Lumpsucker Welfare as Cleaner Fish in Salmon Aquaculture

Lumpsuckers are used as biological sea lice control in Atlantic salmon pens, but face severe welfare problems in a role for which they are poorly adapted and receive minimal welfare consideration.

Key Facts

Lumpsuckers adhere to surfaces using a sucker disc and consume sea lice from salmon in open-net pens
Mortality rates of lumpsuckers in salmon pens frequently exceed 50% over a production cycle
Lumpsuckers do not readily eat lice in winter when water temperature drops below 6 degrees Celsius
UK and Norwegian regulations provide limited welfare protection for cleaner fish despite their intentional use in food production

Welfare Considerations

Lumpsuckers in salmon pens face aggressive interactions with salmon that cause fin damage, scale loss, and physical injury. They cannot seek refuge from harassment in barren pen environments. High mortality rates suggest chronic welfare failure rather than normal production attrition. Cold winter conditions reduce feeding activity and leave lumpsuckers nutritionally stressed. Being crushed during mechanical delousing treatments is a documented lumpsucker mortality cause. The welfare of cleaner fish is systematically undervalued because they are perceived as a tool rather than animals in their own right.

What You Can Do

Advocate for cleaner fish welfare to be included in all salmon aquaculture welfare certification standards
Support RSPCA and academic calls for mandatory welfare assessment of lumpsucker and wrasse in salmon farming
Choose salmon from operations with verified low cleaner fish mortality rates
Raise awareness that lumpsucker welfare is a hidden but significant welfare issue in salmon aquaculture