Farmed Salmon Lice Cleaner Fish Welfare: Wrasse and Lumpfish in Sea Cages

Cleaner fish including wrasse and lumpfish are widely used to biologically control sea lice in salmon farms. Their welfare as working animals in sea cages requires dedicated attention.

Key Facts

Wrasse and lumpfish are deployed in salmon sea cages to eat sea lice from salmon skin
Over 50 million cleaner fish are produced annually for use in Norwegian salmon farming alone
Cleaner fish suffer high mortality rates in sea cages - often 50-80% per production cycle
Wrasse are predominantly wild-caught, raising sustainability and stress-from-capture welfare concerns
Welfare standards specific to cleaner fish are less developed than for salmon despite comparable numbers used

Welfare Considerations

Cleaner fish welfare represents a significant but often overlooked dimension of salmon aquaculture welfare. Wrasse and lumpfish experience the cold, crowded, high-density environment of salmon sea cages for which they are not well-adapted. Wild-caught wrasse face capture stress, transport trauma, and cage adjustment challenges. Mortality rates reaching 50-80% indicate severe welfare problems. Lumpfish reared in hatcheries have better survival but still face sea cage challenges. Shelter provision, appropriate temperature management, and protection from salmon aggression are key welfare interventions. The welfare case for cleaner fish has gained attention as their numbers approach salmon numbers in some systems.

What You Can Do

Support salmon aquaculture welfare standards including cleaner fish welfare provisions
Choose salmon from farms with good cleaner fish welfare monitoring
Advocate for welfare research into cleaner fish stress and mortality causes
Learn about the ecological and welfare implications of cleaner fish use in aquaculture