Sea lice infestations are a major welfare and economic problem in salmon farming, driving research into non-chemical control methods.
Sea lice represent one of the most significant welfare problems in salmon aquaculture. Individual lice cause localized damage, but heavy infestations lead to large lesions exposing underlying tissue, osmotic stress from skin damage, and behavioral changes indicating chronic pain. Fish in high-lice pens show increased stress hormones, altered swimming behavior, and reduced feeding. Mechanical removal methods such as freshwater treatments and thermal delicing cause acute stress even when effective. Laser systems offer promising low-stress lice control but require precise calibration to avoid inadvertent injury. The move toward enclosed or semi-enclosed systems represents the most comprehensive solution by preventing infestation rather than treating it.