This fall, biologists from the Oregon Department of Fish and Wildlife will capture adult Chinook salmon in the Siuslaw River near Mapleton. It's part of a study to estimate this year's return. The last time a study this extensive was conducted was 8 years ago.
The data collected from this year's study will be used to test methods developed 8 years ago and estimate populations for the future. Biologists capture Chinook in nets as they travel upstream and use a hole-punch in their cheek near the gill to mark them. Shelly Miller is a Project Reader for the ODFW. She says this data is important to fishery management and is used in the Pacific Salmon Treaty.
Miller: "And that's an agreement between, or treaty between, the U.S. and Canada, and affects local fisheries and international fisheries off the coast of Alaska and British Colombia where a lot of Oregon fish are intercepted in both commercial and sport fisheries."
Once salmon migration into the river has peaked, activities will shift to counting live spawning and examining carcasses on spawning grounds. Since 2007, population estimates for Siuslaw fall Chinook have ranged from a low of 7,000 to a high of 31 thousand in 2011.
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