High school students use DNA testing to spot fishy seafood

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Sandra Porter

Two teenagers, Kate Stoeckle and Louisa Strauss, carried out their own science project over the past year. They visited 4 restaurants and 10 grocery stores and gathered 60 samples of fish and sent them off to the University of Guelph to get sequenced.

I like this story. One of my former students did a project like this for the FDA years ago, sampling fish from the Pike Place Market and identifying them with PCR. He was an intern, though. Here we have students identifying sushi on their own!

Quoting the New York Times article:

They found that one-fourth of the fish samples with identifiable DNA were mislabeled. A piece of sushi sold as the luxury treat white tuna turned out to be Mozambique tilapia, a much cheaper fish that is often raised by farming. Roe supposedly from flying fish was actually from smelt. Seven of nine samples that were called red snapper were mislabeled, and they turned out to be anything from Atlantic cod to Acadian redfish, an endangered species.

[snip]

They hit 4 restaurants and 10 grocery stores in Manhattan. Once the samples were home, whether in doggie bags or shopping bags, they cut away a small piece and preserved it in alcohol. They sent those off to the University of Guelph in Ontario, where the Barcode of Life Database project began. A graduate student there, Eugene Wong, works on the Fish Barcode of Life (dubbed, inevitably, Fish-BOL) and agreed to do the genetic analysis. He compared the teenagers' samples with the global library of 30,562 bar codes representing nearly 5,500 fish species. (Commercial labs will also perform the analysis for a fee.)

Three hundred dollars' worth of meals later, the young researchers had their data back from Guelph: 2 of the 4 restaurants and 6 of the 10 grocery stores had sold mislabeled fish.

I think about all the people I know who carry cards from their local aquariums spelling out which species are okay to eat and which are endangered. Maybe we need more than the aquarium information cards. Maybe we should be carrying DNA testing kits. None us really know if we're eating the species we think we're eating.

But these students do.