Published by Communications and Public Affairs (519) 824-4120, Ext. 56982 or 53338
April 29, 2004
U of G casting a net for old Atlantic salmon
Pondering what to do with that big, stuffed fish great-grandpa pulled out of Lake Ontario that has been mouldering away in your attic? Give researchers at the University of Guelph a call.
U of G scientists are searching for salmon that were caught and mounted in Ontario during the late 1800s. By testing DNA from these specimens, they hope to prove that stocks of Atlantic salmon living in the headwaters of the Andes are of Canadian descent.
“You can rescue DNA from dry fish,” said U of G zoology professor David Noakes, adding it only involves removing a small fin ray. “You can take material from dried specimens, extract the DNA and say this is what the DNA was like 125 years ago in Lake Ontario.”
Noakes belongs to a scientific advisory committee established to run this novel genetic and ecological repatriation project. “We believe the Argentinian salmon in are actually Canadian at heart – even though they speak Spanish,” he said. The group’s ultimate goal is to restore salmon to Ontario by having the Argentinian fish kick-start a renewed population.
It’s been more than a century since the last native Atlantic salmon flashed their way from Lake Ontario to spawning grounds in adjoining creeks and rivers. Lake Ontario was the only Great Lake in which Atlantic salmon once thrived. Reports from the early 1800s say the fish, with their characteristic black backs and silvery sides, were so plentiful that they could be removed easily with pitchforks in spots.
Their habitat came under threat when silting caused by erosion and sawmills and gristmills choked their spawning grounds. Dams built on the rivers also blocked the fish from reaching those spawning areas. The last Atlantic salmon was caught in Lake Ontario in 1898.
But today, salmon are thriving in Argentina’s Patagonian region, in landlocked lakes and rivers that are similar to Lake Ontario in structure, chemistry and habitat. Salmon fish eggs were hatched and established in Argentina in the early 1900s. U of G researchers believe that some of those eggs came from fish in Maine’s Sebago Lake — fish that descended from salmon taken from Lake Ontario to Maine in the mid-1800s.
“There’s a possibility that the original strain found in Lake Ontario and the Finger Lakes region may still exist in Argentina,” said Jack Imhof, national biologist with the conservation organization Trout Unlimited Canada and an adjunct professor in U of G's School of Environmental Design and Rural Development. Imhof is also a member of the the scientific research group.
The researchers hope to compare genetic material from the fish in Argentina with the only known source of DNA from those long-ago Great Lakers. Working with the Royal Ontario Museum, scientists have already extracted strands of DNA from about six stuffed specimens in the ROM’s collection.
They’d like to find more samples. Trout Unlimited Canada began a publicity campaign this year that involves contacting Ontario museums and asking around at fishing shows for old stuffed specimens. “We suspect there are not a lot of mounts out there,” said Imhof. But even three to five specimens would double the size of the preserved genetic pool, he added.
After confirming that the Argentinian fish do hail originally from Lake Ontario, the researchers hope to obtain eggs to stock a few tributaries. Even if they find a genetic match, Imhof cautioned that it would take years to pass stringent control standards and hold public consultations before the fish could be raised and released in Ontario.
Jack Imhof, National Biologist, Trout Unlimited Canada