Sea lice treatment in salmon aquaculture involves a welfare-cost tradeoff, as both untreated infestation and some treatment methods cause significant fish suffering.
Sea lice management presents aquaculture welfare teams with difficult trade-offs: untreated infestations cause progressive suffering, while many treatment methods themselves cause acute stress and injury. Thermal and mechanical treatments are physically stressful events for fish. Cleaner fish such as wrasse and lumpfish that consume lice offer a welfare-superior alternative, but raise their own welfare questions about the conditions in which cleaner fish are kept. The search for effective, low-welfare-cost treatments is an active research area.