Sushi-bar-coding in the UK

Critically-endangered species of fish are being sold in sushi restaurants in the UK without adequate labelling.

Overfished species of tuna and eel are among the sushi dishes being served up without adequate information to consumers, according to research published in the journal PeerJ.

An investigation by scientists in Salford, Bristol and Exeter, to identify levels of mislabelling or 'non-labelling' on restaurant menus found evidence that the lax labelling practice in the UK's service sector - compared to the retail sector - may have undesirable consequences.

Stefano Mariani, professor of conservation genetics at the University of Salford said: "The sale of rare fish species under generic terms such as 'tuna' or 'eel' hinders consumer choice with potentially damaging economic, health and environmental consequences.

"As consumers we are getting much better at demanding information in shops but we do not demand the same standards when eating out."

Scientists investigated levels of seafood labelling accuracy in 31 sushi bars and restaurants across England.

They used DNA barcoding to screen samples of tuna, eel, and a variety of other products characterised by less visually distinctive 'white flesh' and found that 10% of seafood served was not correctly described on the menu.

A recent study of retail sales by the University of Salford found 3.3% of fish was mislabelled in leading supermarkets.

Fraud levels in the UK's sushi bars were, however, significantly lower than that observed in studies in North America.

While seafood labels currently appear to be more effective in the European Union than in North America, it should be recognised that labelling accuracy also depends on the type of fish served; for instance, the term 'snapper' typically harbours much mislabelling but is not as popular in British sushi bars as it is in the USA.