Farmed Salmon Lice Cleaner Fish Welfare: Wrasse and Lumpfish Care

Cleaner fish deployed in salmon cages to control sea lice often suffer high mortality. Improving cleaner fish welfare is a critical and frequently overlooked aquaculture priority.

Key Facts

Approximately 60 million wrasse and lumpfish are deployed annually in Norwegian and Scottish salmon farms as biological lice control
Cleaner fish mortality rates commonly exceed 50% over a production cycle, with many farms reporting much higher losses
Wild-caught wrasse have complex social lives in rocky reef habitats — removal for aquaculture is ecologically and welfare-significant
Lumpfish are increasingly farmed as cleaner fish alternatives, but their specific welfare requirements are poorly understood
Cleaner fish require different diets and environmental conditions than salmon — standard salmon cage conditions are poorly suited
The Animal Welfare Institute and other organizations have highlighted cleaner fish welfare as an urgent priority

Welfare Considerations

Cleaner fish represent a significant welfare blind spot in salmon aquaculture. While their deployment reduces chemical treatment frequency — benefiting salmon welfare — the welfare costs to cleaner fish themselves are enormous given the scale of mortality. Wrasse removed from reef habitats experience stress during capture, transport, and introduction to open salmon cages in which they cannot find appropriate shelter or food. Lumpfish farmed for this purpose require species-specific husbandry standards that are only recently being developed. The high mortality rates reflect how poorly current salmon cage conditions meet cleaner fish needs. Species-appropriate shelter structures, correct diet, and monitoring systems for cleaner fish health are needed. Regulatory attention to cleaner fish welfare is increasing in Norway and Scotland, the primary salmon farming nations.

What You Can Do

Support welfare standards for cleaner fish through aquaculture certification schemes that address their specific needs
Advocate for regulatory requirements on cleaner fish mortality reporting and welfare management in salmon farms
Support research into salmon lice management alternatives that reduce reliance on cleaner fish
Choose certified salmon products from farms using welfare-assessed cleaner fish management protocols
Engage with salmon aquaculture sustainability conversations that include cleaner fish welfare alongside environmental impacts