Farmed Salmon Welfare and Density

Stocking density is one of the primary determinants of welfare in farmed Atlantic salmon, with high density contributing to aggression, disease spread, and chronic stress.

Key Facts

ASC-certified salmon farms must not exceed 25 kg per cubic metre stocking density as a welfare and environmental standard.
Norwegian regulations set maximum stocking density at 25 kg per m3, while many uncertified farms operate at higher densities.
High stocking density increases aggression, fin damage, cortisol levels, and susceptibility to disease.
Salmon actively space themselves in high-density conditions and spend more time in avoidance behaviour than in low-density systems.
Recirculating aquaculture systems can control density more precisely but introduce different stressors through water treatment.

Welfare Considerations

Stocking density in salmon farming is a welfare lever that connects directly to individual fish experience every minute of every day. Fish in overcrowded conditions cannot escape social pressure, injury risk, or the reduced water quality that accumulates with higher biomass. Even within certified systems, density at the maximum permitted level may still compromise welfare significantly in species that evolved to range widely in open ocean. Welfare-first salmon production would set density limits below current certification standards.

What You Can Do

Choose ASC-certified salmon as a basic welfare standard for farmed salmon purchases.
Support organizations advocating for stricter density standards in salmon aquaculture certification.
Reduce farmed salmon consumption overall and focus on certified products when purchasing.
Stay informed about developments in recirculating aquaculture that may offer welfare improvements over net pen farming.