When Going “Green” Isn’t Good – the Case of Lake WInnipeg

Over the past summer, increasing algae blooms along popular beaches in Manitoba have brought Lake Winnipeg to the forefront of public debate. What is causing these increases in blue-green algae and what is being done to restore the lake’s ecological balance?

Although algae blooms are a major reason that the general public is paying more attention to Lake Winnipeg these days, scientists have been studying the lake’s health for years. It’s a fact that water quality in Lake Winnipeg has been diminishing because of increased nutrients, such as phosphorus and nitrogen, mainly from agricultural run-off and municipal wastewater. Blue-green algae blooms in the water reduce oxygen levels, clog fishing nets, foul beaches and produce toxins harmful to humans, wildlife, and the lake’s entire aquatic ecosystem.

Science at work

It is well known that presence of nutrients is the leading cause of the lake’s problems. But more knowledge is still needed to make informed decisions about how to best clean up the lake. Through the four-year Lake Winnipeg Basin Initiative, Environment Canada researchers are working with Manitoba Water Stewardship colleagues and other federal departments and partners to provide a more comprehensive understanding of the lake and its watershed. Their goals include:

• Developing the historical and current data to illustrate the state of the lake and its physical, chemical and biological make-up to better understand how nutrients can be balanced and their impacts on fisheries.
• Establishing goals and monitoring sites for future management of nutrient levels in the lake.
• Locating and managing sources of nutrients flowing into the lake and reviewing beneficial management practices for agricultural producers.
• Assessing the economic value of clean water and the effectiveness of regulations and social policy on nutrient management across the watershed.
• Developing a scientific basis for establishing nutrient level goals across the watershed.
• Creating a single on-line portal for sharing data among key scientific partners and networks.

Current federal science on the lake

Algae blooms

Environment Canada scientists, Manitoba Water Stewardship and other key research partners are conducting studies and activities on topics ranging from models of the lake’s circulation to tracing the processing of nutrients, and providing a deeper understanding of how algae blooms form and expand across the lake. This work is being conducted directly on the lake with the Lake Winnipeg Research Consortium’s M.V. Namao research vessel, as well as using satellite imagery, remote sensing and sampling instruments moored in tributaries across the watershed.

Dr. Sue Watson’s research on the link between phosphorous and nitrogen levels and algae blooms is a key project of interest to the general public and decision-makers across the watershed.  Along with other researchers from within and outside the federal government, Dr. Watson is studying the species that make up algae blooms and their impact on water quality – particularly toxic blooms such as cyanobacteria which are harmful to humans, livestock, fish and wildlife.

Research scientists, Dr. Robert Bukata and Dr. Caren Binding have also been working with partners to further develop an understanding of algae blooms. Their work looks at the relationships between wind stirring and the movements of algae blooms by using satellite imagery and remote sensing. Their methods complement sampling done on the ground in other parts of the lake and provide excellent tracking of large-scale algal blooms, such as the Lake of the Woods bloom of September 2009. 

Dr. Ram Yerubandi’s work combines field studies and scientific modeling to create a more concrete understanding of possibilities for the future management of nutrients and, ultimately, algae blooms. The research and modeling of Dr. Yerubandi and his colleagues will show how water movements at different levels of the lake impact nutrient levels and algae blooms to increase or decrease eutrophication.

Before goals can be set for improving the health of Lake Winnipeg, and reducing algal blooms, it is important to understand the extent of the current problem and its impacts on the lake. One of the key impacts of the algae blooms in Lake Winnipeg is eutrophication, lowering oxygen levels created by the presence of excess nutrients, such as nitrogen and phosphorus. Dr. Leonard Wassenaar’s work on stable isotope tracers and oxygen mapping will help illustrate changes that are occurring within Lake Winnipeg’s eutrophic ecosystems by tracking changes in the food chain and “finger-printing” sources of nutrients. This research will provide a benchmark for oxygen levels that can be used to measure future improvements in the lake’s health.

The impact of human activities--for instance, releasing effluents into waterways and agricultural practices--are also being studied to determine how the interaction of climate and geography and agricultural land-use have contributed to phosphorus and nitrogen levels in Lake Winnipeg. Dr. Terry Prowse, Dr. Phillip Marsh and partners are studying Lake Winnipeg’s tributaries to see if changes in farming practices and levels of run-off or spring flows have a relationship to changes along key tributaries such as the Red River and areas where there has been significant wetland drainage. To further measure the impact of human activities, Dr. Patricia Chambers is working with research partners to determine the runoff rate of agricultural nutrients (nitrogen and phosphorus) into streams and ditches and entering major rivers such as the Red and Assiniboine.

Dr. William Booty is now undertaking work in to establish a Lake Winnipeg Research Portal that will ultimately tie together all the ongoing scientific research in the Lake. According to Dr. Booty, “The portal will be a one-stop shop for all Lake Winnipeg researchers. Technically, it will provide all the data required to support research on the lake. From a communications perspective, it will allow us to share results with the public once the research is fully reviewed.”

The portal is in the final stages of testing with stakeholders in the scientific community and is expected to be completed in 2012. All key partners in Lake Winnipeg research will have access to consistent and continually updated data on the state of the lake. A report that will be a key complement to this portal is the State of the Lake Report, a historical portrait of the lake’s physical and chemical composition from 1999-2007, developed by the Government of Canada and Manitoba Water Stewardship.

While significant work has already been completed, the scientific community working on Lake Winnipeg acknowledges that there is still more to be done. Lake Winnipeg’s basin is geographically daunting, encompassing almost one million square kilometres and ranging across four provinces and four U.S. states. To make decisions, governments need to work collaboratively and they need solid data and research on which to base their decisions. The work of the Lake Winnipeg Basin Initiative’s scientists will help partners across the watershed to act on the lake’s condition based upon solid scientific data and conclusions. Scientifically sound and informed actions for the future and health of Lake Winnipeg will leave a healthier lake for all to enjoy.

This September, the Government of Canada and the Province of Manitoba officially signed the Canada-Manitoba Memorandum of Understanding Respecting Lake Winnipeg and the Lake Winnipeg Basin. This agreement provides the foundation for a long-term, collaborative and coordinated approach between the two governments to ensure the sustainability and health of Lake Winnipeg. Also formalized in this accord is the assurance of ongoing collaboration between the two governments in scientific research and monitoring throughout the basin, and in coordinating their respective program activities to protect the health of Lake Winnipeg and its watershed.

For more information on this recent announcement, the Lake Winnipeg Basin Initiative’s science program and other new on what Government of Canada is doing for Lake Winnipeg, visit Environment Canada’s Cleaning Up Lake Winnipeg website.