Crowding fish during harvest operations is one of the most welfare-costly stages of aquaculture. Understanding the welfare impacts helps drive improvements in slaughter procedures.
The final hours before slaughter are among the most welfare-compromising in salmon aquaculture. Crowding fish into small net sections to facilitate harvest creates hypoxia, physical injuries from collisions, and extreme crowding stress. Fish that have been well-cared for throughout production are subjected to severe acute stress at the end of their lives. Pre-slaughter handling practices affect both welfare and flesh quality — stressed fish produce stress hormones that affect meat quality — creating an alignment between welfare and commercial quality that should drive industry change.