Salmon Aquaculture Sea Lice Management

Sea lice are parasitic copepods that infest farmed salmon, causing skin lesions, stress, and mortality. Their management is one of the central welfare challenges in salmon farming.

Key Facts

Sea lice (Lepeophtheirus salmonis) cost the salmon industry over 1 billion dollars annually
Heavy infestations cause scale loss, lesions, secondary infections, and death
Treatments include hydrogen peroxide baths, thermolicer heat treatment, and laser systems
Biological controls using cleaner wrasse fish are increasingly deployed
Wild salmon passing farms face elevated lice pressure from farmed fish

Welfare Considerations

Sea lice infestations cause significant suffering to farmed salmon. The lesions created by feeding lice are painful and can expose muscle tissue; secondary bacterial and fungal infections compound the harm. Treatment methods themselves cause additional stress — bath treatments involve crowding fish and exposing them to chemical or thermal stressors. The welfare imperative is to prevent infestations through better monitoring and early intervention, use the least harmful effective treatments, and develop closed containment systems that eliminate sea lice entirely.

What You Can Do

Choose salmon from farms with transparent lice count reporting
Support campaigns for closed containment salmon farming
Reduce salmon consumption to reduce demand pressure on intensive fish farms
Advocate for independent monitoring of sea lice levels on salmon farms
Support research into non-chemical lice control methods