Posted by: genghisprawn | August 27, 2008

DNA Barcoding Reveals Fishmonger Fraud

If Soylent Green is people . . . what is Red Snapper?  Adapted from this news release.

In what is being touted as “the first known student use of the four-year-old DNA barcoding technology in a public marketplace,” Kate Stoeckle, 18, and Louisa Strauss, 17, of New York’s Trinity School sent 60 samples of fish tissue from 14 grocery stores and restaurants in New York City to the University of Guelph’s Biodiversity Institute of Ontario.

There, Dr. Robert Hanner, Campaign Coordinator for the Fish Barcode of Life (FISH-BOL) initiative, and masters student Eugene Wong analyzed the specimens’ “barcodes” — a 652 bp region of their COI gene (mitochondrial cytochrome c oxidase subunit 1).

It's harder if they're in small chunks (The Consumerist).

Red snapper (Lutjanus campechanus) below, red sea bream (used in reference to both Pagrus major and Pagellus bogaraveo) above. It's harder to tell if they're in bite-sized chunks (Consumerist).

Of the 56 samples with identifiable matches in the Barcode of Life Data Systems library, exactly one-fourth were mislabeled — “in all cases as higher-priced or more desirable species.”  Here’s the rundown (ironically, I had to add in the scientific names myself):

. . . In two cases DNA barcode tests revealed that filleted fish sold as the popular Red Snapper [Lutjanus campechanus] (caught mostly off the southeast U.S. and in the Caribbean) was instead the endangered Acadian Redfish [Sebastes fasciatus] (which swims in the North Atlantic).

The DNA of fish from a sushi restaurant, mislabeled “White Tuna” (also known as Albacore tuna [Thunnus alalunga]) matched the barcode for Mozambique Tilapia [Oreochromis mossambicus], commonly raised on fish farms. Farmed, freshwater tilapia sells for a fraction of the price of wild tuna.

A restaurant menu entrée, said to be “Mediterranean Red Mullet,” [generally either Mullus barbatus or Mullus surmuletus] matched the DNA barcode of Spotted Goatfish [Pseudupeneus maculatus], which inhabits the Caribbean.

Seven of nine samples said on packaging to be the popular “Red Snapper” were mislabeled. The DNA of those mislabeled fish matched these species:

· Acadian Redfish [Sebastes fasciatus, critically endangered on the International Union for Conservation of Nature’s Red List]
· Nile Perch [Lates niloticus]
· Lavender Jobfish [Pristipomoides sieboldii]
· Slender Pinjalo [Pinjalo lewisi]

Even bleaker results were obtained by a 2007 expose by the Chicago Sun-Times, which similarly tested “red snapper” from 14 restaurants in the titular city and its suburbs — of which none were actually L. campechanus.

The notion of COI barcodes as “the core of a global bioidentification system for animals” (as his 2003 paper Biological Identifications Through DNA Barcodes puts it) owes a great deal to Guelph professer Paul Hebert.  Fittingly enough, “Identifying Canadian Freshwater Fishes through DNA Barcodes,” a new paper by Hubert and colleagues, became available earlier this summer through PLoS ONE (see here).

According to the press release, Hebert isn’t stopping there:

[Hebert] has also co-authored an upcoming article on using DNA barcodes to reveal the substitution of seafood in North American markets, describing the potential use of barcodes to harmonize across jurisdictions various names for the same fish.

But the champions of marine COI barcoding have hopes far grander than a glorified Peterson’s Guide to Piscine Fauna of Upper Manhattan Fusion Eateries.  The U.S. National Oceanic and Atmospheric Administration, for one, pictures:

· Reliable identification of catch and by-catch on vessels and at the dock;
· Analysis of gut contents to understand food chains in the ocean; and
· Assessment of fish stocks by identifying fish larvae as well as juveniles and
adults.

Yet COI is not without its critics, an issue I’ll leave for another post.

Useful links:

· Barcode of Life Database : www.barcodinglife.org
· Consortium for the Barcode of Life: barcoding.si.edu
· Barcoding marine species: www.marinebarcoding.org
· FishBol: www.fishbol.org
· Barcoding blog: http://phe.rockefeller.edu/barcode/blog
· Ten Reasons for Barcoding Life: http://phe.rockefeller.edu/barcode/docs/TenReasonsBarcoding.pdf

Resources:

Hubert N, Hanner R, Holm E, Mandrak NE, Taylor E, et al. (2008) Identifying Canadian Freshwater Fishes through DNA Barcodes. PLoS ONE 3(6): e2490. doi:10.1371/journal.pone.0002490

Hebert, P.D.N., A. Cywinska, S.L. Ball and J.R. deWaard. 2003. Biological identifications through DNA barcodes. Proc. Roy. Soc. Lond. Ser. B: 270: 313-321.

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Responses

  1. […] fascinating posts on using DNA barcoding to identify fish being sold as more expensive varieties – DNA Barcoding Reveals Fishmonger Fraud. You should also check out the rather tragic tale of the marine-related taxa from a hypersaline […]


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