Fish hatcheries producing juveniles for grow-out aquaculture operations handle billions of small fish under conditions that create significant welfare challenges during the most sensitive life stage.
Hatchery welfare is often overlooked in aquaculture welfare discussions that focus on grow-out systems, yet the juvenile phase may be the highest-risk period for welfare harm per fish. Sorting machinery, dense stocking, and the physiological sensitivity of juvenile fish to environmental parameters create conditions where welfare failures affect enormous numbers of individuals simultaneously. Improved hatchery design, gentler sorting technology, better water quality management, and welfare monitoring from the earliest life stages are all areas where welfare improvement is both feasible and impactful at population scale.