Welfare considerations for European and Japanese eels in aquaculture, covering the extraordinary biology of these animals, welfare challenges in production, and the conservation crisis surrounding wild eel populations.
Farmed eel welfare combines significant individual animal welfare concerns with a conservation crisis of extraordinary severity. All European and Japanese eels in aquaculture start as wild-caught glass eels — juvenile eels that enter rivers from the Atlantic and Pacific after oceanic migration. Their capture for aquaculture depletes wild populations that are already critically endangered, creating an ethical problem in which the welfare of farmed individuals and the conservation of wild populations are directly linked. The farming process subjects these animals to conditions distant from their natural ecology: elevated temperatures, high densities, artificial light cycles, and regular handling for grading and feeding. Eels are particularly sensitive to handling — their skin produces copious mucus as a stress response, and physical damage from handling creates infection vulnerability. Slaughter welfare for eels is largely unaddressed: traditional methods including live gutting, skinning, or simple cold water shocking without prior stunning cause prolonged suffering. Electrical stunning protocols appropriate for eels exist but are rarely implemented. Addressing eel welfare requires simultaneously improving farm conditions, implementing humane slaughter, and resolving the fundamental conservation problem of wild capture dependency.