Are You Really Eating Wild Salmon? Scientists Expose Rampant Mislabeling

A new study found that grocery stores were more accurate in labeling salmon correctly compared to sushi restaurants.

A DNA analysis study of salmon samples from grocery stores and sushi restaurants in Seattle, Washington, found that 18 percent were mislabeled. Tracie Delgado and her colleagues at Seattle Pacific University, Washington, USA, recently published these findings in the open-access journal PLOS ONE.

Washington State is one of the top suppliers of wild salmon eaten in the United States. The price of salmon depends on the species and whether it is farmed or wild-caught. Prior studies have revealed frequent mislabeling of salmon in Washington markets and restaurants. In 2013, the state made it illegal to mislabel salmon, citing negative effects for customers, fishers, distributors, vendors, and ecosystems.

To help illuminate the impact of that legislation, Delgado and colleagues collected and analyzed salmon samples from 67 grocery stores and 52 sushi restaurants across Seattle from the fall of 2022 through the fall of 2023.

DNA analysis revealed that 18 percent of all 119 fish were mislabeled. Mislabeling farmed salmon as wild occurred for 32.3 percent of the restaurant samples and none of the grocery samples. Mislabeling of one wild-caught species as another occurred for 38.7 percent of the restaurant samples and 11.1 percent of the grocery samples.

Financial Impact of Mislabeling

Financial analysis revealed that mislabeling at sushi restaurants was at the expense of the customer, while mislabeling at stores had no significant effect. The researchers note that it is unknown where along the supply chain mislabeling tends to occur, but that it is unlikely at the point of harvest.

A prior study found a 20 percent rate of mislabeling in Washington between 2009 and 2011, and a 2 percent rate was observed in Seattle in 2012, soon after a nearby major distributor was sentenced to jail for fraudulently mislabeling salmon. The new rates cannot be directly compared to the old, given different study designs and other underlying factors. However, as most samples in the new study were collected when salmon were in season, the researchers expressed surprise at the high rate of mislabeling they found.

On the basis of the findings, the researchers call for continued development and enforcement of legislation against salmon fraud.

Tracie Delgado adds: “Despite recent legislation that makes mislabeling of salmon illegal, salmon mislabeling fraud is still a problem in Seattle. We found Seattle sushi restaurants are far more likely to give you farmed salmon in place of vendor-claimed wild salmon. Failure to properly label wild salmon is a serious problem because it prevents accurate tracking of supply chains and therefore makes it more difficult to sustain and conserve wild salmon. It’s important to continue to develop and enforce legislation that requires accurate seafood labeling, from fisher to plate, and educate the public on how commercial salmon fraud impacts wild salmon conservation.”

Reference: “Fishy business in Seattle: Salmon mislabeling fraud in sushi restaurants vs grocery stores” by Jewel L. Garcia, Yennifer A. Gaspar, Angelique Djekoundade, Mhicca Dalere, Asmaa A. Al-awadi, Marjolene Allossogbe, Thania C. P. Allossogbe, Itzel S. Aparicio, Hannah N. Buller, Hera Beatrice F. Cadelina, Isabella K. Camarillo, Kayla Case, Abigail E. Dean, Sara M. Dean, Jordyn F. DeJong, Elizabeth Delgado, Renske J. Dupar, Emma N. Ely, Mia C. Ewing, Delina N. Filli, Spencer E. Fleming, Mackenzie R. Garrett, Blair P. Graves, Marie M. Hafez, Weston P. Hanson, Alexander D. Heller, Anthony J. Hernandez, Elizabeth K. Horton, Ellie G. Jancola, Lauryn A. Keith, Madison J. Knoke, Jared D. Larkin, Andre’ G. Marineau, Fabiola Martin-Ortiz, Olivia L. Mayer, Yolanda M. Mendoza, Peter V. Nalivayko, Nguyen Nguyen, Eloisa T. Nguyen, Henry Nguyen, Griffin L. Ovenell, Lay G. Paw, Spencer R. Raymond, Janetta J. Redzic, Madelyn T. Rice, Ashlie T. Rodrigo, Jonathan M. Savell, Ben R. Sheirbon, Dulce S. Torres, Kalena A. Warrick, Eric S. Long, Timothy A. Nelson and Tracie Delgado, 6 November 2024, PLOS ONE.
DOI: 10.1371/journal.pone.0311522

This project was funded by the Seattle Pacific University Biology lab fund.

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