2024 A-, B-run Steelhead, OR-Columbia Ocean Coho Abundance Forecasts Out

Columbia A- and B-run steelhead will continue their slow crawl back from low marks seen in recent years, if the 2024 forecast is any indication.

The U.S. v. Oregon Technical Advisory Committee estimates 89,900 and 32,400 of the fish, respectively, will swim past Bonneville Dam this summer and fall.

At face value, it’s a far rosier forecast than 2023’s, which came out a year ago this week and had managers worrying about the potential for a worst-ever run of just 63,400 summer-runs back in 2023 before ultimately 110,687 showed up, including 90,900 As and 19,787 Bs.

This year’s combined forecast is for 122,100 A and B steelhead, which would be the most going back to 2016’s actual return of around 172,000. Low marks include 67,752 in 2021 and 72,466 in 2019.

But the run is still nowhere close to where it was through the first decade and a half of this millennium.

“Steelhead abundance is still low, particularly when you compare it to the run sizes pre-2017, which were greater than 200,000,” noted WDFW’s Ryan Lothrop. 

High marks since 2000 are 601,505 in 2001 and 587,735 in 2009.

Recent years have seen steelhead restrictions up and down the Columbia and Snake in response to the low forecasts. Stay tuned to North of Falcon to see how 2024 shapes up, but it’s likely this year will see a continuation of those.

A and B are designations given to steelhead that pass through Bonneville from July through October, with the former fish measuring less than 30.7 inches and the latter longer than that. While the Bs primarily return to Idaho’s Salmon and Clearwater, As run up streams throughout the Columbia Basin east of the dam, but mostly go back to Snake tributaries.

More than a third of this year’s As are expected to be wild, but only an eighth of the Bs will be.

Another caveat with this year’s forecast might be, what did the warm waters of a very strong El Niño do to these surface-swimming fish while on their North Pacific sojourn over the past 18-plus months at sea?

Managers also came out with ocean abundance estimates for coho today. They expect a total of 636,600 Columbia and Oregon Coast fish to be chomping herring off the Northwest Coast this season, down from last year’s actual estimated abundance of 699,900 silvers and well below the preseason forecast of 1.135 million.

While the expected Columbia coho ocean abundance is down about 110,000 from last year’s actual abundance, the predictions for Oregon Coast river and lake fish out on the briny blue are actually both up from 2023’s actual numbers and in line, roughly, with their 2023 preseason forecast.

This is the first year for a new coho modeling tool. The Pacific Fishery Management Council gave the nod to use what’s known as the ARIMA MAPE-weighted ensemble forecast methodology.

The council will make formal Columbia and other river mouth forecasts in April, Lothrop says