The welfare cost of sea lice treatment procedures in salmon aquaculture is significant and requires protocol design to minimise acute stress and mortality.
Sea lice treatment welfare sits at the intersection of the primary welfare problem (sea lice infestation) and the treatment solution (delousing procedures). Neither untreated infestation nor inadequately managed treatment is welfare-acceptable; the challenge is designing treatment protocols that minimise acute stress while achieving sufficient lice reduction to prevent ongoing welfare compromise from infestation. Pre-treatment welfare assessment, ensuring fish are in adequate condition before subjecting them to treatment stress, is an emerging best practice. Post-treatment monitoring for mortality and behavioural recovery indicators provides data for protocol improvement. Industry investment in treatment welfare protocols is ultimately driven by both ethical obligation and the economic cost of treatment-associated mortality.