Lumpfish, used alongside wrasse as biological sea lice control in salmon farms, face specific welfare challenges that are increasingly recognised by the industry.
Lumpfish have been deployed at scale in salmon aquaculture with limited welfare consideration, partly because they are considered utility animals rather than the primary production species. However, lumpfish experience welfare problems from inappropriate sea cage environments including lack of resting substrates, incorrect temperature ranges, and predatory behaviour from salmon. Providing shade and resting surfaces substantially reduces lumpfish mortality and likely improves welfare. The development of lumpfish-specific welfare guidelines by Norwegian research institutions has improved industry practices, but uptake is variable. Treating lumpfish welfare as seriously as salmon welfare is essential for ethical deployment.