Aquatic Animals

Farmed Salmon Sea Lice Welfare

Sea lice infestation in salmon aquaculture causes significant fish suffering and is also a major conservation threat to wild salmon.

Key Facts

Sea lice attach to salmon skin and feed on mucus, skin and blood
Heavy infestations cause open wounds, secondary infections and behavioral changes
Salmon farms create lice reservoirs that amplify exposure for wild juvenile salmon
Treatment methods including freshwater baths, laser systems and cleaner fish have welfare implications of their own

Welfare Considerations

Sea lice infestations cause measurable suffering in salmon — fish with heavy infestations show stress behavior, reduced feeding and impaired swimming. Treatment methods also carry welfare costs: chemical treatments cause acute stress, mechanical removal is physically traumatic and cleaner fish (wrasse and lumpfish) themselves have welfare needs that are often unmet. Reducing sea lice load while minimizing treatment trauma is a central challenge in salmon welfare.

What You Can Do

Choose salmon certified to standards with sea lice management requirements
Support research into wrasse welfare in salmon farming systems
Advocate for maximum allowable sea lice levels in national regulations
Support development of vaccine or genetic resistance approaches