Fish hatcheries supplement declining wild salmon populations but raise welfare questions about the conditions and practices used to produce billions of juvenile fish.
Hatchery welfare for salmonids spans the entire life cycle from gamete collection to juvenile release. Broodstock capture and spawning procedures cause acute stress; artificial fertilization and incubation remove early developmental stages from natural conditions; high-density juvenile rearing causes chronic social stress, aggression, and injury. The welfare cost is paid by billions of fish annually, making even incremental improvements significant in aggregate. Conservation hatcheries that prioritize post-release survival increasingly incorporate welfare considerations - recognizing that stressed, behaviorally impaired fish released into rivers have poor survival, creating alignment between welfare and conservation outcomes.