Ever wondered where that fish you're eating comes from or if it's the species you think it is?
Researchers at Dalhousie University have developed a publicly available DNA database that identifies all the fish commonly found in the oceans off Atlantic Canada. The work is part of a worldwide effort to catalogue plants, animals, fungi and other life.
The Atlantic fish DNA database will not only help prevent seafood fraud, but assist with species tracking and benefit ocean conservation efforts.
"What we've done is collected a little bit of DNA sequence information from (about) 200 species of fish in the Western Atlantic, and we've looked at this little piece of DNA," explained Dalhousie University biology professor Paul Bentzen.
"It evolves in a way that's almost perfect for identifying species, as even closely related species have differences."
Canada is a leader in this process known as DNA barcoding. Bentzen said the applications of the Atlantic Canada fish DNA database are broad.
"As we are hearing in the media, there is a lot of fraud and misrepresentation of one species for another. A couple of years ago (Dal) students were instructed to gather a variety of (fish) samples from local sushi bars and stores and found some substitutions," he recalled.
"Many studies I've read that looked at sushi restaurants found that when you see red snapper on the menu, it never seems to be red snapper."
Instead, Bentzen said it's often tilapia. Red snapper isn't easily available and tends to claim a premium price. This is just one example of many.
"It's like having factory chicken when you think you're buying pheasant," he said. "It's always a cheaper product that's being substituted."
The database can also help conservation officers ensure species at risk aren't being passed off as non protected species. In 2005, work by one of Bentzen's PhD students helped prosecute an Eastern Shore fisherman who chopped off the heads and tails off seven protected Northern Wolffish in the hopes of disguising them.
Tissue samples were sent to Bentzen's lab, and they proved it was indeed the protected fish.
"Where I would like to go next with it is looking now for DNA-based methods of determining not only what a species is, but where in the ocean it came from ... It is doable," Bentzen said.
"Being able to say where in the Eastern Atlantic fish came from is really important for conservation. If regulations say it's okay to catch here but not there to rebuild the stock, we can get around people claiming they caught fish where they weren't supposed to."
The database can be accessed at www.barcodinglife.com .
ydentremont@hfxnews.ca
