CHAPEL HILL – While learning in a course how to extract, amplify and sequence the genetic material known as DNA, University of North Carolina at Chapel Hill graduate students got a big surprise. So did their marine science professors.
In violation of federal law, more than 75 percent of fish tested and sold as tasty red snapper in stores in eight states were other species. How much of the mislabeling was unintentional or fraud is unknown, said Dr. Peter B. Marko, assistant professor of marine sciences at UNC’s College of Arts and Sciences.
"Red snapper is the most sought-after snapper species and has the highest prices, and many people, including me, believe it tastes best," Marko said. "Mislabeling to this extent not only defrauds consumers, but also risks adversely affecting estimates of stock size for this species if it influences the reporting of catch data used in fisheries management. The potential for this kind of bias in fisheries data depends on at what point in the commercial industry fish are mislabeled, which is something that we currently know little about."
A report on his group’s research appears in the July 15 issue of the journal Nature. Co-authors are his colleague Dr. Amy L. Moran, research assistant professor of marine sciences, and graduate students Sarah C. Lee, Amber M. Rice, Joel M. Gramling, Tara M. Fitzhenry, Justin S. McAlister and George R. Harper.
"The red snapper, or Lutjanus campechanus, is found in offshore waters around coral reefs and rocky outcroppings and is one of the most economically important fisheries in the Gulf of Mexico, with greater total landings…than any other snapper species," Marko and colleagues wrote. "In 1996, the Gulf of Mexico Fishery Management Council and the U.S. Department of Commerce declared that L. campechanus was grossly overfished and called for strict management measures to restore stocks to sustainable levels.
"Such restrictions create an economic incentive for seafood substitution, where less valuable species are mislabeled and sold under the names of more expensive ones. Substitutions among closely related fish are difficult to detect, because most distinguishing features are lost during processing."
The team conducted molecular analyses of 22 fish bought from nine vendors in Delaware, Florida, Illinois, Massachusetts, New York, North Carolina, South Carolina and Wisconsin. They found 17, or 77 percent, of the samples sold as red snapper were other species.
"Our work has a margin of error of 17 percent, meaning that between 60 percent and 94 percent of fish sold as red snapper in the United States are mislabeled," Marko said.
Among those sold as red snapper were lane snapper and vermilion snapper, two other species from the western Atlantic Ocean. Also surprising was that more than half the DNA sequences came either from fish from other regions of the world such as the western Pacific or from rare species about which little is known, he said.
"The remarkable extent of product mislabeling of red snapper threatens to distort the status of fish stocks in the eyes of consumers, contributing to a false impression that the supply of marine species is keeping up with demand," Marko said.
Cite This Page: