How Fish Fraud Works

It's pretty hard to pass off certain seafood as something else; lobster is one that comes to mind. Yet it's relatively easy when you're looking at less-identifiable types of fish. Here's a list of some of the more commonly mislabeled fish, along with their often-used substitutes [source: Oceana]:

Alaskan/Pacific cod: Asian catfish, Atlantic cod, threadfin slickhead, tilapia

Alaskan/Pacific halibut: Atlantic halibut, blueline tilefish

Atlantic cod: Pacific cod, white hake

Chilean seabass: Antarctic toothfish

Grouper: Asian catfish, king mackerel, whitefin weakfish

Lemon sole: Blackback flounder, summer flounder, flathead sole, yellowfin sole

Red snapper: Caribbean red snapper, crimson snapper, Pacific ocean perch, yellowtail rockfish, madai, tilapia, white bass

Salmon (wild, king, sockeye): Farmed Atlantic salmon

Sea bass: Antarctic toothfish, Patagonian toothfish

Snapper: Giltheaded seabream, madai, tilapia, Pacific ocean perch, widow rockfish, yellowtail rockfish

White tuna: Escolar

Some of the fish most often mislabeled from the list above are grouper, snapper and white tuna. Grouper is an obvious choice for fraudulent substitutions, as swapping it out for Asian catfish, for example, nets the seller four times more money. But another problem with grouper is that the Food and Drug Administration (FDA) recognizes 66 species of fish as "grouper," making it difficult for distributors and restaurateurs to know what's what [source: Lou].

In the Oceana study, an astonishing 87 percent of snapper samples were mislabeled, making it the most mislabeled type of fish. Tuna came in second, with a 59 percent mislabeling rate. White tuna is especially problematic. It's not even a real fish species. Albacore tuna is, and that's considered white meat, which is how the term "white tuna" came into existence. Escolar is almost always slipped in as white tuna's substitute, though escolar is banned by the FDA because it acts as a laxative [sources: Goetz, Oceana].

If we purchase a particular type of fish because we like its taste — say, lemon sole —does it really matter if it's actually summer flounder? Well, yes. Swapping one kind of fish out for another has several implications, some of which could be serious.

Since many forms of fish fraud are perpetrated to allow the fish-seller to increase his profit margins, someone is getting ripped off. It might be the middleman who buys the fish from the seller; it might be the restaurateur or the grocer; or it might be you, the consumer.

Fish fraud also can put all sorts of endangered or threatened species in trouble. Snapper, for example, is currently being overfished. But many swindlers will say their whitefish is snapper. With so much "snapper" in markets and on restaurant menus, people will think the species is thriving, when actually it's not. In addition, some consumers concerned about the health of our oceans carry wallet cards created by groups such as the Monterey Bay Aquarium's Seafood Watch; the cards list fish species to eat or avoid, based on sustainability. Someone trying to eat responsibly could end up downing the very fish she is trying to avoid eating [source: Barclay].

There are also health concerns with fish swapping. King mackerel, often labeled as grouper, is high in mercury; escolar, marketed as white tuna, can cause GI distress due to a naturally occurring toxin it contains. And some fish have allergenic proteins which certain consumers need to avoid. Experts say that such health concerns are generally minor. You might have diarrhea from accidentally eating escolar, but it won't kill you. However, even small risks can become large issues for certain at-risk populations, such as the elderly, children and pregnant women [sources: Barclay, Goetz].

Unless you're a fisherman (or -woman) who really knows fish species, it's difficult to fight fish fraud. Still, there are some steps you can take. Whenever possible, purchase a whole fish — fins, head and tail still attached. It's a lot more difficult for swindlers to substitute another fish for the one you're seeking when you can see exactly what the fish you're buying looks like. (Of course, this assumes you know what a red snapper or Chilean sea bass looks like, so bone up on that in advance.) Whether you're dining in a restaurant or browsing a fish market, ask lots of questions. Ask if a particular fish was wild- or farm-raised, where it was raised, or when and how it was caught. If the seller doesn't know or hedges, be suspicious [source: Oceana].

The FDA also maintains a list of acceptable market names for seafood. If you spot a fish labeled with a name that's not on the FDA's list, such as "white tuna," you can pretty much be assured that the fish is actually another species. Vet your fish retailer with the Better Seafood Board. Perhaps the easiest way to fight fraud, though, is to be wary of a quality fish carrying a low price. Sockeye salmon, for example, is not cheap. So if you're ordering or purchasing Sockeye salmon for a bargain-basement price, it's probably farmed Atlantic salmon or something else [sources: Goetz, Lou].

Lest you think the onus of fish fraud is only on consumers, it's not. While some complain the U.S. government isn't doing enough to fight fish fraud, a presidential task force made several recommendations on the topic in December 2015. One was for better international cooperation and collaboration on seafood labeling. Oceana is pushing for an international traceability system. The idea is that fish retailers would be required to know where and when a fish was caught, and even what gear was used, and would also be required to pass this info to consumers [sources: Lou, Barclay]

Scientists at the University of South Florida's College of Marine Science recently unveiled Groupercheck, a portable, handheld sensor that can identify grouper in 45 minutes, using DNA markers only found on real groupers. The device can be used by anyone from distributors to restaurateurs; the scientists hope to unveil similar devices for red snapper, shrimp, tuna and halibut [source: Trigaux].

Now that more attention is being focused on fish fraud, hopefully the practice will soon be on the wane.