Fish Fraud: Mislabeled Mahi-Mahi and Suspect Shark

On Wednesday, the nonprofit group Oceana released a report, “Bait and Switch: How Seafood Fraud Hurts Our Oceans, Our Wallets and Our Health,” about rampant fraud with the fish in your supermarket case and restaurant table. Fraud in some species is as high as 70%: That mahi-mahi might be yellowtail; that snapper could really be Vietnamese catfish. A few years ago, restaurants in the Midwest who thought they were serving walleye discovered that they were actually offering diners zander, an eastern European fish, says the Journal-Gazette.

84% of seafood consumed in the US is now imported. Often, fish comes already processed and, as the New York Times notes, even experienced fishmongers are hard-pressed to identify a piece of fish without scales or fins. DNA barcoding, which looks at gene sequences in the flesh of a fish, can readily detect fish species. Recent studies by North American and European researchers have found that as much of 20 to 25% of seafood products checked are fraudulently labeled.

The Food and Drug Administration is indeed at work with scientists to study the use of DNA barcoding and the labeling of fish and seafood. The FDA has acquired gene sequencing equipment for five FDA field laboratories and is hoping to use it “on a routine basis” by the end of this year.

Accurate labeling of fish is important not only so that consumers are not deceived. Environmentalists are concerned that “duped diners may be unwittingly contributing to declining fish stocks, buying food they have been told to avoid.” Dr. Paul Hebert, scientific director of the Barcode of Life project, based in Guelph, Ontario, points out that:

… in testing samples from the United States and Canada, his lab had even detected meat from endangered sharks being sold to diners. “If it were labeled endangered species,” he said, “you couldn’t sell it and you wouldn’t buy it, right?”

DNA barcoding is becoming more and more accessible, the New York Times says: with desktop DNA bar coding systems set to be available within five years. In ten years, inspectors will carry hand-held detectors — all of which could make the story about the fish you buy a lot less fishy.


Photo by The Boreka Diary.


W. C
W. C3 months ago


William C
William C3 months ago

Thank you for the article.

Jim Ven
Jim Venabout a year ago

thanks for sharing.

Jo S.
Jo S2 years ago

Thank you Kristina.

Su H.
sue H4 years ago

Over fishing and greed is causing all sorts of problems that you would think could not happen!!

Anna Undebeck
Anna Undebeck4 years ago

oops this was an OLD post.... thanks anyway ;)

Natasha Salgado
Past Member 4 years ago

It's non-stop deceipt...pitiful.

Ellie Damann
.6 years ago


Masha Samoilova
Past Member 6 years ago

I like whole fish anyway

Kaitlin Carney
Kaitlin Carney6 years ago

Just make sure to buy from your local fish market and you should be safe. I'm lucky to live in a town that has two great local fish markets that are delivered fresh seafood from the coast on a daily basis. Whenever I go to a supermarket and look at fish, it always says "farmed" or "color added". No way am I going to buy that! Best just to stick with local, fresh fish and know what it is that I'm buying.