Study confirms microplastic pollution in the Ottawa River Watershed


OTTAWA, ON: October 17, 2016. The Ottawa River is joining the ever increasing list of water bodies across the globe experiencing significant microplastic pollution according to researchers from Ottawa Riverkeeper and Carleton University who have just completed the first-ever study of microplastic pollution in the Ottawa River watershed.  Microplastics – defined as plastic fragments, fibres, and microbeads of less than 5mm in diameter – are entering our surface waters in significant concentrations.  Plastic don’t break down, accumulating in our waterways in the water column and sediment as well as the aquatic food chain.   

First ever study in the Ottawa River

Dr. Meaghan Murphy (Ottawa Riverkeeper) and Dr. Jesse Vermaire (Carleton University) deployed a manta trawl, a large net system with a fine mesh net that attaches to the back of a motorboat, to collect surface water samples above and below the City of Ottawa’s sewage treatment plant. In addition, twenty citizen scientist volunteers from Ottawa Riverkeeper’s Riverwatch program hand-filtered samples at locations spanning over 550 km of river, from Lake Timiskaming in the north to Hudson, Quebec near the mouth of the river.

  • The Ottawa River has microplastic pollution levels higher than those reported in some ocean studies.
  • Microplastic concentrations in the Ottawa River are similar to those reported for Great Lakes Tributaries [1] and other major rivers in Europe [2].
  • Microplastics were found at all 58 sampling sites throughout the watershed including 6 tributaries which had the highest concentrations in Ottawa/Gatineau region.

“It is worrying how wide spread this type of pollution really is and how little we actually know of the long term impacts on river health and human health,” says Dr. Meaghan Murphy, staff scientist at Ottawa Riverkeeper and one of the lead researchers on this study.  

Microbeads in our watershed

The international movement to ban microbeads in personal care products has gained significant momentum globally with the help of studies such as this that have highlighted the problem to our waterways. The US banned the sale and use of microbeads in personal care products (e.g. toothpaste, soaps, shampoos, etc.) in December 2015.  Thanks to the work of many Canadian organizations such as Ottawa Riverkeeper and Lush Cosmetics, Canada’s federal government has listed microbeads as a toxic substance under the Canadian Environmental Protection Act, and is on track to ban microbeads by December 2017.  

  • This study found that concentrations of microbeads were nearly 16 times higher directly downstream of the City of Ottawa’s sewage treatment plant, indicating that the plant is a significant source of microbead pollution to the river.
  • With this baseline data, researchers will be able to quantify reductions in microbeads pollution as the ban comes into effect in Canada.

“The microbead ban is set to be a major victory for Canada’s waterways,” says Ottawa Riverkeeper’s Executive Director, Patrick Nadeau. “However, until the ban is actually put in place, microbeads will continue to make their way into our watershed’s rivers. We all need to do our part by continuing to pressure the government to implement this ban in a timely manner, and avoiding the purchase of products that contain microbeads.”  

So where are all these microplastics coming from?  

Our increasing reliance on plastics in our everyday lives is the main culprit behind widespread microplastic pollution in our waterways.  Everyday microplastics are washed down our drains, into our treatment plants and out into our rivers. Rain and wind also carry micoplastics from land into our waterways.  

The study separated the microplastics into different types and found the majority (74%) of microplastics in the Ottawa River are plastic fibers, followed by plastic fragments (18%) and finally microbeads (9%)

  • Synthetic clothing is thought to be a major source of microplastic fibers, with a single garment releasing nearly 2000 fibers when washed [3].  
  • Plastic fragments generally come from the breakdown of larger plastic garbage (e.g. bottles, straws, cigarette tips)
  • Microbeads largely originate from personal care products that we wash with including soaps and toothpaste.  
  • The Ottawa sewage treatment plant was found to be a point source of microplastics for the river, with concentrations downstream of the plant that were 3 times higher than upstream.

The upcoming regulation to ban microbeads in personal care products is an important first-step in tackling the microplastic pollution issue in the Ottawa River watershed and waterways throughout Canada. However, there is still more to be done.  “More than 90% of the microplastic pollution in the Ottawa River comes from sources other than personal care products,” says Dr. Murphy, “We can all do our part by going on a plastic diet…reducing, reusing and recycling the plastics we do use, and picking up plastic litter in our neighborhoods, but the government needs to do its part too.  We need more research on the environmental impacts of these pollutants and strategies for reducing inputs from other major sources besides personal care products.”


Ottawa Riverkeeper is grateful to all our sponsors, collaborators, and volunteers: without their assistance, we would not have been able to carry out a study of this magnitude. Funding was provided by the Ottawa Wave Makers grant program created by Impact Hub Ottawa and World Wildlife Fund Canada, and the Muskoka Brewery & Evergreen Fresh Water Grant Program.

[1] Baldwin, A.; Corsi, S.; Mason, S. Plastic Debris in 29 Great Lakes Tributaries: Relations to Watershed Attributes and Hydrology. Environmental Science & Technology. 2016 Sept. 14

[2] Breuninher, E; Bänsch-Baltruschat, B; Brennholt, N; Hatzky S, Reifferscheid, G.  Plastics in European Freshwater Environments. June 2016.

[3]  O’Conner, Mary Catherine.  “Inside the lonely fights against the biggest environmental problem you’ve never heard of.” The Gaurdian, 27 Oct. 2014,  Accessed 3 Oct. 2016.




Ottawa Riverkeeper:


Dr. Meaghan Murphy

Staff Scientist

Tel: 613-301-9762


Adele Michon

Director of Operations for Quebec

Tel: 819-576-2123



Carleton University:

Dr. Jesse Vermaire

Assistant Professor, Department of Environmental Science, Geography & Environmental Studies

Tel: 613-520-2600 x 3898


About Ottawa Riverkeeper:

Ottawa Riverkeeper (in French: Sentinelle de la rivière des Outaouais) is a citizen-based action group that brings people together to protect and promote the ecological health and diversity of the Ottawa River and its tributaries.  Expert and independent, our organization advocates for responsible decision-making, public education, participation, access to information, and compliance with protective regulations, for the benefit of our river and our communities.
Ottawa Riverkeeper is a licensed member of Waterkeeper Alliance, an international grassroots advocacy organization, founded by Robert F. Kennedy Jr.


2 responses to “Study confirms microplastic pollution in the Ottawa River Watershed”

  1. […] becoming apparent that our freshwater ecosystems aren’t immune. Studies in the Great Lakes and Ottawa River reveal a higher density of microplastics than in ocean […]

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