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New Concerns About Plastic Pollution in Great Lakes ‘Garbage Patch’

Microplastics fro Great Lakes on Penny
A penny provides scale for the size of micro plastics being found in the Great Lakes ‘Garbage Patch.’ Credit: 5Gyres.

Until recently, my concept of a ‘garbage patch’ was of an area of ocean with large pieces of floating debris, the kind of stray fishing gear and trash from ships and shorelines that collect where currents form eddies far from view of most people.

Having seen my share of sea trash in 20,000+ miles of lake and ocean sailing and even untangled sheets of plastic and thick ropes from the propeller and rudder of my 37-foot sailboat, I was shocked to learn that the kind of garbage scientists are most concerned about is invisible to the naked eye. They’re finding tiny bits of plastic known as “micro-plastics” floating near the surface of the water in high concentrations. The particles are so small that a microscope is needed to even see them.

The scary news this week was about a garbage patch discovered in the Great Lakes last year. Although scientists have studied plastic pollution in the oceans since NOAA researchers discovered the “Great Pacific Garbage Patch” in 1988, a team of scientists is conducting the first-of-its-kind research on the open water of the Great Lakes. One of the team members presented preliminary results of a study on the topic at meeting of the American Chemical Society.

Photo: Great Lakes Garbage Patch research team. Source: 5Gyres
The team of researchers studying the Great Lakes ‘Garbage Patch’ in 2012. Credit: 5Gyres.

I spoke with Lorena Rios-Mendoza, an environmental chemist at the University of Wisconsin-Superior, and found that the buzz was certainly justified. Her background includes studying plastic debris and persistent organic pollutants (POPs) in the Pacific Garbage Patch and in the Southern Ocean. Now an assistant professor at the University of Wisconsin-Superior, she has turned her attention to these same issues on the North American Great Lakes.

“I’m interested in learning more about what happens to persistent organic pollutants when they attach to the plastic particles,” Rios-Mendoza told me. She is now studying 110 fish samples to see if they have plastic debris in their guts and to learn more about what happens to POPs associated with the plastic pollution. She wonders whether the accidental consumption of tiny bits of plastic by fish might be a new source for toxins in the food chain.

Photo: Sampling plastic pollution on the Great Lakes. Source: 5Gyres.
Sam Mason (on right) collecting samples of plastic pollution aboard the “Niagara” on the Great Lakes. Credit: 5Gyres.

Rios-Mendoza is working with a team of researchers led by Sherri “Sam” Mason, a SUNY-Fredonia chemistry professor and researcher at the forefront of research on plastic pollution within freshwater ecosystems, including the Great Lakes. Mason is actually an atmospheric chemist, but she also has a passion for environmental sustainability. A few years ago, a colleague at Niagara University invited her to teach an environmental science course aboard the Flagship Niagara, a rebuilt version of a tall ship used during the War of 1812 that is now used for on-water education programs. Having lived near the shores of Lake Erie for over ten years, she had never been out on the lake, let alone a sailboat, before teaching the summer course. Mason’s time on the water inspired her to take up an entirely new area of research: studying plastic pollution in the Great Lakes.

Modeling herself after scientists like Rachel Carson who are committed to sharing relevant research, Mason found that studying and trying to raise awareness about plastic pollution in freshwater systems suited her. “This is a fantastic area for research because the information is much needed and relevant to the scientific community and to people concerned about the Great Lakes,” she told me.

Mason and Rios-Mendoza have been working in collaboration with the 5Gyres Institute, a research and education group studying garbage patches in five subtropical gyres in the Atlantic, Pacific, and Southern Oceans.

Photo: Microplastic pollution in Lake Erie. Source: 5Gyres
Tiny pieces of plastic pollution found while sampling in Lake Erie. Credit: 5Gyres.

The team of researchers studying the Great Lakes wasn’t surprised to find plastic pollution, especially in Lake Erie, the smallest (by volume) and shallowest of the five lakes. They did find something interesting when comparing their results to the research in oceans. The concentration of PAHs (polyaromatic hydrocarbons) in Lake Erie is twice as high as what is found in the world oceans. “This makes sense because the oceans are so much larger – there’s a dilution factor,” Rios-Mendoza said.

