Sushi barcoding in the UK: another kettle of fish

Authors: Vandammen SG, Griffiths AM, Taylor S-A, Di Muri CD, Hankard EA, Towne JA, Watson M, Mariani S
Journal: PeerJ, DOI 10.7717/peerj.1891 (31 March 2016)

Abstract: Although the spread of sushi restaurants in the European Union and United States is a relatively new phenomenon, they have rapidly become among the most popular food services globally. Recent studies indicate that they can be associated with very high levels (>70%) of fish species substitution. Based on indications that the European seafood retail sector may currently be under better control than its North American counterpart, here we investigated levels of seafood labelling accuracy in sushi bars and restaurants across England. We used the COI barcoding gene to screen samples of tuna, eel, and a variety of other products characterised by less visually distinctive ‘white flesh’. Moderate levels of substitution were found (10%), significantly lower than observed in North America, which lends support to the argument that public awareness, policy and governance of seafood labels is more effective in the European Union. Nevertheless, the results highlight that current labelling practice in UK restaurants lags behind the level of detail implemented in the retail sector, which hinders consumer choice, with potentially damaging economic, health and environmental consequences. Specifically, critically endangered species of tuna and eel continue to be sold without adequate information to consumers.

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Commentary by F. Stein (SEG): From my perspective it is quite interesting that the study identified 4 anguillid species being present in the analysed sushi samples from the UK: Anguilla anguilla (European Eel), Anguilla japonica (Japanese Eel), Anguilla rostrata (American Eel) and Anguilla marmorata (Giant Mottled Eel). Most probably, Japanese restaurant based in Europe, do not purchase European-sourced eels. More likely, processed eels and eel products are purchased directly or indirectly from Asian wholesalers. Since Asian eel farms source glass eels of different species from around the globe (legally and illegally), it is not surprising that the study identified 4 out of the 20 eel samples were A. rostrata and A. marmorata which are not abundant in Europe or Asia.

Possibly, the occurence of European eel (Anguilla anguilla) in the sushi samples is the most concerning. Since trade of European eels from Europe to Asia is banned since 2010 and there is much evidence that European eels are illegally traded in conflict with European legislation, it is possible that the glass eels were fished in Europe, illegally exported to and farmed in Asia and finally sold back to Europe in order to end up on our plate… with a Yeti-sized carbon footprint.