Sea lice infestations cause significant welfare impacts in farmed salmon and the treatments used to control them carry their own welfare costs.
Sea lice management creates a welfare dilemma: untreated infestations cause progressive tissue damage and suffering, but most available treatments also cause welfare impacts. The ideal solution combines prevention through lower stocking density, faster currents and submerged cages with early detection allowing treatment when lice numbers are lower. Biological control using cleaner fish reduces chemical and mechanical treatment needs but requires careful welfare management of the wrasse and lumpfish themselves. Sea lice management epitomises the complexity of farmed fish welfare.