Pre-slaughter handling and stunning of farmed salmon has major welfare implications, and significant progress has been made in developing humane methods.
Salmon pre-slaughter welfare has seen genuine progress driven by a combination of welfare advocacy and economic incentives - stressed fish produce lower quality flesh with higher cortisol levels affecting taste and texture. The traditional method of allowing fully conscious salmon to asphyxiate in ice slurry caused prolonged suffering lasting minutes to tens of minutes. Percussive and electrical stunning render fish immediately unconscious when applied correctly - a welfare improvement achievable at commercial scale. The challenge is consistency of method application across farms and at different times of year when fish condition changes. Fish welfare at slaughter is now a serious focus of aquaculture welfare science, and consumer-facing certification schemes are beginning to include slaughter method requirements.