pollution from contaminated 

 runoff, Rader says. 



Wetlands near the 

 headwaters of streams are 

 the most important in 

 removing pollutants such as 

 sediment and nitrates, 

 according to some research- 

 ers. These areas are less 

 likely to be inundated for 

 extensive periods. 



"When water flows over 

 the land, it carries with it 

 sediments, nutrients from 

 fertilizer and toxic metals 

 that pose a real threat to 

 surface waters," says Rader. 

 He estimates that more than 

 60 percent of the state's 

 surface water degradation is 

 caused by non-point source 

 pollution, primarily agricul- 

 tural in origin. 



Turbid waters can create 

 real problems in the aquatic 

 community. Excess sedi- 

 ment buries the eggs and 

 larvae of fish and other 

 aquatic organisms on river 

 bottoms. It also interferes 

 with the respiration and filter feeding 

 of aquatic organisms and prevents 

 light from reaching bottom-dwelling 

 plants. 



"In landscapes where wetlands are 

 still intact, the vast preponderance of 

 sediment is trapped by wetlands," 

 says Rader. 



Wetlands also convert potentially 

 harmful nutrients such as nitrates and 

 phosphates — which can cause algal 

 blooms and fish kills in coastal basins 



— into nourishment for microorgan- 

 isms adapted to the anaerobic condi- 

 tion of wetland soils. If these wetlands 

 are lost, the additional nitrogen 

 pollution could require billions of 

 dollars in improvements to U.S. 

 sewage treatment plants alone, some 

 scientists say. 



Because of their ability to remove 

 nutrients and minerals, some wetlands 



— such as cypress swamps — have 



Doug Rader, 

 N.C. Environmental Defense Fund 



Regulations 



should be made 



according to 



id values. 



not more or less 



protected. 



but differently, 1 



Rader says. 



actually been used as a 

 natural method of sewage 

 treatment. In other areas, 

 people have constructed 

 artificial wetlands to cleanse 

 polluted water. 



Because they absorb 

 sediment and nutrients, 

 wetlands can be highly 

 productive. To witness this, 

 one need only survey the 

 incredibly fertile farm land in 

 the Roanoke River flood- 

 plains. 



Fisheries 



North Carolina's sport 

 and commercial fishery is 

 directly dependent on the 

 habitat, food and water 

 supply of saltwater and 

 brackish wetlands. But the 

 fishery is inextricably bound 

 to the preservation of fresh- 

 water wetland areas as well. 



Anadromous fish, which 

 spawn in fresh water but live 

 their adult lives in the ocean, 

 and freshwater fish depend 

 on shallow pockets of fresh- 

 water wetlands and flooded 

 bottomlands for rearing and feeding 

 their young. 



In coastal North Carolina, wetlands 

 such as pocosins — fire-adapted 

 shrubby areas that naturally filter 

 rainwater — are the source of high 

 quality fresh water that flows into 

 streams and estuaries. These areas 

 maintain the necessary balance of 

 fresh and salt water in productive 

 coastal estuaries that are home to fish 

 and shellfish. (See story on pocosins, 

 page 15.) 



Drainage of these upstream 

 wetlands can result in too much 

 freshwater discharged too fast into 

 fragile, primary nursery areas and 

 spell disaster for species such as 

 brown shrimp. 



Waterfowl 



Millions of ducks, geese and swans 

 depend on wetlands for food, breed- 



4 MARCH /APRIL 1992 



