Mapping the Microplastics Threat in Georgian Bay - An Interview with Dr. Melissa Duhaime

In strategic partnership with an anonymous foundation, Georgian Bay Forever was chosen in 2026 to select for funding five standout research projects aimed at fortifying Georgian Bay’s ecosystem. Due to disbursement requirements, this funding could only be given to organizations registered in both the US and Canada, so while GBF could not directly receive funding, we have the honour of choosing and facilitating five projects directly in line with our mission to protect and conserve Georgian Bay through scientific research for long-term impact.

Project: Mapping the Microplastics Threat in Georgian Bay: Next-Generation Methods for Plastics Distributions and Ecotoxicology

Principal Investigator: Dr. Melissa Duhaime

Institution: Regents of the University of Michigan (U-M)

Ecology and Evolutionary Biology; Department Administration

How would you describe this project to someone you just met who knows nothing about the current state of this specific area of environmental research?

Microplastics are everywhere, in our water, our bodies, and the bodies of the animals that live in our lakes. Georgian Bay is a beautiful, ecologically rich freshwater environment, and we know plastics are there too. Yet, very little data exists for the smallest microplastics most important for Georgian Bay health and the animals, including humans, that depend on it for sustenance. These plastics are barely visible to the human eye, and we don’t have a good idea of where they are accumulating in the environment, which organisms are most exposed to them, or what the impacts of that exposure are on their health.

Together with my colleagues, doctors Anne McNeil (University of Michigan) and Matt Hoffman (Rochester Institute of Technology), we are using advanced laboratory instruments to identify and map microplastics across Georgian Bay's waters and sediments at a level of detail that hasn't been done before. Based on the amounts of microplastics we find, we will use laboratory experiments to find out at what concentrations microplastics are harmful to worms that live in lake sediments; these organisms are at the base of the food web and are a bellwether for ecosystem health. We will also use knowledge of Georgian Bay hydrology, how water flows, to simulate the ways that currents move and transport microplastics of different sizes and shapes to better predict whether there are microplastics hotspots that can guide mitigation efforts. Our goal is to co-create science that results in open data and tools that Georgian Bay communities and decision-makers can use.

How did you get started in this area of research? What interests you about this field of study? (You can start with a childhood fascination, your work history and education—make it autobiographical.)

I am a microbiologist who studies aquatic ecology. This means I'm drawn to the question of what the small things that live in water are, and what their impacts are on how the total ecosystem functions. I began my career studying viruses in the ocean. Viruses are among the most abundant and impactful entities in any aquatic ecosystem. That work trained me to think carefully about the invisible parts of ecosystems, the things you can't see that have enormous consequences for ecosystem health.

Microplastics pulled me in through a similar logic. Once while on an ocean research expedition in 2011, I began seeing plastics turn up in Southern Ocean samples collected around Antarctica. I’d been looking for zooplankton zipping around in small jars of water, but instead I saw bright orange, yellow, purple, and blue thin filaments. It was obvious from their size and shape that they were fibers that had shed from fishing lines, especially given the fisheries activity in that most remote part of our planet. The discovery hit me hard, a sinking feeling in my gut that imparted the gravity of the observation.

I founded my own lab in 2012 and, together with the lab members, we turned our sights on the Great Lakes. We joined a growing number of microplastics researchers who were beginning to understand how little was known about where they go and what they do. This hits close to home for many of us who grew up in Great Lakes states and provinces. The issue of microplastics is both urgent and local. The Great Lakes are a vital part of our identity in this part of the world; many of us feel a strong connection to them. Day to day, they provide drinking water and food for millions of people. This centrality to the livelihoods of the people in our region makes the research a responsibility, not just a career or intellectual pursuit.

Why does Georgian Bay and the environment at large need this research right now?

This is an important moment for microplastics research. Legislation to address microplastics pollution is being discussed at the federal level in both the US and Canada, and in multiple Great Lakes states and Ontario. Policymakers want to act, but the science they need to set data-driven and enforceable thresholds doesn't yet exist. One challenge for this new research field has been that discoveries are highly dependent on the analytical and statistical methods that exist. This has meant that early data can be inconsistent, collected with different methods, and often focused on the largest plastic particles. However, we know that the smallest ones carry the greatest biological risk. 

Georgian Bay is a perfect study system to address this challenge. It's large, biologically rich, and very important for fisheries, for drinking water, for Indigenous communities who have stewarded these waters for generations, and for the millions of people who recreate and live along its shores. And, like many places, the microplastics data for Georgian Bay are sparse and patchy.

But the research community is at a place where our analytical tools have caught up to the questions we are trying to answer. Methods like O-PTIR spectroscopy can now detect and characterize plastic particles down to one micrometer, the size range that may matter most biologically, in ways that weren't possible just a few years ago. We have an opportunity to generate high-resolution, harmonized data that can support the policy and management decisions being advocated for.

How will this project affect the ecosystem of the Georgian Bay area and the Great Lakes in the long run? (Even if you don’t anticipate immediate change, tell us about the ripple effect, the long-term implications, etc.)

The most immediate contribution is data. Right now, the absence of good data is itself an obstacle to protecting Georgian Bay. Risk assessments can't be built on sparse or inconsistent measurements. As a human, I believe that there is no “minimum threshold” of microplastics that is ethically permissible. There should be no microplastics in Georgian Bay. Yet, I’ve also come to understand how thresholds can be used as a tool for communicating risks, and these thresholds need evidence from dose-response experiments. Our work will fill those gaps directly. We will generate open-access maps of microplastics distribution across Georgian Bay's waters and sediments, and we'll produce a controlled ecotoxicology study of a Great Lakes benthic species under environmentally realistic microplastics exposures.

That data will flow into the models, risk assessments, and policy frameworks that govern how these lakes are protected. It will be submitted to international databases that researchers around the world use to calibrate their own assessments. It will be shared with Georgian Bay Forever, the Anishinabek/Ontario Fisheries Resource Centre, and regional communities, so that local stewardship can be grounded in local data.

Longer term, I hope this project helps establish the monitoring infrastructure and community capacity for ongoing observation of microplastics in Georgian Bay, so that this isn't a one-time snapshot, but the beginning of a sustained effort. The ripple effect we are hoping for is a Georgian Bay where communities have the evidence they need to protect these waters and the ongoing capacity to keep watching.

What advice would you give to individuals who want to help create a more sustainable environment?

Start with what's in front of you, what is in your hands, at your feet, in your gaze. The Great Lakes hold 20% of the world's surface freshwater. Paying attention to your local water, your local land, your local food systems is not a small thing. It's how change happens. Stop talking just for a moment. And take notice.

From there, I'd say underestimate the power of community knowledge and get engaged. The most important insights come from residents and Indigenous communities who know these waters and have been watching them for generations. Strong environmental stewardship is always collaborative.

And on the personal side, reduce your plastic footprint where you can. Know that individual choices matter, but they're not sufficient; we are parts of a bigger strategy. Advocate for system change and strategy designed in a new vision. Support organizations doing monitoring and restoration work in your communities. Show up to town halls. Communicate to representatives when microplastics legislation is being considered. Science can only do so much if it isn't met by political will, and political will follows from an engaged, informed public.