Provincial, federal and state fisheries management agencies around Lake Superior are working together to monitor lake sturgeon populations in the lake. Using a method developed by the Great Lakes Fishery Commission’s Lake Superior Lake Sturgeon Working Group, the agencies are both independently and jointly capturing and tagging juvenile lake sturgeon in the vicinity of the fishes’ birth rivers.
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| Ian Senecal holding a 22 kg (48.5 lb) lake sturgeon. |
In Sault Ste. Marie, Ontario, the people doing the capturing and tagging are biologists with the Ministry of Natural Resources’ Upper Great Lakes Management Unit (UGLMU) and district species-at-risk program working together with Fisheries and Oceans Canada’s Great Lakes Lab for Fisheries and Aquatic Science (GLLFAS).
An UGLMU assessment crew heads out daily to lift its four or five gillnets and to take measurements – like length and weight – from any sturgeon caught. A crew member removes some boney material from each fish, which is used to determine the fish’s age. A small passive integrated transponder or PIT tag is injected under one of the tough, bony plates (called scutes) along the fish’s back. Another crew member makes a small incision in the fish’s belly through which a slightly larger external tag is inserted identifying the fish as one captured in this study of lake sturgeon in Ontario waters. Captured fish are kept cool and oxygenated during examination using a large cattle trough with a recirculating pump.
The crew regularly captures lake sturgeon ranging from 15 centimetres to 1.5 metres in length. Occasionally, a monster-sized sturgeon is brought to the surface only to break the net and escape. Ian Senecal, a fisheries technician with the Ministry’s UGLMU, has handled more than 450 sturgeon in his two summers as an assessment crew member. This is more sturgeon than most fisheries biologists will handle over their entire careers.
The PIT tags stay with the fish for life, and can be scanned using a handheld device to determine if an individual fish has been caught before. Since sturgeon are a very long-lived fish species (on occasion living more than 100 years) and external tags are prone to detach, this technology will be helping fisheries biologists for well into the future. Biologists also will be able to retrieve data and other details about the fish by checking the Great Lakes Lake Sturgeon website maintained by the U.S. Fish and Wildlife Service.
Ministry biologists and partners are trying to piece together a more detailed picture of the life history of Superior’s lake sturgeon populations. In a future project, biologists will use an in-water antenna array connected to a land-based receiver to help track the movements of these “tagged” sturgeon once they have matured and begin to travel up Lake Superior’s rivers each spring to spawn. Continued monitoring of Superior’s juvenile and adult lake sturgeon populations is needed to track our progress in removing the lake sturgeon from its current status as Threatened in the Great Lakes.
The lake sturgeon work on Lake Superior was made possible with funding through the 2007 Canada-Ontario Agreement Respecting the Great Lakes Basin Ecosystem (COA) and the support of the Coordinated Science and Monitoring Initiative by fisheries managers at Environment Canada and the U.S. Environmental Protection Agency.
Click here to view a map of Lake Superior tributaries with spawning sturgeon populations
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Project Partners and Supporters:
The partners of this lakewide survey include the following:
- For Ontario:
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- Fisheries and Oceans Canada’s Great Lakes Lab for Fisheries and Aquatic Sciences
- Ontario Ministry of Natural Resources
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- For the United States:
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- U.S. Fish and Wildlife Service, Ashland
- Minnesota Department of Natural Resources
- Michigan Department of Natural Resources
- Wisconsin Department of Natural Resources
- 1854 Treaty Authority
- Great Lakes Indian Fish and Wildlife Commission
- Grand Portage Tribe
- Redcliff Tribe Natural Resource Division
- Keweenaw Bay Indian Community
- Fond du Lac Tribe
- Bay Mills Tribe
- Lake Superior State University
- Michigan Technical University
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For more information, contact:
- Sue Greenwood, Management Biologist, Upper Great Lakes Management Unit – Lake Superior, Ontario Ministry of Natural Resources, Sault Ste. Marie, (705) 946-7488
- Marilee Chase, COA Lake Superior Basin Coordinator, Upper Great Lakes Management Unit – Lake Superior, Ontario Ministry of Natural Resources, Thunder Bay (807) 475-1371