SPECIES DISTRIBUTION 



Sockeye salmon are found along the North American coastline from the Seschutes River in 

 Oregon to the Yukon in Alaska but occur in considerable numbers only from the Columbia River 

 north to Bristol Bay in Alaska. Along the coast of the eastern Pacific they are reported from Cape 

 Chaplina in the northern part of the Bering Sea southward around the Kamchatka peninsula to 

 the northern shore of the Okhotsk Sea. The only remaining population of Snake River sockeye 

 salmon spawns in Redtlsh Lake, Idaho, which is located near the head of the middle fork of the 

 Salmon River. Adults of this population travel a greater distance from the sea (almost 900 miles) 

 and to a higher elevation (6.500 feet) than adults of any other population. 



Critical Habitat 



Critical habitat for Snake River sockeye salmon consists of river reaches of the Columbia, Snake, 

 and Salmon Rivers; Alturas Lake Creek and Valley Creek; and Stanley. Redfish, Yellow Belly, 

 Pettit, and Alturas Lakes, including their inlet and outlet creeks. 



MAJOR IMPACTS 



Hydropower development has resulted in blockage of habitat, turbine-related mortality of 

 juvenile fish, delay of juvenile migration through the Snake and Columbia rivers, increased 

 predation on juvenile salmon due to residualism in reservoirs and increased predator populations 

 due to ideal foraging areas created by impoundments, and delay of adults on their way to 

 spawning grounds. 



Water withdrawal and storage and irrigation diversions and blockage of habitat for purposes such 

 as agriculture have also contributed to the destruction of Snake River sockeye salmon habitat. 



Available information indicates that commercial fisheries in the lower Columbia River and 

 harvest on the spawning grounds were primary factors in the decline of Snake River sockeye 

 salmon. Commercial fisheries for sockeye in the Columbia River have been closed since 1988, 

 and recreational harvest of sockeye salmon in the Columbia River is negligible. There is no 

 information available to indicate that ocean harvest of Columbia River (including Snake River) 

 sockeye salmon is significant. 



The effect of potential bacterial, protozoan, viral, and parasitic organisms on Snake River 

 sockeye salmon is not documented. Predators include northern squawfish, birds, and marine 

 mammals such as harbor seals and California sea lions. The extent to which predation is a factor 

 causing the decline of Snake River sockeye salmon is unknown. 



Drought is the principal natural condition that may have contributed to reduced Snake River 

 sockeye salmon production. There is no direct evidence that artificially propagated fish have 

 compromised the genetic integrity of Stanley Basin sockeye salmon. Artificial production of 

 other species may have an adverse impact on Snake River sockeye salmon as they jointly migrate 

 through the rivers, estuary and ocean, and may compete with sockeye salmon for food. 



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