Aquaculture

Salmon Sea Lice Resistance: Welfare Implications

Drug resistance in salmon sea lice populations is undermining chemical control, with welfare implications for both salmon and cleaner fish.

Key Facts

Resistance to multiple chemical treatments is now documented in sea lice populations globally
Lice infestations cause skin damage, stress, and secondary infections in farmed salmon
Cleaner fish including wrasse and lumpfish are deployed as biological control agents
Wrasse welfare is a growing concern as millions are captured from wild fisheries annually

Welfare Considerations

Sea lice resistance creates a welfare trap: chemical efficacy decreases, lice burdens increase, and pressure mounts to use treatments at higher frequencies. Sustainable control requires integrated approaches that prioritise biological methods and reduce chemical dependence.

What You Can Do

Support certified salmon producers investing in non-chemical lice control
Engage with research on sea lice vaccine development
Advocate for welfare standards for cleaner fish including captive-reared wrasse and lumpfish