Salmon slaughter methods vary widely in their humaneness, with growing evidence that fish experience pain making pre-slaughter stunning an increasingly important welfare requirement in aquaculture.
Salmon slaughter welfare is one of the clearest areas where relatively modest operational changes can dramatically reduce suffering across hundreds of millions of individual fish. The difference between death by prolonged asphyxiation and death from effective percussive or electrical stunning is the difference between a prolonged period of distress and near-immediate unconsciousness. The technology exists; the knowledge exists; the barrier is cost, habit, and the residual assumption that fish do not experience suffering in a welfare-relevant sense. That assumption is increasingly unsupported by neuroscience, and the regulatory trend toward mandatory pre-slaughter stunning for farmed fish reflects this shift.