Marketable commodities other than fish, shellfish, 

 and fur bearers include timber, grazing for 

 livestock, cranberries, blueberries, wild rice, and 

 peat. Besides their use for livestock grazing, 

 wetlands can be used to grow hay for winter feed. 

 However, the harvest of peat is not compatible with 

 wetland preservation because it destroys the 

 wetland. ^ 



Nonmarket values from wetlands are also 

 numerous. Wetlands are popular sites for recreation 

 activities such as birdwatching, water sports, hik- 

 ing, picnicking, and photography. Wetland areas 

 often have high aesthetic appeal. As scientific 

 research areas, wetlands can be an important 

 resource for learning about these unique 

 ecosystems and their associated species. The diver- 

 sity and uniqueness of some of these wetlands may 

 make them important reservoirs of genetic diver- 

 sity. Finally, wetlands have an option value for 

 people who are willing to pay to preserve them for 

 future use, and an existence value for people who 

 are willing to pay simply for their continued 

 presence. 



Estimation of Economic Values 



A number of studies have attempted to estimate the 

 value of wetlands for various purposes. Although 

 economic measurement techniques are well 

 developed, a lack of data, as well as scanty informa- 

 tion on the physical and ecological processes of 

 wetlands, plague most studies. In a recent review of 

 wetland valuation studies, Shabman and Batie (37) 

 concluded that few studies have used conceptually 

 valid techniques or considered key linkages be- 

 tween wetland services provided and the wetland 

 area studied. Therefore, the values reported here 

 should be considered indicators, not exact 

 estimates. 



Wetlands are a critical factor in commercial 

 fisheries. For the 15 most important commercial 

 species of fish and shellfish harvested in 1980, 61 

 percent of dockside value was attributed to 

 estuarine-dependent species, for a total value of 

 more than $1 billion (28). A 1973 study of Virginia 

 wetlands estimated that the annual potential 

 benefits of the State's tidal marshes for fish produc- 

 tion were $108 per acre, while the potential value 

 for aquaculture ranged from $350 to $900 per acre 

 (4). The total harvest value of unfinished mam- 

 malian pelts in the 1979-80 season was $295 

 million; 32 percent of that value was from mink, 

 muskrat, and nutria, three wetland species. In Loui- 

 siana, 16,000 alligators were harvested in 1979 for a 



total value of approximately $1.7 million (28). Pelts 

 and skins acquire further value as they are used to 

 make retail products such as coats and shoes. A 

 final renewable resource of wetlands is timber. The 

 estimated standing value of southern wetland 

 forests alone is $8 billion [43). The value of the 

 timber on the 2,300-acre wetland ecosystem of 

 Georgia's Alcovy River was estimated at more than 

 $1.5 miUion, or $686 per acre (9). 



Ecological values also have been estimated in 

 several studies. The value of the Alcovy River 

 ecosystem for sediment accretion was estimated at 

 $3,000 per year, and for water quality improvement 

 at $1 million per year. Virginia tidal marshes were 

 estimated to have a value of $2,500 per acre for 

 waste assimilation and $4,150 per acre for total life 

 support, which encompasses a variety of ecological 

 functions (4). The Army Corps of Engineers 

 estimated the flood control benefits of the Charles 

 River Basin wetlands at more than $1.2 million per 

 year (9). Finally, Michigan's coastal marshes were 

 estimated to have a value of $2,600 per acre for 

 ecological functions (4). 



The benefits of wetlands for fish and wildlife and 

 recreation were also estimated in two of the above 

 studies. In the Charles River Basin, recreation and 

 fish and wildlife benefits from the wetlands were 

 estimated to be $124,800 per year (9). The Michigan 

 coastal marshes were estimated to provide $490 per 

 acre in recreation benefits and commercial fishing 

 and trapping (4). 



Two additional studies focused on the value of 

 wetlands for waterfowl. Hammack and Brown (16) 

 combined a population dynamics model with a 

 recreation valuation study of waterfowl hunters in 

 the Pacific flyway. They estimated a marginal value 

 of $3.10 to $3.29 per bagged waterfowl. Miller and 

 Hay (26) studied the relationship between habitat 

 availability, hunter success, and hunting participa- 

 tion in the Mississippi flyway. Using a consumer 

 surplus value of $29 per day of waterfowl hunting, 

 they estimated that the loss of 10 percent of water- 

 fowl habitat in the flyway would result in an 

 annual loss of recreation benefits of $17 million per 

 year. 



Swader and Pavelis (41) used the values from the 

 two waterfowl studies to compare land values for 

 agriculture to those for duck hunting. Using a 

 7.75-percent discount rate and a bag rate of 1.6 

 birds per acre, Hammack and Brown's marginal 

 rate was translated into a capitalized land value of 

 $220 per acre in 1984 dollars. The habitat value 

 from Miller and Hay's study was capitalized into a 



18 



