Sea lice are a major welfare and production problem in salmon farming, and advances in management strategies are reducing infestation rates and associated suffering.
Sea lice management in salmon farming illustrates the complexity of welfare trade-offs in aquaculture: the treatments and interventions used to control sea lice often cause their own welfare harms. Handling and treatment stress, cleaner fish mortality, and chemical treatment side effects must be weighed against the welfare benefits of reduced lice burden. The ideal welfare solution is prevention through farm siting, snorkel cages, and early intervention - avoiding heavy infestations that require aggressive treatment. The industry's adoption of integrated pest management approaches that reduce reliance on chemical treatments is both a welfare and environmental advance.