SEATTLE - Starting this month, more than 314,000 chinook salmon are expected to make their way up the Columbia River - an impressive spring return, if it happens. However, the actual numbers often end up being very different than the early projections, and last year, none of the salmon stock returns lived up to the early estimates.
According to Doug DeHart, a former Oregon Chief of Fisheries, the most common methods for these "educated guesses" haven't proven especially reliable in recent years.
"These large error rates have led the scientific folks who do this stuff to have a whole series of little conferences about, 'What's going wrong here? Should we change how we project these numbers?'"
The projections are used to set fishing seasons, make management plans for dams and hatcheries, and more. Over the last 30 years, they have been higher than actual returns 11 times and lower 19 times; only seven of the forecasts were close to the actual fish numbers.
DeHart, who is a fisheries biologist, agrees it should be a good year for salmon fishing, both spring and fall. He says there is always uncertainty where nature is involved, although efforts to boost salmon survival appear to be working - most notably, the additional water spilled over the Columbia River dams as required by a court order.
"The spills clearly produced additional survival. We saw it in the juveniles and now we're seeing it in the numbers of adults. It's an important addition, and one of the few new tools in the toolbox."
Fish and wildlife departments in Washington and Oregon also credit good ocean conditions for improved fish survival.
DeHart points out that at least 80 percent of the returning fish originated in hatcheries. The separate counts for the endangered, wild fish don't look as impressive, he adds.
"They're the ones that are ESA-listed and constrain fisheries. That's the big challenge. And there the news is cautiously optimistic, but not great."
If the forecast of 462,000 returning fish for a different salmon stock, the sockeye, is true, it would set a Columbia River record.
Fish forecast numbers are from the Washington Dept. of Fish & Wildlife and Northwest Sportsman