Cleaner Wrasse Welfare in Salmon Aquaculture

Wrasse used as biological sea lice control in salmon farms raise serious welfare concerns; their complex social behavior and habitat needs are incompatible with salmon net-pen conditions.

Key Facts

Over 50 million cleaner wrasse are used annually in Norwegian salmon aquaculture alone
Wrasse are wild-caught from inshore waters, with significant capture and transport mortality
Wrasse are territorial, shelter-dependent fish that require complex habitat structure
Net pens provide none of the habitat complexity wrasse require for welfare
End-of-season disposal options include slaughter; wrasse often die before season end from disease

Welfare Considerations

Cleaner wrasse represent a welfare problem that exists entirely because they are instrumentally useful for another welfare problem (sea lice control in salmon). The conditions in which wrasse are expected to function - open net pens without shelter, territory, or social group structure appropriate to their needs - are fundamentally incompatible with their welfare. Wild capture adds additional welfare burden through capture stress and transport. The scale of use - 50+ million animals annually in Norway alone - makes this one of the largest individual welfare harms in aquaculture practice. Developing alternative lice control methods that do not require cleaner fish would resolve this welfare problem.

What You Can Do

Support research and development of salmon lice control methods that do not use cleaner fish
Choose salmon from farms with low lice burdens managed without cleaner fish where possible
Advocate for welfare standards specifically covering wrasse housing requirements in salmon farms
Support NGO campaigns for improved wrasse welfare standards in salmon aquaculture regulations
Engage with retailers about wrasse welfare in their salmon supply chain requirements