Forecast: 198K Upriver Springers In 2011

Columbia salmon managers are forecasting a total of 198,400 upriver-bound spring Chinook back to the river’s mouth in 2011 — and 20 percent of the run will be beefy 5-year-olds.

“It’s a forecast that’s above average,” says Kathryn Kostow of the Oregon Department of Fish and Wildlife. “We are expecting quite a lot of 5-year-olds to follow on this year’s 4-year-olds.”

She heads up the joint Oregon-Washington-tribal US v OR Technical Advisory Committee that early this afternoon came out with the annual prediction for the tastiest of all salmon. Managers will now begin to craft policies to guide fishing seasons.


The forecast is just 42 percent of 2010’s whopper preseason guess of 470,000, but about 62 percent of what actually returned, 315,345.

It’s more than returned in 2000, 2005, 2006, 2007, 2008 and 2009, but less than returned in the bumper years of 2001 to 2004.

Managers expect the run to tributaries above Bonneville Dam to be comprised of 158,400 4-year-olds and 40,000 5-year-olds. Less than 3 percent of last spring’s run were 5-year-olds.

Just over 91,000 Snake River springers are expected, 22,000 upper Columbia kings.


Forecasts for the Willamette, Sandy, Lewis, Kalama, Cowlitz and downstream netpens are still to come.

Following the spring run is a “record” — at least forecasted — return of summer Chinook, some 91,100.

The fishery panel also expects 162,000 sockeye, though Kostow admits that biologists don’t have a great handle on what the species is doing. This season saw a record return of 387,858, over three times the forecast.


The difference between how many spring Chinook the smart folks in Vancouver and Portland say will hit the Columbia and how many actually return has been way off in recent years, but managers are trying to dial that in with more data.

“There’s been a chronic problem since 2000 of missing our forecast. We’re not sure why that is,” Kostow says.

However, she points out that the jack-to-adult relationships that made for fairly good predictors at run sizes of under 150,000 just don’t work too well at the big run sizes we’ve seen since 2000.

An example of that would be 2009’s return of 80,000 jacks, which — on paper — penciled into a return of 1 million to 1.5 million springers. Nobody took that seriously, of course.

As a result, biologists began folding many more factors into their projections starting with the 2010 prediction. If the blizzard of numbers above hasn’t crossed your eyes, perhaps this from today’s forecast on all those variables will:

“TAC looked at multiple models for the Upriver Spring Chinook forecasts, including over 40 models just to predict the age 4 fish abundance. The models included linear and logarithmic sibling regressions, multiple regressions, cohort ratios (ratio of younger/older age classes), and historic relationships among return groups. Variables that were considered in these models include jack counts at Bonneville, Lower Granite and Rock Island dams, an index of jacks returning to areas upstream of Bonneville Dam, different years of historic sibling relationships, and environmental variables including spill at Columbia River dams and the ocean PDO index. Models were selected based on statistical indices of model fits and historic forecasting success from hind-casting analyses.  Subsets of models were selected for each forecasted group and the final forecasts were ensemble means of these subsets.”

“That all takes more time,” Kostow notes.

But to be more accurate requires more data, she adds.

Now, Washington, Oregon and the tribes along the Columbia will hash out 2011’s fishing seasons. Word should come out in late February.

Managers will likely again use a buffer to set fisheries to prevent a repeat of 2009’s large downriver catch that shorted upriver anglers.

“We’ve learned to be cautious,” says Kostow.

But Northwest Sportsman hasn’t: Time to sharpen hooks and brine some bait, boys!!

Tables from “2010 Columbia River Spring Chinook Management,” November 2009:

Editorr’s note: Kathryn Kostow’s name was misspelled with an extraneous “r” in an earlier version of this post.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: