Light management in aquaculture significantly affects fish physiology, behavior, and welfare — with photoperiod manipulation used to control reproduction and growth having both productive and welfare dimensions.
Lighting management in aquaculture demonstrates how production-focused interventions can have hidden welfare costs. Continuous light to prevent maturation serves production goals but may deny fish normal circadian cycles essential for physiological regulation and rest. The welfare implications of disrupting natural photoperiod patterns in fish whose biology evolved around day-night cycles deserve more research attention than they have received. High-welfare operations consider lighting as a welfare variable alongside its production implications.