Cleaner fish including wrasse and lumpfish are used in salmon farming to control sea lice, but their own welfare is often neglected in the focus on the salmon crop.
Cleaner fish represent a hidden welfare crisis within salmon aquaculture. These fish are treated primarily as pest control tools rather than sentient animals, and their welfare has received little attention relative to the salmon they service. High mortality rates indicate that conditions in salmon cages fail to meet basic welfare needs for many cleaner fish species. Wrasse in particular require refuges, appropriate diet, and social environments that are rarely provided. The shift toward cleaner fish use as an alternative to chemicals has created a welfare problem that the industry has been slow to acknowledge and address.