Sushi has a reputation for purity. Fresh fish, minimal fuss, clean flavors. It’s part of why people pay a premium for a good omakase or a neighborhood spot they trust. The problem is that the fish on your plate may not be what the menu says.
Up to 20 percent of fishery and aquaculture products globally are mislabeled, according to a report published in early 2026 by the United Nations Food and Agriculture Organization. The scale of the problem is significant, and sushi restaurants are among the most affected venues. Here’s what the research actually says, and what to look for next time you sit down for a meal.
1. The Menu Lists “White Tuna” or “Super White Tuna”
This is one of the most reliable red flags you can spot before a single piece of fish reaches your table. “White tuna” is an incorrect name for any fish, including tuna, according to the FDA. The term has no official standing, which makes it easy to exploit.
Escolar, often fraudulently sold as “white tuna” or “super white albacore,” contains wax esters that humans cannot digest, causing severe diarrhea, cramping, and nausea. Due to these adverse effects, it’s banned in countries like Japan, Italy, Sweden, Denmark, and South Korea. Despite this, it remains legal and widely served in the United States.
For those wary of escolar’s side effects, or who simply wish to enjoy genuine white tuna, there is one important visual difference: genuine white albacore tuna is often actually pale pink in color, while escolar is opaque white with absolutely no pinkness in its flesh. That stark white, almost waxy appearance is a signal worth paying attention to.
2. The Price Seems Suspiciously Low for Premium Fish
Pricing inconsistencies are one of the clearest indicators of fraud in any food market, and sushi is no exception. Researchers have found a “pretty significant price differential” in certain substitutions, such as farmed salmon labeled as wild salmon, tilapia labeled as red snapper, and basa labeled as haddock and cod.
Be wary if the price seems too low. Inexpensive “wild” salmon, say at $8.99 a pound, for example, is likely to be farmed Atlantic salmon, especially in the winter when wild salmon is in limited supply. The same logic applies at restaurants offering premium species at suspiciously low prices.
When a plate of halibut sashimi is priced the same as a basic California roll, that’s worth a second thought. The economics of the seafood market do not support deep discounts on genuinely premium species.
3. Red Snapper or Halibut Appears on the Menu
These two species are among the most consistently mislabeled fish in American sushi restaurants, and the data here is striking. Out of 43 orders of halibut and 32 orders of red snapper, DNA tests in the UCLA study showed the researchers were always served a different kind of fish. That’s not sometimes or often. It’s every single time.
Using standard DNA barcoding protocols to determine the identity of products labeled as “red snapper” from sushi restaurants, seafood markets, and grocery stores in the Southeastern United States, researchers found that overall, nearly three quarters of samples were mislabeled, with sushi restaurants mislabeling samples 100 percent of the time.
What you’re eating is far more likely to be tilapia, according to Oceana, a Washington, D.C.-based ocean conservancy organization. Flounder also shows up frequently as a substitute. Both are cheaper, and visually similar once filleted and served raw.
4. The Restaurant Can’t Tell You Where the Fish Is From
Transparency about sourcing is a meaningful differentiator between restaurants that take fish quality seriously and those that don’t. Sometimes qualities of seafood beyond species name are mislabeled, such as the country of origin. This allows processors to avoid regulations and fees, or even to sneak illegally caught fish into the supply chain.
For much of the seafood served in sushi restaurants, it’s a long supply chain: fishing boats far offshore, shore-side purchasers, import-export companies, regional wholesalers, local distributors, and finally the restaurant staff. Each step in the chain offers a possibility for intentional or unintentional mislabeling.
A restaurant that knows its supplier, can name the fishery, and is willing to share that information when asked is operating with a level of accountability that reduces the chance of fraud reaching your plate. Blank stares or vague answers are worth noting.
5. Farmed Salmon Is Being Sold as Wild-Caught
This is one of the most economically motivated swaps in the sushi world. Wild-caught Pacific salmon commands a significantly higher price, and the visual difference after slicing and serving is minimal to the average diner. Unlike grocery stores, Seattle sushi restaurants often sold farmed salmon mislabeled as wild salmon. Specifically, substitutions of vendor-claimed wild salmon with farmed salmon occurred in nearly a third of sushi restaurant samples compared to zero percent of grocery store samples.
All salmon substitutions in sushi restaurants harmed the customer financially, as they were given a cheaper market-priced fish. A 2024 peer-reviewed study published in PLOS ONE confirmed this pattern across Seattle, a city that sits in the heart of Pacific salmon country.
Despite recent legislation that makes mislabeling of salmon illegal, salmon mislabeling fraud is still a problem in Seattle. Researchers found Seattle sushi restaurants are far more likely to give you farmed salmon in place of vendor-claimed wild salmon.
6. The Mislabeling Rate at Sushi Bars Is Consistently Higher Than at Grocery Stores
This is something that multiple independent studies have confirmed, and it holds up across different cities, time periods, and research teams. The overall mislabeling rate was highest in restaurants, at roughly 55 percent, and lowest in grocery stores. Sushi and sashimi samples were among the most mislabeled products, which could explain the higher rate in restaurants.
