Pre-Harvest Welfare Management in Farmed Salmon

The period immediately before salmon harvest is a high-risk welfare window, with crowding, food withdrawal, and transfer stress all concentrated in a short period, requiring careful management to minimize suffering before slaughter.

Key Facts

Food withdrawal before harvest (typically 24-72 hours) reduces gut content but causes hunger stress in salmon
Crowding to facilitate capture and pump transfer to harvest vessels causes acute stress and injury
The transition from seawater to freshwater tanks in some harvest systems causes osmotic stress
Transport from sea cage to slaughter vessel involves multiple handling events each causing cumulative stress
Water temperature at harvest significantly affects salmon stress responses and slaughter welfare
Electrical stunning followed by immediate killing is considered best practice but not universally implemented
Pre-harvest stress is measurable through cortisol, blood lactate, and behavioral indicators
The Fish Welfare Initiative and other organizations are working with producers on pre-harvest welfare protocols

Welfare Considerations

Pre-harvest management concentrates multiple stressors into a short period for salmon, making it one of the most welfare-challenging phases of the production cycle. Food withdrawal causes hunger that is measurable in behavioral indicators. Crowding for capture causes physical injury from conspecific contact and physiological stress from oxygen depletion. Transfer stresses add to cumulative physiological burden before slaughter. If slaughter is then performed without adequate stunning, fish may experience pain and distress at the point of killing. Best practice pre-harvest management minimizes handling steps, maintains water quality throughout, and ensures effective stunning at slaughter.

What You Can Do

Support welfare standards that include pre-harvest management protocols for farmed salmon
Advocate for mandatory stunning before slaughter for all farmed fish species
Choose salmon from operations with transparent welfare practices including pre-harvest management
Support research into pre-harvest welfare assessment and minimally stressful capture methods
Learn about farmed salmon welfare across the full production cycle when making purchasing decisions