People in the U.S. eat more salmon than any other fish, chowing down on an annual average of nearly 3.5 pounds per capita, according to the National Fisheries Institute. It’s second only to shrimp in the seafood popularity contest. But not all of that salmon is as advertised, according to new research.
Salmon sold in Seattle-area sushi restaurants and grocery stores is mislabeled about 18 percent of the time, according to a study published November 6 in the journal PLOS One. Different species of salmon are occasionally mixed up. In at least one instance, trout was sold as salmon. Yet the most prominent sort of mislabeling occurs in restaurants, where farmed salmon is presented as wild-caught, at the customer’s expense, per the new genetic analysis.
Out of the 67 total grocery store samples assessed in the new study, nine were mislabeled, a rate of about 13 percent. However, the grocery salmon was not labeled in ways that uniformly benefitted the stores and there were no instances where farmed salmon was falsely advertised as wild. Instead, certain wild species were sometimes sold as others, and in a handful of cases wild fish was labeled as farmed.
“It seems like there might have been honest mistakes here and there,” says Tracie Delgado, senior study author and a biology professor at Seattle Pacific University. Despite the fact that whole fish of different salmon species have identifying trademarks and stores often receive their fish intact, seafood workers unfamiliar with species ID might occasionally error, she explains. Or, perhaps there are mix-ups after processing.
In contrast, restaurant fish followed a clearer, more exploitative trend. Of the 52 sushi samples collected and assessed, 12 were mislabeled– a 23 percent rate across the restaurants. In all cases, the fish were hawked as a pricier variant of salmon than they actually were. In 10 of those instances, farmed Atlantic salmon was labeled as wild-caught and in two instances a cheaper wild species was labeled as a more expensive one.
To come to these findings, Delgado conscripted her genetics students over two terms to visit and collect samples of salmon directly from businesses. Every student followed protocol to preserve the fish and minimize contamination, in many cases hauling gloves, test tubes, and coolers around in their cars. “I wanted to bring research into the classroom… I wanted my students to feel like they were doing something that was contributing to science,” she says.
Delgado and her students used standard genetic analysis techniques, including polymerase chain reaction (PCR) to amplify DNA segments and parse out code, which they then compared to known sequences specific to each species of salmon. They specifically looked at the cytochrome c oxidase gene which is involved in mitochondrial respiration and cellular energy metabolism. Cytochrome c oxidase is a gene sequence critical enough to be conserved and nearly identical across individuals, but slight variations mean the gene can be used to easily distinguish between species.
Nearly all farmed salmon in the U.S. is Atlantic salmon, a different species from the Pacific salmon caught in commercial fisheries in Alaska and along the West Coast. And all Atlantic salmon sold in the U.S. is farmed. There are five distinct species of Pacific salmon–some more highly valued than others–which made it easy to determine if establishments were labeling their fish accurately. However, the analysis can’t indicate exactly where the point of mislabeling is happening. It may be in restaurants, or it may be higher up the food supply chain, with distributors. As in the 2011 case of a major Seattle-area fish distributor who was jailed over false labeling.
The overall rates of restaurant mislabeling found in this study are on par with past assessments of seafood in the Seattle region, despite 2013 state-level legislation that made it illegal to mis-market fish. The 2013 policy also specifically dictates that all seafood needed to be correctly labeled by common-name species and whether it was wild-caught or farm-raised.
Fish fraud is not a new problem. But the new research emphasizes we’re not addressing it well enough. Washington’s policy may have had the positive, intended effect in grocery stores, which –from national chains to local mom and pops–proved “very reliable,” says Delgado. But restaurants are still lagging behind. “We need to have more inspections,” she adds–hopeful that the new research will bring renewed attention to the problem.
Washington state–where some wild salmon is sourced and with its proximity to Alaskan suppliers–has routinely tested as one of the most reliable fish markets for consumers, with relatively low rates of mislabeling, notes Delgado. In other parts of the country, where salmon passes through even more hands before reaching your plate, rates are likely higher, she says.
Obviously, paying a premium for a falsely advertised product is not ideal and getting ripped off feels bad. “People want to know what they’re eating, and they expect, if they’re paying for something, that they’re getting what they asked for,” the biologist says.
But salmon mislabeling may also have larger impacts. Salmon populations are struggling amid threats from climate change, overharvesting, invasive species, pollution, and irresponsible farmed fish practices. Incorrectly labeled fish can undermine conscious consumers’ efforts to purchase responsibly. It can also complicate fishery conservation efforts, as mislabeling obscures the actual number of fish of each species caught and sold. “If it’s mislabeled, the supply and demand assessment is not actually an honest reflection,” says Delgado.
Finally, past research indicates that mislabeling seafood enables businesses to sell imported fish from illegal or unregulated sources that endanger fishery health globally. In all, fishy, fraudulent practices make domestic conservation and ecological monitoring more difficult and can enable unsustainable practices elsewhere. False advertising, at king salmon-scale, goes beyond your restaurant bill or dinner plate.