While 38 percent of restaurants carried mislabeled fish in Oceana’s study, only 18 percent of retail outlets had fish swaps. Grocery stores have stronger labeling requirements up front. Sushi bars in particular are worse about mislabeling their seafood, unless a customer asks a lot of questions.
The practical implication is simple. The looser the labeling environment, the easier fraud becomes. Sushi restaurants operate with far less visible documentation than a grocery fish counter, and that gap creates opportunity for mislabeling to go undetected.
7. The Fish Color Looks Too Perfect, Too Uniformly Red
Fresh fish changes color as it ages. Tuna browns and dulls. A piece of sashimi that maintains an almost unnaturally vibrant red hue may have been chemically treated to look that way. To keep fish looking “fresher” longer, some sushi restaurants treat tuna with carbon monoxide, which locks in a bright red color regardless of age or spoilage.
Appearance plays a huge role in maintaining a premium look, and that look is achieved with carbon monoxide. The industry uses CO to redden fish and prevent browning as it ages, regardless of how it’s stored. For escolar, a solid white fish that doesn’t resemble tuna at all, this treatment is especially useful. Injected CO allows aging or misrepresented fish to hold onto a bright, high-end appearance that would normally raise eyebrows.
This practice is legal in the United States, though it is banned in some other countries precisely because it disguises freshness issues. Knowing that this happens doesn’t make every piece of red tuna suspect, but it does explain why visual perfection alone isn’t a reliable indicator of quality.
8. The Restaurant Offers No Sourcing Certifications or Staff Knowledge
Staff who can’t answer basic questions about the fish they’re serving are a soft signal that sourcing isn’t a priority. Some industry experts suggest asking your server or chef whether the establishment is a Better Seafood Board member, since members must adhere to industry principles that include correctly labeling products. It’s a simple question that can reveal a lot.
In light of widespread mislabeling, researchers recommend buying seafood from reputable companies and looking for abnormal labeling and pricing. It’s also important to know where the products you purchase come from and to look at a company’s food safety practices. At a restaurant, ask questions about what’s on the menu.
A long-running Loyola Marymount University study, published in the international journal Food Control in October 2024, found reasons for optimism after 10 years of research and lab testing. Researchers concluded that awareness and intervention are critical to ongoing efforts to reduce fraudulent labeling in seafood, and documented a significant drop in mislabeling rates among restaurants that actively participated in the monitoring project. The clearest takeaway from all of it is that engagement, asking questions and expecting answers, is still the best tool an ordinary diner has.
How Widespread Is This Problem, Really?
An investigation using DNA barcoding to assess the scale of mislabeling in Los Angeles found that while mislabeling is quite low in processing plants, it is moderate among grocers, and particularly prevalent in sushi restaurants. That pattern has held across multiple studies, in multiple cities, across more than a decade of research.
The $195 billion global seafood industry is uniquely vulnerable to fraud due to complex supply chains and over 12,000 traded species. Mislabeling and fraud are more prevalent in the aquatic sector than in many other food sectors, according to the United Nations Food and Agriculture Organization.
The seafood industry is prone to mislabeling because of rising demand, complex global supply chains, similar appearance of species, and wide price variation. None of these factors are disappearing anytime soon, which is why consumer awareness remains genuinely useful.
What You Can Actually Do About It
The research is clear that most fraud doesn’t begin at the restaurant counter. It often enters the supply chain earlier, through distributors or importers, and the restaurant itself may not know. Still, there are practical steps that matter. Danish marine biologist Dr. Marine Cusa warns: “I would avoid any product with poor labeling or where the species is not indicated.” In the US, snapper, salmon, prawns, and tuna are the most commonly mislabeled fish in sushi and sashimi.
It can be difficult to determine the species of a fish once it has been filleted and skinned. Some sellers take advantage of this and substitute a low-valued species for a more expensive one, for example marketing catfish as grouper. Asking for species specifics rather than generic names is one of the most effective things a customer can do.
If enough people start asking where the fish is from, the restaurants will ask that of their distributors, and the distributors will ask this of the fishermen. This will work only if the people who pay the bills demand accountability. That’s not a guarantee, but it is a mechanism that has shown real results in cities where monitoring projects and consumer pressure have been combined.
Conclusion
Seafood fraud is not a fringe issue or a paranoid concern. It is documented, measurable, and ongoing. The good news is that focused efforts, like those seen in Los Angeles, show that mislabeling rates can drop significantly when restaurants, researchers, and regulators work together.
The signs outlined here won’t give you a DNA test at the table, but they give you a reasonable framework for evaluating your local spot. Restaurants that are transparent, that can name their suppliers, and that don’t rely on vague menu language tend to be the ones actually serving what they say they are.
The fish you’re paying a premium for may or may not be exactly what the menu claims. Knowing the signs at least puts the odds a little more in your favor.
