Aquaculture

Salmon Sea Lice Welfare Impacts and Management

Sea lice infestations cause significant welfare impacts in farmed salmon through tissue damage, osmotic stress, and secondary infection.

Key Facts

Sea lice are parasitic copepods that graze on salmon skin, mucus, and underlying tissue
Infestations above 0.5 adult female lice per fish trigger treatment obligations in Norway
Treatment methods include in-feed medicine, bathing in hydrogen peroxide, and thermolicer
Cleaner fish (wrasse and lumpfish) provide biological control with their own welfare concerns
Wild salmon migration past farms is compromised by sea lice pressure from aquaculture

Welfare Considerations

Sea lice cause pain through tissue erosion and can reach welfare-critical levels rapidly. Treatment methods themselves cause additional stress, highlighting the importance of prevention through early detection, cleanerfish integration, and reduced infestation thresholds.

What You Can Do

Choose salmon certified under standards with low sea lice thresholds
Support research into biological sea lice control without cleaner fish welfare compromise
Advocate for sea lice monitoring data to be publicly accessible
Learn about sea lice ecology and its welfare significance