Growing in popularity, unagi kabayaki - grilled freshwater eel in soy sauce - can be found on the menu of many Japanese restaurants, and is stocked by Asian shops and in specialist supermarkets. But new research tracing the DNA of eel fillets used for this dish has found that fraudulent food labelling is rife, with a third of the products violating EU regulations on the provision of food information. With certain species of eels now endangered, the researchers say that accurate labelling on these products is vital if the global eel trade is to be sustainable.
The European eel is a critically endangered species with trade strictly regulated, and import and export banned across the EU's external borders. While the researchers found little evidence of illegal trade in European eel in the products they examined, the prevalence of fraudulent labelling suggests that EU, and current UK, labelling requirements are insufficient.
"Only through DNA analysis were we able to demonstrate that more than ten percent of the unagi kabayaki fillets were prepared from species other than that indicated on the label" said Florian Stein, the lead author from the Technische Universität Braunschweig in Germany. He added, "In times when eel trafficking is considered to be one of the biggest wildlife crimes and consumer awareness regarding the source of their products in general is increasing - the level of evident labelling fraud is alarming."
The origins and labelling of 108 unagi kabayaki products for sale in the Netherlands, Germany, Belgium, France and the UK were investigated by the researchers. Being prepared fillets covered in sauce, it was impossible to identify the species without molecular analysis. Taking DNA and cross-referencing this information with a global database meant that researchers could pinpoint the species involved and check the accuracy of each product label.
The researchers found that none of the products purchased in Europe were produced in Europe, all were imported from China and Taiwan. Each product contained the fillets of one type of eel, but in total four species were detected across the sample group, only one of which is found in Chinese waters. 73 samples were American eel, 33 Japanese eel, and a single sample of European eel and Indian shortfin eel were identified.
"The presence of eels originating from various parts of the world points at the global nature of the eel trade", said Vincent Nijman, Professor in Anthropology at Oxford Brookes University in the UK, and one of the authors of the paper.
"American eel is transported from the east coast of the US to southern China, where it is turned into eel fillets, these are then exported to the Netherlands from where they end up in UK supermarkets. At the same time, in another shop, also in the UK, you can buy similar looking fillets that are actually Indian eels imported from Germany, that also were processed in China but which originated from perhaps the Philippines".
The research paper says it is vital that the EU and the UK achieve straightforward labelling requirements that include the scientific name of the species, and that this is made mandatory for prepared and preserved fish products.
Andrew Kerr, Chairman of the Sustainable Eel Group in Brussels, who was not involved in the research, noted, "Eel is essentially a wild fish and finite - control is therefore an essential requirement for a sustainable global trade. Accurate and fully traceable labelling are in everyone's long term interests."