Aquaculture Cleaner Fish Welfare

Wrasse and lumpfish used as cleaner fish in salmon farming face significant welfare challenges in their own right as a biological lice control tool.

Key Facts

Approximately 60 million cleaner fish (wrasse and lumpfish) are deployed annually in Norwegian salmon farms for lice control
Wrasse species including ballan, corkwing, and goldsinney are collected wild or farm-raised for salmon farming deployment
Lumpfish are the most commonly farmed cleaner fish with Norwegian production exceeding 30 million annually
Cleaner fish experience high mortality in salmon farms due to salmon predation, disease, and inadequate environmental conditions
Wrasse require complex habitat with substrate for hiding since they are prey species in open-water salmon pens
Lumpfish and wrasse welfare standards are beginning to be incorporated into salmon aquaculture certification requirements
The mortality of cleaner fish is so high that their use as a lice control tool raises significant welfare concerns about their own welfare

Welfare Considerations

Cleaner fish welfare has emerged as an important issue precisely because their deployment as a welfare improvement tool for salmon (reducing chemical lice treatments) comes at a cost to the cleaner fish themselves. Wrasse are predated upon by salmon, struggle to find hiding places in the barren environment of salmon net pens, and experience significant mortality from environmental mismatch. Lumpfish suffer high mortality from both predation and the immune challenges of the high-pathogen environment of intensive salmon farms. The welfare calculus of cleaner fish use requires honest accounting: do the benefits to salmon (reduced lice burden, reduced chemical treatment) outweigh the welfare costs to the cleaner fish used as living tools? This calculation is increasingly being examined by welfare researchers and certification bodies. Improvements to cleaner fish welfare including shelter provision, appropriate stocking ratios, and health monitoring are beginning to be required by certification schemes.

What You Can Do

Support aquaculture certification schemes that include cleaner fish welfare alongside salmon welfare requirements
Advocate for research into cleaner fish welfare needs including shelter requirements and mortality targets for their welfare assessment
Purchase salmon from producers who can demonstrate monitoring of cleaner fish welfare alongside salmon welfare outcomes
Support alternatives to cleaner fish including laser lice removal that reduce lice without requiring living cleaner fish at scale