There’s something fishy about the seafood business. According to a recent report by the ocean conservation group Oceana, seafood suppliers are pulling a bait and switch on consumers, mislabeling a full 20 percent of fish globally. That means, whether you’re dining out or purchasing fish at your local grocery store, there’s a good chance you’re not eating the fish you think you are.

The New York Times explains that the report, which looked at 200 studies from 55 countries and a total of 25,000 seafood samples, found instances of fish fraud all around the world. In some cases, the vast majority of the fish tested were mislabeled: In Brazil, for instance, 80 percent of the “catfish” tested were not, in fact, catfish, while in Italy 82 percent of the perch, groupers, and swordfish tested were mislabeled. Other major phony fish included red snapper (in South Florida, for instance, 90 percent were mislabeled) and wild salmon (in New York City, 75 percent of “wild salmon” were actually cheaper farm-raised salmon).

For the most part, the report explains, seafood suppliers simply swap expensive fish for cheaper ones. But in some cases, suppliers are selling fish known for dangerously high mercury levels or fish on the endangered species list: In one particularly egregious case, California sushi chefs were even discovered serving endangered whale meat as tuna. The report also notes that it can be hard to tell exactly where fraud is occurring; instances of mislabeling were discovered on every rung of the supply chain from wholesalers and importers to retailers.

“We kept thinking we’d find a success story, a place where seafood wouldn’t be mislabeled,” Oceana senior campaign director Beth Lowell told The New York Times. “Every single study that we reviewed except for one found seafood fraud.”

Check out the interactive map below to see the fish fraud for yourself:

[h/t New York Times]