Species At Risk

Lake Sturgeon

(Acipenser fulvescens)

Threatened (Great Lakes-Upper St. Lawrence River population, Northwestern Ontario population)
Special Concern (Southern Hudson Bay/James Bay population)

Lake Sturgeon


The Lake Sturgeon is Canada’s largest freshwater fish, weighing up to 180 kilograms and reaching over two metres long. It has an extended snout with four whisker-like organs hanging near the mouth. Its body is covered with large bony plates, pronounced in juveniles but less pronounced in larger fishes. It is dark to light brown or grey on its back and sides with a lighter belly.

Unlike other fish found in Ontario, the Lake Sturgeon has a skeleton made up of cartilage instead of bones. The Lake Sturgeon has ancestral ties to related species dating back 200 million years. It can live more than 100 years.

Action we are taking:


In North America, Lake Sturgeon can be found from Alberta to the St. Lawrence drainage of Quebec and from the southern Hudson Bay to the lower Mississippi.

In Ontario, the Lake Sturgeon is found in the rivers of the Hudson Bay basin, the Great Lakes basin and their major connecting waterways, including the St. Lawrence River. There are three distinct populations in Ontario: Great Lakes - Upper St. Lawrence River, Northwestern Ontario, and Southern Hudson Bay - James Bay.


The Lake Sturgeon lives almost exclusively in freshwater lakes and rivers with soft bottoms of mud, sand or gravel. They are usually found at depths of five to 20 metres. They spawn in relatively shallow, fast-flowing water (usually below waterfalls, rapids, or dams) with gravel and boulders at the bottom. However, they will spawn in deeper water where habitat is available. They also are known to spawn on open shoals in large rivers with strong currents.


Historically, harvesting, dams and other river barriers, habitat loss, and poor water quality were responsible for the decline of Lake Sturgeon throughout North America.

With improvements in water quality and the strict regulation or elimination of commercial and recreational fisheries in Ontario, habitat fragmentation and regulated water flows from dams are the greatest threats to the species.


The Northwestern Ontario and Great Lakes – Upper St. Lawrence River populations of Lake Sturgeon and their habitat are protected under Ontario’s Endangered Species Act.

What You Can Do to Help the Lake Sturgeon

  • The Ministry of Natural Resources tracks species at risk such as the Lake Sturgeon. The Ontario Reptile and Amphibian Atlas collects observations of all Ontario reptiles and amphibians. Submit your observations to either of these databases at nhic.mnr.gov.on.ca/species/species_report.cfm and www.ontarionature.org/atlas. Photographs are important to help confirm the identification of species and are always helpful.
  • Volunteer with a local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.
  • Contact your local Ministry of Natural Resources office to find out how you can become involved in hands-on fish and wildlife management activities
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Private land owners have an important role to play in species recovery . You may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats. For more information, visit: ontario.ca/speciesatrisk.

Did you know?

The oldest known specimen of Lake Sturgeon is 155 years old from Lake Huron. The largest Lake Sturgeon recorded was from the Roseau River of Manitoba, weighing 185 kg and measuring 4.6 m in length!

Did you know?

The inner lining of the Lake Sturgeon’s swim bladder (an air-filled sac that helps the fish float) was used to clarify wine, beer and other liquids.

Did you know?

Subsistence fishing for Lake Sturgeon is a long-standing tradition for many Aboriginal communities.

Did you know?

Lake Sturgeon are migratory and travel upstream to spawning grounds and downstream to deeper water during the summer. Some adults travel up to 400 km to spawning areas!

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.