Sea lice infestations in salmon farms cause significant welfare problems, and many of the treatments used to control them add further stress and injury to fish.
Sea lice welfare is a double problem: untreated infestations cause chronic pain and immune suppression, while treatment methods impose acute trauma. Thermal and mechanical delousing operations result in measurable spikes in stress hormones and visible physical damage. Welfare-conscious aquaculture must balance infestation control against treatment harm, prioritising cleaner fish and preventive approaches.