Welfare challenges for salmon in hatchery production and the implications for both farmed and wild populations.
Salmon hatcheries represent a welfare environment that shapes the entire subsequent life of fish entering both aquaculture and wild supplementation programmes. The conditions in which juvenile salmon develop — crowding, handling, feeding regimes, and environmental complexity — affect their stress physiology, immune function, and behavioral development in ways that persist long after they leave the hatchery. Investing in enriched rearing conditions that more closely simulate natural stream environments improves welfare during the hatchery phase and produces more resilient, welfare-capable fish at release or sea transfer.