Salmon Sea Lice Welfare in Aquaculture

Sea lice infestations are a major welfare and production challenge in farmed salmon, causing pain, tissue damage, and secondary infections that can be severe when inadequately managed.

Key Facts

Sea lice are ectoparasitic copepods that attach to salmon skin and feed on mucus and flesh
Heavy infestations cause severe tissue damage, secondary infections, and can be fatal to individual fish
Treatment methods include medicine baths, cleaner fish, and physical removal technologies
Mechanical sea lice removal using warm water or lasers causes acute stress and injury
Wild salmon populations near fish farms face elevated sea lice pressure that can harm their welfare

Welfare Considerations

Sea lice welfare impacts are severe and multifaceted. Attached lice cause continuous irritation and pain. Heavy burdens damage skin and underlying tissue, leading to open wounds susceptible to secondary bacterial and fungal infection. Treatment itself causes welfare harms: medicine baths cause stress from crowding and chemical exposure; mechanical removal using high-pressure water or thermal shock causes acute pain and stress. Laser lice removal systems cause less collateral damage than bath treatments. Integrated pest management combining cleaner fish, selective treatments, and biological controls offers better welfare outcomes than reliance on single-treatment approaches. Welfare-positive sea lice management is both an ethical requirement and an economic priority.

What You Can Do

Choose salmon certified to standards that include sea lice management welfare requirements
Support research into welfare-positive sea lice control methods including cleaner fish
Advocate for science-based sea lice management regulations in all salmon-producing countries
Learn about the welfare impacts of sea lice on both farmed and wild salmon
Reduce consumption of salmon from farms with documented sea lice management failures