UK fish and chip shops and fishmongers are selling endangered sharks to unsuspecting customers, according to DNA barcoding by researchers at the University of Exeter.

The research found that most fish tested under general names such as huss, flake, rock, rock eel and rock salmon were found to be spiny dogfish, an endangered and protected species of shark.

Fin samples from scalloped hammerheads, which are subject to international trade restrictions, shortfin mako and smalleye hammerhead sharks were also found to be unknowingly sold by a British wholesaler. Other endangered sharks sold include starry smooth-hounds, nursehounds and blue sharks.

Researchers have called for stricter food labelling to inform consumers on what they are buying and its origins.

University of Exeter first research author Catherine Hobbs said: “It’s almost impossible for consumers to know what they are buying. People might think they’re getting a sustainably sourced product when they’re actually buying a threatened species.

“There are also health issues. Knowing what species you are buying could be important in terms of allergies, toxins, mercury content and the growing concern over microplastics in the marine food chain.”

The DNA barcoding analysed samples from 78 fish and chip shops and 39 fishmongers, predominately in southern England and ten fins from a wholesaler selling to restaurants and specialist supermarkets.

University of Exeter research co-author Dr Andrew Griffiths said: “The discovery of endangered hammerhead sharks highlights how widespread the sale of declining species really is – even reaching Europe and the UK.

“Scalloped hammerhead can be imported under strict conditions, but the wholesaler had no idea what species the fin belonged to.”

Endangered sharks sold: Industry reaction

National Federation of Fish Friers (NFFF) president Andrew Crook said: “As an industry we firmly believe in fish species labelling at point of sale for cod, haddock, plaice, hake and any species used.

“Working closely with our industry fish suppliers we encourage NFFF members and non-members alike to showcase and display the catch information. This includes fish species on offer, the area in which it was caught, through to which vessel it was caught on.

“We work closely with The Marine Stewardship Council (MSC) who are a world leading eco-label for sustainable fish and seafood, which means any fish with the MSC label can be traced back to a sustainable source.

“Having spoken to industry suppliers, one of which is the largest suppliers of rock salmon in the UK market, the species that they import, squalus acanthias, is sourced from North American/Canadian MSC Certified Sustainable Fisheries.”