Farmed Salmon Lice Biological Control: Cleaner Fish

Cleaner fish including wrasse and lumpfish are used to control sea lice on farmed salmon but face significant welfare challenges themselves.

Key Facts

Wrasse and lumpfish are deployed in salmon sea cages to eat sea lice from salmon skin
Wrasse are harvested from the wild in large numbers, raising sustainability and welfare concerns
Lumpfish are now primarily hatchery-reared reducing wild harvest pressure
Cleaner fish mortality rates are extremely high - often 60-80% die before completing their service period
Wrasse and lumpfish have distinct behavioral and environmental needs incompatible with salmon cage conditions
Cold water periods cause hypothermia in wrasse from southern waters used in northern salmon farms
Welfare standards for cleaner fish are significantly below those for the salmon they serve

Welfare Considerations

Cleaner fish welfare is profoundly neglected in the salmon aquaculture system. High mortality rates indicate that conditions in salmon cages are fundamentally inadequate for these small fish. Cold temperatures, high salmon stocking densities, and lack of shelter cause chronic stress and rapid death. The welfare cost of using cleaner fish - tens of millions dying annually in poor conditions - is a substantial welfare concern within the salmon welfare system.

What You Can Do

Advocate for cleaner fish welfare standards to be included in salmon aquaculture certification schemes
Support research into alternative sea lice control methods that don't require cleaner fish
Choose salmon certified under schemes that explicitly address cleaner fish welfare
Engage aquaculture companies on reducing cleaner fish mortality through better housing and care
Support development of mechanical sea lice removal methods as alternatives to biological control
Donate to fish welfare research organizations investigating cleaner fish welfare needs