Seafood fraud is rife throughout the supply chain with one in five products mislabeled.
Research found that in many cases consumers were actually being served critically endangered species or fish that posed a health risk.
Campaign organisation Oceana’s report, detailing the global scale of seafood fraud, tested more than 25,000 samples of seafood worldwide, finding 20% were not correctly labelled.
Mislabelling occurred in every sector of the seafood supply chain: retail, wholesale, distribution, import and export, packaging and processing and landing.
However, the practice was less common within the EU than in other areas.
This led the report to conclude the EU’s attempts to crack down on illegal fishing and improve transparency and accountability in the seafood supply chain were working.
Numerous seafood fraud investigations over 12 years in the EU have led to fraud rates dropping from 23% in 2011 to 8% in 2015.
“According to Oceana’s analysis, preliminary data out of the EU suggests that catch documentation, traceability and consumer labeling are feasible and effective at reducing seafood fraud,” the report said.
Earlier this year the US president’s Task Force on Combating Illegal, Unreported, and Unregulated (IUU) Fishing and Seafood Fraud produced proposals requiring traceability for 13 at-risk seafoods from the fishing boat or farm to the US border.
Oceana believes that while this would be a step forward, traceability should be extended to within the US and throughout supply chains.
The report found the most commonly mislabelled fish were hake, escolar and Asian catfish, which was sold as 18 different types of higher-value fish. In 65% of cases there was a clear economic motivation for mislabelling.
Some 58% of the samples substituted for other seafood were a species that posed a health risk to consumers.
More than eight in 10 grouper, perch and swordfish samples tested in Italy were mislabeled, and almost half of replacements were species considered to be threatened with extinction by the International Union for Conservation of Nature (IUCN).
In Brazil, 55% of shark was actually largetooth sawfish, a species considered by the IUCN to be critically endangered and which is banned in Brazil.
And 98% of bluefin tuna dishes tested in Brussels restaurants were another species.
Kimberly Warner, report author and senior scientist at Oceana, said: “Because illegally caught seafood, some caught or processed with slave labour, could be making its way onto our dinner plates disguised as legal catch, it is doubly important to improve transparency and accountability in the global seafood supply chain.”