European eels are critically endangered in the wild while being farmed in significant numbers, creating complex welfare and conservation intersections.
Farmed eel welfare raises multiple interconnected concerns. The reliance on wild glass eel collection means every farmed eel begins life with welfare costs of capture, transport and stocking into artificial systems. The density and conditions of recirculating eel farms are poorly matched to the territorial lifestyle of wild eels. Pain and stress responses in eels are documented and comparable to other fish. Slaughter methods vary widely in humaneness. Overlaying all welfare concerns is the conservation reality: farming critically endangered eels requires continued wild capture, depleting populations that need protection. Welfare improvement in eel aquaculture is inseparable from urgently developing captive breeding to end wild glass eel capture.