The final hours before slaughter are among the most welfare-critical for farmed salmon, involving crowding, fasting, and transport that cause significant stress.
Pre-slaughter management of farmed salmon concentrates welfare harms in the final stages of an already welfare-compromised life. Crowding during harvesting causes extreme social stress, oxygen competition, physical injury from contact, and physiological responses including elevated cortisol that may persist to the point of slaughter. Pump transfer through mechanical systems causes scale loss, bruising, and spinal fractures in some fish. The fasting period before slaughter may reduce gut contamination but does not reduce the stress of crowding and handling. At the slaughter plant, electrical stunning is effective only when correctly calibrated and consistently applied, conditions that are not universally met. Consumer demand for high welfare seafood can drive processor investment in better stunning equipment, calibration protocols, and worker training. Certification schemes that include pre-slaughter welfare process standards rather than only outcome indicators offer the most comprehensive welfare protection.