According to a report released by the international group Oceana, as much as half of all seafood products are mislabeled.
Researchers conducted DNA tests on more than 1,000 fish fillet samples from dozens of U.S. cities. About half the time, the fish was not what was advertised. Most commonly, cheaper fish was substituted for more expensive varieties.
The group says the practice also allows illegal fish to be laundered into the U.S. seafood market and is calling for the use of a national tracking database.