Your red snapper is probably fake


A pair of high school kids did a DNA-barcode test on New York City sushi and found that one-quarter of the fish they tested was really a cheaper species than what the seller said. The kids, Kate Stoeckle and Louisa Strauss, got some help from Eugene Wong, a graduate student at the University of Guelph in Ontario, but these new quick DNA tests show both how easy testing is becoming -- and how prevalent fish fraud is.

The girls sampled 60 different kinds of sushi, then Wong ran them up against the growing library of DNA at the Fish-Barcode of Life. He could get a reading on 57 samples and found that 14 of them were mislabeled. And all the labeling errors went in the seller's favor, making the fish more expensive.

The most mislabeled fish was red snapper: seven of nine samples (77%) were really something else. Most egregiously, some of it was really the endangered Acadian redfish. Their results are no fluke. This spring the Chicago Sun-Times did a great investigation on Chicago sushi and found all 14 of its samples of red snapper were fake, mostly the cheaper tilapia. They say a congressional report found that 37% of fish and 80% of red snapper sold in America is mislabeled. That's consistent with a 2004 University of North Carolina study that found 75% of red snapper was fake.