Pre-slaughter handling of farmed salmon causes significant welfare harm through crowding, pumping, and inadequate stunning that occurs across the industry.
The pre-slaughter period for farmed salmon concentrates multiple welfare stressors into a short time before death. Crowding causes severe competition and oxygen depletion that stresses fish for extended periods before actual slaughter. Pumping through pipes causes physical trauma including scale loss and barotrauma. Percussion stunning, when correctly applied, can provide instantaneous unconsciousness, but operator skill and equipment calibration significantly affect consistency. Inadequately stunned fish regain consciousness before bleeding is complete, experiencing the pain of gill cutting while conscious. The scale of salmon slaughter - hundreds of millions annually in Norway alone - makes pre-slaughter welfare improvement one of the highest-impact opportunities in fish welfare.