Atlantic salmon farming is the most welfare-scrutinised aquaculture sector, with significant ongoing challenges from sea lice, disease, and slaughter practices.
Atlantic salmon welfare is both the most studied and the most challenged of any farmed fish. The sea lice problem creates a persistent welfare dilemma: lice cause suffering, but many delousing treatments also cause significant stress and sometimes mortality. Thermal and fresh water treatments stress fish through rapid temperature change; bath treatments use chemicals that require careful dosing; mechanical removal can cause physical damage. The cumulative welfare impact of repeated delousing across a salmon's production cycle is substantial. Sea cage farming in lice-endemic environments may therefore involve chronic welfare compromise that is difficult to resolve within the current production model. Land-based RAS systems eliminate lice entirely, representing the most complete welfare solution, but at significantly higher cost.