European and Japanese eels are farmed for high-value markets, but their complex biology and welfare during intensive aquaculture raise significant concerns.
Farmed eel welfare involves a species whose conservation status makes the entire industry ethically problematic at its foundation. European eel farming depends almost entirely on wild-caught glass eels because the species cannot yet be bred in captivity at commercial scale. Farming a Critically Endangered species by capturing wild juveniles perpetuates population decline, making the welfare question inseparable from conservation. For the individual eels in farming systems, welfare challenges include: high-density recirculating systems that cause chronic stress; handling during grading and transport; and slaughter practices that are poorly regulated and often involve prolonged suffering. Eels have pain-sensitive nervous systems and show nociceptive behavior — the welfare case for improved slaughter methods is strong. The sustainable path for European eel involves habitat restoration and population recovery rather than farming expansion.