More fish are killed for food than all other vertebrates combined, yet slaughter practices often involve prolonged conscious suffering with welfare standards far behind those for mammals and birds.
Fish slaughter represents potentially the largest source of preventable animal suffering in global food systems by volume of animals affected. If fish have welfare-relevant capacity for suffering - and the scientific consensus is moving strongly toward this conclusion - then standard commercial slaughter practices for both wild-caught and farmed fish cause suffering at an almost incomprehensible scale. Asphyxiation in air for wild-caught fish can take minutes; chilling in ice water without stunning for farmed fish causes a prolonged period of cold distress before unconsciousness. These methods persist because welfare requirements for fish slaughter have lagged far behind those for mammals and birds, reflecting both historical dismissal of fish welfare and practical challenges of scaling humane slaughter to commercial fish volumes. The welfare benefit per unit of improvement in fish slaughter practice is immense given the scale of the problem.