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Science Goals of the Lake Winnipeg Basin Initiative  


Science Goal 3

Assess and manage non-point source contributions of nutrients in the watershed and ultimately to the lake, and assess the efficacy of agricultural Beneficial Management Practices (BMPs) on the landscape.

Update on Recent Research: Environment Canada and partners are studying where nutrients enter Lake Winnipeg and how agricultural beneficial management practices may help reduce these nutrient levels. There are five projects and monitoring activities currently underway to examine flow rates and precipitation along the Red, Assiniboine and Saskatchewan rivers. Scientists are also reviewing historical data on nutrient concentrations and ecological conditions within specific sites across the watershed.

The final results from these studies are expected in 2011/12. Data on changes in flow and nutrient transport for rivers in southern Manitoba under both the past and present climate and under climate change scenarios will be included. Results are also expected to indicate the amount of nutrients entering the Red and Assiniboine rivers and agricultural contributions of nutrients. These findings will be useful for management strategies to control agriculturally-derived nutrients (e.g., at what time of year and where in the watershed to target actions) and to inform decisions on effort that should be directed toward controlling point-sources (e.g., sewage) as opposed to diffuse sources (e.g., agricultural) of nutrients.

  • Research is underway to examine the type and variety of nutrients entering Lake Winnipeg with emphasis on the areas that flow into the Red and Assiniboine Rivers in southern Manitoba. Interim results indicate that over the past four decades, there has been no statistically significant change in precipitation in the Canadian prairie portion of the Lake Winnipeg watershed and, with the exception of the Red River, there has been no change in the amount or frequency of flooding and runoff. Increased flow within the Red River has, however increased the quantity of water flowing into the Lake Winnipeg.
  • A compilation and evaluation of scientific models for climate, landscape, and nutrient transport was completed in 2009. Based on the results of these models, mean annual precipitation in the Lake Winnipeg watershed is expected to increase by approximately 6–8% by mid-century and result in enhanced annual runoff for the upper Assiniboine and Morris catchments. Testing and validation is ongoing to combine the models with climate data.
  • In addition to these hydrological studies, field work was conducted on the LaSalle, Morris and Rat Rivers to determine the rate at which nutrients are lost from agricultural fields, the extent to which these nutrients are retained in adjacent streams/ditches or supplemented by instream nutrient sources as a result of biological activity, and the quantity of nutrients that are then transported from fields to the Assiniboine and Red rivers. Research to date indicates that it is possible to estimate potential input of nutrients to Lake Winnipeg tributaries from various human activities. Preliminary results indicate that approximately 3% of nitrogen and 6% of phosphorus enter adjacent streams from cropland, with considerable quantities leaving small agriculturally dominated streams during snowmelt. Work is also underway to identify the importance of agricultural nitrogen to key changes in stream biological processes.
  • In collaboration with Agriculture and Agri-Food Canada, work is underway to assemble data and predict the impacts of land use on water quality within the Red and Assiniboine Rivers. This project focuses on identifying land use practices that impact surface water quality at a watershed scale, and recommends beneficial management practices.


PHOTOS

image of scientific equipment along riverbank near Rat River

Sonde and ambient light meter used along the headwaters of the Rat River to measure instream oxygen levels. Photo by Adam Yates, May 2010.

scientist collecting samples along the bank of the Rat River, Manitoba

Collecting benthic algae samples for Chlorophyll A and Nitrogen isotope analyses in the headwaters of South Tobacco Creek. Photo by Adam Yates, Oct. 2009.

scientists wading in Rat River to collect samples with net

Sampling aquatic benthic invertebrate communities in Tobacco Creek near Rosenort, Manitoba. Photo by Adam Yates, Oct. 2009

two researchers collect samples of sediment from Tobacco Creek

Collection of sediment cores for nutrient and particle size analyses in the lower reaches of Tobacco Creek, Manitoba. Photo by Adam Yates, July 2010

scientist on bank of Rat River collecting samples in container

Processing a benthic sample in the headwaters of the Rat River, Manitoba. Photo by Daryl Halliwell, Oct. 2010

photo of snow melting on Tobacco Creek in Manitoba

Beginning of snowmelt in spring 2010 at South Tobacco Creek near Miami, Manitoba where Environment Canada scientists are researching the impacts of nutrient inputs resulting from overland flooding. Photo Credit: Dr. Julie Corriveau, 2010.

photo of snow melting on Elm River, Manitoba

Beginning of snowmelt at Elm River near Winkler, Manitoba where Environment Canada scientists are researching impacts of nutrient inputs from overland flooding. Photo credit: Dr. Julie Corriveau, 2010.

photo of snow melting on Shannon Creek, Manitoba

Snowmelt during the spring of 2010 at Shannon Creek, near Winkler, Manitoba where Environment Canada scientists are researching impacts of nutrient inputs from overland flooding. Photo Credit: Dr. Julie Corriveau, 2010.

sampling equipment on bridge spanning Tobacco Creek, Manitoba

Installation of automatic sampling equipment on Tobacco Creek. Photo Credit: Dr. Julie Corriveau, 2010.

scientist standing on riverbank checking research equipment

Environment Canada scientist checking automatic sampling equipment installed on a tributary of Buffalo Creek, Manitoba. Photo Credit: Dr. Julie Corriveau, 2010.