brown offshore shrimp, respectively. A similar technique was used to estimate 

 a marginal value product for tidal marsh acreage in the harvesting of oysters. 

 They used the figure provided by Lynne, Conroy, and Prochaska ([51]) for the 

 marginal value product of marshland acreage in the harvesting of blue crabs. 

 For menhaden harvesting and for trapping, they imputed the entire market value 

 of the harvest to the marsh. However, the estimated marginal value product of 

 the various harvests was only $37.46 per annum per acre in 1983 dollars. 



To estimate the consumer surplus for the various recreational activities 

 (hunting, fishing, boating, and shoreline activities) pursued at the wetlands, 

 both the travel cost (TCM) and contingent value (CVM) methodologies were 

 employed. The TCM produced an estimated consumer surplus of $6.00 per annum per 

 acre, while the CVM produced an estimated consumer surplus of $4.86 per annum 

 per acre. In previous research, Farber had estimated a wind damage decay 

 function, in which hurricane wind damage was allowed to diminish as the distance 

 from landfall increased. The wind damage decay is a function of the distance 

 traveled by the storm over wetlands. This functional relation was the basis for 

 the estimated social marginal product of wetlands in providing storm damage 

 protection. The estimated value, $0.48 per annum per acre, was small, but not 

 insignificant. Moreover, these estimates suggest that flood protection provision 

 may be a very important social benefit conferred by tidal wetlands systems; wind 

 damage is only 5.4% of total storm damage in the wetland region. The total 

 annual benefits flow for the provision of habitat, recreation, and storm 

 protection is $43.90 per acre. The present value of the discounted infinite 

 horizon benefits stream, using an 8% discount rate and the conventional 

 methodologies is $568.73. A 2.6% rate of population growth is incorporated in 

 the capitalized values of the recreation benefits. 



The imputed per acre value of tidal marshland derived from the energy 

 analysis evaluation, which is highly similar conceptually with the imputed value 

 for the ecosystem life support function of Pope and Gosselink (see [8]), is much 

 larger. It lies somewhere in the $6,400-$10,602 range (discounted per acre value 

 at 8%). Costanza and Farber estimate the plant biomass production per annum per 

 acre of marsh, and convert this number into a fossil fuel energy consumption 

 equivalent. The fossil fuel equivalent was then used to determine a dollar value 

 for the production of primary plant biomass. Some of the conversion factors and 

 other pertinent details are omitted from the summary discussion. 



80. Goldstein, J.H., and B. Wilen. 1987. Response to an assessment of the 

 impact of Federal programs on prairie pothole drainage. National Wetlands 

 Newsletter 9(6):11-12. 



The authors were the project officers for a research project initiated by 

 the U.S. Fish and Wildlife Service to estimate the potential effectiveness of 

 the swampbuster provisions of the Food Security Act of 1985 in slowing farmland 

 conversion and drainage of wetlands. The results of this research project were 

 discussed in the National Wetlands Newsletter (see [81]). Goldstein and Wilen 

 have doubts about the validity of the conclusions reached by McColloch, Wissman, 

 and Richardson ([81]) in that study with regard to the efficacy of swampbuster 

 in slowing wetland drainage in the prairie pothole region of the northern Great 

 Plains of the U.S. McColloch, Wissman, and Richardson ([81]) used a farm 

 simulation computer model to show the impact of the swampbuster legislation on 



58 



