UCLA researchers using a unique genetic sequencing test say that their work reveals that Sushi mislabeling is pervasive. The new monitoring project of UCLA researchers and partners aims to take “fake sushi” off Los Angeles diners’ plates. 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 monthly from 10 restaurants. Back in the laboratory, they extract DNA and analyze the fish.
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. One example is red snapper often sold is a fish called red sea bream.
The researchers are working with the FDA’s Center for Food Safety and Applied Nutrition in Los Angeles, which manages the FDA’s seafood guidelines that restaurants follow. They have already drafted recommendations for the labeling of yellowtail.
Recent investigations and studies have shown mislabeling “sometimes due to error but often the result of outright fraud” is rampant in the seafood industry, showing up both in the marketplace and on restaurant menus. One study of retailers found seafood like grouper, cod, and snapper may be mislabeled up to 87 percent of the time, swapped out for less desirable and cheaper varieties. For example, only seven of the 120 samples of red snapper were actually red snapper.
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.
The researchers are not identifying the restaurants, but some have chosen to identify themselves. One such restaurant is Sugarfish, which is now implementing suggestions from the project and whose menu identifies fish species’ names based on DNA sequencing.
“Seafood mislabeling is a global issue, but by banding together, we can do something about it,” Cheng said. “I’m excited to see how this partnership develops.”
Willette, Cheng, Barber and colleagues reported in a January 2017 study of the DNA of fish ordered at 26 Los Angeles sushi restaurants from 2012 through 2015 that 47 percent of sushi was mislabeled. Out of 43 orders of halibut and 32 orders of red snapper, DNA tests showed the researchers were served a different kind of fish 100 percent of the time. Previous studies detected similar problems nationally and internationally, Willette said. However, halibut bought at grocery stores and tested showed nearly 100 percent accuracy of the labeling.
