by: Native Fish Society McKenzie River Steward Dave Thomas
You are most likely familiar with current reports of Coho salmon in our cherished McKenzie. Usually, we think about the McKenzie as a sanctuary for Spring Chinook salmon and undoubtedly this run is secured under the threatened types act. So, what are Coho doing trespassing on Chinook waters? ( spoiler alert, we do not understand).
Initially some background on Coho in the Willamette Basin. These types appear to have actually been endemic to the Willamette above Willamette Falls, a minimum of given that the 1950’s when ODFW began an equipping program. Nevertheless, there are some reports of earlier periodic passages of Coho above the Falls, most likely due to uncommonly high-water circulations. The equipping program ended in 1996. Ever since, till 2022, approximately eleven thousand Coho got in the river each year in the late Fall. Practically all of these fish generated in the Western drains of the Upper Willamette. It is thought that this types of salmon chooses the warmer waters and lower circulations of these environments, compared to the chillier, higher-flowing eastern rivers.
So, what altered? In the Fall of 2023 around 28,000 Coho passed Willamette Falls and 50+ of these passed above Leaburg Dam. There are likewise reports of Coho in the Santiams, however exact counts are not offered. In reaction to the schedule of these fish, ODFW released a short-lived policy enabling harvest of Coho anywhere salmon harvest was allowed the Willamette system.
In 2024, ODFW was all set to keep track of the Coho intrusion and undoubtedly, in between late September and early November more than 52,000 Coho passed above Willamette Falls, about 5 times the number we had actually concerned anticipate. Nevertheless, the variety of Coho passing Leaburg Dam was one! In anticipation of a Coho fishery in the Upper Willamette like 2023, ODFW once again released a short-lived policy enabling Coho harvest.
Now in 2025, we wait for the Fall counts of Coho fish passage at Willamette Falls. There is speculation that the current boost numbers in 2023 and 2024 was because of enhanced ocean efficiency. While this might hold true, the existing state of modeling does not enable positive quantitative quotes of specific types, much less specific runs of types. Despite the variety of fish passing the Falls, we still have the evident abnormality of greater variety of Coho passing the Falls in 2024, however the variety of Coho passing Leaburg Dam from 50+ to 1. Nevertheless, in anticipation of what may occur with Coho numbers in the Willamette Basin, ODFW means to make the short-term Coho harvest an irreversible part of Willamette Basin fishing regulations.Given our existing absence of understanding of the procedures underlying the motion of these fish, a range of futures appear about similarly possible. That is, the varieties of Coho might hang back to something like the 11K we are utilized to seeing, or, for example, Coho broadening their called throughout the Willamette basin and perhaps even displacing Winter season Steelhead and Spring Chinook salmon. This will definitely make enjoying the Falls fish counts more fascinating than normal.
