translate into economic values through reduction in flood and storm damage, conservation of water supplies, treatment of wastewater, and production of food.

Moreover, wetland recreation often leads to private profits. Consider, for example, anglers who buy special gear and clothing; the growing numbers of bird watchers who purchase books, cameras, and binoculars; the publication of sport and wildlife magazines; and the tourism that is generated by aquatic reserves and a new generation of visitor centers in places as unlikely as wetlands constructed to treat urban wastewater (e.g., Arcata, California). Habitats that provide opportunities for research and education contribute additional human values, with increasing numbers of programs for field experiences at the elementary and high school levels, as well as college and graduate course work.

Because wetlands are extremely valuable natural resources, their degradation or loss results in real costs to society. As Dahl (1990) concluded, "Environmental and even socioeconomic benefits (i.e., ground water supply and water quality, shoreline erosion, floodwater storage and trapping of sediments, and climatic changes) are now seriously threatened." However, these values are principally societal values, whereas private wetland owners receive few direct economic benefits from wetlands—and the ownership of wetlands is largely private. Of the acres of wetlands that remain in the United States, almost three-fourths (74 percent) are privately owned (CEQ, 1989).

Restoring damaged wetlands should be a high priority, now that wetlands are recognized as valuable environmental and socioeconomic systems. However, restoration is often very expensive—with estimates as high as $10 million to $50 million for a small (260-acre), urban wetland in Los Angeles, depending on the degree of restoration selected. Restoring farmlands to wetlands may be inexpensive and easier to accomplish. Whereas the costs of wetland draining and filling were borne largely by private owners seeking to achieve a direct personal increase in economic benefits, the restoration of wetlands will be borne almost entirely by the public. Exceptions are wetlands restored within the regulatory process: landowners who disturb or destroy existing wetlands often propose to mitigate the damages by restoring or creating degraded wetlands.

King (1990) has begun an analysis of the cost effectiveness relationship for wetland restoration projects. His approach is to model combinations of tasks that will speed wetland restoration (e.g., site contouring, vegetation planting, soil augmentation, control of exotic species) and the degree of functional equivalency achieved with each