Wildlife on the Brink: Chinook Salmon

SCIENTIFIC NAME: Oncorhynchus tshawytscha

STATUS: Endangered/Threatened (different river populations listed separately)

HABITAT: Freshwater streams and rivers at birth; juveniles mature in estuaries before migrating to open ocean

LIFE HISTORY: Ocean salmon have blue-green backs with silver sides; color changes to bright red at spawning, and males develop hooked snout.

THREATS: Loss of freshwater spawning habitat due to dams; pollution; overfishing

RANGE: Pacific Ocean from Kotzebue Sound, Alaska, to Santa Barbara, California

CURRENT POPULATION: Varies by population

The largest of Pacific salmon species, an adult chinook salmon is a monstrous fish, often five feet long and weighing 100 pounds or more. After years at sea, this powerful fish makes an epic journey to spawn in the stream where it was born—and then dies.

Once abundant from Alaska all the way down to Santa Barbara, populations of chinook salmon have been declining steadily. Human modification of natural water flow for dams, hydropower and agriculture has cut into salmon habitat. Nine regional subgroups of chinook salmon are listed as threatened or endangered.

NRDC is fighting several court battles to protect the chinook, as well as other endangered fish in threatened river systems, from illegal water diversions.

Photo: chinook salmon © Roger Peters, USFWS