European and Japanese eels are farmed at large scale with almost no welfare regulation. As a species with complex life history and significant welfare capacity, farmed eels deserve substantially more welfare attention than they currently receive.
Farmed eel welfare represents perhaps the most severe welfare gap in aquaculture. These are fish with demonstrated pain responses farmed at extreme densities with methods that would be considered unacceptable for vertebrate species receiving more regulatory attention. The conservation crisis — European eels are critically endangered partly because of wild-capture for aquaculture — means that the welfare problem is compounded by a sustainability emergency. Improving eel welfare requires simultaneously addressing farming conditions, developing humane slaughter methods, transitioning to farmed rather than wild-caught juveniles, and reducing overall demand for eel products.