Recreational and commercial fishing along the U.S. southeast coast alone represents a billiondollar industry. Hunters and trappers also depend on wetlands for their game. Three- quarters of U.S. bird species, including mallard and wood ducks, geese, swans, herons, and rails, need wetlands for sanctuary. Wetlands help control the runoff of pollutants, such as excess nitrogen in rainwater, which helps clean municipal water supplies. Wetlands can trap and absorb some natural and man-made chemicals and recycle them to support wildlife, as long as the water running through a marsh is not too polluted.
Wetlands also help restore underground water supplies and help stem potential floodwaters.
Yet since the Pilgrims arrived, Americans have drained swamps and eliminated wetlands. Much of the federal bureaucracy in Washington, D.C., is built atop drained Potomac River marshland. Twentytwo states have lost more than 50 percent of their wetlands, and the United States will lose more than four million additional acres by the year 2000. A 1987 National Wildlife Federation report found the loss of wetlands ecologically significant since marshes and estuaries are used or populated by 45 percent of endangered animals and 26 percent of endangered plants. In terms of federal policy, the U.S. Congress has been both friend and foe of wetlands preservation.