Buyer beware: Your salmon may be lying to you. In a study published today, researchers found evidence that these products are regularly mislabeled as wild salmon when they are actually farmed salmon; this can be costly, especially for customers at sushi restaurants.

Salmon and seafood mislabeling It’s a known issue for a while; so that Washington state, The salmon industry is particularly importantIn 2013, he passed legislation aimed at reducing this and other types of fish fraud. Senior study investigator Tracie Delgado, a biology professor at Seattle Pacific University, had read past studies on the subject and knew about the 2013 law, so she decided to have students in her Genetics lab course investigate for themselves whether things had gotten better since then. .

“When we started this project, we had no idea what the results would be, and we were very surprised by the results,” Delgado told Gizmodo. “Despite legislation making it illegal to mislabel salmon in Washington state, salmon mislabeling fraud is still a problem in Seattle.”

Delgado and his students collected and analyzed DNA from salmon samples from 67 grocery stores and 52 sushi restaurants in the Seattle area between fall 2022 and fall 2023. In total, 18% of these samples were said to be mislabeled. The team’s findings were: It was published In the magazine on Wednesday PLOS-One.

While mislabeling was relatively common in both grocery stores and restaurants, it was a more serious problem in the latter. About a third of samples taken from restaurants were mislabeled as wild salmon rather than farmed salmon, compared to zero such mislabeled samples from grocery stores. And sometimes sushi samples marketed as a particular type of wild salmon could instead be another wild species, although this also occurred in grocery stores (the combined rate of mislabeling from wild to farmed salmon and from wild salmon to wild salmon was 38% in restaurants and 11% in restaurants). stores).

On the bright side, researchers found no examples of farmed salmon being falsely labeled as wild in grocery stores. This suggests that seafood identification laws in Washington are helping to reduce fraud at least somewhat. However, the overall mislabeling rate of salmon found in this study was some hindsight Washington had a mislabeled rate before the 2013 law, while later studies found even higher rates in other states. And the cost of mislabeling salmon at sushi restaurants is almost certainly passed on to customers, as some people will pay more for “wild” salmon that should actually be cheaper farmed salmon (this potential impact, however, has been found to be negligible in grocery stores).

Mislabeling salmon is also likely to have a negative impact on the environment, according to Delgado.

“Dishonest reporting of catch data and mislabeling of seafood complicates fisheries conservation efforts because it prevents accurate monitoring of supply chains and complicates effective fisheries management efforts,” he said. “Therefore, fisheries managers may erroneously conclude that wild salmon stocks, which are actually depleted, continue to remain at sustainably harvestable densities.”

Researchers say more needs to be done to stop salmon and other seafood fraud, such as encouraging restaurants to periodically test that the fish they buy is real. there is a current audit program Although participation is voluntary, it was established by the National Oceanic and Atmospheric Administration for fishing boats, processing plants and retailers to test their fish, Delgado said. Even though sushi customers can’t physically smell mislabeled fish, they can at least take steps to reduce their chances of being scammed.

“Customers can ask sushi restaurants if they have a quality control process that verifies the identity of the salmon and if the sushi restaurant sources reliable vendors,” Delgado said. “Customers can also ask sushi restaurants whether they purchase the salmon whole and whether the restaurant receives the salmon filleted or whether the resulting salmon has already been processed.” “If the salmon is filleted fresh at the restaurant, then a good sushi chef can tell the difference between wild and farmed salmon by looking at it,” he explained.

Ultimately, however, stricter seafood fraud laws will likely need to be enacted and enforced to effectively rein in this practice.