Aquaculture Welfare

Salmon Welfare: Pre-Harvest Fasting and Welfare

Pre-slaughter fasting of farmed salmon reduces gut contents for processing efficiency but causes welfare costs including hunger stress and increased aggression that require management.

Key Facts

Pre-slaughter fasting periods of 24-72 hours are standard in salmon processing
Fasting reduces contamination risk during slaughter but causes hunger and social stress
Longer fasting periods are associated with increased aggression and fin damage in salmon
Some evidence suggests brief fasting (12-24 hours) is sufficient for processing without prolonged welfare cost
Welfare guidelines recommend minimum effective fasting periods rather than extended starvation

Welfare Considerations

Pre-slaughter fasting represents a welfare cost that must be balanced against processing requirements. Extended fasting causes measurable hunger stress, aggression and physiological changes in salmon. Welfare-conscious operations minimise fasting duration to the shortest period required for safe processing and monitor aggression and injury during fasting to adjust protocols as needed.

What You Can Do

Support aquaculture welfare certification schemes with fasting duration standards
Advocate for minimum effective fasting periods in salmon welfare guidelines
Learn about the welfare implications of pre-harvest management in salmon farming
Choose certified salmon products with transparent pre-harvest welfare protocols