Sea lice treatments impose additional welfare stress on salmon alongside the disease itself.
Salmon being treated for sea lice experience the stress of crowding before treatment, the acute stress of the treatment process itself, and recovery from both. Treatment stress compounds the welfare burden of lice infestation rather than simply resolving it. Developing preventive strategies — lice-resistant breeds, closed containment, and cleaner fish — that reduce the need for stressful treatments is a priority welfare improvement for the salmon farming sector.