Aquaculture Welfare

Aquaculture: Salmon Lice Resistance Management

Resistance to medicinal treatments for sea lice in Atlantic salmon is a growing welfare and production challenge requiring integrated management.

Key Facts

Sea lice (Lepeophtheirus salmonis) cause skin damage and stress in farmed Atlantic salmon
Resistance to multiple chemical treatments including emamectin benzoate is documented across Norway
Resistance surveillance programmes monitor lice susceptibility across salmon farming regions
Biological controls using cleaner fish and laser systems offer resistance-independent alternatives
Integrated pest management combining multiple control methods reduces selection pressure for resistance

Welfare Considerations

As chemical resistance spreads, farms lose effective tools for controlling sea lice, leading to higher lice burdens and greater welfare harm. Lice cause skin damage, osmotic stress, secondary infections, and reduced feeding efficiency. Resistance management that preserves treatment efficacy is therefore directly equivalent to welfare management - maintaining control options protects fish from uncontrolled lice burdens.

What You Can Do

Support research into non-chemical sea lice control methods
Advocate for coordinated resistance surveillance and management programmes
Choose salmon certified from farms using integrated lice management
Support development of sea lice vaccines as a sustainable long-term solution
Learn about sea lice as a major welfare challenge in salmon aquaculture