Stocking density in salmon aquaculture directly impacts fish welfare through stress, disease susceptibility and injury. Lower densities significantly improve welfare outcomes.
Crowding causes measurable physiological stress in salmon including elevated cortisol, immune suppression and behavioral abnormalities. Fish at high density show reduced swimming space, impaired ability to orient in current and increased competition for resources. Welfare certification schemes that cap density at evidence-based thresholds provide consumers with meaningful assurance.