European and Japanese eels are farmed in intensive systems with little welfare oversight, despite being caught as wild juveniles and facing serious questions about their capacity for suffering.
Eel farming occupies a uniquely problematic position: it involves catching wild, critically endangered juveniles to stock intensive systems, raising both conservation and welfare concerns. Within farms, the welfare conditions are poorly studied and largely unregulated. Slaughter methods in some eel processing facilities involve practices that would be prohibited for vertebrates with stronger welfare protection. The combination of endangered status, intensive captive conditions, and poor slaughter welfare makes eel one of the highest-concern aquaculture species for welfare-conscious consumers.