Celebrate Autumn with Salmon

Fish half in and half out of water

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:

Chinook Salmon

Overhead shot of two chinook salmon in a river.
Chinook salmon is the largest salmon species in the 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.

Video footage of chinook salmon in the Credit River.

Atlantic Salmon

An Atlantic salmon showing the hooked jaw and spots.

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.

Underwater footage of chinook salmon in the Credit River. 

Coho Salmon

Like the Atlantic salmon, cohos begin their spawning journey between the ages of two and three. Coho salmon also die after spawning.

Close-up photo of fish laying on rock in water
Coho salmon after spawning.
Close-up of small fish
Juvenile coho salmon.

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.

If you take photos or videos of the salmon migration, share them with us on Facebook, Instagram, Twitter and TikTok.

By Kimberley Laird, Associate, Marketing and Communications

Comments (8)

    1. Credit Valley Conservation

      Thanks Fraser, you’re right, rainbow trout are also salmon species. We wanted to highlight three that people can see during the main migration period in the fall.

  1. Thank you for the wonderfully informative and helpful post! I am so fortunate to live close to Credit River in Mississauga. From my place it’s a 15 minute walk down Hewick Meadows where one can view the salmon run over the rapids just 10 feet away! After reading your article I now know the type of salmon I have seen: Chinook. What I notice is down river there are anglers in knee-deep water who fish during the salmon run. Even if it’s only to catch and release them, I often wonder if this is a good idea. The poor salmon are exhausted from swimming upstream in a quest to lay their precious eggs before dying. By the way, from the Eglinton Bridge above Hewick Meadows I have observed salmon eating eggs just laid by another salmon. I guess it’s their way to regain some strength for the rest of the swim, and to ensure their batch of eggs have a better chance to hatch and survive.

    1. Credit Valley Conservation

      Hi there, check our social media @cvc_ca for updates on when the migration is happening! There have already been sightings in Mississauga.

  2. Is it legal for someone to catch salmon swimming upstream? Today I saw something disturbing on the riverside. This man was fishing with his son and he had a string tied to a stone and at the other end in the water was a salmon trying to get free. How do you report something like that? It was disturbing to see, to say the least.

    1. Credit Valley Conservation

      Hi there, the salmon have started spawning in the Credit River. Meadowvale Conservation Area is a great place to view them underneath the bridge.

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