The pre-slaughter period for farmed Atlantic salmon involves crowding, pumping, and transport steps that cause significant stress, injury, and potentially pain before slaughter — making stunning practices critically important.
Atlantic salmon have well-developed nociceptive systems and show behavioral and physiological stress responses to the pre-slaughter process. The cumulative welfare burden of crowding, handling, pumping, and inadequate or absent stunning is substantial across the billions of salmon slaughtered annually. The transition from consciousness to death can involve minutes of distress in poorly designed systems, or be near-instantaneous with well-applied percussive stunning. The economics of high-volume slaughter create pressure to process fish as quickly as possible, sometimes at the expense of stunning quality. Investment in stunning technology and verification systems represents a significant but achievable welfare improvement.