Overfished species of tuna and eel are among the varieties being served without customers realising.
Researchers at Salford, Bristol and Exeter universities investigated seafood at 31 sushi bars and restaurants across England.
They collected 115 fish samples from venues in Manchester, London, Bristol, Liverpool, Exeter and Newcastle between September 2014 – 15.
Scientists used DNA testing to screen samples of ‘white flesh’ fish, and found that 10 per cent of seafood served was not correctly described on the menu.
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.”
How to create a sustainable seafood menu
Sustainability has become a major watchword for the restaurant industry over the last few years, with celebrity chefs including Rick Stein, Jamie Oliver and Hugh Fearnley-Whittingstall committing to using responsibly-sourced fish in their restaurants.
Sixty per cent of UK consumers believe restaurants should offer sustainable seafood options, according to the Marine Stewardship Council (MSC).
But a recent study by the MSC and Fish2Fork found that more than half of the UK's high street restaurant chains are serving seafood from over-fished areas or are failing to be transparent about where their fish comes from.
Dr Andrew Griffiths, from the University of Exeter, said: “Many consumers do not realise that there are probably 10 different species that we can legitimately call tuna, but they all differ remarkably in size, habitat and vulnerability to exploitation, so label or menu information is paramount.”
The United Nations Food and Agriculture Organisation claims that 85 per cent of the world's fisheries are currently fished up to or beyond their limit, and around 90 per cent of the world's largest fish species - including cod and swordfish - have been lost since the 1950s.
The research in to UK sushi restaurants was published in the scientific journal Peer J.