Farmed Salmon Cleaner Fish Welfare

Key Facts

Cleaner fish including wrasse and lumpfish are deployed in salmon cages to eat sea lice off salmon
Wrasse are wild-caught from coastal habitats where their removal affects reef ecosystems
Mortality rates of cleaner fish in salmon cages are extremely high — often 40-80% by end of deployment
Lumpfish can be farmed, reducing wild capture welfare and conservation concerns
Cleaner fish welfare is regulated minimally compared to the salmon they serve — a significant welfare gap

Welfare Considerations

The welfare of cleaner fish in salmon aquaculture represents an often-overlooked welfare problem within a welfare problem. Wrasse and lumpfish deployed to control sea lice face conditions in salmon cages for which they are poorly adapted — high stocking densities, inadequate shelter, predation from salmon, and disease. Their mortality rates are extraordinary by any welfare standard, and the regulatory attention they receive is minimal compared to the salmon they serve. The wrasse wild-capture pipeline also depletes coastal reef populations where these fish play important ecological roles. Lumpfish farming offers a welfare-preferable alternative to wild-caught wrasse, though lumpfish welfare on farms also needs development. The fundamental challenge is that biological controls with high inherent mortality rates have inherent welfare costs.

What You Can Do

Support salmon certification schemes that include cleaner fish welfare requirements
Ask salmon producers about their cleaner fish sourcing — farmed lumpfish is preferable to wild-caught wrasse
Advocate for cleaner fish to be included in aquaculture animal welfare regulations
Support research into cleaner fish welfare improvement including shelter provision and density management
Follow developments in non-biological sea lice control that could reduce reliance on cleaner fish