Aquaculture

Salmon Lice Biological Control Welfare

Cleaner fish used as biological control for sea lice on salmon farms face their own welfare challenges and require species-appropriate care standards.

Key Facts

Wrasse and lumpfish are used as cleaner fish in salmon farms across Norway and Scotland
Cleaner fish eat sea lice off salmon, reducing chemical treatment need
Millions of cleaner fish are deployed annually but mortality rates are often very high
Wrasse require complex habitat and diet that standard salmon cage environments do not provide
RSPCA standards now include specific provisions for cleaner fish welfare

Welfare Considerations

Cleaner fish welfare is an often-overlooked aspect of salmon aquaculture. Lumpfish and wrasse are placed in salmon cages with inadequate shelter, food, and environmental complexity for their species needs. Mortality rates in some operations exceed 50% within months of deployment. These fish have their own sentience and welfare requirements that are frequently subordinated to their utility as biological pest control.

What You Can Do

Choose salmon certified by standards that include cleaner fish welfare provisions
Advocate for cleaner fish welfare to be included in all salmon farming standards
Support research into optimal cleaner fish housing and nutrition
Engage with certification bodies about strengthening cleaner fish requirements
Support development of non-biological lice management alternatives