More alarming than the price-gouging is the potential health hazard: The FDA recommends that all pregnant women, nursing mothers and women who might become pregnant avoid eating king mackerel, swordfish, shark and tilefish because they contain high levels of mercury, a contaminant that can harm the nervous system of a fetus or baby. (Mercury is harmful to you at any age, but it's particularly dangerous to a developing fetus.)
Yet high-mercury species can sometimes stand in for safer fish: Reports have found king mackerel and tilefish being sold as grouper, red snapper and halibut. An investigation by Consumer Reports discovered that 56 percent of the salmon marketed as wild was actually farmed, which could increase your risk of being exposed to PCBs, contaminants often found in farmed salmon that have been shown to cause cancer in animals.
Reel in Good Picks
Seafood fraud probably will not go away anytime soon. But that doesn't mean you should avoid fish entirely. Use the following moves to help ensure that you get what you paid for:
Avoid supply-chain shenanigans by going directly to the fisherman (at a farmers market or pier). "I buy crab, flounder and porgy at my local market," Warner says.
Get With the Program
Some grocery chains—such as Wegmans and Whole Foods—and hundreds of restaurants offer information on the source of seafood through companies including Trace Register and Trace and Trust. Go to traceandtrust.com to find participating restaurants. When you order a fish, it comes with an ID number. Typing it into the website turns up the species of fish, when the batch was caught and even a picture and bio of the boat captain. "It's the seafood equivalent of farm-to-table, only better in many cases," says Moonen.
Stick with Safer Bets
In restaurants, mahimahi, flounder and tilapia were least likely to be mislabeled, per Oceana. Salmon is also unlikely to be mislabeled, other than sometimes being called wild when it's farmed. Shellfish isn't usually mislabeled, though crabmeat is sometimes falsely said to be from Maryland. Red snapper, grouper and halibut are among the fish most likely to have species substituted for them, per Oceana.
While research is preliminary, tests so far have not found labeling problems with canned tuna, says Dirk Steinke, PhD, director of education and outreach at the University of Guelph's Biodiversity Institute of Ontario. The potential for mislabeling is likely reduced because canned fish passes through fewer hands than fresh fish.
Ask Lots of Questions
In some regions, supermarket chains are half as likely to sell mislabeled fish as restaurants or small stores, since big companies generally require higher levels of accountability, Warner says. But don't give up on the little guys.
"Get to know your fishmonger and ask where the seafood came from," she says. "If they can tell you, for instance, that it's from a fisherman they've worked with for years, it justifiably increases your confidence level." Ditto for restaurants. "Chefs are motivated by what their customers want," Moonen says. "If they have customers asking details about the seafood, they're obligated to spend more time investigating the best choices themselves."