Chip shops and fishmongers are selling endangered species of shark to unsuspecting consumers, according to a study.

The majority of chip shop fish sold under generic names like huss, rock salmon and rock eel turned out to be spiny dogfish – a species of shark which is endangered in Europe and classed as vulnerable worldwide.

Scientists used DNA barcoding to take samples of shark products from fishmongers and chip shops, as well as shark fins from an Asian food wholesaler in the UK.

The fin samples included scalloped hammerheads, which are endangered globally and subject to international trade restrictions.

  • huss
  • rock salmon
  • rock eel

The research was carried out at the University of Exeter and the scientists are calling for more accurate food labelling so people know what species they are eating.

“The discovery of endangered hammerhead sharks highlights how widespread the sale of declining species really is – even reaching Europe and the UK,” said Dr Andrew Griffiths.

“Separate investigations focusing on Asia have commonly identified scalloped hammerhead in fin processing.

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

The fins from the UK wholesaler, who intended to supply them to UK Asian restaurants and supermarkets, also included other threatened sharks such as shortfin mako and smalleye hammerheads.

The analysis of chip shop samples also identified globally threatened shark species.

Fishing for spiny dogfish has been prohibited in most circumstances under EU rules.

The spiny dogfish found in many chip shop samples could have been sourced from more sustainable stocks elsewhere, but it highlights the problems of selling shark meat under “umbrella” terms that cover multiple species.

“It’s almost impossible for consumers to know what they are buying,” said lead author Catherine Hobbs.

“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.

“Our findings demonstrate the need for more informative and accurate seafood labelling.”

As well as spiny dogfish, the researchers found species including starry smooth-hounds, nursehounds and blue sharks on sale in fishmongers and chip shops.

The study analysed 78 samples from chip shops and 39 from fishmongers, mostly in southern England, as well as 10 fins from a wholesaler.

It also analysed 30 fins seized by the UK Border Force on their way from Mozambique to Asia. These came from species including bull sharks.

The study – Using DNA Barcoding to Investigate Patterns of Species Utilisation in UK Shark Products Reveals Threatened Species on Sale – is published in the journal Scientific Reports.