European and Japanese eels are farmed under conditions that raise significant welfare concerns; their complex biology and cryptic lives make welfare assessment particularly challenging.
Eel welfare in aquaculture is compounded by conservation concerns: the entire farmed eel industry depends on wild-caught juveniles, directly threatening already critically depleted wild populations. Welfare conditions in eel farms are poorly studied — high stocking densities, aggressive conspecific interactions, and water quality management challenges create significant risk of chronic stress. Slaughter welfare is particularly problematic: eels are difficult to stun effectively and may be killed by salting (immersion in salt solution, which causes slow death from osmotic stress) or chilling without stunning. Consumer demand reduction is the most impactful action, both for welfare and conservation.