How farmed salmon are killed has profound welfare implications for one of the world's most consumed fish. Current slaughter practices vary widely in humaneness, and the gap between best practice and industry standard remains significant.
Slaughter is a critical welfare moment for farmed salmon: the method used determines whether fish experience seconds or minutes of suffering, or none at all. Air asphyxiation — still common in parts of the industry — causes salmon to experience up to ten minutes of distress before losing consciousness. Carbon dioxide stunning, while widely used, may itself be aversive before inducing unconsciousness. Percussive stunning, when properly implemented, achieves near-instantaneous insensibility but requires training, equipment maintenance, and quality control. Electrical stunning is highly effective when correctly calibrated but requires investment in specialised equipment. Industry adoption of humane slaughter has been slower than in terrestrial livestock sectors, partly due to cultural and regulatory factors and partly because fish welfare has historically attracted less regulatory attention. Consumer demand for certified humane products is an important lever for change.