The smoltification period in Atlantic salmon hatcheries is a welfare-critical transition requiring specific management to support physiological adaptation.
Smolt welfare during the transition from fresh to saltwater is a welfare-critical period with both short and long-term consequences. Poorly smolted fish transferred to seawater experience osmoregulatory failure, chronic stress, and high mortality. Management of photoperiod and temperature to synchronise smoltification timing, combined with smolt quality testing before transfer, reduces both acute and chronic welfare compromise. The transfer event itself requires careful planning including good water quality in transport tanks and rapid transfer to minimise stress duration.