Steve Palumbi’s molecular forensics exposes the seedy side of seafood.

The problem of mislabeled seafood, be it whales or fish, is not a new one. As far back as the 1930s, mackerel was being canned and sold as salmon, and anecdotes have always floated around of more exotic substitutions—of shark being shopped as swordfish, say, or skate wings for scallops. These days, thanks in part to the work Palumbi helped spearhead, the fish-eating public is used to a steady flow of sophisticated, DNA-based studies and exposés. A 2004 paper by Peter Marko, then of the University of North Carolina, found that 77 percent of red snapper bought in the United States was actually a cheaper, smaller species. In 2008, Palumbi found something similar with Pacific red snapper—the market name for a suite of species called rockfishes. In December, the conservation group Oceana released a report showing that nearly 40 percent of fish in New York restaurants was mislabeled, which followed a similar investigation in Los Angeles. In 2011, the Boston Globe found widespread fraud at area eateries, and a follow-up in 2012 showed that little had changed. And on and on.

Such studies empower the consumer only by showing them just how much they’re being disempowered. “This story isn’t about information anymore,” says Jennifer Jacquet, an environmental studies professor at NYU. “It’s gone way past that, to something deeper.” What’s most insidious, she says, is how mislabeling undercuts even the most conscientious consumer, giving them the illusion of choice. Even seafood that is labeled sustainable at the store sometimes turns out not to be, as Marko showed in a paper from 2011, and Jacquet has argued that such sustainable sanctioning schemes are potentially unreliable. What’s the good of carrying a little card around in your wallet listing the most sustainable species if you have no idea what you’re actually buying?

For his part, Palumbi has since turned his molecular eye to other things, as is his wont. “Once you’ve trained someone and they leave your lab, you immediately turn into competitors,” he says, and he’s happy to let them continue the research while he seeks out new topics. He doesn’t exactly face a shortage of issues to investigate, what with ocean acidification, overfishing, and the like. He compares problems with the health of the ocean to “the flashing lights in your rearview mirror that you’d maybe rather ignore.” Of late he is working in American Samoa on corals that show a surprising capacity to withstand temperature fluctuations that normally kill corals—except these corals mysteriously do not die. It is another way for him to use molecular forensics as he searches throughout the South Pacific for hardy corals and reefs.

Still, he keeps tabs on fish labels. So pervasive is the problem that he can send students from his university biology courses out to test the offerings of local stores every year, confident that something strange will turn up. “It’s a terrific teaching tool,” he says. “The data themselves are boring. It’s what you add to the data. What does it tell you about what is going on?” Just a couple of years ago, he tested the aquatic wares at his local Whole Foods grocery. “I’m usually reluctant to test food at my favorite places, but they were pretty good,” he says. “All but one of the fish was labeled correctly.” The one that wasn’t, and within sight of Monterey Bay’s famed Cannery Row? A sardine.