Imagine you’re at a sushi restaurant and you’ve carefully combed the menu and ordered your favorite type of fish. When the plate arrives, you probably just assume it’s what you requested, right? Well, according to a new study, you might actually be getting something else almost half of the time.
Researchers at UCLA and Loyola Marymount teamed up for four years to check up on sushi menus at restaurants and grocery stores around Los Angeles. In their sample, 47 percent of fish tested came back as a different species than what it had been sold as. For the study, the researchers collected 364 pieces of fish from 26 different locations, each chosen for their high scores on Yelp.
“Half of what we’re buying isn’t what we think it is,” UCLA professor Paul Barber wrote in the journal Conservation Biology, where the study was published. He added, “I suspect that in some cases the mislabeling is very much intentional, though it’s hard to know where in the supply chain it begins.”
The extent of the fishy business varies by the type of seafood in question. Halibut is the most likely to be swapped, with almost 70 percent of ‘halibut’ actually turning out to be a mix of red snapper, flounder or other species. Every sample that was labeled as bluefin tuna actually was bluefin tuna, though two samples that were sold simply as ‘tuna’ turned out to be endangered sub-species of bluefin. Vulnerable, overfished bigeye tuna also turned up, being sold under the label of yellowfin.
In addition to the risk of endangered species illegally making it into the supply chain, mislabeling also presents a health risk. Pregnant women and others who want to limit their exposure to fish that have higher mercury levels might inadvertently be slipped mercury-rich fish. In multiple cases, the researchers even caught raw olive flounder—a fish known to carry parasites and be the source of huge foodborne illness outbreaks in Japan—masquerading as harmless halibut.
While fish fraud may be happening all around us, new U.S. regulations on seafood imports just went into action this week which might help stem the tide of mislabeling. And there’s no substitute for going to a reputable sushi establishment with fresh fish, though even still, we might think twice before ordering halibut.
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