WHERE DOES THE “P” GO?​

Literature used

• State of Lake Winnipeg 2^nd edition
• The cumulative effects of climate warming and other human stresses on Canadian freshwaters in the new millennium

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Acknowledgements  �A gigantic ‘ekosani’ to following individuals for the support:

Dr. Nora Casson for helping with every step of this project�Dr. Geethani Eragoda-Arachchilage for the lab training, preparing the lab experiment ,and data analysis.

Brad Russell for all the technical support and printing �Karl Friesen-Hughes for sample collects

Cyril and Janice Favell for helping collect samples

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Patterns of phosphorus during a spring flood in the Lake Winnipeg Basin​

Marika ​Roman and Nora Casson – Department of Geography– University of Winnipeg

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Results

Peak discharge from the Red River at Emerson from 1912 to 2022 (Water Survey of Canada)

howell-favell-m@webmail.uwinnipeg.ca

Let’s chat!

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@marikahfr

Marika Roman, Undergraduate Student�University of Winnipeg

Where does phosphorous come from during a spring flood?

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Ten samples were taken from the Red River during a major flood since 62% of annual total phosphorous loads are from spring melt (Rattan et al. 2016).

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Methods

• Samples were filtered through a 0.45 um filter and analyzed for dissolved reactive phosphorus using the molybdate blue method (Murphy and Riley 1962)

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• Each sample location's concentrations were mapped by point, the points were interpolated using spline method and represented using geometric intervals.

Below we can see a clear and distinct pattern in P concentration.

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During a flood, P levels in the Red River are high enough by the time the Red is just south of Winnipeg's Perimeter highway, that we can see clear variability in P levels when other bodies of water outflow into it. 

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We can see that the greatest variation occurs at the Forks which is where the Assiniboine River flows into the Red. The variation in P is consistent with the evidence that the Assiniboine River is a source of less P pollution than the Red.

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The second greatest variation in P concentration is at the North Floodway outflow. Before the Red flows into Winnipeg, some of the Red is diverted by a floodway it travels around the city and flows back into the Red in the town of Lockport. Since the site where the floodway re-enters the Red has lower concentrations than the Red River that suggests that the floodway's P levels are used up along their route somewhere

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What is phosphorus?

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In aquatic ecosystems, Phosphorus (P) is a limiting nutrient, that comes from rocks and benthic sediments.

P is also used as a major component in fertilizers.

Excess P from those fertilizers enter our waterways in runoff, entering our waterways, creating an explosion in available P giving rise to harmful algal blooms (HAB), which can create dead zones.

Lake Winnipeg Basin

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• The total watershed coverage is just barely under one million square kilometres, making it the second largest in the world! 

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• The Red River is the single largest source of P to lake Winnipeg accounting for 69% of the average total load with only 16% percent of the flow.

• The Lake Winnipeg watershed extends across two ecoregions, prairie and boreal, four provinces and four states.

You can see that from the North Perimeter sample site to the Floodway Outflow sample point that P levels seem to decrease, that is due to the interpolation methods used, and it is likely that the P levels only drop once the Floodway outflows into the Red.

Discussion

This map visualizes P levels in a way that hasn’t yet been done. While there is a lot of research being done on Lake Winnipeg, having data that is visualized and easily accessible is important. We need data that doesn’t just speak to experts but can be read by the general population. We are so passionate in science because we can understand our data, but it takes years to do so, including the general population as an audience for our data gives it a larger reach. �Incorporating Traditional Ecological Knowledge (TEK) is an important next step. Indigenous peoples have valuable knowledge that science can learn from and be incorporated into western science.

There are many next steps to this data including taking soil and vegetation samples and finding out where the P comes from!

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