A new study from an American university shows the problem of seafood mislabeling is not just about one species being substituted for another, but that substitutions can happen even within a single species.
The study, conducted by Peter Marko (pictured), a biologist at the University of Hawaii at Mānoa, concerned Patagonian toothfish, more commonly known as Chilean Sea Bass. In the study, researchers purchased samples of the fish at retail seafood counters in 10 different U.S. states to see where the fish actually came from.
The issue, Marko said, is that some toothfish bears the label of Marine Stewardship Council (MSC) certification, while other toothfish does not, and the certification depends largely upon where the fish is caught. MSC-certified toothfish is usually caught off the coast of South Georgia, near Antarctica, since that area is remote enough to avoid contaminants such as mercury.
“Seafood mislabeling distorts the true abundance of fish in the sea, defrauds consumers, and can cause unwanted exposure to harmful pollutants such as mercury,” Marko wrote.
In 15 percent of the samples, Marko wrote, the fish had genetic markers indicating they were not sourced from the South Georgia fishery, despite being labeled as such, and 20 percent of the samples did not appear to be Patagonian toothfish at all.
Marko’s study suggested the geographical mislabeling is dangerous because mercury contamination in toothfish varies based on where the fish is caught, and mislabeling, even within the same species, could have consequences regarding mercury exposure.
