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Alaska Department of Fish and Game

Snake River Fall Chinook Salmon

(Oncorhynchus tshawytscha)
color drawing of a Chinook Salmon
Status

Alaska species of special concern; Federal threatened species

Description

Chinook salmon are the largest species of Pacific salmon, commonly exceeding 30 pounds in weight. They have small black spots on both lobes of their tail fins and black pigment along the base of their teeth. In the ocean, chinook salmon are bluish-green on the back, fading to a silvery color on the sides and white on the belly. When spawning in fresh water, chinook range in color from red to copper to almost black.

Habitats and Habits

Spawning habitat of Snake River fall chinook salmon is in the Snake River below Hells Canyon Dam and in the lower reaches of several big rivers. Spawning occurs from October through November and fry emerge from March through April. Downstream migration generally begins within several weeks of hatching. The fish spend three years at sea prior to returning to their birth streams. During this time, some of them range into Alaska waters.

Causes of Decline

During the 1940s, about 70,000 fall chinook spawned in the Snake River. Then in the 1960s and 1970s, a series of dams were constructed, blocking access to and from spawning habitat. Since the mid-'70s, about 500 fall chinook have returned to the Snake River. Overharvest in commercial, recreational, and subsistence fisheries, as well as hatchery-produced fish, disease, and other man-made factors such as water diversion, may contribute to the decline of this stock.

range map for the fall stock Snake River Chinook SalmonRange of the fall stock of the Snake River Chinook Salmon in Alaskan waters
Research and Recovery

Fisheries that incidentally harvest Snake River chinook have been closed or curtailed, including some fisheries in Southeast Alaska. A team of scientists and other experts was created in 1991 to develop a strategy for aiding in the species' recovery. One challenge facing the team is the difficulty of determining whether an individual chinook salmon caught at sea is from a threatened stock.

Text: Tamra Faris

For Additional Information
Please contact:
Doug Vincent-Lang
(907) 267-2339

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