How sea lice infestations cause significant suffering in farmed salmon and how treatment approaches affect welfare outcomes.
Sea lice represent one of the most significant ongoing welfare challenges in salmon aquaculture, both through the direct pathological effects of infestation and through the welfare impacts of some treatment methods. The suffering caused by heavy louse burdens is genuine - the parasites cause inflammation, lesions, and physiological stress equivalent to other recognized pathological conditions. Treatment methods vary enormously in their welfare profiles - some mechanical treatments cause acute stress and physical trauma, while cleaner fish welfare is often poorly considered. Closed containment remains the most welfare-positive solution but requires industry transition. Consumer pressure for lice-free salmon production without welfare cost is a legitimate and important advocacy position.