–

Chum salmon are one of the smaller species of salmon; they may grow to over 1 m in length, but most in California are less than 65 cm (26 in.). They are best known for their slight hump, hooked snout, and protruding canine-like teeth during spawning. They are dark olive on the back and dark maroon on the sides, with irregular greenish vertical bars on the sides and no spots on the back or tail.

Chum salmon have likely always been uncommon in California, and more common in Oregon and Washington. Chum salmon may spawn sporadically in California streams from San Francisco Bay north to the Oregon border, but the rivers with the most reliable spawning populations are the Smith, Klamath, and South Fork Trinity rivers. Most occurrences of spawning Chum in California today are likely strays from the Pacific Northwest from both natural and hatchery production.

Chum salmon live to two to seven years of age, though most spawn between the ages of three and five. Most Chums spawn within 200 km (approximately 124 mi.) of the Pacific Ocean due to their poor swimming ability, and some populations even spawn in the intertidal reaches of streams. In California, they enter streams from August through January on their spawning run. Unlike Chinook or Coho salmon, juvenile Chum salmon quickly migrate downstream to spend several months feeding on abundant copepods and amphipods in estuaries rather than rearing in freshwater. As a result, their survival is more closely tied to ocean productivity than freshwater conditions.

Chum salmon are closely related to sockeye and pink salmon. No genetic studies on California populations are available, but the fish are considered to be part of the loose Pacific Coast ESU.