More returns in 2023?

Fishery managers are predicting more spring Chinook salmon will be returning to the region this year, although only 10 percent are likely to be wild fish. According to a recent report, Oregon’s and Washington’s when native returns in 2022 amounted to 15.5 percent.

Historically, wild spring Chinook spawned in nearly all the eastside Willamette tributaries above Willamette Falls. During 1952–1968, the U.S. Army Corps of Engineers (USACE) dam-building projects blocked more than 400 miles of wild spring Chinook spawning and rearing habitat.

Some residual areas remain, including about two-thirds of the McKenzie River and about one-quarter of the North Santiam River. However, upstream dams affect these areas through the alteration of flows and temperature. The majority of the Clackamas River Basin remains accessible to natural production, although a three-dam hydroelectric complex has impacted its migration and rearing conditions.

The wild Willamette spring Chinook population was previously estimated at about 10–12%, with the majority destined for the McKenzie River. However, the wild percentage of that run has been higher in recent years, averaging 22% since 2010 - as tabulated over the Leaburg and North Fork Clackamas dams, plus red and dam counts in the North Santiam River.

In the 1980s the average return was 84,511 fish per year, the 1990s averaged 68,998 fish. 1995 was a low point when just 12,792 upriver fish returned to the river. The average annual return in the 2000s was 209,985, with a high of 439,885 in 2001.

The Washington Department of Fish and Wildlife says coastal conditions have played a role: “Several ocean ecosystem indicators, especially in near-shore areas, were tracking in a manner that generally leads to low ocean survival for some salmon stocks from 2015 - 2017 but began to improve in 2018. These indicators include Pacific Decadal Oscillation (PDO), upwelling, sea-surface temperature, and plankton abundance. Based on these indicators, adults returning in 2023 generally experienced improved ocean conditions during their ocean migration period.”