 changes point to a stressed ecological system. 



Although the causes of this vegetation decline are hard 

 to pinpoint, researchers suggest a combination of natural 

 and human-induced factors. Natural stresses include 

 overgrazing by carp and cownose rays. Hurricane Agnes. 

 a general warming of Bay waters, and natural diseases. In 

 June 1972, Hurricane Agnes hit the Bay region. Its heavy 

 rainfall lowered salinity in Chesapeake Bay and buried 

 numerous grass beds with sediment carried by runoff. 

 Human impacts on the submerged vegetation are largely 

 from two general sources of water pollution: point and 

 nonpoint sources. Point source pollution comes mainly 

 from industrial and sewage treatment plant discharges, 

 while nonpoint sources include failing septic systems. 

 agricultural runoff or urban runoff. These sources cause 

 increased turbidity and sedimentation, nutrient overload- 

 ing, and chemical pollution which have reduced or elimi- 

 nated aquatic beds from many areas. Channelization 

 projects in bottomland hardwood forested wetlands have 

 undoubtedly contributed to the problem by accelerating 

 the discharge of agricultural runoff and eroded soil into 

 the Bay. 



The problem of the Bay's submerged aquatic vegeta- 

 tion is receiving special attention from the U.S. Environ- 

 mental Protection Agency (EPA) and others. EPA 

 established a Chesapeake Bay program to address this 

 problem. Future studies should increase our understand- 

 ing of the causes of the decline of submerged aquatic 

 vegetation and will hopefully lead to improved watershed 

 management to restore and maintain a healthy Chesa- 

 peake Bay. Meanwhile, the governors of Maryland, 

 Pennsylvania and Virginia have joined together to ad- 

 dress water quality problems in the Chesapeake Bay wa- 

 tershed. Only through interstate coordination and action 

 can the Bay's problems be solved. 



South Florida's Palustrine Wetlands 



South Florida encompasses a 9.000 square mile area of 

 lakes, rivers and wetlands which extends from Orlando 

 south to the Florida Keys. While the Everglades domi- 

 nates this region. Big Cypress Swamp, the Kissimmee 

 River and Lake Okeechobee are equally important. 

 Freshwater runoff from this area helps maintain the salin- 

 ity balance of estuaries which support 85% of South Flor- 

 ida's offshore fishery (Yates 1982). The wetlands are 

 breeding grounds for many birds, notably wood and other 

 ibises, roseate spoonbills, herons, egrets and Florida 



Fig. 37. Channelization of the Kissimmee River directly destroyed many 

 wetlands and facilitated drainage of more than 100,000 acres of 

 wetlands. 



ducks . They also support winter populations of numerous 

 waterfowl, especially lesser scaups, ringnecks. blue- 

 winged teal, canvasbacks, and wigeons. Rare and threat- 

 ened animals depend on these wetlands, including the 

 Florida panther. American crocodile, manatee, brown 

 pelican. Everglades kite and southern bald eagle. The 

 Everglades National Park was established to protect these 

 natural resources. 



South Florida's waters and wetlands have been subject- 

 ed to various uses for many years (Yates 1982). In the 

 1920"s, large wetland areas were drained and converted 

 to sugar cane farms. Severe floods in 1928, 1947 and 

 1948 stimulated a massive flood control project in South 

 Florida. The Central and Southern Florida Flood Control 

 Project, authorized by Congress, required the U.S. Army 

 Corps of Engineers to construct a network of nearly 800 

 miles of new or improved levees and 500 miles of canals. 



