Ch. 1— Summary • 7 



P/io(o cred/(. US. Fish and Wildlife Service 



Wetlands provide food and habitat for many species of fish and wildlife. Waterfowl, in particular, often require wetland 



habitats for breeding and nesting. 



Table 1.— Wetland Conversions From Mid-1950's 

 to Mid-1 970's 



Original acreage 



nnid-1950's 



(million acres) Million acres Conversion rate 



Net loss^ 



Coastal . 

 Inland . . 



4.8 

 100.0 



0.4 

 11.0 



8.3% 

 11.0% 



^Net losses are calculated by subtracting the gains in wetlands (from man- 

 induced and natural causes) from the actual losses of wetlands. 



SOURCE: Original data from FWS National Wetland Trends Study, 1983. 



Ninety-seven percent of actual wetland losses 

 (or conversions from wetland to nonwetland areas) 

 occurred in inland, freshwater areas during this 20- 

 year period (fig. A). Agricultural conversions in- 

 volving drainage, clearing, land leveling, ground 

 water pumping, and surface water diversion were 

 responsible for 80 percent of these conversions. Of 

 the remainder, 8 percent resulted from the con- 

 struction of impoundments and large reservoirs, 6 

 percent from urbanization, and 6 percent from 



other causes, such as mining, forestry, and road 

 construction. Fifty-three percent of these conver- 

 sions occurred in forested areas, such as bottom 

 lands. Of the actual losses of coastal wetlands, ap- 

 proximately 56 percent resulted from dredging for 

 marinas, canals, and port development, and to a 

 lesser extent from shoreline erosion; 22 percent re- 

 sulted from urbanization; 14 percent from dispos- 

 ing of dredged material or from creating beaches; 

 6 percent from natural or man-induced transition 

 of saltwater wetlands to freshwater wetlands; and 

 2 percent from agriculture. 



Wetland conversions have adversely impacted 

 the environment in some regions of the country. 

 For example, reductions in Pacific-flyway migra- 

 tory waterfowl have been directly correlated to the 

 conversion of about 90 percent of California's wet- 

 lands. While the ecological significance for the Na- 

 tion of wetland conversions over the last several 

 decades is uncertsdn, the environment will undoubt- 

 edly be negatively affected if conversions continue. 



PROGRAMS AND POLICIES AFFECTING WETLAND USE 



Wetland use is directly and indirectly affected 

 by a variety of Federal (table 2), State, local, and 

 private programs that were developed, for the most 



part, during the past two decades. These programs 

 affect wedand use through regulation, acquisition, 

 leasing, easements, and general policy guidance. 



