Growing consumption of the American eel may lead to it being critically endangered like its European counterpart

Current research has focused on the critically endangered Anguilla anguilla, commonly known as the European eel. While its export outside the European Union is tightly regulated, large quantities of A. anguilla juveniles continue to be smuggled out of the EU to Asia where they are grown in eel farms until reaching a marketable size.

To investigate the prevalence and consumption of endangered eels -- particularly the European eel -- a Yale-NUS College research team examined 327 individual eel products purchased across 86 retailers throughout Singapore. However, instead of prevalence of the European eel, the team identified 70% of another species in the sample -- Anguilla rostrata, commonly known as the American eel. While not critically endangered like the European eel, the American eel is also considered an endangered species. The findings suggested a possible shift in trade and consumption of eel to the American eel.

Given these findings, the research team called for specific attention to the American eel, with increased enforcement and monitoring needed as proactive steps necessary to avoid the same dramatic population declines that have been documented in other eel species like the European eel.

The paper was a result of Yale-NUS alumnus Joshua Choo (Class of 2024)'s Environment Studies capstone, which he did under the supervision of Yale-NUS Assistant Professor of Science (Marine Biology) Benjamin Wainwright. The paper was published in Conservation Science and Practice. In July 2024, Joshua presented the research at the 2024 International Eel Science Symposium in Liverpool, UK.

Joshua said, "It was sad to connect Singaporean unagi with the history of anguillid eel exploitation -- where a crash in one anguillid's stock repeatedly leads to another's overexploitation and crash. It was, however, heartening to see so many researchers and Indigenous groups invested in anguillid recovery in Liverpool -- from Japan to Aotearoa to the EU and UK. There's room for Southeast Asian perspectives in eel science -- it's important to protect tropical anguillids from the endangerment plaguing their temperate cousins, and to explore conservation solutions for our food that can bypass profit-driven overexploitation."

Joshua and the research team performed DNA barcoding of the samples of eel meat, sold as 'eel' or 'unagi' by supermarkets, restaurants, and wholesalers. Their findings found three pieces of the critically endangered European eel (which is banned from export outside the EU), and that 217 of the 257 products he tested were the endangered, though not internationally regulated, American eel.

"The mislabelling of seafood products is a significant global problem that contributes to ongoing biodiversity losses in the oceans. This deliberate mislabelling can have negative consequences for the health of human consumers and presents numerous opportunities for organised crime to prosper. The trade in eels is described as the greatest wildlife crime on Earth, it supports vast criminal networks that illegally traffic many hundreds of millions of glass eels (juvenile eels) to Asia each year," said Asst Prof Wainwright.

He further explained, "What we show with this work is a likely shift in trade, this shift could be the consequence of EU enforced rules and regulations making it harder to smuggle the European eel to Asia, consequently suppliers have now shifted their focus to the less regulated American eel. If the American eel is to avoid a similar fate to that suffered by the European eels, it will be important to closely monitor the American eel trade and introduce rules and regulations designed to prevent overexploitation."