Net pen aquaculture for salmon and other species creates environmental conditions that affect fish welfare through water quality, parasite exposure, and crowding.
Net pen aquaculture welfare involves chronic and acute stressors that are difficult to fully eliminate within the production system. Chronic crowding at commercial densities causes ongoing social stress and competition; acute treatment events cause significant distress through handling and chemical exposure. The search for lower-impact production systems is active, with land-based recirculating aquaculture offering welfare improvements at higher capital and energy cost. Consumer, regulatory, and investor pressure is the primary driver of welfare standard improvement in the net pen sector.