Wildlife

Chinook Salmon

Oncorhynchus tshawytscha
King Salmon

Description

To 4'10" (1.6 m); 126 lbs (57.2 kg). Elongate, fusiform. Marine coloration: greenish-blue to black above, silvery-white below, oblong, black spots on back and entire caudal fin; very dark overall in fresh water. Gums at base of teeth black. Adipose fin present; striations on caudal fin rays smooth.

Endangered Status

The Chinook Salmon is on the U.S. Endangered Species List. The Sacramento River winter-run population in California is classified as endangered wherever it is found. Other naturally spawned populations in California, Idaho, Oregon, and Washington are classified as threatened. Why the Chinook and other Pacific Northwest salmon have declined is no mystery. The causes are known as "the four H's": harvest, habitat, hatcheries, and hydroelectric power. Harvest refers to the overfishing of these species by commercial fishing interests. Habitat refers to the degradation of habitat, usually by pollutants or sediment in the water that make it uninhabitable by the salmon or their eggs. Logging, agriculture, and mining interests have had a large hand in contaminating fish-run habitats. Captive-bred hatchery fish, released in the waterways used by native fish, compete and interbreed with the natives, weakening their stocks. Hydroelectric dams have had perhaps the largest impact, blocking migration routes and changing the quality, quantity, rate of flow, and temperature of the water in rivers, lakes, and tributary streams that once supported tens of millions of salmon.

Similar Species

Coho Salmon (O. kisutch) lacks spots on lower lobe of caudal fin; gums at base of teeth white; striations on caudal fin rays strong, rough.

Habitat

Ocean near surface and at mid-depths, may feed near bottom; spawns in fresh water in large rivers.

Range

Bering Straight south to S. California; in freshwater streams south to Sacramento River; widely introduced.

Discussion

 Chinook Salmon enter fresh water most months of the year, but their major spawning runs occur in the spring and fall. Their diet, similar to that of the Coho Salmon, consists of a variety of crustaceans, and fishes such as anchovies, herrings, young rockfishes, and sand lances. Chinook Salmon are the most highly prized ocean game fishes from Alaska to northern California. They also support a large and valuable commercial troll fishery.