Once a Year, Salmon Migrate up the Credit River
Autumn and the annual salmon migration go together like peanut butter and jelly. While the calendar still says summer, the amazing salmon run will be happening in the Credit River Watershed before we know it.
Every fall chinook, coho and Atlantic salmon leave the waters of Lake Ontario and head up the Credit River to spawn. Lake Ontario salmon return to the streams where they were born to reproduce. Migration begins when water temperatures cool and water levels rise from summer rains. This is usually in early September but you can see salmon in the Credit River as early as mid-August.
While salmon are usually associated with Canada’s coasts, before the 19th century, Lake Ontario had the greatest population of freshwater Atlantic salmon. Their population decline inspired conservation efforts in Lake Ontario. The fish found in the lake today are descendants of three broodstocks (a group of mature individuals used in aquaculture for breeding purposes) from Nova Scotia, Quebec and Maine.
In the 1940s, the Canadian Department of Lands and Forests attempted to stock the lake using fish from New Brunswick. Unfortunately, this effort failed because of high water temperatures and predation. In 1995, the Ministry of Natural Resources and Forestry (MNRF) stocked up to 200 fry (very young fish) per year for eight years. Learn how this program is doing now.
To prepare for the arrival of the great migration, here are some facts about three salmon species found in the Credit River Watershed:
When an adult chinook salmon reach maturity, which can be anywhere from three to seven years of age, it makes the long migratory journey back to the site of its birth stream to produce young. This species dies after completing its journey and spawning.
Chinook salmon can grow up to an astounding three feet in length and can weigh over 40 pounds. The Ontario record is 46 pounds, caught near Oakville in 2000. Chinook are piscivorous, which means that they eat other fish.
Female Atlantic salmon lay approximately 7,000 eggs. Around one per cent of eggs survive to adulthood–no wonder they have to lay so many!
Atlantic salmon are between two and three years old when they begin their spawning journey. Unlike chinook salmon, Atlantic salmon do not die after spawning. They will make their way back to Lake Ontario.
Atlantic salmon are the native salmon to Lake Ontario while chinooks and cohos are introduced from the west coast. Atlantic salmon continue to be stocked in the Credit River as part of the Lake Ontario Atlantic Salmon Restoration Program.
Like the Atlantic salmon, cohos begin their spawning journey between the ages of two and three. Coho salmon also die after spawning.
In order to give the salmon the best chances of survival during their spawning migration, please respect their space. Stay on marked trails and always practice water safety.
By Kimberley Laird, Associate, Marketing and Communications