Farmed Salmon Pre-Slaughter Welfare: Crowding Stress

The period immediately before salmon slaughter involves crowding and handling that cause significant welfare harm. Improving pre-slaughter conditions is an achievable and important welfare goal.

Key Facts

Pre-slaughter crowding of salmon begins the fasting period required before processing and transport to the slaughterhouse
Crowding into smaller and smaller net volumes causes increased swimming speed, oxygen depletion, and physical injury
Stressed salmon show elevated cortisol levels, physiological hypoxia, and increased aggression during crowding
The duration of pre-slaughter crowding varies from hours to days depending on logistics and weather conditions
Optimal stunning (percussion or electrical) requires calm fish - pre-slaughter stress reduces stunning effectiveness
RSPCA Assured salmon standards require maximum crowding densities and duration limits to reduce pre-slaughter stress
Higher-welfare slaughter systems like HumaniSlaughter use in-water CO2 narcosis before crowding to reduce stress

Welfare Considerations

Pre-slaughter salmon welfare is critically important because the duration and severity of crowding stress directly affects the welfare experience at the end of a salmon's life. Animals that have lived in relatively good conditions for two or three years can experience intense suffering in their final hours through extreme crowding, hypoxia, and physical injury from collisions with other fish and nets. Welfare-focused pre-slaughter protocols - minimal crowding duration, maximum density limits, effective stunning immediately after crowding - represent achievable improvements that matter enormously to individual animals.

What You Can Do

Choose RSPCA Assured salmon which requires welfare standards at pre-slaughter as well as during rearing
Ask supermarket fish buyers about pre-slaughter welfare standards and crowding duration limits at their supplier farms
Support the RSPCA and Fish Welfare Initiative campaigns for higher pre-slaughter welfare standards in salmon farming
Advocate for third-party auditing of pre-slaughter welfare conditions at salmon processing facilities