Largest-Ever Seafood Fraud Study Has Guelph Ties

February 22, 2013 - News Release

The largest-ever market study on mislabelled seafood now making headlines around the world has roots at the University of Guelph.

DNA analysis showing mislabelling of 33 per cent of fish sold in grocery stores, restaurants and sushi bars in the United States was conducted at the Canadian Centre for DNA Barcoding based in U of G’s Biodiversity Institute of Ontario (BIO).

The Guelph centre was commissioned to conduct the testing by Oceana, the largest international oceans advocacy group. Overall, the study found 44 per cent of all retail outlets sold mislabelled fish.

Since Oceana released its findings Thursday, stories have appeared on CNN news and in newspapers, including the Globe and Mail, Boston Globe, USA Today, Washington Post, Chicago Tribune and San Francisco Chronicle.

“DNA Barcoding has ‘arrived’ as a standard method for food ingredient authentication,” said Prof. Bob Hanner, associate professor at BIO, who was consulted by Oceana on the design of its study and interpretation of its results.

“The technology was developed here — it’s a Guelph innovation," he said. "We are recognized as the premier service provider for this type of work, which is allowing us to capture this emerging market. We’ve expanded an incredible research innovation to the point where we can provide a much-needed commercial biospecimen identification service. That’s another thing that the University of Guelph is known for — capitalizing on a demand.”

DNA barcoding is a technique developed by Guelph integrative biology professor Paul Hebert. The method allows scientists to identify species of organisms using a short standardized region of their DNA.

DNA testing for the Oceana study took more than two years. “It took a lot of time for them to collect all of the samples, which kept coming in from numerous venues in 21 states,” Hanner said.

More than 1,200 fish samples from almost 700 retail outlets were tested. Researchers found seafood fraud in every region tested, Oceana’s report said.

The highest mislabelling rates were in sushi venues (74 per cent), followed by other restaurants (38 per cent) and grocery stores (18 per cent).

By region, the highest rates of mislabelling occurred in southern California (52 per cent), Austin and Houston (49 per cent), Boston (39 per cent) and New York City (39 per cent).

The study looked at fish with regional significance and species frequently mislabelled in previous studies, such as red snapper, cod, tuna and wild salmon. Snapper and tuna were most frequently mislabelled (87 and 59 per cent, respectively).

Among the report’s other key findings:
• Only seven of the 120 red snapper samples collected nationwide tested correctly.
• Eighty-four per cent of the white tuna samples were escolar, a fish species that can cause serious digestive issues in some people.
• Cheaper farmed fish had been substituted for wild fish. Pangasius was sold as grouper, sole and cod; tilapia, as red snapper; and Atlantic farmed salmon, as wild or king salmon.

The results resemble those in a 2008 study by Hanner. Looking at about 100 samples from restaurants and markets in Toronto, Guelph and New York City, he found about 25 per cent of fish were mislabelled, and the majority were sold as species of a higher market value.

Hanner co-ordinates the Fish Barcode of Life campaign, an international research collaboration that is building the barcode reference sequence libraries needed to identify the world’s fish species.

Regulatory agencies have used DNA barcoding to identify other mislabelled foods, including meat, and other consumer products.

In addition to identifying known species, scientists have used the method to discover hundreds of overlooked species of animals, plants and even marine algae. All of these data are maintained on the Barcode of Life Data System, an international mega-science project that aims to establish a DNA-based identification system for all life.

For media questions, contact Communications and Public Affairs: Lori Bona Hunt, 519-824-4120, Ext. 53338, or; or Kevin Gonsalves, Ext. 56982, or

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