Harvest crowding is the most acute welfare challenge in salmon farming. Minimising crowding duration and severity reduces cortisol exposure and improves welfare in the final hours of life.
Harvest crowding represents the culmination of the welfare challenges facing farmed salmon. Fish that have lived at elevated densities throughout rearing are concentrated further still for the minutes to hours of pre-harvest processing. The cortisol responses, aggression, oxygen depletion, and physical trauma of this process are measurable and real. Welfare-positive harvest management minimises crowding duration, maintains oxygen saturation through supplementation, uses low-impact pump and handling systems, and integrates effective stunning at the point of slaughter. Treating the harvest chain as a welfare continuum — rather than beginning welfare consideration only at the point of killing — produces better welfare outcomes for the large number of fish whose final hours are determined by how the harvest is conducted.