Animal Field Guide

Kokanee Salmon

Oncorhynchus nerka
(Salmonidae)

Global Rank: G5
State Rank: SNA

Agency Status
USFWS:
USFS: none
BLM: none

The kokanee is the landlocked version of the sockeye salmon. Kokanee were first introduced into Montana in Flathead Lake in 1914 and are currently fairly widespread in the western half of the state on both sides of the Divide. Kokanee can achieve sizes of 3 to 5 pounds but 1-pounders are most common. The size of kokanee in Montana waters is a function of two factors, their own population density and the abundance of their available food supply. Kokanee are strictly plankton feeders and they can rapidly overpopulate, resulting in large numbers of stunted fish. Kokanee spawn naturally in many Montana waters. They either run upstream from their lake habitat or spawn along the lake shorelines in the fall. Most kokanee reach sexual maturity in their fourth year of life and they then undergo a dramatic transformation prior to spawning. The silvery specimen seen here becomes a smooth-skinned, red-colored spawning fish with large hooked jaws and teeth on the males. All the adults die after spawning, making for a tremendous food source for bald eagles, grizzly bears, and other animals. Kokanee are very sensitive to water temperature and school in lakes at a certain depth. Once located, they are readily caught and provide excellent sport as well as table fare.

The anal fin has 13 to 17 rays; its base is longer than the base of the dorsal fin. There are 29 to 40 gill rakers on the first arch.

Kokanee are an important commercial and sport fish. They are commercially important from the Columbia River to Bristol Bay, Alaska and are the most valuable commercial fishery in both Alaska and British Columbia. They are important as a subsistence and ceremonial fish to indigenous peoples of Alaska, British Columbia, and Washington. See Pauley et al. 1989 for many details on commercial fisheries. Kokanee have also been used in carcinogen testing (Metcalfe 1989).

This species often ascends tributary streams to spawn. The runs may be as early as September and October.

Habitat consists of cold, clear lakes and reservoirs and Kokanee Salmon are found at all depths. They spawn over loose rubble, gravel, and sand in lower portions of tributary streams or along lake shores (Holton 1981, Brown 1971).

The diet consists mostly of plankton. Micro-crustacea are most important, but midges and other aquatic insects are often taken (Brown 1971). Daphnia thorata is a principal food for all size classes in Flathead Lake (Leathe and Graham 1982).

Construction of Lake Koocanusa has been very favorable for populations in the Kootenai River. They are now common in the reservoir, but did not occur prior to inpoundment (Huston et al. 1984).

Kokanee sexually mature usually in 4 years and spawn in pairs during November-December. Eggs are laid in redds and hatch in 110 days at 43 degrees F. Fry emerge in spring and enter the lake. Adults die soon after spawning (Brown 1971).