Recognizing the value of wetlands and 

 educating the public and public officials 

 to these values are important milestones 

 that have led to legislation (particularly 

 Section 404 of the Clean Water Act of 

 1977) protecting marshes from unconsidered 

 modification. Wetland management did not 

 begin with this legislation, hut certainly 

 the Clean Water Act has focused attention 

 on many wetland issues. Some of these 

 Issues, particularly those that relate 

 directly to Mississippi delta marshes, 

 will be discussed in the rest of this 

 chapter. 



Probably the most used instruments 

 for ecological evaluations in general are 

 the U.S. Fish and Wildlife Service Habitat 

 Evaluation Procedures (HEP, USFWS 1980) and 

 the U. S. Army Engineers Habitat 

 Evaluation System (HES, USAE 1980). Both 

 were developed for upland sites. HES has 

 not been adapted for wetlands, and HEP 

 wetland applications are still evolving. 

 These procedures are most valuable when 

 used to compare two different areas or to 

 compare an area before modification to the 

 expected state afterward. 



WETLAND EVALUATION 



One important component of wetland 

 management is the evaluation of proposed 

 actions in wetlands. Under Section 404 of 

 the Clean Water Act of 1977 a perniit is 

 required for wetland activities that might 

 affect water quality. For activities that 

 require an environmental impact statement 

 (as required by the National Environmental 

 Policy Act) two different kinds of 

 evaluation are involved. First, the 

 ecological value of the area in question 

 is determined - that is, the quality of 

 the site as compared to other similar 

 sites or its suitability for supporting 

 wildlife. Second, the ecological value of 

 the habitat is compared to the economic 

 value of some proposed activity that would 

 destroy or modify the habitat - in other 

 words, a benefit:cost analysis. Both pro- 

 cedures are fraught with difficulties. 

 Both require an evaluation of the relative 

 values of different commodities, like com- 

 paring apples and oranges. Above all, both 

 require numerous value judgments about 

 what is ecologically desirable. 



The HEP procedure, probably the aiore 

 detailed, illustrates both the potential 

 and the problems of evaluation. In this 

 procedure the suitability of a site is 

 evaluted for a number of different game 

 species, commercially important species, 

 and species of special interest for 

 ecosystem structure or function. For each 

 species, habitat suitability is evaluated 

 on a scale of - 1.0 for a number of 

 habitat characteristics. These Habitat 

 Suitability Indices (HSI's) are multipl ied 

 by the area of each species' habitat under 

 consideration to yield Habitat Units 

 (HU's). Thus both habitat quality and 

 area are combined in one number. 

 Schamberger et al. (1979) listed the 

 assumptions of the system: (1) habitat 

 value can be quantified; (2) habitat 

 suitability for a species of concern can 

 be evaluated from habitat characteristics; 

 (3) overall habitat value can be 

 determined by assessing suitability for 

 selected species; (4) habitat quantity and 

 quality are directly related to animal 

 numbers. It is apparent that the 



community HSI's depend on the species 

 selected for evaluation. 



Essentially all proceaures now in use 

 assess the relative value of wildlife 

 habitat. Lonard et al . (1981) evaluated 

 20 different wetland valuation systems. 

 The enphasis in all of them was 

 overwhelmingly on the evaluation of the 

 ecological habitat function of wetlands. 

 Hydrology functions are poorly documeted 

 and difficult to quantify. Evaluation of 

 silviculture, heritage, and recreation 

 functions are also considered open for 

 improvement (Lonard et al . 1981). 



The result of the HEP analysis is a 

 set of HU's for individual species for the 

 site or sites in question. The HU's can 

 be compared within a site or among sites 

 for determining best management scenarios. 

 The values can be used to help make a 

 management decision about the site, as for 

 instance, offsetting project impacts 

 through mitigation. In this case, sites 

 with equal value in terms of HU's are 

 created or set aside for use by the 

 species in question. 



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