More than 10 million pieces of litter have been removed from all five Great Lakes' shorelines.
The Chicago-based Alliance for the Great Lakes has been tracking trash collected by its Adopt-a-Beach volunteers for 21 years.
Surprisingly, it's not bikes or tires that volunteers find, the alliance said. It's mostly smaller bits of plastic trash.
Data from last year found 86% of collected trash was either fully, or partially made from plastic.
That's troublesome because single-use plastic breaks down into much smaller pieces called microplastics.
And those microplastics are making their way into our drinking water, fish and even human tissue.
"I am consistently humbled and inspired by the hard work Alliance Adopt-a-Beach volunteers do, using their precious free time to clean up the region's beaches. Plastic producers should give our volunteers a break by taking responsibility for the pollution they produce," said Joel Brammeier, Alliance for the Great Lakes President and CEO.
Follow this link to volunteer or join an Alliance for the Great Lakes Adopt-a-Beach cleanup event.