Conservationists in Northumberland County were thrilled in 2008, and again in 2009, when they heard that a number of maturing Atlantic salmon were detected returning to Cobourg Brook to spawn.
A grilse or young salmon returns Cobourg Brook to spawn after spending winter “at sea,” or in this case, Lake Ontario.
Photo: Russ Bobrowski, Trent University
Everyone hopes it’s the start of a trend. Since 2006, a total of 2.5 million Atlantic salmon have been stocked in Cobourg Brook, the Credit River in Mississauga and Duffins Creek in Durham Region. The ultimate goal? To re-establish the native Atlantic salmon populations of Lake Ontario.
The return of spawning Atlantic salmon in coldwater creeks means efforts to improve habitat —another step toward the goal — are working. Biologists are now carrying out more than a dozen habitat improvement projects on Cobourg Brook. These include:
- Planting buffer strips of trees along the brook’s banks to prevent soil sediments and farm nutrients from entering the brook’s waters and to create added shade so the water is cleaner and cooler for the coldwater-loving Atlantic salmon and other native Great Lakes fish species.
- Installing fencing to discourage livestock from entering spawning areas.
- Placing structures, such as clean rubble and boulders, in the brook to provide cover/shelter for young fish.
Cobourg Brook, as well as the Credit River and Duffins Creek, were chosen as restoration areas because of their high quality spawning and nursery habitat – the presence of gravel streambeds – and because of strong community support. If these pilot projects are successful, then rehabilitation will be expanded to include other streams.
Atlantic salmon require cool, fast waters and clean habitat. As an indicator species, their survival is solid evidence an aquatic ecosystem is healthy. Efforts to rehabilitate their habitat will benefit not only Atlantic salmon but many other native Great Lakes fish species as well.
Click here to view a map of the project area
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Atlantic Salmon: Lake Ontario’s Heritage Fish
• The Atlantic salmon is Ontario’s only native salmon and an important part of the natural and cultural heritage of the Lake Ontario basin. The Atlantic salmon’s ancestors migrated from saltwater after the glaciers retreated and adapted to freshwater in what eventually became the Great Lakes.
• Atlantic salmon almost certainly were important in the history of the rolling hills of Northumberland County. Coldwater creeks like Cobourg Brook fed millions of Atlantic salmon into Lake Ontario. Early settlers caught them by the barrelful, especially during lean times when the fish was their main source of food.
• But the tide of settlement that salmon helped support, helped in turn to erase them. Dam building to create hydro power for grain and lumber mills, farming, and development on salmon spawning streams combined to cancel future generations of salmon. Massive over-fishing in both spawning streams and Lake Ontario simply hastened the end.
• More than 50 conservation-minded individuals and organizations are working together to restore this treasured native species to Lake Ontario. Find out more at www.bringbackthesalmon.ca
Project Partners and Sponsors:
- Australia’s Banrock Station Wines
- Ganaraska Region Conservation Authority
- Northumberland Stewardship Council
- Liquor Control Board of Ontario
- Oak Ridges Moraine Foundation
- Ontario Federation of Anglers and Hunters
- Ontario Ministry of Natural Resources
- Private landowners and anglers
For more information, contact:
- Marion Daniels, Management Biologist, Lake Ontario Management Unit, Ministry of Natural Resources, Peterborough (705) 755-1345
- Alastair Mathers, Lake Ontario COA Basin Coordinator, Lake Ontario Management Unit, Ministry of Natural Resources, Picton (613) 476-8733