New Report Warns of Persistent Fish Fraud Across Seafood Markets

The seafood on your plate may not always be what it claims to be.

A new report by the Food and Agriculture Organization of the United Nations (FAO) reveals that fish fraud is widespread across global markets, posing risks not only to consumers’ health but also to marine biodiversity and economic systems.

Titled “Food Fraud in the Fisheries and Aquaculture Sector,” the report paints a detailed picture of deceptive practices affecting the $195 billion global seafood industry. Produced through collaboration between FAO’s Fisheries and Aquaculture Division and the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, the study highlights both the scale of the problem and emerging scientific tools that can help combat it.

A Global Problem with No Clear Baseline

While there is no official global estimate of how common fish fraud is, empirical studies suggest that up to 20 percent of seafood trade may be affected by some form of deception, higher than fraud levels reported for meat, fruits, and vegetables. The complexity of the seafood sector, which includes more than 12,000 species, makes oversight particularly challenging.

In some markets, the situation appears even more troubling. Studies cited in the report indicate that as much as 30 percent of seafood served in restaurants may be mislabeled. In the United States, up to one-third of aquatic products sold could be incorrectly labeled, yet less than one percent of imports are tested.

Cases of fraud have been documented worldwide, from ceviche vendors in Latin America and seafood restaurants in China to canned tuna products in the European Union. Notably, Antarctica remains the only continent without reported cases.

What Is Fish Fraud?

The FAO defines fish fraud as “a deliberate practice intended to deceive others,” and identifies several common forms of deception within the seafood trade. One of the most widespread practices is species substitution, such as selling tilapia as red snapper to command a higher price. Mislabeling is also frequent, including false claims about sustainability certifications or geographic origin.

Other forms of fraud include adulteration, for instance adding coloring to tuna to make it appear fresher than it is, and counterfeit products such as imitation shrimp made from starch-based compounds. Simulation is another tactic, where processed fish like surimi is packaged and marketed to resemble more expensive crab meat.

The report also highlights overrun and diversion, which involve distributing products outside their intended markets or exceeding legal catch limits. Tampering, including falsified expiry dates, further undermines consumer trust, while outright theft and overfishing pose risks not only to markets but also to the sustainability of fish stocks.

Such practices can endanger public health. Certain fish species pose risks when consumed raw, and improperly handled or refrozen seafood increases the risk of bacterial growth. Fraud can also undermine fish stock sustainability, particularly when geographic origin is concealed or illegal catches are laundered into the market.

Economic incentives remain the primary driver of seafood fraud.

The report notes that selling farmed Atlantic salmon as wild Pacific salmon can generate nearly $10 more per kilogram. Similarly, farmed seabass marketed as locally sourced Italian fish can sell for two to three times the price of the same fish from Greece or Turkey, and even more if falsely labeled as wild-caught.

Another common practice involves adding water to fish to increase weight and price, a method also observed in land-based meat production.

Science Offers New Tools

Detecting seafood fraud is complex, but advances in science are offering new solutions.

The report highlights technologies such as enzyme-linked immunosorbent assays (ELISA), stable isotope analysis, nuclear magnetic resonance, portable X-ray fluorescence devices, and machine-learning models as promising tools for regulators. DNA barcoding has also proven effective in identifying species substitution.

In Los Angeles, a DNA-based investigation found low levels of mislabeling at processing plants but moderate levels among grocers and particularly high levels in sushi restaurants. Retail mislabeling was rare for tuna and salmon but common for red snapper and halibut. A local initiative combining education campaigns and routine blind testing reduced seafood mislabeling by two-thirds over a decade.

However, not all countries have access to advanced testing technologies, underscoring disparities in enforcement capacity.

To address the problem, FAO advocates for harmonized labeling requirements, mandatory inclusion of scientific names where possible, and improved traceability systems throughout the supply chain.

The report concludes that prevention and enforcement, combined with active participation from the private sector, are critical to reducing and ultimately eliminating fish fraud.