摘要：This study demonstrates a method to calculate the economic value of the loss of a highly valued ecosystem service—the provision of recreational fishing—across a multi-state assessment region. We estimated annual freshwater fishing expenditures foregone from degraded conditions in wadeable streams that are potential habitat to one or more of four sportfish species. Using probability-based federal surveys for data on sportfish presence, we developed range models for the four species in the mountainous portions of four U.S. mid- Atlantic states based on geophysical stream variables unrelated to habitat condition. From these models, we determined the proportion of the wadeable stream resource (44.2%) that could potentially host sportfish and allocated an estimate of annual regional freshwater fishing expenditures (US$826 million) from the National Survey of Fishing, Hunting, and Wildlife- Associated Recreation to these stream segments. We attributed the absence of sportfish in these segments to stream degradation; an additional US$239 million was estimated as lost freshwater fishing expenditures. These figures suggest a considerable annual economic incentive for stakeholders to restore and protect stream habitat for the maintenance of sport fisheries. This method is readily transferable to other U.S. regions where long-term surveys that collect metrics linked to ecosystem services are in place.
