The US Food and Drug Administration (US FDA) has notified the domestic seafood industry that agency and state regulatory personnel will be sampling and testing 100 high value species of fish over the next four months to determine the accuracy of their species labeling. The initiative grew out of concern that inexpensive species or species with potential safety concerns are being intentionally mislabeled for resale as higher value species or to avoid import restrictions. Mislabeled seafood is considered to be misbranded under the Food Drug and Cosmetic Act, violating the law.

The most commonly mislabeled seafood, according to the FDA, is as follows.

Examples of Commonly Substituted Seafood 
 (less expensive products are in column B)
Red Snapper Rockfish
Mahi Mahi Yellowtail (Seriola lalandi)
Swordfish Mako Shark
Orange Roughy Oreo Dory or John Dory
Cod Alaska Pollock
Halibut Sea Bass
Dover Sole Arrowtooth Flounder
Red Drum Black Drum
Snapper (Lutjanus sp.) Tilapia
Grouper Basa or tra
Lake or Yellow Perch White Perch or Zander
Caviar (Sturgeon species) Paddlefish or other fish roe
Walleye Sauger or Alaska Pollock
Chum Salmon Pink Salmon
Salmon Steelhead Trout
Pacific Salmon Atlantic Salmon
Blue Crabmeat Imported Crabmeat
Wild-Caught Salmon Farmed-Raised Salmon

The US FDA under the Fish and Fishery Product Hazards and Controls Guidance has a list of fish which, when labeled as a different fish species, can create a food safety hazard.

Due to the subtle differences in taste and texture between different fish species, identifying fish species can be particularly difficult when the fish is filleted or processed. Therefore fish species identification usually requires DNA testing. Fish identification will be performed by the US FDA using a system based on the research done by the University of Guelph’s Barcode of Life/Fishbol and the Smithsonian Natural History Museum’s library of authenticated samples. FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes.

The FISH-BOL project uses a DNA-based identification system, founded on the mitochondrial gene, cytochrome c oxidase subunit 1. As shown in recent studies this gene allows diagnosing species across the animal kingdom. Moreover, the results indicate that sequence divergences at cytochrome c oxidase subunit 1 regularly enable the discrimination of even closely allied species in nearly all animal phyla .

As part of the Barcode of Life project, DNA sequences have been identified for 172 authenticated fish representing 72 species from 27 families. For animals, a fragment of 655 base pairs of amino acids starting near the 5’ end of the cytochrome c oxidase subunit 1 mitochondrial gene has been shown in most cases to be reliable for species identification.

For their project the US FDA utilizes Polymerase Chain Reaction (PCR) and subsequent DNA sequencing to generate DNA barcodes for fish species identification . They have established a reference standard sequence library for seafood identification in conjunction with this methodology .

SGS is offering services in the area of PCR testing, species identification, and a broad range of other food-related services through our global network of laboratories. We are also committed to keeping interested parties informed of developments on regulatory activity and new methodology development.

Please contact us for further information.

James Cook 
291 Fairfield Ave, Fairfield, NJ 07004

t: 973 575 5252
f: 973 575 7175


SGS is the world’s leading inspection, verification, testing and certification company. SGS is recognized as the global benchmark for quality and integrity. With more than 67,000 employees, SGS operates a network of over 1,250 offices and laboratories around the world.