The advocacy organization reviewed more than 200 published studies covering 55 countries.
They found mislabeling at retail, wholesale, distribution, import/export, packaging/processing and landing in an update to a 2014 analysis.
About 65% of the studies included evidence of economically motivated adulteration of seafood products. Cheaper or less desirable fish were mislabeled as more expensive varieties.
In 141 instances, pangasius was swapped for 18 different types but mostly perch, grouper and sole, said Oceana.
Seafood fraud includes species substitution - often a low-value or less desirable item swapped for a more expensive or desirable choice - improper labeling, including hiding the origin of seafood products, or adding extra breading, water or glazing to increase their weight.
Beth Lowell, Oceana senior campaign director, said the path from the fishing boat or farm to dinner plates is long, complex and non-transparent, rife with opportunities for fraud and mislabeling.
“Without tracking all seafood throughout the entire supply chain, consumers will continue to be cheated, hardworking, honest fishermen will be undercut, and the long-term productivity of our oceans will continue to be in jeopardy,” she said.
“American consumers deserve to know more about their seafood, including what kind of fish it is, how and where it was caught or farmed, and they should be able to trust the information is accurate.”
NFI disputes findings
One in five of the more than 25,000 samples of seafood tested were mislabeled.
The National Fisheries Institute (NFI) said the focus on the most often mislabeled species distorts the findings by design.
“Oceana’s continued focus on expanded regulation illustrates a fundamental lack of understanding when it comes to fish fraud and what works in policing it. The laws, rules and regulations we need are already on the books. This is an issue of enforcement,” it said.
“Oceana would do much more in helping to get rid of seafood fraud if it focused on lobbying for greater enforcement rather than a misguided effort to expand regulatory bureaucracy.”
The non-profit organisation said when Oceana started work in fish fraud its efforts were welcome but they have begun to evolve into a distraction for those doing work in the area.
Health risk posed
Oceana said Asian catfish, hake and escolar were the three types of fish most commonly substituted. Farmed Asian catfish was sold as 18 different types of higher-value fish.
More than half (58%) of samples substituted for other seafood posed a species-specific health risk to consumers including parasites, environmental chemicals, aquaculture drugs and other natural toxins.
Escolar and oilfish contain naturally occurring gempylotoxin and have been associated with outbreaks of gastrointestinal problems. Oceana said its investigations revealed more than 50 cases of escolar being sold as “white tuna” in sushi restaurants in the US.
It found 82% of the 200 grouper, perch and swordfish samples tested in Italy were mislabeled and in Brazil, 55% of “shark” samples were actually largetooth sawfish for which trade is prohibited.
A total of 98% of the 69 bluefin tuna dishes tested in Brussels restaurants were also mislabeled.
EU and US action
Overall fraud rates in the EU appear to have decreased from 23% in 2011 to 8% in 2015.
Oceana said preliminary data suggests that catch documentation, traceability and consumer labeling are feasible and effective at reducing seafood fraud.
A US presidential task force proposed rule addresses Illegal, unreported and unregulated (IUU) fishing and seafood fraud.
Oceana said it would only apply to 13 types of seafood deemed “at-risk” of illegal fishing and seafood fraud and only from the boat or farm to the US border.
“Because illegally caught seafood, some caught or processed with slave labor, 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,” said Dr Kimberly Warner, report author and senior scientist at Oceana.
“The increased traceability and consumer labeling efforts in the EU point us to solutions that really do work to decrease seafood fraud, particularly in sectors and products covered by these legal provisions.”