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Description of Dams and Diversions Use as a Human Activity Affecting Fish Habitat in Pacific Coast States

from the National Fish Habitat Partnership's 2015 Through a Fish's Eye Report


The rivers of the Pacific Coast states are heavily altered by dams and diversions ( over 1,400 dams in California, 1,039 in Oregon, 1,174 in Washington ). The dams generally are used for hydropower generation, irrigation, and transportation, all essential to supporting the region’s extensive agricultural and manufacturing (aluminum, aircraft, shipbuilding) industries. Dams create problems for fish such as salmon and steelhead by interrupting or halting their migration from the Pacific to upstream habitats and killing large numbers of young salmon (smolts) as they move downstream through powerhouses or spillways. Numbers of salmon and steelhead have declined drastically from historic levels, and many populations are listed as threatened [...]


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The U.S Geological Survey (USGS) is partnering with the National Fish Habitat Partnership (NFHP) to produce the 2015 report entitled, "Through a Fish's Eye: The Status of Fish Habitats in the United States 2015". The information contained within this item is a product of NFHP. The Bureau is neither responsible nor liable for the accuracy or the use of the scientific content within this item. This content is considered preliminary pending subsequent review and approval.
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