The quality of the wetland acreage may be more important than the quantity of 

 the wetland acreage; the relation between acreage and biomass is plausible but 

 not based on scientific evidence. Yet the Batie-Wilson model only includes two 

 biological (environmental) variables, wetland acreage and the dummy variable for 

 salinity level of the coastal waters of the county. This dummy variable was zero 

 or one; the dividing line between high and low salinity coastal waters was 

 17 ppt. 



The authors indicate that salinity level may be the most important 

 independent variable limiting oyster biomass production because high salinity 

 water precludes the presence of important oyster predators. Oysters are 

 harvested by tongs or by dredge, but dredges are more efficient than tongs. The 

 particular specification of the effort variable was determined by the use of 

 principal components analysis. 



The marginal product of wetland acreage was determined by the estimation 

 of a Cobb-Douglas production function and differentiation with respect to the 

 wetland variable. A discounted marginal value product was determined by 

 multiplying the marginal product of wetland acreage by the dockside price of 

 oysters, then dividing by the discount rate of 10%. The discounted marginal 

 value product of a wetland acre was estimated for various counties; it varied 

 from $11 to $1,414. 



24. Chabreck, R.H. 1978. Wildlife harvest in wetlands of the United States. 

 Pages 618-631 in P.E. Greeson, J.R. Clark, and J.E. Clark, eds. Wetland 

 functions and values: the state of our understanding. Proceedings of a 

 national symposium on wetlands. Various Federal agencies and the American 

 Water Resources Association, Minneapolis, MN. 



This paper contains some interesting information on migratory waterfowl 

 harvests. Some of the information presented, such as that on the distribution 

 of the waterfowl harvest by flyway, renders Chabreck' s paper a useful supplement 

 to the work of Hammack and Brown (see [10]) on the social marginal value product 

 of prairie potholes. Chabreck also introduces some data on the fur-bearing and 

 alligator harvests in Louisiana. 



Louisiana is the leading fur-producing State. During the 1976-1977 season 

 Louisiana trappers and landowners received $24.1 million from the sale of pelts, 

 and $0.6 million from the sale of meat. About 85% of the various animals were 

 harvested from wetlands; major wetland-dependent fur-bearing species include 

 nutria, muskrat, mink, raccoon, and river otter. The value of the harvest per 

 thousand acres of coastal marsh and swamp totaled $13,300. The value of the 

 total alligator harvest is not reported here, but the author does estimate the 

 number and value of alligators harvested--12.1 and $1,114 respectively--per 1,000 

 acres of wetland in Cameron and Vermilion Parishes. 



25. Foster, J.H. 1978. Measuring the social value of wetland benefits. Pages 

 84-93 in P.E. Greeson, J.R. Clark, and J.E. Clark, eds. Wetlands functions 

 and values: the state of our understanding. Proceedings of a national 

 symposium on wetlands. Various Federal agencies and the American Resources 

 Association, Minneapolis, MN. 



25 



