False food labels put the skate on thin ice

One third of fish sold as 'sustainable' is no such thing, DNA tests show

Celebrity chefs' recipes for skate pan-fried with beurre noisette or poached in miso and ginger have seen the fish endure as a dinner party favourite despite concerns over its conservation status.

New research, however, has shown that ethical consumers who want to keep eating skate while minimising their impact on dwindling stocks could find they have been misled into thinking they are buying less-threatened types of the fish than they actually are.

DNA analysis of skate or ray purchased at supermarkets in the UK found that up to a third of wings may be incorrectly labelled as coming from more sustainable sources.

The findings, which come in the wake of concerted efforts by the EU, the fishing industry and retailers to improve sustainability, have prompted calls from marine scientists for fishmongers to be legally compelled to identify the types of skate they are selling to avoid confusion and safeguard future fish populations.

Dr Stefano Marini of the University of Salford said that, while he was pleased the research showed that no endangered species were making their way to the slab, consumers were being misled.

"We should extend the rules that already exist for many other products, and there is no reason why skate should not be treated in the same way," he said.

"The way to increase this information – which we have at the landing stage – is to make it compulsory to sell [the fish] to the consumer with a species name. We already do this with cod, haddock, salmon and trout.

"You could then say, 'I don't want to buy a blonde ray – I want to buy at a place where they can guarantee they are selling a cuckoo ray,' for example," he added.

The study identified six types of ray available in UK supermarkets and in fishmongers and takeaways in Ireland: blonde, spotted, thornback, cuckoo, small-eyed and shagreen.

While all are legal to sell, the larger, slower-growing blonde ray, thornback, small-eyed and shagreen are rated as near-threatened, whereas spotted and cuckoo rays are smaller, faster-growing species that are considered of least concern and ultimately more sustainable.

But researchers found that blonde rays were the most common type on sale. Of six wings analysed from one chain, which identified its product as coming from smaller rays, two were from thornbacks.

Selling practice continues to vary. Britain's largest retailer, Tesco, said it sold cuckoo, spotted and starry rays under separate labels, whereas Waitrose said it sold the same species but all were labelled as "fresh ray wings, caught in the north-east Atlantic Ocean".

Skate: The facts

* 0.001 per cent of British seas are protected against all fishing.

* 3 per cent of the world's oceans have some kind of protection. Less than 1 per cent is 'highly protected' and closed to fishing.

* 6 per cent of the world's land surface is protected in national parks and similar designations.

* 90 per cent of UK waters are open to high-impact fishing methods such as scallop dredging.