Monday, December 14, 2009

Record Run Forecasted for Columbia Chinook

Biologists are cautiously predicting a record return of 470,000 upriver spring chinook this year, exceeding the previous record of 439,885 fish in 2001. In the past preseason run size predictions were based almost entirely on the number of jacks that returned from the previous year. Jacks are salmon which return after only one summer at sea and their abundance is thought to be a good indicator of the overall abundance of fish their age, the adults typically return after 2 or 3 summers at sea. Over the last few years, jack counts have become a less reliable predictor of chinook abundance. This year managers have retooled their model for preseason predictions and for the first time included information on ocean productivity in their run forecast. While there is considerable uncertainty surrounding the forecast last years record return of jacks coupled with excellent ocean conditions in the spring of 2007 bode well for a large return of the economically valuable fish.

Large returns are encouraging, however most of the run is of hatchery origin, and wild upriver spring chinook remain imperiled. Bycatch in large commercial fisheries as well as the broad range of hatchery impacts from massive supplementation and mitigation programs are both driving wild productivity down and until dams are removed on the Snake recovery of wild spring chinook on the Columbia is unlikely. Still this years forecast calls for over 70,000 wild fish meaning that for at least another generation the fish are holding on.

More information on the Spring Chinook Forecast in the Columbia Basin Bulletin:

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