Last year, a shocking report by the seafood sustainability nonprofit Oceana concluded that 33 percent of fish sold in American retail outlets is mislabeled. The findings – based on DNA testing of 1,200 samples from 674 stores in 21 states – were in line with other recent international investigations that have all highlighted a worrisome lack of transparency in the seafood industry. On top of bilking customers who think they are paying for a top-shelf fish, such as tuna and snapper, but are actually taking home a cheap farmed or high-mercury fish, like tilapia or tilefish, fraudulent labels are often applied to cover up a product’s unscrupulous and unsustainable sourcing.
Hoping to further examine the corruption of the seafood supply chain in North America, a team of researchers from the University of British Columbia collaborated with Oceana to collect and genetically analyze 285 seafood samples from grocery stores and restaurants across the Vancouver area.
Writing in Food Control, lead author Xiaonan Lu and his colleagues reveal that 25 percent of their samples belonged to a different species than their seller claimed. With a 29 percent mislabeling rate, restaurants were the worst offenders, followed by grocers at 24 percent. Sushi restaurants specifically – with a 23 percent rate – showed the lowest mislabeling. In contrast, Oceana previously found a nationwide mislabeling average of 74 percent.
And if you’re a fan of red snapper, Lu’s team has some sobering news – only 9 percent of samples were actually that fish. Given that the past study found a less than 6 percent rate of honest labeling, we have to wonder how many people have ever truly eaten red snapper.

“Evidence of the various motivations of the mislabeling, including intentional substitution using less expensive species, purposed mislabeling of by-catch or illegal, unreported and unregulated fishing products, and unintentional misidentification or misuse of dialects and vernaculars were all observed,” the authors wrote.
The accidental misidentification they mention arises because several popular types of fish are colloquially known by numerous different names, depending particularly on where you are and who you’re talking to. To give you a taste of the issue, per the US FDA, any of 64 different species of fish can be legally sold as "grouper", 56 can be marketed as "snapper", and 60 can be "rockfish".
"Seafood fraud cheats Canadian consumers and hurts local, honest fishers as well as chefs and seafood companies looking to buy sustainable seafood. It causes health concerns and masks global human rights abuses by creating a market for illegally caught fish," Julia Levin, an anti-fraud campaigner with Oceana Canada, said in a statement. "The key to fighting seafood fraud is boat-to-plate traceability. This means tracking the seafood product through the supply chain and requiring that key information travels with the product."