Salmon hatcheries produce billions of smolts annually for both aquaculture and wild stock supplementation, with welfare considerations at every stage from egg incubation through release.
Hatchery welfare starts from egg incubation and shapes the entire subsequent life of salmon. Poor hatchery conditions — inadequate oxygen, disease pressure, excessive density — produce physiologically and behaviorally compromised fish who survive hatchery conditions but show impaired welfare and survival after transfer to sea cages or wild release. The precautionary principle suggests that optimizing early life conditions produces benefits across the entire subsequent life of the fish. Leading hatcheries are implementing welfare-conscious management including enhanced water quality monitoring, reduced density, vaccination programs, and behavioral assessment of smolt quality before transfer.