Seafood fans in Chicago have a high chance of being cheated when they buy fish in restaurants and grocery stores. A new study by Oceana, a national conservation group, found 32 percent of samples tested in Chicago were mislabeled as another fish entirely.

But Chicago fishmonger Dirk Fucik says the false fish sales are probably not entirely the fault of retailers or fishermen.

“The fisherman who catches the actual fish is not really the one playing games, I don’t think,” he said. “If he catches a red snapper, he goes to shore and sells it as such. But then once it gets to a processor, or to a broker, somewhere in that range I think things get mismarked.”

By the time a restaurant or grocery store gets the packaged and filleted fish, it’s undergone a covert change of identity somewhere up the chain. Fucik gave the example of a Vietnamese catfish called basa or swai that’s imported in large amounts into the U.S. every year.

“You’ve never seen that on a menu, I’ll betcha,” he said. “So that’s getting used for something, somewhere. Mixed in with fish sandwiches or fish sticks, or whatever.”

The study was neither random nor comprehensive. Volunteers sought out retailers that advertised fish species considered likely to be fakes based on previous cases or regional popularity, and the sample pools focused heavily on those types.

The two-year project analyzed the DNA of the purchased samples and found that a full 33 percent of the specimens were sold under a false name. Snapper was a scam in 87 percent of the samples, and 59 percent of tuna was actually another fish. 

Fucik thinks high-end markets like his are less likely to fall into a counterfeit fish situation, because they tend to know more about their fish and it doesn’t usually come tightly packaged.

“I like to buy everything whole, because then you know exactly the species of fish you’re buying,” he said.

If anything is suspicious, he sends it back.

“If you know what you’re doing, hopefully you don’t get duped,” Fucik said.

Chicago was noted in the study for its “unusual seafood substitutions.” In one case, a fish sold as Alaskan cod turned out to be the charmingly-named threadfin slickhead, a fish not even known to be sold in the U.S. And while most red snapper scams substitute rockfish and tilapia, two Chicago grocery stores were peddling the far less common goldbanded jobfish and slender pinjalo as red snapper.

Sushi venues had the highest incidence of mislabeling at a whopping 74 percent, although the total number of sushi sellers surveyed was far less than restaurants or retailers. But in the 118 sushi outlets tested, 92 percent of the fish sold as snapper and 71 percent of the so-called tuna were mislabeled specimens of other fish.

Mislabeling can mean feeling ripped off, but it can also be dangerous for those with allergies and mislead shoppers trying to pick out sustainably harvested or low-mercury fish products. Oceana, the study’s publisher, says seafood should be traceable, and argues that current laws for seafood inspection should be more stringently enforced.

For now, the implications for the consumer are cloudy. Fucik says the best way for the fish purchaser to get to know their product is to ask questions - but if you ask whether your sashimi is actually make with snapper, you’ll almost definitely get a yes.

And taste tests are mostly a dead end, too. Even he can have trouble telling one filet from another in many cases of substitution, and he’s been in the business for forty years.

People who want to stay on top of their fish-shopping game can do themselves a favor by favoring fresh fish markets that sell whole fish. And if you’re trying to go upscale with your purchases, check out average prices and ask questions if a fish product seems to be cheaper than what it should be.

Finally, Fucik strongly recommended looking out for “tuna” that’s white in color when it’s raw; there’s no such thing, he said, as actual “white tuna”.

The canned stuff has been cooked, but it used to be pink. If it’s white and it’s raw it could be escolar, also known as oilfish.

Escolar has a special effect on digestion that Fucik compares to the cleansing effects of Ex-Lax, and it’s already banned in Japan and Italy for the gastrointestinal problems it can cause.

Next up in fish troubles: Frankenfish. (That’s the derisive name for genetically modified salmon that’s swimming closer to FDA approval as we speak.)

And in case you haven’t had enough seafood malaise for the day, WBEZ’s food blogger Louisa Chu will be with us soon to reflect on what her fishing trip in Alaska taught her about the fish supply chain - and all the ways it can go wrong.

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