Humane stunning or stun/killing in the slaughter of wild-caught finfish: The scientific evidence base

An estimated 0.9 to 2.5 trillion individual wild finfish, destined for human or animal consumption, are captured globally each year by commercial fisheries. The majority of wild-caught fish die either from asphyxiation or evisceration; slaughter methods considered inhumane. Humane stunning or stun/killing may improve the welfare of wild-caught fish at the time of slaughter by rendering fish immediately insensible to pain, stress and suffering. Reducing fish stress during slaughter may also improve product quality. This study systematically mapped and narratively evaluated scientific research regarding humane stunning or stun/killing of wild finfish caught for food and feed on a commercial scale. Multiple knowledge gaps were identified: Key humane stunning parameters have only been scientifically tested, in terms of fish welfare and/or flesh quality, for a minority of wild-caught fish species and stunning methods. More species-specific protocols and use of brain activity measurements to accurately assess state of consciousness on application of the stunning method are required. More scientific testing of stunning methods in commercial wild-capture settings is needed to validate findings of controlled laboratory studies and ensure the methods are practical in fisheries. Research is needed to better understand the potential economic benefits of humane stunning for fishermen. From a donor perspective this review highlights the need to support more primary research into the feasibility and implementation of humane stunning or stun/killing in wild-capture fisheries.