Sea lice infestations in salmon farming cause severe welfare harms, and many treatments also cause significant stress. Integrated pest management approaches protect both fish welfare and production.
Sea lice welfare represents a multi-layered problem where the infestation itself causes suffering and most treatment approaches also cause acute stress. Mechanical treatments like warm water delicing involve handling and thermal shock that affects fish physiology. Chemical treatments have ecological side effects. The most welfare-positive approach is prevention through site selection, fallow periods, and coordinated area management that reduces ambient lice pressure. Cleaner fish used for biological control have their own welfare needs that are now receiving growing attention - the welfare of the pest control animals is part of the overall welfare equation in integrated pest management.