Farmed Salmon Lice: Cleaner Fish Welfare

Wrasse and lumpfish deployed in salmon farms as biological sea lice controls face their own welfare challenges including inadequate shelter, inappropriate stocking, and high mortality.

Key Facts

Approximately 50 million cleaner fish are deployed in Norwegian salmon farms annually
Wrasse require complex habitat with shelter, hiding spaces, and appropriate thermal conditions
Lumpfish show shoaling behavior and need appropriate stocking density and group conditions
Mortality rates in cleaner fish are very high - often exceeding 50% within months of deployment
Wrasse are often wild-caught, raising conservation concerns alongside welfare concerns
Captive breeding of wrasse and lumpfish for salmon farms is growing but welfare standards lag

Welfare Considerations

The use of cleaner fish as biological sea lice control creates an often-overlooked welfare problem within salmon aquaculture. Wrasse and lumpfish deployed in salmon pens face conditions very different from their natural habitat - exposed to water temperatures outside their preference range, lacking the complex habitat they need for shelter, and subject to high mortality from disease, salmon predation, and stress. These are sentient fish with welfare needs that are routinely neglected in the service of salmon lice management. Improving cleaner fish welfare requires species-appropriate housing design, thermal management, and reduced deployment numbers as other lice control methods improve.

What You Can Do

Support research into lice management alternatives that reduce cleaner fish use
Advocate for welfare standards specifically addressing cleaner fish conditions in salmon farms
Donate to fish welfare organizations working on cleaner fish welfare science
Choose salmon from producers with strong cleaner fish welfare policies and lower cleaner fish mortality rates