Escolar masquerading as white tuna. Flounder passing for Vietnamese catfish. Pricey baby cod replaced with lesser quality hake instead. Once fish is filleted and skinned, it can be difficult to distinguish, as a Boston Globe investigative report found after testing 183 pieces of fish and finding that 87 were mislabeled. This type of fraud has long vexed the seafood industry, especially for popular species such as red snapper, wild salmon and Atlantic cod, which could be mislabeled as much as 70 percent of the time. But all this fishy business could soon change.
The U.S. Food and Drug Administration, often criticized for less-than-rigorous inspection and enforcement efforts when it comes to seafood fraud, is rolling out new DNA-sequencing equipment in nine of its major laboratories across the country in a push to squelch this type of substitution. Officials say they are targeting cod, grouper, snapper, tuna and other high-value species (which are more likely to be substituted), and have already begun sequencing samples taken from retailers and wholesalers.
The FDA has been looking into such genetic identification—called DNA bar coding—since 2007, when toxic puffer fish from China entered the country labeled as monkfish and sickened several people. At the time the standard way of testing seafood was though protein analysis (through so-called isoelectric focusing). But the technique was not effective if fish samples were processed or cooked.
To read the rest of the story, please go to: Scientific American