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5 

 50 years. This was determined by comparing quantitative habitat 

 surveys, completed between 1989 and 1992, with surveys done by 

 the Bureau of Fisheries, now the National Marine Fisheries 

 Service, between 1936 and 1942. The Bureau of Fisheries surveys 

 are unique because they are the only long-term data set that 

 quantifies fish habitat in a way that is replicable over time. 

 In the Washington and Oregon Cascade Mountains, and Middle Fork 

 Salmon River in Idaho, the historical surveys were generally in 

 pristine areas that had not been extensively roaded and 

 harvested. Over all, there has been a 3 to 70 percent 

 reduction in the number of large, deep pools in resurveyed 

 streams on National Forests within the range of anadromous fish 

 over the last 50 years. 



HYDRO, HATCHERIES, HARVEST, AND HABITAT ARE THE FOUR PRIMARY 

 MANAGEMENT FACTORS CONTRIBUTING TO THE DECLINE IN STOCKS. 



The reasons for the decline of the Pacific anadromous fish 

 stocks vary by species and geographic area. The depressed 

 status of the stocks reflects the interaction of inherently 

 variable environmental conditions, such as oceanic productivity 

 and weather patterns, and a variety of management activities. 

 In general, stock survival is threatened by some combination of 

 hydroelectric development and operation, fish harvest, fish 

 hatchery influences on disease and genetic fitness, and fish 

 habitat conditions. For those stocks affected primarily by 

 habitat factors, the management of watersheds to ensure good 

 fish habitat on National Forest System lands is important. 

 Management of National Forest System lands also can play an 

 important role in moderating the rate of decline for those 



