Many consumers are being reeled in and are paying high prices for fish that has been mislabelled, according to a University of Guelph study.

The study, which will be published next week in the journal of Food Research International, tested the DNA of 100 fish samples taken from restaurants and markets in Toronto, Guelph, Ont., and New York City.

The researchers found that 25 per cent of the fish tested were mislabelled. The study showed, for example, that Atlantic Halibut was often sold as Pacific Halibut and samples of Atlantic cod and Acadian redfish were mislabelled as the pricier Red Snapper.

"This not only raises concerns of consumer fraud, but also public health," said Robert Hanner, the associate director for the Canadian Barcode of Life Network, in a release.

"A person could have allergies to a certain species and if it's mislabelled that could have dangerous consequences."

Researchers also noted that some labels for endangered fish species had been swapped.

"Consumers may think they are doing the right thing for the environment by buying a certain type of fish that is eco-friendly when really they could actually still be buying exploited species," said Hanner.

Hanner and Eugene Wong, a graduate student at the University of Guelph, teamed up with Kate Stoeckle and Louisa Strauss, two recent high school graduates in New York City.

Stoeckle told the New York Times she initiated the project because she was curious about checking the genetic fingerprinting of sushi samples. She enlisted Strauss to help with the project and sent the samples to Wong to compare against Guelph's Barcode of Life Database.

Stoeckle and Strauss plan to publish their findings in Pacific Fishing Magazine.