Conservation Issues
Though the U.S. Fish and Wildlife Service deposits billions of salmon eggs and young, propagated in nurseries, into natural breeding grounds and constructs fish ladders for the upstream journey of mature salmon, wild Atlantic and Pacific salmon populations remain severely threatened. In particular, the drastic decline of wild Pacific salmon populations has raised alarm and become one of the most important conservation issues in the Pacific Northwest.
Less than 2 percent of the wild salmon population of the Columbia River Basin (including parts of Washington, Oregon, Idaho, Montana, Wyoming, and British Columbia) remains and only one individual sockeye salmon returned to the Snake River in Idaho in 1994.
Coho salmon in the Snake River have been declared extinct by the U.S. Fish and Wildlife Service, as have 106 other salmon populations on the West Coast.
The causes of this dramatic decline include the construction of dams, which interfere with both upstream and downstream migration of the fish-15 to 30 percent of young salmon die at each dam as they migrate down river; loss of spawning habitat due to development; and logging and agriculture near waterways, which lead to erosion, siltation (the clouding of waterways with fine soil), toxic runoff, and high water temperatures, all of which interfere with salmon spawning and migration.
The decline of salmon populations is uniting environmentalists and fishers with industries that extract natural resources, such as hydroelectricity, timber, and water, to find a compromise that saves both the wild salmon populations and the fishing industries that depend on the species' continued health. Efforts to protect salmon populations in the Pacific Northwest include barging or trucking young salmon around dams; reducing industrial and agricultural water withdrawals from river systems; prohibiting logging near streams or rivers; dramatically limiting salmon fishing seasons; and increasing water flow, or spillage, through hydroelectric dams.
"Salmon (fish)," Microsoft¨ Encarta¨ Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.
