Eels are farmed in significant quantities across Asia and Europe, yet their welfare during farming and slaughter is poorly understood and largely unregulated despite evidence of sentience.
Eel welfare is poorly addressed by both regulation and consumer awareness. The evidence for eel sentience — including complex learning, pain responses, and stress hormones — is sufficient to apply the precautionary principle. Yet eels are routinely slaughtered using methods that would be illegal for vertebrates in many jurisdictions if applied to mammals. Salt and vinegar immersion cause prolonged, distressed writhing before death — clear behavioral indicators of aversive experience. Percussive stunning followed by rapid decapitation or spiking of the brain (ikejime method) represents a significantly more humane alternative. The conservation dimension compounds the welfare concern: wild glass eel harvesting for aquaculture contributes to the decline of an already Critically Endangered species. Choosing alternatives to eel products addresses both welfare and conservation simultaneously.