Stocking density in salmon aquaculture is a primary determinant of welfare outcomes, with overcrowded pens causing stress, aggression, disease, and poor water quality that harm fish health.
Stocking density is one of the most controllable determinants of salmon welfare in aquaculture, yet commercial pressure consistently pushes farms toward higher densities that reduce individual welfare. Crowded salmon experience chronic stress measurable through cortisol levels, show increased aggression, sustain more fin and scale damage, and suffer higher rates of stress-related disease. Welfare-progressive aquaculture requires mandatory density limits enforced through routine monitoring, not just maximum thresholds on paper. Consumer demand for certified lower-density salmon creates the market signal needed to make welfare-positive production economically viable.