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Most known sockeye salmon populations
are associated with lakes where the juveniles rear for one or two years
before going to sea. However, small groups of sockeye are occasionally
observed spawning in Washington river systems that do not have suitable
lakes. Though the observations are often a single occurrence, there are
several locations in Puget Sound rivers where small numbers of sockeye
are known to spawn on an annual basis. These sockeye have been assumed
to be strays from lake-rearing sockeye populations or perhaps kokanee
offspring that had gone to sea. Recent research by the National Marine
Fisheries Service has shown that genetic samples from sockeye from the
upper Skagit, Sauk, and Nooksack Rivers display no relationship to any
known lake populations. However, they appear to be genetically similar
to known sockeye populations in British Columbia, Alaska, and Russia that
use off-channel river habitat (river type) or marine waters (sea type)
instead of lakes for juvenile rearing. Although the rearing habitats of
the Washington populations are in most cases unknown these local sockeye
populations are labeled as "river" sockeye here for convenience.
Locations in Puget Sound drainages
where sockeye are observed to spawn on a regular basis include the North
and South Forks of the Nooksack River, the lower Samish River, the upper
Skagit River near Newhalem, the upper Sauk River, the North Fork Stillaguamish
River, the Wallace River (a Skykomish tributary), the Green River, the
Skokomish River, and the Dungeness River. River sockeye have also been
observed in coastal river systems but the genetics of these fish is unknown.
The numbers observed at any one time in a single location are low, usually
less than one hundred individuals. Because these fish are found in such
low numbers in Washington it is premature to make any definitive statements
regarding distribution and genetics. It is possible that Puget Sound river
sockeye are part of one wide ranging west coast population. |
