Tuesday, June 23, 2009

Kokanee Salmon

For those readers that do a little angling in their spare time I thought it would be fun to talk about a really neat fish that we are lucky enough to have up here in Montana as an introduced species to our local lakes, the kokanee salmon.
The kokanee salmon (Oncoryhnchus nerka) is actually the landlocked version of a sockeye salmon found in the Pacific ocean. Kokanee salmon are the product of evolutionary changes in sockeye salmon that were prevented from migrating to the ocean, and thus adapted to surviving exclusively in freshwater lakes. The kokanee salmon never migrate out to the ocean to feed so they have become a little smaller than their sockeye counterparts due to a more limited diet (plankton, insects, bottom organisms, and larval fish), but visually they are the same.

The migration of the kokanee salmon during spawning season is much more limited than that of the sockeye. Kokanee return to the site of their birth within their freshwater systems between August and November, normally along inlet streams of the lakes or shoreline gravel beds. Mature kokanee turn bright orange-red before the spawning season. The male displays more prominent coloration and develops a hooked jaw and humped back. The female selects a suitable nesting site, called a redd, and creates the egg bed by fanning or knocking gravel away with her tail. The male fends off intruders while the female works the redd. After the female lays up to 2,000 eggs in various batches, the male fertilizes them. The kokanee hatch in late winter and remain in the gravel feeding on the egg-sac nutrients. The fry will then emerge from the redds in the spring.

The kokanee is not an anadromous salmon, thus it inhabits only freshwater lakes and tributaries. The fish prefers cool, well-oxygenated water with temperatures of 50 to 59 F. Kokanee are generally found near the surface of the water as long as the temperature remains in their preferred range or cooler. As the surface water warms, kokanee may choose deeper water. Most kokanee live in a lake for most of their lives, so you can usually see them spawning either near the edge of a lake or in the small tributaries that feed into the lake of origin.

Kokanee salmon are a popular sports fish. Their red, oily, high-quality flesh can be cooked in a variety of ways or canned. It is important to clean and ice the kokanee soon after the catch, because its high oil content can cause it to spoil quickly. One of the best methods for catching kokanee is trolling with small, brightly colored lures at the depths where the fish congregate. This can be near the surface during cooler months and in deep waters during warmer seasons.

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