Atlantic salmon farming faces persistent welfare challenges including sea lice infestations, crowding stress, and handling during treatment that require systemic solutions at industry level.
Farmed salmon welfare is characterized by a cluster of interconnected problems where the primary welfare challenges — sea lice infestations and their treatments — are consequences of the production system's fundamental design. Open-net pen aquaculture exposes salmon to wild sea lice that proliferate in the concentrated biomass around farms. Treatments cause additional acute welfare harm while addressing the chronic welfare harm of infestation. This welfare trap is addressed most effectively through prevention — through genetic selection for lice resistance, biological control using cleaner fish, physical lice barriers, and ultimately transition to closed containment systems. Short-term mitigation through less stressful treatment methods is also important while systemic solutions are implemented.