Eel farming — primarily of European and Japanese eel — faces serious welfare challenges rooted in species biology, high sensitivity to stress, and the ethical controversy over wild-caught glass eel supply chains.
Eel aquaculture welfare is complicated by the species' unique biology and the ethical paradox of farming a critically endangered species using wild-caught juveniles. The harvesting of wild glass eels further reduces populations already facing collapse — a sustainability and indirect welfare concern for wild populations. In farms, eels' exceptional stress sensitivity means that routine management events cause acute welfare impacts. Crowding, sudden handling, and water temperature fluctuations trigger extreme cortisol responses and mucus loss that predispose fish to secondary infections. Pre-slaughter practices are particularly problematic: traditional methods including live skinning, brine and salt submersion, and decapitation without stunning cause severe suffering in fully conscious animals. Chilling or electrical stunning before slaughter represents a major welfare improvement, but adoption is uneven. The lack of captive reproduction means the industry fundamentally depends on a wild population that it simultaneously threatens.