The method of slaughter used for farmed Atlantic salmon has profound welfare implications, with best practice requiring immediate stunning before gill-cutting to prevent a prolonged conscious death.
Salmon harvest presents one of the starkest welfare contrasts in food production: the difference between a percussion-stunned fish, rendered insensible in under a second, and an unstunned fish placed in ice slurry is the difference between rapid death and potentially 6-9 minutes of consciousness while blood draining causes progressive hypoxia. Salmon have functional nociceptors in their trigeminal neurons, show avoidance responses to noxious stimuli, and demonstrate analgesic responses to opioids — the neurobiological substrate for pain experience is present. The welfare case for pre-slaughter stunning is therefore strong, and best-practice standards require it. However, mechanical percussion stunners require capital investment, trained operators, and maintenance — barriers that have slowed adoption in some markets. Consumer pressure through certified welfare schemes that require stunning, and regulatory requirements mandating it, are the most effective levers for improving the welfare of billions of fish slaughtered annually.