Unveiled Discoveries: Latest Research Reveals Widespread Deception in Sushi Salmon Supplies
Caveat emptor: Your salmon might be deceptive. Researchers have uncovered proof that these items are regularly misrepresented as wild salmon in shopping centers, conceivably inconveniencing clients at sushi spots the most.
The matter of seafood and labeling misrepresentation has been a persistent concern—so much so that the state of Washington, where the salmon sector holds significant importance, enacted a law in 2013 aimed at lessening it and other types of fish deceit. Senior study researcher Tracie Delgado, a professor of biology at Seattle Pacific University, had read past studies on the issue and was aware of the 2013 law, prompting her to task her Genetics lab course students with investigating for themselves whether the situation had improved since then.
"We had no idea what the results would be when we started this project and we were quite taken aback by the results," Delgado shared with Gizmodo. "Despite legislation in Washington state that makes mislabeling of salmon illegal, salmon mislabeling deceit remains an issue in Seattle."
Delgado and her students gathered and analyzed the DNA of salmon samples from 67 grocery stores and 52 sushi restaurants in the Seattle area between fall 2022 and fall 2023. All told, 18% of these samples were misrepresented. The group's findings were published on Wednesday in the journal PLOS-One.
While misrepresentation was relatively common across both grocery stores and restaurants, it was more serious in the latter. About a third of samples from restaurants were erroneously labeled as wild salmon instead of farmed, for instance, compared to no such misrepresented samples from grocery stores. Additionally, sushi samples advertised as a particular species of wild salmon were sometimes another wild species, although this also happened in grocery stores as well (the combined rate of wild to farmed and wild to wild salmon misrepresentation was 38% in restaurants and 11% in stores).
On the positive side, the researchers found no instances of farmed salmon being misrepresented as wild in grocery stores. This suggests that seafood labeling laws in Washington have at least somewhat reduced fraud. However, the overall rate of salmon misrepresentation found in this study is consistent with some past estimates of Washington's misrepresented rate prior to the 2013 law, while later studies have found even higher rates in other states. And the costs of salmon misrepresentation at sushi restaurants are likely being passed on to customers, as some individuals will end up paying more for "wild" salmon that should actually be cheaper farmed salmon (it should be noted, however, that this potential impact was found to be insignificant in grocery stores).
Salmon misrepresentation is also likely to have a negative environmental impact, according to Delgado.
"Dishonest reporting of catch data and misrepresentation of seafood complicates fisheries' conservation efforts because it prevents accurate tracking of supply chains and complicates effective fishery management efforts," she said. "Therefore, fisheries managers may erroneously conclude that wild salmon stocks that are actually depleted are persisting at sustainably harvestable densities."
More measures are required to halt salmon and other types of seafood deceit, the researchers assert, such as urging restaurants to periodically test that the fish they're receiving is authentic. There exists an existing inspection program established by the National Oceanic and Atmospheric Administration for fishing boats, processing plants, and retailers to test their fish, Delgado mentions, though participation is voluntary. And while sushi customers may not be able to physically detect misrepresented fish, they too can take steps to lower their chances of being defrauded at least.
"Customers can ask sushi restaurants if they have a quality control process that confirms salmon identification and if they have reliable vendors the sushi restaurant sources from," Delgado said. "Customers can also ask the sushi restaurants if they purchase the salmon whole and then fillet the salmon at the restaurant," or if the sourced salmon is already processed. "If the salmon is filleted fresh at the restaurant, then a good sushi chef would know the difference between a wild vs farmed salmon by looking at it," she explained.
Ultimately, it is likely to take the passing and enforcement of stricter seafood deceit laws to effectively curb this practice.
In light of the persistent issue of seafood mislabeling, particularly with salmon, the use of advanced scientific techniques and technology in future investigations could provide more accurate data and help identify key areas for improvement in seafood labeling regulations.
Given the environmental implications of salmon misrepresentation, leveraging future advancements in science and technology could also aid in the development of more effective tracking systems for seafood supply chains, enabling fisheries managers to make data-driven decisions and ensuring sustainable harvesting practices.
