Pre-slaughter stunning is a critical welfare intervention for farmed salmon, ensuring fish are rendered insensible before killing. Methods vary widely in efficacy, and industry adoption of effective stunning is a major welfare priority in aquaculture.
The welfare case for pre-slaughter stunning rests on evidence that salmon possess nociceptors, show pain avoidance learning, and display stress responses to noxious stimuli. Without stunning, slaughter methods including live chilling and asphyxiation in air may involve prolonged conscious suffering. Correctly applied percussive stunning renders fish insensible within milliseconds, dramatically reducing potential suffering at the moment of death. Monitoring stunning efficacy through behavioural and neurological indicators is essential, as improper application leads to stunning failure and recovery before death. Consumer demand for welfare-certified salmon has driven commercial adoption of stunning in major producing nations.