Farmed Salmon Sea Lice Infestation Welfare

Sea lice infestations are a major welfare crisis in farmed Atlantic salmon, causing painful lesions and chronic stress to millions of fish.

Key Facts

Sea lice are parasitic copepods that attach to salmon skin and feed on mucus and flesh
Infestations cause open wounds that expose salmon to secondary infections
Heavy infestations reach brain tissue causing severe neurological damage
Sea lice from farms spread to wild salmon populations threatening conservation
Chemical treatments are becoming less effective as lice develop resistance

Welfare Considerations

Sea lice infestation is arguably the most significant welfare issue in Atlantic salmon aquaculture. These parasites cause progressive, painful lesions that worsen over time if untreated. Heavily infested fish show stress behaviors, reduced feeding, and compromised immunity. The pain signals from open wounds reaching brain tissue in severe cases represent acute suffering. Industry reliance on chemical treatments that are losing efficacy means the welfare problem is worsening, making investment in mechanical and biological control methods urgent.

What You Can Do

Choose salmon farmed in land-based recirculating systems with lower sea lice risk
Support investment in non-chemical sea lice control technologies
Advocate for stricter maximum infestation thresholds and enforcement in salmon farming
Reduce consumption of conventionally farmed Atlantic salmon until welfare improves