Salmon Welfare: Stress, Lice, and Humane Slaughter

Atlantic salmon are one of the most widely farmed fish species globally. Their welfare has improved significantly through better slaughter practices and disease management, but significant challenges remain at massive production scale.

Key Facts

Norway produces over 1.3 million tonnes of farmed Atlantic salmon annually — the world's largest aquaculture industry.
Salmon have cortisol stress responses comparable to mammals and show avoidance learning consistent with pain experience.
Sea lice infestations cause skin lesions, secondary infections, and elevated stress hormones in affected fish.
Percussive stunning followed by exsanguination is now standard in Norwegian salmon slaughter and significantly reduces suffering.
Crowding before slaughter for lice treatment purposes causes acute stress responses measurable in cortisol and behavior.

Welfare Considerations

Farmed salmon experience multiple welfare challenges across their production cycle: high-density rearing stress, sea lice infestation and treatment, handling stress during transfers, and slaughter-related suffering. Welfare science in salmon has advanced considerably, driven partly by economic incentives — stressed fish have poorer flesh quality and higher disease susceptibility. The implementation of humane slaughter standards in Norway has been a significant welfare improvement, but global salmon farming includes many operations with lower standards.

What You Can Do

Choose farmed salmon certified by ASC (Aquaculture Stewardship Council) with welfare standards.
Support the implementation of humane slaughter requirements in aquaculture regulations.
Follow welfare guidelines from the Fish Welfare Initiative for salmon and other species.
Ask supermarkets and restaurants about the welfare standards of their salmon suppliers.
Consider reducing salmon consumption given ongoing welfare challenges in production.