Something else the research team didn’t expect was the predominance of micro-plastic particles (less than 1 millimeter in diameter). In the world’s oceans, scientists have found higher percentages of debris in the 1-5 millimeter diameter size range as compared to the micro-plastics. Mason suspects that this is because of the larger ratio of shoreline to open water, creating an abrasive action to break down the plastic.

Photo: Sample of micro plastics from Lake Erie. Source: 5Gyres.
A sample taken from Lake Erie showing micro plastics less than 1 millimeter in size. Credit: 5Gyres.

They’re finding tiny, perfectly round beads of plastic in many of the samples, and this might hold another clue about the source of particles. “The cosmetics industry uses plastic micro-beads in soaps, toothpaste and other products. Because the products are not designed for ingestion, they don’t have to test for this. It’s completely unregulated and may be a significant source of micro-plastics finding their way into the environment,” she says.

Finding the sources of plastic pollution and getting a better idea of the degradation process is the subject of follow-up studies Mason and her team are working on.

More research is needed to compare the amount of plastic pollution from one lake to the next, but Rios-Mendoza explained to me that it takes more than two hours of towing the fine-mesh sampling net in Lake Superior to recover the amount of plastic in a 30-minute trawl from Lake Erie. The team plans to sample the St. Lawrence River and Lakes Erie, Michigan, and Ontario this summer, and as funding allows, to carry out more systematic studies of all five lakes.

How do plastics end up in oceans and now lakes? Well to begin with, we have become a throwaway society. We’re using and throwing away more and more plastics, sometimes after only using them once. The plastics are designed to last a long time, more than 500 years in some cases, Mason told me. In the U.S. alone, we consume “billions” of plastic bags and bottles. According to the 5Gyres website, only five percent of the plastics produced for things like water bottles, cups, utensils, toys and gadgets are recycled. “Roughly 50% is buried in landfills, some is remade into durable goods, and much of it remains unaccounted for, lost in the environment where it ultimately washes out to sea,” their website states.

Photo: fishing boats on Lake Erie. Source: Lisa Borre.
From the deck of a boat on Lake Erie, micro plastics are not visible in the water. Photo by Lisa Borre.

Plastic pollution is not only a problem in the water but along beaches and shorelines as well. Beaches in Hawaii were found to contain 50% sand and micro-plastics, Rios-Mendoza told me. The research team has not studied the amount of micro-plastics on Great Lakes beaches yet.

The Alliance for the Great Lakes leads an Adopt-a-Beach program to address the problem of beach pollution throughout the Great Lakes region. Mason participates in the Adopt-a-Beach program and says that her students are always surprised by how much trash they find on a beach that doesn’t look that bad at the outset. She is also leading a one-week course this summer in collaboration with Pangaea Expeditions, collecting samples for future research along the way.

“People need to be aware that we are the source of the problem, and because of this, we need to be part of the solution,” Mason said. “We all need to become aware of how much plastic we use in our lives and avoid using single-use products. Don’t buy water in plastic bottles or cosmetic products with micro beads. Bring re-usable bags to the store with you. Simple things like this make a big difference, but it’s also important to keep talking about this issue and raising awareness about how it affects the Great Lakes and the world’s oceans.”

It turns out that even this observant sailor has sailed right through garbage patches on the Atlantic Ocean and Great Lakes without noticing anything but the deep blue water that appears infinitely transparent. Now I realize what all the fuss is about. These new findings give me all the more reason to find ways to reduce, re-use, and recycle plastic at home and on my boat.

In short, I need to do my part to reduce plastic pollution in the world’s lakes and oceans.

Lisa Borre is a lake conservationist, freelance writer and sailor based in Annapolis, Maryland. With her husband, she co-founded LakeNet, a world lakes network, and co-wrote a sailing guide called “The Black Sea” based on their voyage around the sea in 2010. She is a native of the Great Lakes region and served as coordinator of the Lake Champlain Basin Program in the 1990s.


  1. kyle
    Hamilton, MI
    December 3, 2015, 10:22 am

    Wow. I never knew. thanks for telling be about this National Geographic! I’ll sure be more careful about having plastic on the beach now!

  2. Sam
    October 11, 2015, 10:46 pm

    Hello, I’m a hs bio student doing some research. After reading your article, it seems there are new pollutants in the water but overall we are becoming more aware of the issues. Do you know if water pollution in Chicago (river and/or lake MI) has improved since the 1970’s?

