Farmed Salmon Sea Lice Management

Sea lice are parasitic crustaceans that cause significant welfare problems in farmed Atlantic salmon, requiring integrated pest management strategies.

Key Facts

Sea lice infestations cost the global salmon farming industry over $1 billion annually
Lepeophtheirus salmonis and Caligus species are the primary lice affecting farmed salmon
Heavy infestations cause skin lesions, secondary infections, and death from osmotic imbalance
Non-medicinal treatments include freshwater baths, thermolicer, and cleaner fish like wrasse
Resistance to chemical treatments is increasing in sea lice populations globally

Welfare Considerations

Sea lice cause direct tissue damage through feeding on skin, mucus, and blood. Severe infestations damage the underlying musculature and expose the skull. The pain and stress response in infested fish is significant. Non-medicinal treatments carry their own welfare costs including thermal injury and handling stress. Cleaner fish introduced to salmon cages experience poor welfare in overcrowded conditions. Integrated management that minimises lice burden while reducing treatment stress is the welfare priority.

What You Can Do

Choose salmon certified under high-welfare standards that include sea lice monitoring
Support research into effective low-stress lice management strategies
Advocate for transparent sea lice reporting by salmon farming companies
Reduce salmon consumption or choose land-based aquaculture alternatives
Support research into the welfare of cleaner fish used in salmon farms