Atlantic salmon farming is a major global industry, but welfare challenges including sea lice infestation and high mortality rates represent significant and often underappreciated animal welfare problems.
The welfare of farmed salmon is compromised at multiple points in the production cycle. Chronic sea lice infestation causes ongoing pain and irritation that suppresses feeding, impairs immune function, and can progress to severe tissue damage. Treatment interventions — particularly thermal and mechanical delousing — cause acute stress responses with elevated cortisol and increased handling-related mortality. The high mortality rates across the industry indicate that millions of fish die from preventable welfare-compromising conditions annually. As scientific understanding of fish sentience and nociception grows, the welfare significance of these deaths and the suffering that precedes them becomes increasingly difficult to ignore. Consumer pressure for welfare certification and regulatory minimum standards for salmon farming are growing, though progress remains slow relative to terrestrial livestock.