Effects of Supplementation in Upper Yakima River Spring Chinook Salmon
To promote recovery of natural salmon populations, managers are utilizing hatchery supplementation programs to increase abundance of spawners on the spawning grounds. However, studies have provided evidence that captive breeding can result in domestication demonstrated by lower fitness of hatchery-origin compared to natural-origin fish. Our study revealed that supplementation increased overall abundance of fish spawning naturally on the spawning grounds. However, on average, compared to natural-origin spawners, hatchery-origin fish had reduced reproductive success, which also translated to reduced reproductive success for natural-origin fish who spawned with hatchery-origin fish.
Other Key Words: Fitness
Koch, I.J., and H.M. Nuetzel. 2022. Effects of supplementation in upper Yakima River spring Chinook Salmon. American Fisheries Society Annual Meeting, August 21-25, 2022. Spokane, WA.