COHO SALMON 



Common Name: 

 Scientific Name: 



COHO SALMON 

 Oncorhynchus kisutch 



Listing Date: 10/31/96 



Species Status: Threatened 



Species Trend: Unknown 



Current Estimated Population: <6.000 



SPECIES POPULATION STATUS 



In the 1940s, estimated abundance of coho salmon in the Central California Coast ESU ranged 

 from 50.000 to 125.000 natural spawning adults. Today, it is estimated that there are probably 

 less than 6,000 naturally-reproducing coho salmon, and the vast majority of these fish are 

 considered to be of non-native origin (either hatcher>' fish or from streams stocked with hatchery 

 fish). 



Two additional ESUs of coho are were proposed along with Central California coast coho on 

 July 25, 1995: Northern California/Southern Oregon, and Oregon Coast. A determination on 

 these ESUs is expected in early 1997. 



SPECIES BIOLOGY 



The coho salmon ( Oncorhynchus kisutch ) is an anadromous salmonid species that was 

 historically distributed throughout the North Pacific Ocean from central California to Point 

 Hope, Alaska, through the Aleutian Islands, and from the Anadyr River, Russia, south to 

 Hokkaido, Japan. Historically, this species probably inhabited most coastal streams in 

 Washington, Oregon, and northern and central California. Some populations, now considered 

 extinct, are believed to have migrated hundreds of miles inland to spawn in tributaries of the 

 upper Columbia River in Washington, and the Snake River in Idaho. 



In contrast to the life history patterns of other anadromous salmonids, coho salmon on the west 

 coast of North America generally exhibit a relafively simple 3-year life cycle. Aduhs typically 

 begin their freshwater spawning migration in the late summer and fall, spawn by mid-winter, and 



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