Atlantic salmon slaughter welfare has improved substantially through the adoption of percussive and electrical stunning technologies. However, uptake is uneven globally and millions of fish are still killed without effective stunning.
Pre-slaughter welfare represents the final welfare event in a salmon's life and determines whether the animal dies quickly or endures prolonged suffering. The contrast between modern stunning technology and traditional methods (asphyxiation, CO2 narcosis) is stark: stunning reduces time to unconsciousness from minutes to fractions of a second. Given the scale of salmon farming — hundreds of millions of fish globally — even a 1-minute reduction in suffering duration per fish represents an enormous aggregate welfare improvement. Regulatory requirements for effective stunning are the fastest route to large-scale welfare improvement in this sector.