Big return this year for spring chinook

Some 291,000 spring chinook have made it past the Bonneville Dam this year, which makes 2010's run among the three best returns of the prized salmon since the dam was built in 1938, according to NOAA Fisheries.

The big run, however, fell short of earlier expectaions. A December forecast pegged the spring run at more than 400,000 fish.

Spring chinook, valued for the high oil content of their flesh, are caught by sport, commerical and tribal fishermen who use them both for subsistence and income. Some of their catch is sold to the public.

The size of a run reflects a variety of factors, including freshwater conditions as the young fish migrate to sea and ocean conditions as they feed and fatten before returning to try to spawn in the Columbia.

What happens next year with the Columbia's spring chinook run is a big question mark.

Forecasters had been using the spring show of undersized males — known as jacks — to estimate future returns. By that indicator, the 2011 spring chinook run may be substantially below average as there's been a weak run of jacks showing up at Bonneville Dam this year.

Scientists, however, say that in recent years the counts have become an unreliable predictor of future runs. And there are some encouraging signs for next year's run of spring chinook as scientists have netted a lot of young salmon in ocean surveys.

Biologists also report that an unusually high number of sockeye salmon has passed Bonneville Dam, with the count of more than 270,000 fish ranking as the highest since 1955.

Hal Bernton: 206-464-2581