Salmon hatchery conditions during the freshwater stage of production significantly affect fish welfare through stocking density, handling and disease management.
Hatchery welfare is the foundation of salmon production welfare - fish starting sea transfer in poor condition have compromised resilience throughout their productive lives. High stocking densities in freshwater cause fin erosion, aggression-related injuries and reduced feeding access for subordinate fish. Disease management including mandatory vaccination causes acute handling stress. Welfare-conscious hatchery management prioritises appropriate stocking density, water quality monitoring, and minimising unnecessary handling while meeting health requirements.