Pre-slaughter stunning of farmed fish renders them insensible before death, reducing potential suffering in what may be the highest-volume slaughter practice globally.
Fish pre-slaughter stunning addresses welfare at the moment of highest potential harm in the entire production cycle. Fish slaughtered without stunning are conscious during the entire dying process, which for gill-cut fish without exsanguination can last minutes. The scale of farmed fish production means that slaughter practices affect more individual animals annually than any other human-animal interaction. CO2 narcosis, while widely used for its convenience and low cost, involves a prolonged period of oxygen deprivation that fish actively avoid in preference tests, suggesting aversive experience before unconsciousness. Percussive stunning that renders fish immediately insensible avoids this period of potential distress and is achievable in commercial settings.