Aquaculture

Salmon Aquaculture Sea Lice Treatment Welfare

Sea lice treatments in salmon aquaculture can themselves cause welfare harms. Reducing lice through prevention reduces reliance on stressful treatments.

Key Facts

Sea lice cause gill damage, fin erosion, and immunosuppression in farmed Atlantic salmon
Medicinal bath treatments expose fish to chemicals in nets or tarps, causing crowding stress
Mechanical delousing using freshwater or laser systems causes injury when incorrectly applied
Cleaner fish such as wrasse and lumpfish are increasingly used for biological lice control
Prevention through fallowing, site selection, and monitoring reduces treatment frequency

Welfare Considerations

Sea lice management is a cycle of welfare trade-offs: lice cause chronic welfare harm, but treatments carry acute welfare costs. The most welfare-positive approach is prevention, reducing lice loads before they reach levels requiring intensive treatment. Biological control through cleaner fish, when cleaner fish welfare is also managed, offers a promising middle path.

What You Can Do

Choose salmon certified from farms using biological lice control preferentially
Support research into low-stress sea lice prevention and monitoring technologies
Advocate for lice threshold standards that trigger treatment before welfare is severely impacted
Learn about the welfare implications of cleaner fish use in salmon aquaculture