Lake Sturgeon in the Winnipeg River

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Knowledge is power, and data is the key to sustainability Lake Sturgeon are present in several locations across Manitoba. They have been hammered by humans for hundreds of years, almost to the point of extirpation. I would like to convey in this article how fisheries research, when done thoroughly and timely, can lead to potential positive change. I will talk about the Manitoba section of the Winnipeg River, since it shows this ‘concept’ rather nicely and is also the area that I have the most hands on experience in.

In 2006 the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) designated Lake Sturgeon in the Winnipeg River as endangered. Reason(s) for status designation provided by COSEWIC were as follows: ‘The limited recent data available show that populations are declining in the Winnipeg River above Seven Sisters Dam, and essentially have disappeared below the dam. Historically, overexploitation probably was the primary threat; now dams and poaching probably are the most important threats’.

Now if that ‘endangered’ status would have been accepted as the status quo without question, Lake Sturgeon would be listed as species at risk under the auspices of the Species at Risk Act (SARA). This would essentially render Lake Sturgeon and its’ habitat ‘untouchable’ until it rebounded past the endangered status. Maybe. SARA is a powerful piece of legislation. Such a status could cost millions in mitigation and habitat restoration and that would be a shame, especially when it might not be needed in this river, or certainly not parts of it.

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Previous to this, a Conservation Closure was initiated by the Province of Manitoba in 1993 for Lake Sturgeon in the Winnipeg River to the Ontario border, including subsistence fishing.

It’s well documented that Lake Sturgeon populations have been seriously impacted by harvest and habitat alterations historically. They simply do not respond well to over exploitation due to their unique biological characteristics. Lake Sturgeon can take as many as 25 years of age until sexual maturity, they rarely spawn annually and when on the spawn they can be easily ‘interrupted’ by large fluctuations in water temperature and not return to the spawning grounds. Kinda reminds me of the cartoon when the male mayfly says to the female mayfly, ‘whaddya mean ya got a headache, we only live for 24 hours’.

Research and data collected in the Manitoba portion of the Winnipeg River up to 2004 is limited and primarily focused on the adult portion of the population. At about the time when Manitoba Fisheries Branch started a seriously intense population estimate program in the Nutimik/Numao reaches of the river (PIT tagging, mark – recapture), several Masters and Ph.D thesis projects were ramping up through the Canadian Rivers Institute (CRI), which was partially funded by Manitoba Hydro.

While our population estimate projects on the Nutimik/Numao reach focused on the adult, sub-adult and juvenile lake sturgeon numbers, we also collected age and growth data as well as movement and habitat utilization. What was seriously lacking in our knowledge about Lake Sturgeon in the river was whole life history insight. By this I mean spawning success and habitat utilization, egg and larval drift, juvenile habitat utilization and diet. Pretty much all of the knowledge you need to properly assess how this species uses the river.

The work conducted by the CRI graduates filled in most of these gaps, from Slave Falls to downstream of Seven Sisters. Absolutely awesome knowledge gaps were filled from juvenile habitat preferences to rates of downstream movement through generating stations to relating large spillway release events with strong year class strengths of Lake Sturgeon. Studies funded by Manitoba Hydro and conducted by consultants garnered more important life history data on Lake Sturgeon in the reach from Pointe du Bois to Slave Falls. This team also completed juvenile Lake Sturgeon assessments in the two reaches below McArthur Falls down to Pine Falls.

Manitoba Fisheries Branch mirrored the work done in the Nutimik/Nuamo reach to the area from Seven Sisters to McArthur Falls. Here we found a dynamic population of Lake Sturgeon with all stages of the population represented from 1.7 metre long behemoths to 15 centimetre long yearlings. The two population estimate sections will be completed in alternate years.

Manitoba Fisheries Branch and Manitoba Hydro consultants teamed up to conduct juvenile and adult Lake Sturgeon surveys from Pointe du Bois to the Ontario border. This reach showed the least amount of sturgeon of all the downstream reaches. It is theorized that with the back flooding of Lamprey Falls after the construction of the Pointe du Bois Generating Station allowed for easier upstream movement, many kilometers into the province of Ontario, where the next dam is located. All the required habitat for all life stages of Lake Sturgeon is available in this reach. However studies completed in the lower sections show Lake Sturgeon densities get lower and lower the farther away (downstream) from the falls or dam blocking their upstream migration.

Future research will include adult Lake Sturgeon surveys by Manitoba Hydro consultants from McArthur Falls to Pine Falls. These surveys are designed to fill knowledge gaps in these reaches.

In 2013 Manitoba Fisheries Branch in conjunction with the Lac du Bonnet Wildlife Federation, with a grant from the Fisheries Enhancement Fund, completed a pilot project on the rate of post release mortality of angled Lake Sturgeon below the Pointe du Bois Generation Station. This was in response to a section in a COSEWIC document outlining that fishing was one of the negative impacts to Lake Sturgeon. Well, one way to address the validity of that statement is to test the hypothesis. Albeit this was really a pilot study with no bloodwork analysis, it showed that 100% of Lake Sturgeon angled by our volunteers all survived after four days in a holding pen. Timely data collected once again. We are hoping a graduate student takes this one step further.

I could go on and on regarding all the fantastic and highly useful information on Lake Sturgeon that has been collected over the last 10 or so years, however the information I’ve highlighted should demonstrate my point.

Lake Sturgeon seem to have adapted to life in the Winnipeg River, specifically in the Manitoba portion. In most reaches they have what it takes to thrive. There is also absolutely no doubt that the conservation closure implemented in 1993 has played a major role in giving them a chance to thrive as they seem to be doing. As researchers, biologists and managers this is the ultimate. It doesn’t always happen this way. We’ve had the time, money and staff to complete this work on our river. We’ve educated kids from Lac du Bonnet and Sagkeeng First Nations schools on sturgeon biology and why we do the things we do. Without the knowledge we have gained I am sure Lake Sturgeon would have been listed, and based on our collective database, this does not seem to be necessary.

When the COSEWIC group sits down again in 2016 to reassess the Lake Sturgeon population status in Manitoba, they may come to a different conclusion that they did in 2006, at least in the Winnipeg River, As well anglers may continue to catch and release Lake Sturgeon in the Winnipeg River and perhaps maybe even harvest some along with our friends from Sagkeeng First Nations as part of their subsistence fishing needs. The beauty is, we’ll eventually have the data we need to bring this to totally sustainable fruition one day.

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About Author

Ken Kansas

Ken has recently retired from a 30+ year career in fisheries research and management conducted all across Manitoba. From the Theliwaza and Lower Nelson Rivers, to Manitoba’s Parkland and Whiteshell areas, Ken has worked tirelessly in efforts to improve fish populations and recreational angling opportunities through science and common sense based realities. A rabid fisher himself, with a penchant for tossing flies at rather large salmonids, Ken hopes to share his knowledge with all Hooked Magazine readers through the unique combination of biologist and angler.

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