While most of us would never willingly consume a highly endangered species, doing so might be as easy as plucking sushi from a bento box. New genetic detective work from the Sackler Institute for Comparative Genomics at the American Museum of Natural History shows that bluefin tuna is routinely plated in sushi bars sampled in New York and Colorado. A quarter of what was labeled as tuna on sushi menus was bluefin, and some was even escolar, a waxy, buttery fish often labeled "white tuna" that is banned for sale in Japan and Italy because it can cause gastrointestinal distress. The new research is published in PLoS ONE.
"When you eat sushi, you can unknowingly get a critically endangered species on your plate," says Jacob Lowenstein, a graduate student affiliated with the Museum and Columbia University. "But with an increasingly popular technique, DNA barcoding, it is a simple process for researchers to see just what species are eaten at a sushi bar."
DNA barcoding efficiently identifies the species from which a chunk of meator even a leather handbagcame from. Using a short sequence of mitochondrial DNA from the cytochrome c oxidase subunit 1 gene, or "cox1," to identify a species, this tool has, among other results, identified the presence of endangered whales in Asian markets, looked at the species of ungulates appearing in African bushmeat markets, and documented fraud in the labeling of caviar and red snapper.
Lowenstein and colleagues used DNA barcoding to identify the kind of fishes labeled "tuna" in one Denver and 30 New York City restaurants. Almost half of the restaurants did not accurately label the kind of tuna sold, and only 14 of the samples used for this study were listed on the menu by a specific name like bigeye tuna, albacore, or bluefin.
Bluefin are three species of large, fast-moving, high-energy tuna that can cover enormous distances in the ocean. All threenorthern, southern, and Pacific blu
|Contact: Kristin Elise Phillips|
American Museum of Natural History