Farmed Salmon Sea Lice Management

Sea lice are the most significant welfare and production challenge in Atlantic salmon farming, causing skin damage, stress, and elevated mortality without effective control.

Key Facts

Sea lice costs the global salmon farming industry over USD 1 billion annually in losses
Heavy infestations cause open wounds, fin damage, and osmotic stress in salmon
Chemical treatments have widespread resistance issues in many farming regions
Biological controls using cleaner fish (wrasse, lumpfish) have expanded but raise own welfare concerns
Closed containment systems largely eliminate sea lice but are expensive to construct

Welfare Considerations

Sea lice attach to salmon skin and feed on mucus, skin, and blood, causing painful lesions that can extend to the underlying muscle in severe cases. Infested fish show abnormal swimming behavior, reduced feeding, and elevated stress hormones. Treatment procedures themselves cause stress and can cause injury. Cleaner fish used as biological control often suffer high mortality and welfare neglect. Sea lice remain a major unresolved welfare challenge in Atlantic salmon aquaculture.

What You Can Do

Choose salmon from certified farms with robust sea lice monitoring and control
Support investment in land-based closed containment salmon farming
Advocate for welfare standards that cover cleaner fish as well as target salmon
Reduce salmon consumption or switch to lower-impact aquaculture species