Aquaculture

Sea Lice Treatment Welfare in Atlantic Salmon Farming

Sea lice infestation and treatment are major welfare concerns in Atlantic salmon aquaculture, with treatments themselves causing significant acute stress.

Key Facts

Sea lice attach to skin and gills causing wounds, osmotic stress, and secondary infection
Chemical bath treatments can cause disorientation and physical damage
Mechanical removal by hydrolicer involves crowding and pressure exposure
Warm water treatments risk thermal shock if temperature not carefully controlled
Cleaner fish including wrasse and lumpsucker help control lice but face their own welfare challenges

Welfare Considerations

Sea lice represent a chronic welfare burden on farmed salmon, and the treatments used to control them impose additional acute stress events. Treatment frequency and method selection require careful welfare-risk balancing. Reducing sea lice through site management and cleaner fish is preferable to repeated treatment.

What You Can Do

Support research into low-stress sea lice control methods
Choose salmon from farms with transparent lice management reporting
Advocate for mandatory welfare monitoring in salmon aquaculture
Donate to fish welfare research programmes