Crowding during pre-harvest management is one of the most significant acute welfare events for farmed salmon. Understanding the physiological stress response informs better handling protocols.
Pre-harvest crowding causes acute, severe physiological stress in salmon that is measurable in cortisol, behaviour, and tissue damage. The convergence of welfare and product quality concerns provides a market incentive for improvement beyond ethical motivation alone. Fish that are chronically stressed before slaughter produce lower quality flesh that buyers can detect — this alignment of welfare and economics creates a pathway for improvement that regulatory requirements alone have not delivered.