Farmed Salmon Crowding and Stocking Density Welfare

Stocking density in salmon farming affects welfare through stress, aggression, disease transmission, and reduced opportunity to express natural behaviours throughout the production cycle.

Key Facts

Norwegian salmon farms can hold up to 25 kg of fish per cubic metre of water
High stocking densities increase cortisol levels, scale loss, and injury rates in salmon
Disease outbreaks spread more rapidly in high-density systems, increasing mortality and suffering
Reduced stocking densities consistently improve welfare indicators including wound rates
RSPCA Assured standards require lower stocking densities than standard commercial practice

Welfare Considerations

Stocking density in salmon aquaculture is one of the most influential variables affecting welfare outcomes throughout the production cycle. At high densities, salmon experience increased competition for food and space, elevated stress hormones, more frequent aggression-related injuries, and faster disease transmission. The economic logic of intensive aquaculture pushes toward maximum stocking densities, creating a direct tension with welfare interests. Welfare-conscious salmon farming requires density limits informed by fish welfare science rather than production economics, alongside management systems that can detect and respond rapidly to welfare deterioration.

What You Can Do

Choose salmon certified to high-welfare standards with verified stocking density limits
Support regulatory stocking density limits for salmon aquaculture based on welfare science
Advocate for transparent reporting of stocking densities and welfare outcomes by fish farms
Encourage supermarkets to commit to minimum salmon welfare standards including density limits
Support research into the relationship between density, stress, and welfare in Atlantic salmon