Aquatic Animal Welfare

Sea Louse Resistance Management in Salmon Farming

Resistance to chemical treatments for sea lice is a growing challenge in Atlantic salmon farming, with welfare implications for both fish and cleaner fish.

Key Facts

Resistance to emamectin benzoate has developed in sea louse populations in Norway and Scotland
Multiple resistance mechanisms including target site modification have been identified
Resistance requires increased chemical doses or more frequent treatments, increasing welfare impact
Rotation of treatment types and inclusion of non-chemical methods delays resistance development
Integrated pest management plans that include biological control are the recommended approach

Welfare Considerations

Sea louse resistance creates a welfare paradox: more frequent or intense chemical treatments increase fish stress while less effective treatment increases lice-caused welfare impacts. Integrated management combining biological, mechanical and chemical methods reduces treatment burden on fish.

What You Can Do

Support certified salmon from farms with documented integrated louse management
Advocate for resistance monitoring standards in salmon aquaculture regulations
Choose lower-frequency treatment certification schemes when purchasing farmed salmon