Farmed Salmon Welfare and Sea Lice Biological Control

Cleaner fish including wrasse and lumpfish are used as biological sea lice control in salmon farming but face their own welfare challenges in this role.

Key Facts

Cleaner fish eat sea lice from salmon and are used in most Norwegian and Scottish salmon farms
Wrasse and lumpfish are caught wild or farmed for use in salmon production
Cleaner fish welfare has been significantly neglected compared to salmon welfare
Mortality rates for cleaner fish in salmon pens can reach 80 to 90 percent
Research into cleaner fish welfare is growing but welfare standards lag behind their widespread use

Welfare Considerations

Cleaner fish welfare represents an unintended welfare consequence of the otherwise positive move away from chemical sea lice treatments. Wrasse and lumpfish introduced into salmon pens face predation by salmon, competition for food, exposure to salmon diseases, and the physical stress of pen conditions they did not evolve for. High mortality rates mean vast numbers of cleaner fish die prematurely in conditions that do not meet their welfare needs. Responsible biological sea lice control requires parallel investment in cleaner fish welfare standards.

What You Can Do

Support salmon producers that invest in cleaner fish welfare alongside salmon welfare
Advocate for cleaner fish welfare standards to be included in salmon aquaculture certification
Support research into cleaner fish behavioral needs and optimal stocking density in salmon pens
Choose salmon from producers with transparent cleaner fish welfare monitoring and mortality reporting