The Urgent Challenge of Toxic Algae Blooms in Lake Winnipeg

Lake Winnipeg, one of Canada's largest freshwater lakes and the 11th largest globally by surface area, has long been plagued by recurrent toxic algal blooms. These events, primarily driven by cyanobacteria—also known as blue-green algae—create thick, scum-like mats visible from space, as captured in satellite images from 2018 showing green streaks stretching hundreds of kilometers. Phosphorus and nitrogen runoff from agricultural fields, urban wastewater, and major floods like 1997 have fueled eutrophication, doubling phosphorus levels between 1990 and 2000. By 2013, the lake earned the grim title of the world's most threatened lake, with blooms closing beaches, killing fish, and posing health risks through cyanotoxins such as beta-methylamino-L-alanine (BMAA), linked to neurodegenerative diseases.

In Manitoba, these blooms disrupt commercial fishing for walleye and tourism, costing millions annually. The south basin, hypereutrophic with high phosphorus, sees the worst impacts, while climate change exacerbates the issue with warmer waters and longer ice-free periods, mirroring Lake Erie's trajectory.

Pioneering Microbial Research at the University of Winnipeg

The University of Winnipeg is at the forefront of addressing this crisis through innovative microbial ecology studies. In the Department of Biology, researchers are delving into the lake's unseen world of viruses and bacteria to unlock natural controls on algal proliferation. This work not only highlights the university's commitment to environmental science but also trains the next generation of Canadian scientists in aquatic microbiology.

Complementing phosphorus reduction efforts—like Manitoba's goal to cut lake phosphorus by 50% and federal funding of $1.6 million in 2025 for nutrient controls—these studies offer biological insights. For aspiring researchers, opportunities abound in higher ed research jobs focusing on freshwater ecosystems.

Dr. Emily Chase: Trailblazing Virologist Leading the Charge

Dr. Emily Chase, who joined the University of Winnipeg in 2025, is spearheading the first-ever study of algal viruses—phycoviruses—in Lake Winnipeg. A virologist and microbiologist with a PhD from Aix Marseille Université and postdoctoral experience in France and the U.S., Chase shifted focus to this understudied lake after returning to Canada amid U.S. political changes.

"Viruses, in particular ones that infect microalgae, are overlooked," Chase notes, emphasizing their role in the lake's dynamics. Funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), her lab collects samples aboard the Lake Winnipeg Research Consortium's M.V. Namao, analyzing virus-microalgae interactions with student trainees.

As one of few women in the field, Chase advocates for diverse perspectives in science, fostering inclusive training environments at Canadian universities.

Decoding Phycoviruses: Nature's Potential Algae Killers

Phycoviruses are viruses specific to phytoplankton, including microalgae at Lake Winnipeg's food web base. These single-celled, photosynthetic organisms convert sunlight to energy, feeding zooplankton, fish, and ultimately walleye. Viruses lyse (burst) infected cells, potentially crashing blooms and regulating populations—much like flu viruses control human outbreaks.

Chase's research maps viral distribution, infection rates, and bloom cycles. Early hypotheses suggest viruses drive 'bloom-bust' patterns: initial non-toxic blooms collapse, releasing nutrients for toxic cyanobacteria secondary blooms. Understanding this could predict safe swimming windows and toxin releases.

Step-by-step: 1) Sample collection across basins; 2) Viral DNA/RNA sequencing; 3) Infection assays; 4) Modeling interactions. This builds on global data but tailors to Lake Winnipeg's unique freshwater profile.

Exploring Bacteria and the Full Microbial Community

Beyond viruses, bacterioplankton—free-floating bacteria—interact with algae, decomposing organics and cycling nutrients. Past studies show Lake Winnipeg's microbes shift seasonally, with cyanobacteria dominating summers. Chase's work integrates these, as bacteria host bacteriophages that indirectly affect algae.

Comprehensive profiling reveals diversity: aerobic anoxygenic phototrophs near zebra mussels, coliforms with cyanobacteria. Toxin biomagnification via BMAA in food chains threatens wildlife and humans. Chase's holistic view could reveal synergies for bloom suppression.

• Beneficial bacteria outcompete algae for nutrients.
• Viral-bacterial loops recycle phosphorus.
• Climate warming alters communities, favoring pathogens.

Methods in Action: From Field Sampling to Lab Analysis

Chase's team deploys across Lake Winnipeg's 24,500 km², targeting north and south basins. Using the M.V. Namao, they filter water for microbes, sequence genomes via metagenomics, and culture viruses. Flow cytometry counts cells; qPCR quantifies viruses.

This rigorous process—seasonal sampling since 2025—yields baseline data absent before. Trainees gain hands-on skills in molecular biology, ideal for academic careers.

Potential Solutions: Biological Controls for Blooms

Harnessing phycoviruses could bio-control blooms, reducing chemical interventions. Modeling predicts collapse timings, aiding advisories. Integrated with phosphorus cuts—e.g., Ducks Unlimited's wetland restorations—offers multi-pronged strategy.

Stakeholders: Lake Winnipeg Foundation, Manitoba government, Indigenous communities. Global parallels: Virus therapy in Lake Erie trials.

Challenges Facing Lake Winnipeg Research

Remote logistics, variable weather, and funding gaps hinder progress. Climate unpredictability complicates baselines. Toxin analytics require advanced labs; public skepticism demands outreach.

Yet, UWinnipeg's interdisciplinary approach—biology, chemistry, modeling—overcomes these, training resilient scientists.

Broader Impacts on Ecosystems, Economy, and Health

Blooms deoxygenate waters, killing fish; toxins bioaccumulate, risking ALS-like diseases. Tourism ($100M+ annually) suffers beach closures; fisheries decline. Chase's insights protect biodiversity, economy, and health.

Training Future Scientists: Student Opportunities at UWinnipeg

Chase mentors undergrads and grads, building capacity in virology. Programs emphasize fieldwork, genomics, ethics—preparing for roles in conservation, policy. Canada needs such talent amid climate crises.

Explore Rate My Professor for insights or university jobs in biology.

Photo by Cohen Berg 🇨🇦 on Unsplash

Future Outlook: Collaborative Paths Forward

Ongoing NSERC funding promises publications, models. Partnerships with Lake Winnipeg Research Consortium expand scope. By 2030, integrated microbe-nutrient strategies could halve blooms.

For researchers, check research assistant jobs. AcademicJobs.com connects talent to these vital roles, positioning Canada as a leader in aquatic science.