Atlantic salmon farming is one of the world's most productive aquaculture systems but faces persistent welfare challenges including sea lice infestations, crowding, delousing treatments, and pre-slaughter practices.
Atlantic salmon welfare has become one of the most intensively studied areas of aquaculture welfare science, driven by the industry's scale and Norwegian research investment. Sea lice infestation is the dominant chronic welfare problem — even at regulatory threshold levels, lice cause tissue damage, physiological stress, and immune suppression. Delousing treatments, while necessary to control infestations, cause acute welfare harm: warm water treatments cause temperature shock, hydrogen peroxide treatments cause irritation and sometimes death, and mechanical methods cause physical injury. The fundamental solution — reducing sea lice pressure through lower density farming, closed containment systems, or biological control using cleaner fish — addresses both welfare and production problems. Pre-slaughter welfare has improved in Norway with wider adoption of electrical stunning, but global standards remain variable. Consumer demand for higher-welfare certified salmon products has driven meaningful industry improvements through standards like RSPCA Assured and Global Salmon Initiative commitments.