Biologists again put through the springer wringer

Spring chinook managers and anglers find themselves in a familiar position, wondering if the meager counts of fish passing Bonneville Dam on the Columbia River signal a late run, a lower-than-expected return or perhaps both.

Through Tuesday, just 267 adult spring chinook had passed the dam, compared to a 10-year average of more than 6,500.

Despite the uncertainty, fisheries managers in Oregon and Washington voted to reopen sport angling below Bonneville Dam during a two-day season that starts Saturday. The states project anglers could catch nearly 500 springers bound for tributaries above Bonneville over the weekend, which would bring the season total for the below-Bonneville recreational harvest of upriver spring chinook to about 1,800. That would represent about 50 percent of Oregon and Washington’s lower Columbia quota of 3,689.

The quota, referred to as upriver mortalities, is based both on the number of hatchery chinook bound for tributaries above Bonneville that anglers catch and keep and a small percentage of the wild chinook they catch and release that may perish from the experience.

The quota includes a 30 percent buffer to guard against overfishing if the run comes in lower that forecast. But in years when the run is showing signs of being lower than projected, the move to reopen fishing in the lower Columbia makes fisheries managers and anglers far upriver in places like Idaho anxious.

“It’s a little disconcerting to folks upriver,” said Alan Byrne of the Idaho Department of Fish and Game at Boise. “The thing that is scary to me is we have been overforecasting the chinook run the last couple of years.”

Bill Tweit of the Washington Department of Fish and Wildlife at Olympia said this year’s run is mimicking the 2018 run that came in below forecast. But Tweit said there are good reasons to conclude this year’s run may be late.

“High water, cold temperatures and dirty water — there are a lot of factors that would make sense that they are late,” he said.

Prior to the move to reopen fishing below Bonnville Dam, Tweit said Washington was leaning toward advocating for holding off on more lower Columbia fishing.

“Our perspective before we have any additional fishing is we need to see some more signs of life in the run,” he said Monday. “The forecast could be right, but it could just as easily be wrong.”

That changed, he said, when fisheries managers determined anglers had accounted for just 37 percent of the buffered quota. An earlier projection indicated anglers in the lower Columbia may have already accounted for 45 percent of the quota.

Washington and Oregon base their lower Columbia River fisheries on the preseason forecast. With no dams on the lower Columbia, fisheries managers don’t have the ability to know if the run is lower than forecast prior to opening fishing. The states allowed anglers to fish for chinook in the lower Columbia from March 1 to April 10. With anglers catching few fish during that time, they opted to reopen the season on April 13 and 14. But that short window coincided with flooding that dirtied the water and made fishing difficult.

Tweit said fisheries managers in the lower Columbia are trying to balance their management of fishing to ensure anglers in the lower Columbia River harvest their share of the run without catching too many wild fish or curtailing the ability of anglers in places like Idaho and eastern Washington from being able to harvest their share of the run. Oregon and Washington had proposed a Friday-through-Sunday season below Bonneville Dam. Tweit successfully advocated for just two days.

Idaho is set to open spring chinook fishing on portions of the Clearwater and Salmon rivers April 27. Washington expects to open a short season on the lower Snake River but has not yet announce when that will be.

Barker may be contacted at ebarker@lmtribune.com or at (208) 848-2273. Follow him on Twitter @ezebarker.