Wrasse Cleaner Fish: Welfare in Salmon Lice Control
Overview: Welfare science for ballan and other wrasse species used as cleaner fish in Atlantic salmon aquaculture.
Key Welfare Facts
Wrasse species including ballan, goldsinny, and corkwing are deployed in salmon cages to eat sea lice.
Both wild-caught and hatchery-reared wrasse face significant welfare challenges in salmon aquaculture cages.
Wild-caught wrasse experience capture stress, transport mortality, and abrupt environmental change on deployment.
Species-specific requirements including temperature range, refuges, and diet are frequently unmet in salmon cages.
Wrasse are temperate species that suffer cold-stress in the northern Norwegian and Faroese cage environments.
Regulations in Norway and Scotland now require minimum welfare standards but enforcement and monitoring are limited.
Welfare Assessment
Wrasse welfare is a significant but systematically overlooked component of salmon aquaculture. Supporting welfare standards for cleaner fish and choosing certified salmon products drives improvements throughout the industry.
What You Can Do
Choose salmon from farms with documented cleaner fish welfare standards and monitoring
Support regulatory enforcement of minimum welfare standards for wrasse deployment
Advocate for reduced reliance on cleaner fish through development of alternative lice control methods
Support research into welfare-positive cleaner fish husbandry and housing design