How Common is Mislabeling of Fish at Retail?
Certain fish species are more commonly misidentified than others. For instance, "Red Snapper", a very commonly mislabeled fish at retail, may actually be Atlantic Cod, Vietnamese Catfish, Mahi Mahi, Nile Perch, Rockfish, or Tilapia. "Grouper" may also be Basa (or Tra), Hake, Nile Perch, Pollock, or Tilapia. Blue Crab may actually be a different imported crabmeat. Chilean sea bass, one of the most expensive fish, was found to be mislabeled even with MSC Certification. In fact, in a recent study in the UK, fraud was found to be four times more likely in Ireland than the UK, even though both operate under the EU policies for seafood traceability and labeling.
Tuna provides another example. The FDA lists 14 species of fish that can be labeled as "tuna", yet escolar, the most common substitute in retail locations, is not one of the fish legally allowed to be labeled as "tuna." In fact, escolar is banned in some places (for instance Japan since 1977) because it can be a serious health risk to consumers and the FDA recommends against the sale of escolar in the US. Canned tuna has also been found to be mislabeled by media reports.
Even experts cannot differentiate species based solely on visual identification of fillets. Even all fillets of the same fish species don't look alike. For instance, Arctic char flesh varies in color and may be red, pink or white.