The International Joint Commission, a treaty organization that advises the United States and Canada, says the two countries should do more to keep microplastics out of the lakes.
Microplastics are tiny pieces of plastic that are five millimeters or smaller. Microbeads are used in things like soap and toothpaste. Microfibers are tiny fibers that wash off our synthetic clothing, like fleece.
Those tiny plastics can end up in the Great Lakes and can get into fish.
Sally Cole-Misch is with the IJC. She says there's growing evidence that microplastics are harming fish and other creatures.
“We know that they are having effects on aquatic life as far as tumors. They have direct impact on survivability of some organisms,” she says.
She says scientists know more about microplastics in the ocean than they do about these plastic particles in the Great Lakes.
"We know there's significant amounts of microplastics out in all five of the Great Lakes," she says. "We don't know how much of that is coming from degraded plastics that's basic garbage, versus how much is released from water treatment plants."
Despite this knowledge gap, she says the IJC is urging the U.S. and Canada to do more.
"We do know enough to know that we need to be controlling the input of microplastics into the Lakes, and we need to do that even without all the extensive research, or even while that research is going on," she says.
The IJC is proposing a binational plan to prevent microplastics from entering the Great Lakes.
“We need to use market-based instruments, such as promoting lifestyle responsibility from plastic producers. We need to support state, provincial, and local policies for education to help people understand how they can reduce their use of plastics,” she says.
Both the U.S. and Canada have already banned the use of microbeads in certain personal care products (the U.S. ban takes effect this July). But Cole-Misch says there’s still more to be done.
“We know that both countries have certainly recognized the issue of microplastics, but we’re just trying to keep spurring them forward,” she says.