Manitoba Prairie Lakes: Mass balance budget for nutrient management at Pelican Lake, Manitoba

The study establishes a nutrient mass balance for Pelican Lake, Manitoba, finding that the lake acts as a net sink for phosphorus and a net source of nitrogen. External nutrient loads are strongly linked to surface hydrology and agricultural land use, with internal recycling from sediments contributing significantly to phosphorus levels. The findings suggest that remediation should focus on high-agricultural sub-catchments and the regulation of the Pembina River inlet dam.

• Pelican Lake is a net sink for phosphorus, retaining approximately 70 per cent of external inputs, with the majority of this accumulation occurring in the water column.
• The lake acts as a net source of nitrogen to the surrounding environment, including groundwater, largely due to biological processes such as N2 fixation driven by high phosphorus concentrations.
• Internal phosphorus recycling from lake sediments and macrophytes contributed approximately 10 per cent of external phosphorus loads, with sediments acting as a net source of P to the water column during the study period.
• External nutrient fluxes are strongly tied to surface hydrology, indicating that climate variability and increased rainfall have significantly contributed to nutrient inputs in recent years.
• Nutrient loading is not primarily determined by catchment size but by land use; the highest nutrient loads originate from the sub-catchment with the highest percentage of agricultural area (PL05), rather than the largest catchment by area.
• A significant portion of phosphorus loading occurs during spring runoff events, specifically when the PL08A-inlet dam is opened to divert water from the Pembina River; approximately 45 per cent of the phosphorus load during the study period was delivered during the March dam opening.
• Groundwater serves as a major output for nitrogen, with 103,007 kg of total nitrogen moving from the lake to aquifers, accounting for 93 per cent of the total outflow nitrogen load.

APA

Lewtas, K., Osman, H., Gunn, G., & Roy, D. (2017). Manitoba Prairie Lakes: Mass balance budget for nutrient management at Pelican Lake, Manitoba. International Institute for Sustainable Development. https://www.iisd.org/system/files/publications/manitoba-prairie-lakes-mass-pelican-lake.pdf

Chicago

Lewtas, Kimberly, Hisham Osman, Geoffrey Gunn, and Dimple Roy. Manitoba Prairie Lakes: Mass balance budget for nutrient management at Pelican Lake, Manitoba. International Institute for Sustainable Development, 2017. https://www.iisd.org/system/files/publications/manitoba-prairie-lakes-mass-pelican-lake.pdf.

Wikipedia

{{cite report |last1=Lewtas |first1=Kimberly |last2=Osman |first2=Hisham |last3=Gunn |first3=Geoffrey |last4=Roy |first4=Dimple |title=Manitoba Prairie Lakes: Mass balance budget for nutrient management at Pelican Lake, Manitoba |publisher=International Institute for Sustainable Development |date=October 2017 |url=https://www.iisd.org/system/files/publications/manitoba-prairie-lakes-mass-pelican-lake.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{lewtas2017manitoba, author = {Lewtas, Kimberly and Osman, Hisham and Gunn, Geoffrey and Roy, Dimple}, title = {{Manitoba Prairie Lakes: Mass balance budget for nutrient management at Pelican Lake, Manitoba}}, institution = {International Institute for Sustainable Development}, year = {2017}, month = oct, url = {https://www.iisd.org/system/files/publications/manitoba-prairie-lakes-mass-pelican-lake.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }