Hatchery conditions for salmon in the first weeks and months of life have lasting effects on welfare, behaviour, and survival both in aquaculture and in stocking programmes for wild population support.
Hatchery welfare is sometimes overlooked because juvenile fish are small, numerous, and managed in bulk rather than as individuals. Yet early life conditions shape the stress response systems and behavioural capacities that determine welfare throughout the production cycle. Hatcheries that manage early density, provide appropriate first feeding, minimise unnecessary handling, and use gradual environmental transitions produce fish that are more robust, less stressed, and better adapted to subsequent rearing conditions. For conservation hatcheries producing fish for wild stocking, the additional challenge is preparing hatchery fish for the very different conditions of natural environments, where their domestication-associated behaviour changes can reduce survival. Welfare in hatcheries is increasingly recognised as a foundation for welfare across the entire aquaculture production chain.