Cleaner fish including wrasse and lumpfish used to control sea lice in salmon farms have their own welfare needs that have been substantially neglected by the industry.
Cleaner fish welfare has been largely overlooked in the rush to adopt biological sea lice control in salmon farming. Wild-caught wrasse undergo capture stress, transport trauma, and must adapt to open net pen conditions entirely unlike their natural rocky shore habitat. Hatchery-reared lumpfish experience high mortality from immune system failure, inadequate diet, and aggression from the salmon they are supposed to clean. The irony is that cleaner fish — introduced to improve the welfare of salmon by reducing lice — experience poor welfare themselves in most commercial deployment settings. Welfare standards for cleaner fish, including appropriate diet, habitat provision, and protection from salmon aggression, are now being developed by the industry.