Atlantic salmon farming is one of the world's fastest-growing food industries. Understanding the welfare challenges these fish face is essential for meaningful improvements in aquaculture standards.
Farmed salmon face multiple simultaneous welfare challenges. Sea lice cause open wounds on the head and body, with severe infestations causing fish to scrape against net walls in pain. Crowding stress suppresses immune function, promotes disease transmission, and causes chronic anxiety in socially complex fish. Cataracts — linked to diet formulation — impair the ability to detect predators and navigate, causing persistent disorientation. Handling stress during treatments, grading, and slaughter involves physical trauma. Pre-slaughter stunning methods vary dramatically in effectiveness: percussion and electrical stunning, when properly implemented, can minimize conscious suffering; but CO2 stunning and live chilling are widely used and cause prolonged distress. Consumer pressure for welfare-certified salmon is growing but must be matched by meaningful on-farm standards.