The handling and slaughter of farmed salmon involves significant welfare risks from crowding stress, inappropriate stunning, and prolonged death. Best practices reduce this harm substantially.
Farmed salmon pre-slaughter welfare has improved in Norway and some other producing countries through regulation and industry adoption of electrical stunning, but globally most farmed salmon are still slaughtered without effective stunning. The combination of extreme crowding during harvest, transport in containers, and then slaughter by asphyxiation or ice water immersion causes significant acute welfare harm measurable in stress hormone levels and behavioral responses. Electrical stunning that renders fish immediately unconscious, followed by rapid killing, is the welfare-positive alternative. The scale of salmon production — over 2.5 million tonnes annually — means even small improvements in the proportion of fish stunned before slaughter represent enormous aggregate welfare gains.