Salmon Farming Welfare: Sea Lice, Crowding, and Slaughter Reform

Salmon farming is one of the most welfare-significant aquaculture sectors, with billions of fish experiencing sea lice infestations, crowding stress, and often-inhumane slaughter practices.

Key Facts

Global salmon aquaculture produces approximately 2.7 million tonnes annually, involving billions of individual fish
Sea lice infestations cause open wounds, stress, and osmoregulatory failure in affected salmon
Chemical delousing treatments like hydrogen peroxide and azamethiphos cause additional acute stress
Crowding density affects immune function, feeding competition, and injury from fin-biting
Percussive or electrical stunning before slaughter is considered welfare-superior to suffocation in ice slurry
Norway, the world's largest salmon producer, has introduced welfare indicator monitoring requirements

Welfare Considerations

Salmon welfare challenges span the entire production cycle. High stocking densities create competition, injury, and chronic stress measurable through cortisol and immune suppression. Sea lice cause physical pain through tissue damage and the disruption of osmoregulation essential for saltwater fish survival. Delousing treatments add further stress. At slaughter, the most common method — live chilling in ice slurry — causes a prolonged stress response before loss of consciousness. Welfare-superior systems use lower densities, integrated pest management, and rapid stunning before killing.

What You Can Do

Choose salmon certified by standards requiring welfare monitoring and humane slaughter
Support the Aquatic Animal Alliance and other organizations developing fish welfare standards
Reduce consumption of farmed Atlantic salmon until welfare standards improve broadly
Advocate for mandatory welfare assessment requirements in aquaculture regulations
Support research into non-chemical sea lice management and welfare-compatible delousing