Pre-slaughter crowding in salmon aquaculture causes measurable physiological stress. Understanding the science drives welfare improvements in the final hours of farmed salmon lives.
The pre-slaughter period for farmed salmon involves a stress cascade from crowding, oxygen depletion, handling, and transport that begins hours before death. Even if slaughter itself is performed humanely, the preceding welfare harm is substantial and poorly regulated. Scientific evidence shows measurable physiological distress during this period. The welfare case for minimising crowding duration, maintaining oxygen levels throughout, and transitioning to rapid-harvest systems is strong. Consumer and retailer pressure for welfare-certified salmon is the primary lever for driving industry change, as regulatory frameworks for fish pre-slaughter welfare lag significantly behind those for mammalian livestock.