Aquatic Animals

Farmed Salmon Lice and Sea Lice Management

Sea lice are among the most significant welfare and environmental challenges in salmon aquaculture. Infestations cause painful lesions and widespread suffering in farmed fish populations.

Key Facts

Sea lice can consume the skin and flesh of farmed salmon, causing open wounds
Chemical treatments for lice are stressful and sometimes fatal for fish
Mechanical treatments including thermal delousing cause significant pain and mortality
Sea lice from farms spread to wild salmon populations, threatening their survival
Closed containment systems eliminate lice entirely but require high capital investment

Welfare Considerations

Sea lice infestations cause significant pain and injury to farmed salmon, with heavy infestations producing erosion of flesh around the head and back. Treatments — including thermal shock with hot water and mechanical brushing — can themselves cause severe stress and injury. Breeding lice-resistant salmon strains, cleaner fish such as wrasse, and closed containment systems represent the most welfare-positive long-term solutions.

What You Can Do

Choose salmon from producers using closed containment or certified low-lice management
Ask retailers about sea lice management practices in their salmon supply chains
Support investment in closed containment aquaculture technology
Advocate for sea lice regulatory limits that account for fish welfare
Reduce farmed salmon consumption or choose plant-based alternatives