Farmed Salmon Cleaner Fish Welfare

The welfare implications of using wrasse and lumpfish as biological control agents for sea lice in Atlantic salmon aquaculture.

Key Facts

Wrasse (various Labridae species) and lumpfish (Cyclopterus lumpus) are used as cleaner fish in salmon sea cages to eat sea lice from salmon
An estimated 50-100 million cleaner fish are deployed in Norwegian salmon farming annually, making them one of the most numerous aquaculture species
Cleaner fish welfare has been largely overlooked in salmon aquaculture welfare discussions despite their significant numerical scale
Wrasse are wild-captured from coastal fisheries, raising sustainability and welfare concerns related to capture methods and handling
Mortality rates for cleaner fish in production are extremely high — estimated at 50-80% per production cycle from predation by salmon and stress
Basic welfare needs of cleaner fish including shelter, appropriate temperatures, and conspecific social contact are rarely provided in sea cages

Welfare Considerations

Cleaner fish represent a significant welfare blind spot in salmon aquaculture. While attention has focused on salmon welfare, the welfare of the cleaner fish themselves — species with their own behavioral needs, stress responses, and likely pain experience — has received minimal attention despite their enormous numbers. Wild-captured wrasse experience capture stress and mortality, then are placed in environments that are fundamentally unsuitable for their behavioral needs as fish that require rocky shelter, appropriate temperatures, and specific social conditions. High mortality from salmon predation and stress means that cleaner fish are consumed in the production process in a welfare-compromising way. The scale of cleaner fish use makes this a numerically significant welfare issue that deserves dedicated attention in aquaculture welfare standards.

What You Can Do

Support salmon aquaculture welfare schemes that explicitly include cleaner fish welfare requirements alongside salmon welfare standards
Advocate for development of cleaner fish-specific welfare guidelines addressing shelter provision, temperature management, and handling
Support research into non-biological alternatives to cleaner fish for sea lice control that achieve the same effect with lower welfare footprint
Ask salmon producers and retailers about their cleaner fish sourcing practices and mortality management programs
Engage with aquaculture welfare organizations to ensure cleaner fish welfare is included in the scope of seafood certification schemes