Farmed Salmon Lice Management and Welfare

Sea lice are the most costly welfare and production problem in Atlantic salmon aquaculture, and treatments raise their own welfare concerns alongside the parasite burden itself.

Key Facts

Sea lice infestations cause lesions, osmotic stress, and secondary infections in farmed salmon
Medicinal bath treatments for lice cause acute stress and can be lethal if incorrectly applied
Mechanical lice removal by water jets causes scale loss and physiological stress
Cleaner fish such as wrasse are used to consume lice but face their own serious welfare problems

Welfare Considerations

Sea lice create a welfare dilemma with costs on multiple sides. Heavy infestations cause chronic pain, immune suppression, and mortality. Chemical treatments stress fish and risk resistance development. Mechanical removal causes physical injury. Cleaner fish used as biological control experience capture stress, inadequate housing, and high mortality rates. The most welfare-protective approaches combine preventive site management, early detection monitoring, and minimally invasive treatment options, alongside development of selective breeding for lice resistance.

What You Can Do

Choose salmon certified under schemes requiring integrated lice management plans
Support research into selective breeding for lice resistance in salmon
Advocate for regulations requiring welfare monitoring of cleaner fish in aquaculture
Reduce salmon consumption or choose land-based aquaculture products to reduce lice problem exposure