Aquaculture

Cleaner Fish in Salmon Farms: Welfare of a Biological Control Method

Wrasse and lumpfish are increasingly used as biological sea lice control in salmon aquaculture. Their welfare in farm conditions has received far less attention than the salmon they are deployed to protect.

Key Facts

Approximately 30 million cleaner fish (wrasse and lumpfish) are deployed in Norwegian salmon farms annually
Lumpfish and wrasse are caught from the wild or increasingly farmed — with little welfare oversight
Cleaner fish in salmon cages face predation from salmon, feed competition, and disease
Lumpfish have significantly shorter lifespans in cages than in the wild
Wrasse and lumpfish mortality rates in cages are often very high — 30-80% within one production cycle

Welfare Considerations

Cleaner fish deployed in salmon cages experience chronic stress from cohabitation with a much larger predatory species. High mortality rates indicate poor welfare. Wrasse are complex, intelligent fish with significant cognitive capacity. Using them as biological pest control without welfare consideration for the cleaner fish themselves is an ethical inconsistency in aquaculture welfare improvement.

What You Can Do

Advocate for cleaner fish welfare standards as part of aquaculture certification schemes
Support research into cleaner fish welfare indicators and improved cage design
Choose salmon products from farms using non-biological sea lice control alternatives
Donate to Fish Welfare Initiative work on cleaner fish welfare in aquaculture