Declining skate and ray wings sold in supermarkets

14 Aug 2013
The blonde ray is a declining species. © Hans Hillewaert / CC-BY-SA-3.0

The blonde ray is a declining species. © Hans Hillewaert/CC-BY-SA-3.0

University of Salford DNA testing has found that that supermarket skate and ray wings, despite being labelled as from sustainable stocks, are actually being taken from declining species.

The most common species found on sale by Dr Andrew Griffiths from the School of Environment & Life Sciences was the blonde ray, which is bottom of the Marine Conservation Society’s sustainability rating.

Species sold as skate are difficult to identify as the body is cut from the fish before being sold to retailers. However, using a technique known as DNA Barcoding, the researchers were able to quickly and cheaply pinpoint the identity of the fish.

One supermarket which had made a commitment to supplying more sustainable species and naming them on its packaging was in fact found to be mislabelling products and included sales of wings from the thornback ray, another declining species.

The researchers are not naming the supermarkets responsible for mislabelling.

Dr Griffiths believes that there is a fundamental problem facing consumers who want to promote sustainable fish. “Currently there is a dichotomy; the EU generally requires skates to be identified to the species level when landed, but this information is not being passed onto consumers,” he said. “This remains a real obstacle in allowing consumers to make informed choices.”

The study was part of a wider project from Salford and University College Dublin called Labelfish, which is looking at a large number of issues relating to the mislabelling of fish across the EU.