Atlantic salmon farming is one of the fastest-growing food production sectors globally, but welfare conditions in intensive sea-cage systems cause significant suffering. Science-based reform is increasingly possible and economically viable.
Farmed salmon welfare encompasses a cascade of interconnected problems in conventional open-net sea cage systems. Sea lice are perhaps the most serious chronic welfare problem: these parasitic copepods feed on salmon skin, mucus and tissue, causing open wounds, secondary infections, and significant pain. Treatment involves either chemical agents with their own toxicity or mechanical removal methods that cause acute handling stress. Crowding suppresses natural behaviors, increases aggression and fin damage, elevates cortisol, and promotes disease transmission. The pre-slaughter period is particularly concerning — crowding for harvest, transport, and slaughter methods including live chilling or carbon dioxide exposure are all documented to cause suffering. The Norwegian government, industry bodies, and researchers have made meaningful progress through the Norwegian Salmon Welfare Index and mandatory reporting, but systemic improvement requires economic incentives aligned with welfare outcomes rather than yield alone.