Spot the Species

When you're in the seafood department at the grocery store, do you really know what you're buying?

You count on labelling to be accurate, and so does the retailer. But some studies have found that seafood may be mislabelled anywhere from 25 to 70 percent of the time for fish like red snapper, wild salmon and Atlantic cod. Along the supply chain, there's an economic incentive to mislabel species that are less expensive—a practice known as market substitution or food fraud.

There's one extremely powerful way to identify any species—DNA—and it doesn't lie.

That's why more authorities, including the U.S. Food and Drug Administration, are using a Canadian innovation—DNA barcoding—to identify processed products that are not readily identified to species using traditional means.

"Species identification matters for many reasons—food fraud is a health and economic issue," says Robert Hanner, who developed applications of the technology in collaboration with its founder Paul Hebert at the University of Guelph. "But it's about much more than that. Identifying invasive pest species is a crucial first step in protecting our agricultural and forestry resources. And cataloguing the world's species is important to protecting biodiversity."

The DNA barcode identifies a species by recognizing short DNA sequences that are unique to the species, just as a packaging barcode is unique to that product. The barcodes collected from expert-identified reference specimens are gathered in a database along with the name, image and where it was found.

Barcodes can be obtained from tiny amounts of tissue taken from any life stage, including eggs and larvae. Even if the specimen is crushed or in fragments, it can still be identified. When profiling so-called "known species", it is not uncommon for the barcodes to reveal deep genetic divergences between specimens thought to be the same species. Future development of a hand-held device could exploit this library of life and put species identification at everyone's fingertips.

These and other benefits have encouraged scientists to use DNA barcodes to refine knowledge of biodiversity. Hanner's and Hebert's technologies are helping to answer one of the most fundamental questions in biodiversity science—how many species are on the planet?

During the last 250 years, traditional scientific methods have formally described nearly two million species, but estimates place the number of species at anywhere from 10 to 100 million.

"This is, obviously, a global imperative, which is why we've been scaling the project up to include an international network dedicated to the creation of a global barcode library," says Hanner.

In 2005, Canada became the first nation to establish a national network dedicated to advancing species identification and discovery through the use of DNA barcodes. The Canadian Barcode of Life Network established the world's first and largest barcode "factory," showing the power of barcoding to the global scientific community.

This led to the International Barcode of Life ( iBOL) project—the largest biodiversity genomics project ever launched. Its inaugural meeting was held in Toronto in September 2010 at the CN Tower. To honour the occasion, the Canadian landmark was illuminated with a giant DNA barcode of the Canadian beaver.

This Canadian-led international movement to barcode species is growing. The Barcode of Life Database now has over 8,000 registered users and receives more than 6 million hits per month. More than 24 nations are working collectively to barcode five million specimens representing some 500,000 species in five years. 

"Canadians should take pride in the world-class science we've launched and our leadership in this global effort," says Hanner.

In January 2012, that leadership found a new official home when the University of Guelph opened the Centre for Biodiversity Genomics, where the iBOL project is now headquartered.