UCLA Newsroom. The Los Angeles Seafood Monitoring Project team — which includes university researchers, students, sushi restaurants and government regulators — is working to reduce sushi fraud and the mislabeling of fish.
Since April, scientists, along with 80 UCLA students and several others at Loyola Marymount University and Cal State University, Los Angeles, have been purchasing small pieces of sushi — each about the size of a kernel of corn — from 10 restaurants each month. Back in the laboratory, they extract DNA and analyze the fish. Each species of fish has a unique genetic sequence. The researchers and the students, who are enrolled in an introduction to marine biology course taught by lecturer Timery DeBoer, study the DNA to distinguish one fish species from another using a tool called DNA barcoding.
The team’s conclusion: “Sushi mislabeling is pervasive; intentional fraud is much less common,” said Paul Barber, a UCLA professor of ecology and evolutionary biology and senior author of an article on the project published in the journal Frontiers in Ecology and the Environment. “If we can solve the mislabeling issues, then we can focus on the intentional fraud.”
Why is the sushi on your plate mislabeled? A primary factor is a discrepancy between FDA regulations and biological reality, said Barber. For example, he said, “Yellowtail has six species. The FDA says one can be called yellowtail and the five others have to be called amberjack,” Barber said. “In Japan, each of these six species of yellowtail prepared by sushi chefs is sold under a different name. These fishes vary in taste and cost. In the U.S., the FDA says five of these have to be sold under just one name. This is the equivalent of saying we know there are Toyotas, Hondas, Nissans, Rolls-Royces, Jaguars and BMWs, but you can call those only Toyotas or BMWs.
“It’s actually impossible for sushi restaurants to correctly identify the fish they are serving for a number of species of fish using the limited FDA-recognized names,” Barber said.
Another example is red snapper. Often, what is sold is a fish called red sea bream, said lead author Demian Willette, who earned his doctorate from UCLA and is now an assistant professor of biology at Loyola Marymount University.
The researchers are working with the FDA’s Center for Food Safety and Applied Nutrition in Los Angeles, which manages the agency’s seafood guidelines that restaurants follow. They have already drafted recommendations for the labeling of yellowtail.
Most fish eaten in the United States are not caught in this country and often are not processed here, either, making it difficult to trace their identities, said co-author Samantha Cheng, an Arizona State University assistant research professor in the life sciences, who earned her doctorate at UCLA under Barber.