Industrial plastic is spilling into Great Lakes, and no one's regulating it, experts warn

As the people of Toronto flocked to the Lake Ontario waterfront to swim, paddle and generally escape pandemic isolation, Chelsea Rochman's students at the University of Toronto were throwing plastic bottles with GPS trackers into the water.

The research team's goal is to track trash that ends up in the lake, to figure out where it accumulates in the water and where it's coming from in the first place.

Using information from the tracking bottles, they chose spots to put in Seabins — stationary cleaning machines that suck in water all day and trap any garbage and debris — at marinas along the waterfront. They are emptied daily, and the debris collected in them is examined to ferret out what kinds of trash is getting into the lake.

The waste includes well-known single-use culprits like takeout containers and clear plastic packaging, but they also include something that gets less attention: pre-production pellets, produced by the plastics industry. 

"They're the tiny little pellets that are later melted down into plastic and different plastic products," Rochman said. 

"So we can trace them back to industry, they have a very distinct look. And then we are now working with industry to try to make sure that they capture them at the source so they don't come down into the lake."

An estimated 10,000 tons of plastic waste are getting into the Great Lakes every year, threatening one of the largest reservoirs of freshwater on the planet that supports nearly 50 million people in Canada and the U.S. A 2021 study on seven fish species in Lake Ontario and Lake Superior found "the highest concentration of microplastics and other anthropogenic microparticles ever reported in bony fish."