Frequent Fraud in Seafood Labeling

Written by on June 5, 2011 in Policy & Ocean Law

Emily Tripp
Senior Writer

Scientists have begun to uncover extensive seafood labeling fraud in supermarkets and restaurants.  The use of gene sequencers proved that in many cases cheap fish is being substituted for expensive species, and overfished species are being sold as species that are still abundant.

Some of the most common label “mix-ups” include:

Atlantic Mahi Mahi

Atlantic Mahi Mahi

  • Yellowtail for mahi-mahi
  • Nile perch for shark
  • Tilapia for just about any white flakey fish

Recent studies by researchers in North America and Europe have consistently found that 20 to 25 percent of seafood products they check are falsely labeled.  This is creating complaints that regulators are negligent in monitoring seafood.

“Customers buying fish have a right to know what the heck it is and where it’s from, but agencies like the F.D.A. are not taking this as seriously as they should,” said Michael Hirshfield, chief scientist of the nonprofit group Oceana, referring to the Food and Drug Administration.

Last week, Oceana released a new report titled “Bait and Switch: How Seafood Fraud Hurts Our Oceans, Our Wallets and Our Health.”  In some species, rates of fraud were found to run as high as 70 percent; because of this, the United States needs to “increase the frequency and scope” of its inspections.

DNA barcoding looks at gene sequences in the flesh of the species.  “The genetics have been revolutionary,” said Stefano Mariani, a marine researcher at University College Dublin.  “The DNA bar coding technique is now routine, like processing blood or urine. And we should be doing frequent, random spot checks on seafood like we do on athletes.”

Unfortunately, regulating the seafood industry has never been an easy task; without fins or scales, it can be extremely difficult to distinguishing some steaks or fillets.  Whole fish are easy to identify, but since a lot of the seafood arrives frozen, pre-packaged and some topped with sauce, it can be a nearly impossible task to identify them by looks alone.

With new genetic techniques, genetic sampling is less difficult and less expensive than it used to be.  Today, the sampled gene sequence is compared with an electronic reference library that now contains 8,000 varieties of fish.  The library has expanded with new species added by biologists over the last five years.  Testing is now relatively cheap: commercial labs charge about $2000 for 100 fish samples, but for labs who own their own equipment, the cost is only about $1 per sample.

In March, the F.D.A. issued an alert to inspectors about mislabeled fish–they also hope to use its new gene sequencing equipment on a regular basis by the end of 2011.  With any luck, this new level of policing could allow hundreds of thousands more samples to be analyzed every year.

While we are now headed in the right direction, it will take time to get this global problem under control.

Dale Sims, chief fishmonger for Cleanfish, a San Francisco-based supplier of high-end sustainable seafood said, “It infuriates me but it’s hard to correct.  I’m embarrassed to say that there’s been a lot of fragmentation in this industry.  So if someone is unscrupulous, it’s been easy to get away with it.”

“If you’re ordering steak, you would never be served horse meat,” said Dr. Hirshfield of Oceana. “But you can easily be ordering snapper and get tilapia or Vietnamese catfish.”

This problem continues to be unfair, as unknowing consumers may be ordering food they think is sustainable and safe, but is really endangered or high in mercury.  It also raises other questions of trust: if the seafood is mislabeled, who’s to say the country of origin, health warnings, and even the date isn’t also false?

In Europe, by law, the fishery must be included on the label, but in the U.S., only the country of origin is required (although it is often the country where the fish was processed, not the country where it was caught).  Today, 84 percent of seafood consumed in the United States is imported.

DNA barcoding is becoming more accessible every year and scientists predict the use of hand-held detectors within the decade.  “Everyone should be using this technique — there should be spot checks and fines,” said Dr. Hebert of the DNA bar coding project.  “If there were no speed traps and radar checks, there would be a lot more speeding.”

Copyright ©  2011 by Marine Science Today, a publication of OceanLines LLC

About the Author

About the Author: Emily Tripp is the Publisher and Editor of She holds marine science and biology degrees from the University of Miami's Rosenstiel School of Marine and Atmospheric Science and a Master of Advanced Studies degree in Marine Biodiversity and Conservation from Scripps Institution of Oceanography. When she's not writing about marine science, she's probably running around outside or playing with her dog. .


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