36 



submerged aquatic beds, (4) South Florida's palustrine 

 wetlands, (5) Prairie Pothole Region's emergent wet- 

 lands, (6) wetlands of Nebraska's Sandhills and Rain- 

 water Basin, (7) forested wetlands of the Lower 

 Mississippi Alluvial Plain, (8) North Carolina's poco- 

 sins, and (9) western riparian wetlands. Most of these 

 regions are under intense pressure from agricultural inter- 

 ests, while the effect of urbanization and industrial devel- 

 opment is more localized. Northern New Jersey is used to 

 illustrate these non-agricultural impacts. The following 

 subsections summarize the nature of these national 

 problems. 



Estuahne Wetlands of the U.S. Coastal Zone 



Estuarine marshes and mangrove swamps are highly 

 regarded for their commercial and recreational fisheries 

 value. Protecting these wetlands has, however, only re- 

 cently received national attention. In the past, coastal 



10 



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lU 

 E 

 U 

 < 

 u. 

 O 

 (0 



z 

 o 



COASTAL WETLAND LOSS IN U.S. 



0.2% loss/yr. 



0.5% loss/yr. 



1922 



YEARS 



1954 



1974 



Fig.31. Rate of coastal wetland loss in the conterminous U.S. (from 

 Gosselink and Baumann 1980). Estimates include both estuarine and 

 tidal freshwater wetland losses. 



wetlands were viewed chiefly as potential sites for devel- 

 opment. Between the 1950's and the mid-I970"s, wet- 

 land losses were heaviest (Figure 31). The National 

 Marine Fisheries Service ( 1983) estimated annual fishery 

 losses at $208 million due to estuarine marsh losses from 

 1954 to 1978. Accelerating wetland destruction aroused 

 much public concern which led to the passage of tidal 

 wetland protection laws in many coastal states and to 

 stricter enforcement of existing Federal laws in the 



1960's and the 1970's. Unfortunately, over half of the 

 coastal wetlands in the lower 48 states have been de- 

 stroyed. Nonetheless, estuarine wetlands are still sought 

 after by developers for residential and resort housing, 

 marinas, and other uses. 



Estuarine wetland losses have been greatest in 5 states: 

 California, Florida, Louisiana, New Jersey and Texas. 

 Louisiana is losing them at a rate of 25,000 acres per year 

 due to coastal subsidence and other causes (Fruge 1982; 

 see the following subsection for discussion). Outside of 

 Louisiana, coastal wetland losses are directly related to 

 population density (Gosselink and Baumann 1980). Ur- 

 banization (i.e., residential home construction) has been 

 responsible for over 90% of the losses directly attributed 

 to human activites (Figure 32; Frayer,etal. 1983). Accel- 

 erated urban development and increased groundwater 

 withdrawals have resulted in salt water contamination of 

 public water supplies in many coastal communities. 



n-= 



original' shoreline of SAN FRANCISCO BAT BEFORE FILLING AND DIKING 



EVCLOPWCHT COMWISI 



Fig. 33. The status of wetland filling and diking in San Francisco Bay 

 prior to the mid-1960's (from Hedgpeth 1978). 



