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Science Goals of the Lake Winnipeg Basin Initiative  


Science Goal 1

Characterize the physical, chemical and biological nature of Lake Winnipeg to better understand the balance of nutrient enrichment to the lake and the productivity of the fisheries in relation to the proliferation of large blue/green algal blooms.

RESULTS TO DATE: There are six projects and activities underway to provide a better understanding of the chemical and biological nature of the lake and how nutrient levels and fisheries activities contribute to algae blooms. Work currently underway Lake Winnipeg and Lake of the Woods is using isotopes to trace the sources of nutrients entering Lake Winnipeg and identify areas that are sources for high algae production.

Scientific modelling of Lake Winnipeg

  • In 2008, researchers developed a three dimensional scientific model to simulate the dynamics of Lake Winnipeg’s temperature structure, surface currents and water levels of Lake Winnipeg. In 2009, work focused on incorporating the movement of algae and nutrients into the model.
  • The Water Quality Analysis Simulation Program (WASP) was applied to Lake Winnipeg to simulate eutrophication, a natural process that is accelerated by decreases in water quality such as excessive nutrients, and examined the potential results following simulations of varying nutrient reduction levels. The models are undergoing further testing and will be useful in estimating the nutrient reduction required to reduce algal blooms and long-term nutrient management goals.

Satellite and remote sensory tracking of algal blooms

  • Studies have begun using satellite and other remote sensing technology to measure the extent of algal blooms in Lake of the Woods and other parts of the Lake Winnipeg watershed. Compared to studies using ground samples alone, these observations provide data on a more regular basis and over a broader area. Observations are used to illustrate seasonal changes in algal blooms and water quality. In September 2009, an extensive cyanobacteria bloom was tracked on Lake of the Woods and will aid in the study of how wind impacts the movement of algal blooms. Field surveys were completed in 2009 and will continue in 2010. In 2012, it is hoped that near-real-time observations will be available through the web to provide prompt assessment of water quality conditions across the Lake Winnipeg basin.

“Fingerprinting” the source of nutrients through stable isotope analysis

  • Researchers are tracking naturally occurring stable isotopes in fish and nutrients as a way to “fingerprint” the source and movements of phosphorus and nitrogen as they move through Lake Winnipeg’s foodweb. These measurements will be useful in tracking changes in nutrients entering the lake and the long-term impacts of eutrophication, invasive species and measures taken to address these issues.
  • From 2008 to 2010, stable isotope research developed a baseline for understanding the structure of Lake Winnipeg’s aquatic food web and its relationship to water and nutrients entering the lake. Beginning in 2010, research will centre on data related to water birds (i.e. cormorants) and trace metal concentrations in the fish they ingest from the lake.
  • Stable isotope fingerprinting is also being used to identify the various point and non-point sources of nutrients to Lake Winnipeg. These studies will analyse the nutrient cycles and how they contribute to algal blooms and eutrophication processes that have the potential to create “dead zones” within the lake. Following two years of sampling (2008-2010), a database of this information is being established for Lake Winnipeg, its major tributaries and wastewater treatment plans. This work will continue along major rivers until 2012 and will ultimately reveal major nutrient sources to the lake and assist in developing targets for future nutrient control.

Monitoring movement of nutrients, toxins and oxygen to Lake Winnipeg

  • Researchers continue to monitor nutrient sources in major tributaries to Lake Winnipeg in order to better understand how nutrients enter and move through the lake and their potential impact on algal blooms. Phosphorus is brought to the lake through external sources such as precipitation, runoff and groundwater. Internal phosphorus is also made available from within the lake through processes such as mixing from bottom sediment
  • In 2008 and 2009, research was conducted on the MV Namao to gather top sediment samples from the lake’s north and south basins. This research is intended to develop a better understanding of nutrients moving through the lake and its tributaries and their contribution to the spread of algal blooms and invasive species. Based upon this research, a summary of the lake’s toxin levels (2008/09) was completed and a preliminary report of nutrient monitoring within the Lake Winnipeg basin was prepared. The collection and analysis of biological and toxin samples are continuing.
  • A long-term investigation is also underway to determine the level and movement of dissolved oxygen within the lake. This research is crucial to better understanding conditions required to ensure future survival of Lake Winnipeg’s aquatic ecosystems because excessive algal growth and increased oxygen demands can result in further eutrophication of the lake. Water quality profiles at various depths is underway at 65 stations across the lake’s north and south basins of Lake Winnipeg to determine seasonal dissolved oxygen patterns and productivity.

Lake of the Woods

  • In 2008, the Lake Winnipeg Basin Initiative and partners launched extensive research and monitoring on Lake of the Woods to evaluate major sources of nutrients entering the lake. Over the first two years of the initiative, 28 stations were monitored for water quality and common algal species. Data on other indicators are also being gathered to establish a baseline for future measurement of the lake’s overall ecological health. Models have also been developed to predict patterns in nutrient growth and movement of algae across the lake and are now being compared with water quality data.

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PHOTOS

photo of scientist holding up container with Lake Winnipeg water sample

Dr. Len Hendzel (Fisheries and Oceans Canada) holds up sample of water taken during algae bloom on Lake Winnipeg Photo Credit: Sue Watson, 2009

scientists observing algae bloom on Lake Winnipeg from deck of ship

Scientists observe algae bloom on Lake Winnipeg from deck of the Lake Winnipeg Research Consortium’s M.V. Namao. Photo Credit: Sue Watson, 2009.

satellite image of algae bloom on Lake of the Woods

Satellite image of algae bloom on Lake of the Woods in September 2010. Photo credit: Caren Binding, Environment Canada, 2010.