Preserving Aquatic Resources One Barcode at a Time

Candace Webb
28 September 2012

Did you know? Dr. Paul Hebert at the University of Guelph developed DNA barcoding.The problem: How to police fish quotas and bycatch, as well as the mislabeling and substitution of fish species. The solution: DNA barcoding!

DNA barcodes are short DNA sequences used for species identification. Conveniently, DNA barcoding doesn’t require a whole fish, just a sample of DNA.

In the U.S., the Food and Drug Administration (FDA) uses DNA barcoding to identify fraudulently mislabeled seafood. The agency focus on high-value species such as cod and tuna, because those are the ones most likely to be replaced with less expensive types of fish. In Canada, the Canadian Food Inspection Agency monitors fish and seafood products.

Did you know? In the U.S., popular species such as red snapper, wild salmon, and Atlantic cod may be mislabeled as much as 70% of the time.Researchers at University College Dublin used DNA barcoding to show that cod and haddock are mislabeled about 25% of the time in Ireland. Scientists worry that mislabeling may contribute to overfishing by wrongly giving the impression that these species are widely available. The same researchers also found that threatened Atlantic cod is often mislabeled as “sustainable” Pacific cod.

Although DNA barcoding is useful, it cannot distinguish between different populations of the same species or between closely-related species. One technique that can make up for these shortcomings has been developed by the international consortium FishPopTrace ( It uses single-nucleotide polymorphisms (SNPs) to distinguish between different populations of the same species with an accuracy rate of 93-100%.

Did you know? SNPs are like typos made during chromosomal duplication. They occur when one DNA base (A, C, T, or G) gets deleted or replaced by another.The Fish Barcode of Life (FISH-BOL) campaign was launched in 2005 by an international group of scientists. The FISH-BOL database aims to collect DNA barcodes for all fish species in order to facilitate the monitoring of fish populations. Although useful, this database has limitations for regulatory purposes. As a result, the FDA has developed its own database in conjunction with the Smithsonian Institute.

The preservation of aquatic resources, as well as the prevention of illegal fishing and seafood mislabeling are important causes. DNA barcoding can help.

Learn More!

Specious Species: Fight against Seafood Fraud Enlists DNA (Scientific American, November 10, 2011) DNA-based Seafood Identification (U.S. Food and Drug Administration) DNA Barcoding Reveals Mislabeled Cod and Haddock in Dublin (ScienceDaily, April 22, 2010) Cod Mislabelling Four Times More Prevalent in Ireland Than UK, Study Shows (ScienceDaily, July 14, 2011) DNA to Curb Illegal Fishing (The Scientist, May 24, 2012) Fish Forensics Gets an Upgrade (Science NOW, May 22 ,2012)

Action Project: The Fish Market Survey (barcoding action project with additional backgrounders & educational resources) Biotechnology @ CurioCity! (with additional backgrounders & educational resources)

Candace Webb

I graduated from the University of Ottawa in 2006 with a PhD in Biology. I am now a postdoctoral fellow at UCLA, studying the funky circadian rhythms of plants. Besides science, I love to write, hike, paint, bike ride, and hang out at the beach.

Une diplômée de l’Université d’Ottawa, j’ai reçu mon doctorat en biologie en 2006. Je suis présentement boursière postdoctorale à l’Université de Californie à Los Angeles, où j’étudie les rythmes circadiens des plantes. En plus des sciences, j’aime écrire, passer du temps à la plage et faire de la peinture, de la randonnée et du vélo.

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