Cleaner Fish Welfare in Salmon Farming

Wrasse and lumpfish used as biological sea lice control in salmon farming have significant welfare needs that are frequently unmet. These fish are often treated as disposable tools.

Key Facts

Around 50% of Norwegian salmon farms use cleaner fish for sea lice control
Annual mortality rates of caged wrasse can exceed 50-80%
Wrasse have complex social behaviours and cognitive abilities inconsistent with their treatment
Lumpfish have specific welfare needs including substrate for attachment and temperature management
Cleaner fish welfare has received increasing attention as an important component of salmon welfare

Welfare Considerations

Cleaner fish placed in salmon cages face acute challenges. Wild-caught wrasse and farmed lumpfish are placed in large salmon cages where they are expected to pick lice from salmon. Wrasse are cognitively complex fish that use tools in the wild and have sophisticated social behaviour. In salmon cages, they may be outcompeted by salmon for food, injured by sea lice treatments toxic to small fish, and exposed to temperatures outside their welfare range. High mortality rates indicate severe welfare problems. The use of billions of cleaner fish without adequate welfare consideration represents a significant and underreported welfare failure.

What You Can Do

Support research into cleaner fish welfare in salmon farming systems
Advocate for cleaner fish welfare standards to be included in salmon certification
Buy salmon from farms with documented cleaner fish welfare protocols
Support development of non-biological sea lice control alternatives
Engage with ASC and RSPCA Assured on cleaner fish welfare requirements