Salmon Welfare in Sea Lice Prevention

Prevention of sea lice infestations in Atlantic salmon farming is both a welfare and a commercial priority, with biological, physical, and chemical approaches offering different welfare trade-offs.

Key Facts

Lumpfish and wrasse are used as cleaner fish to reduce sea lice on salmon, but raise their own welfare concerns
Deep lights and feeding strategies can reduce lice burden by keeping salmon away from surface where lice larvae concentrate
Snorkel barriers and underwater feeding reduce salmon time in the surface zone where copepodid infestations occur
Selective breeding for sea lice resistance is ongoing but has not yet produced commercially significant resistance levels
Site selection away from strong tidal exchange and fallowing of sites between crop cycles reduces lice pressure
Integrated Pest Management (IPM) approaches combining multiple methods reduce reliance on any single treatment

Welfare Considerations

Sea lice prevention is preferable to treatment from a welfare perspective, as it reduces both the disease burden and the stress of treatment interventions. The welfare of cleaner fish used in biological control is an emerging concern that requires parallel attention. Site selection, physical barriers, selective breeding, and IPM approaches collectively represent a welfare-positive prevention strategy that is also commercially advantageous through reduced treatment costs.

What You Can Do

Support salmon producers using integrated pest management approaches to minimise lice burden
Advocate for cleaner fish welfare standards to be included in salmon farming certification
Support research into lice-resistant salmon genetics as a long-term welfare solution
Ask salmon retailers about their supplier lice prevention management strategies
Choose salmon from producers with documented low lice burden and IPM programmes