European and Japanese eels are among the most welfare-concerning farmed fish species, with complex biology, poor adaptation to captivity, and slaughter methods that cause significant suffering.
Eel welfare presents a particularly acute combination of welfare and conservation concerns. The reliance on wild-caught glass eels for aquaculture stock depletes already critically endangered wild populations while simultaneously exposing juvenile wild fish to the stresses of captive rearing. The traditional practices of live storage in tanks and live slaughter are inconsistent with any welfare standard. The combination of conservation collapse and welfare concern makes eel consumption a strong candidate for avoidance. Until closed-cycle breeding removes the wild capture dependency and humane slaughter methods are universally adopted, the ethical case for consuming eel is very weak.