Examining the welfare of farmed salmon during the final hours before slaughter — crowding, pumping, and the transition to slaughter — and how improved practices reduce suffering.
Pre-slaughter welfare represents the last welfare opportunity for farmed salmon, and the evidence shows that current practice in many facilities involves significant, preventable suffering. Crowding-induced stress, rough handling during pumping and transfer, and ineffective or absent stunning create a welfare-negative final experience for billions of fish annually. The technology for welfare-positive salmon slaughter exists: electrical stunning that renders fish unconscious within one second is commercially available and increasingly adopted in leading producing countries. The welfare gap between best practice (Norwegian electrically stunned salmon) and common practice (crowded, CO2 stunned, or unstunned fish in many countries) is large and represents an addressable welfare improvement through consumer, corporate, and regulatory pressure.