The freshwater smolt phase of salmon aquaculture involves high-density rearing in hatcheries before sea transfer — a period with distinct welfare challenges.
Smolt welfare represents the starting point of the salmon farm welfare continuum. The conditions in which young salmon spend their early months — density, water quality, handling frequency, vaccination stress — influence their health and welfare trajectory into sea cage production. Malformations, which are welfare harms in themselves, also predict poorer health outcomes at sea. Hatchery welfare investment pays dividends throughout the production cycle. The transition from hatchery to sea cage is a particularly stressful period — transfer in good condition, appropriate timing, and post-transfer monitoring are welfare-critical management points.