Aquaculture Salmon Lice Cleaner Fish Welfare

Cleaner fish including wrasse and lumpfish are used to control sea lice on farmed salmon, but their own welfare is frequently overlooked in aquaculture management.

Key Facts

Wrasse and lumpfish are placed in salmon sea cages to eat sea lice from salmon skins
Millions of cleaner fish are deployed annually in Norwegian and Scottish salmon farming
Cleaner fish are often overcrowded in salmon cages with inadequate refugia from salmon aggression
Mortality rates for cleaner fish are very high - many do not survive the growing cycle
Wild-caught wrasse removal may affect reef ecosystems where they are important cleaners
Cleaner fish have their own behavioural needs including territorial space and shelter

Welfare Considerations

Cleaner fish welfare is a significant and largely unaddressed issue in salmon aquaculture. These are sentient fish being used as a biological pest control tool with minimal welfare consideration. High mortality rates indicate severe welfare problems from salmon aggression, stress and inadequate provision of species-specific needs like shelter and territory. Wrasse are particularly vulnerable - territorial fish placed in densely stocked salmon cages face constant aggression. Improving cleaner fish welfare requires shelter provision, appropriate stocking ratios, and consideration of whether cleaner fish are a welfare-compatible solution or whether pharmaceutical alternatives should be preferred.

What You Can Do

Support aquaculture certification that explicitly includes cleaner fish welfare standards
Advocate for welfare requirements for cleaner fish including shelter provision and maximum stocking ratios
Choose salmon certified by schemes that address cleaner fish welfare
Support research into pharmaceutical or mechanical sea lice alternatives that avoid cleaner fish welfare harms
Ask salmon retailers about the cleaner fish welfare policies of their suppliers