Aquaculture

Salmon Pre-Slaughter Crowding: Welfare Crisis Before Death

The crowding of salmon before slaughter is associated with acute stress, injury, and impaired slaughter efficacy. Pre-slaughter welfare protocols significantly affect outcomes.

Key Facts

Pre-slaughter crowding causes cortisol surges, scale loss, and physical injury
Crowding duration and density directly affect fish welfare and fillet quality
Pump systems and crowding nets used in harvest cause physical damage
Starving fish for 24-48 hours before slaughter reduces gut contamination but causes hunger distress
Best-practice pre-slaughter protocols minimise crowding time and density
RSPCA Assured salmon standards require documented pre-harvest welfare protocols

Welfare Considerations

Pre-slaughter crowding may cause the most intense acute suffering in farmed salmon production. Fish are compressed into decreasing volumes, triggering fear responses, aggressive interactions, and physical injury. The welfare window before stunning is critical - longer crowding causes more harm. Rapid, efficient harvest with immediate effective stunning minimises the pre-slaughter welfare cost. Certification requirements for pre-harvest protocols are an important lever.

What You Can Do

Choose salmon certified to schemes requiring pre-harvest welfare protocols
Advocate for mandatory pre-slaughter welfare standards in aquaculture regulation
Support research into rapid harvest systems that minimise crowding duration