  3. aye
    February 18, 2015, 3:38 pm

    that did not help

  4. dominear
    maple hight
    May 21, 2014, 3:05 pm

    help environment

  5. cory brown
    April 4, 2014, 1:02 pm

    i was at the beach with my youngings and our giant eagle bag we had got caught in the wind and flew away and i was unable to retrieve it is that bad???

  6. Brandon Polzin
    Marinette, WI
    October 24, 2013, 3:54 pm

    I like to eat a lot of plastic, is that OK?

  7. Tom Kelly
    Suttons Bay, MI
    June 10, 2013, 10:31 am

    Inland Seas Education Association will be working with Sherri Mason this summer to begin plastic sampling with our students aboard our schooner Inland Seas. We hope to make this a regular part of our sampling in northern Lake Michigan.

    • Lisa Borre
      June 10, 2013, 10:48 am

      Thanks, Tom, for all of the good work you’re doing on the schooner Inland Seas. That’s great news that you will be collaborating with Dr. Mason. Let us know what you find.

  8. Jeff
    June 8, 2013, 12:35 am

    It’s the earth + plastic.

  9. PeaceSeeker
    April 19, 2013, 1:42 am

    What do beer cans, car tires and water bottles have in common? Not much unless you’re renegade architect Michael Reynolds, in which case they are tools of choice for producing thermal mass and energy-independent housing. For 30 years, New Mexico-based Reynolds and his green disciples have devoted their time to advancing the art of “Earthship Biotecture” by building self-sufficient, off-the-grid communities where design and function converge in eco-harmony.

  10. Lisa Tyler
    Atlanta, Georgia
    April 18, 2013, 9:05 pm

    There are so many reasons that we need to curtail our plastic usage….this is just one of many. Modern usage of plastics is just ridiculous, wasteful and ugly. What was once considered a convenience is now causing all kinds of problems on our planet. It’s hard not to use it when it’s all that is offered in stores and restaurants but I’m trying to cut way back. I saw a documentary called “Bag it” that really opened my eyes. It’s even thought to cause health problems in children now. I wish they’d bring back the returnable pop bottles and all these water bottles that people buy and throw away, that’s just the silliest thing and should be banned.

  11. paulb
    April 17, 2013, 11:28 am

    excellent research focus – there’s a collaborative map i’ve started to engage people in Great Lakes issues – perhaps you could share some key findings on it? i hope so – we’ve got to get the word out. thanks for your work.

    • Lisa Borre
      April 17, 2013, 1:58 pm

      Paul, thanks for the information about your mapping project.

  12. Patricia Corcoran
    Western University, London, Ontario
    April 15, 2013, 11:36 am

    My research group has already published data concerning plastics pollution along the shoreline of Lake Huron (see Zbyszewski et al. 2011 in Water, Air and Soil Pollution). We also have data from Lakes Erie and St. Clair that will be published shortly.

    • Lisa Borre
      April 15, 2013, 12:57 pm

      I heard about your excellent research along the Lake Huron shoreline. Thanks for sharing the information here. I look forward to learning more about what you found on Lakes Erie and St. Clair.

  13. Matt
    April 15, 2013, 10:48 am

    Sounds a lot like my research 🙂

  14. Kip Cronk
    Bay City Michigan
    April 13, 2013, 12:04 pm

    We are a small grassroots organization with the vision of updating Michigan’s bottle bill to include all drink containers except dairy products. We know that 97% of containers with a deposit on them are returned in Michigan but only 20-30% of them without deposits are recycled. Our goal would have a significant impact on the amount of plastic littered in Michigan. We thank you for your article and hope that we can move ahead with our vision and reduce the amount of disposable plastics in our lakes, streams, wetlands and Great Lakes.

    We can be found at http://www.facebook.com/expandMIbottlebill or https://sites.google.com/site/embb2014.

    • Lisa Borre
      April 13, 2013, 12:55 pm

      Kip, thanks for your comment and the information about your efforts to reduce plastic pollution from drink containers. Good luck!

  15. merl
    April 12, 2013, 3:08 pm

    At the very least, don’t screw the lid back on an empty bottle or milk jug.

    • Lisa Borre
      April 12, 2013, 3:12 pm

      Good advice, Merl. Thanks for the comment!