Salmon hatcheries supplement wild populations but can inadvertently harm them through genetic dilution and behavioral simplification. Welfare-informed practices minimize these impacts.
Hatchery supplementation of wild salmon represents a welfare paradox: releasing millions of fish to save populations, but inadvertently compromising the fitness and welfare of wild fish through genetic introgression and competition. The welfare dimension extends beyond individual hatchery fish (who face poor survival in the wild) to wild fish whose adaptations are diluted by interbreeding with hatchery-origin fish. Welfare-conscious hatchery programs minimize these impacts through careful genetic management that preserves wild fish origin integrity, short rearing periods that minimize domestication selection, conditioning programs that improve predator avoidance in hatchery fish, and supplementation designed to support rather than replace wild population recovery. The goal is to use hatcheries as a bridge until habitat restoration supports naturally self-sustaining populations.