Salmon Sea Lice Treatment Welfare

Sea lice are a serious parasite problem in Atlantic salmon farming. Treatments themselves cause welfare harm alongside the lice infestation.

Key Facts

Sea lice cause skin lesions, physiological stress and reduced welfare in farmed Atlantic salmon
Chemical treatments including emamectin benzoate are effective but associated with welfare costs
Mechanical treatments including warm water and high-pressure wash cause acute stress and injury
Freshwater bathing is effective and relatively low-stress but requires appropriate equipment
Biological controls using cleaner fish including wrasse and lumpfish have welfare implications
Lice resistance to chemical treatments is driving more intensive mechanical treatment use
Prevention through lower stocking densities and closed containment significantly reduces lice burden

Welfare Considerations

Sea lice management represents a compounding welfare problem - the lice themselves cause suffering, and many treatments also cause acute welfare harms including scale loss, trauma, hypoxia and mortality. The welfare ideal is prevention through housing conditions that reduce lice exposure. Treatment selection should prioritise methods with lower welfare costs, and biological controls require their own welfare assessment.

What You Can Do

Choose RSPCA Assured salmon which has welfare standards for lice treatment
Ask salmon suppliers about their sea lice prevention and treatment approach
Support regulatory requirements for welfare-positive lice management standards
Reduce farmed salmon consumption where welfare standards cannot be verified