Scientists have found tiny plastic particles in all of the Great Lakes, the waste is bad news for both humans and the critters that call the bodies of water home.

"The accumulation of plastic particles is a great threat to our natural ecosystem and to the humans who use Lake Superior for our drinking water supply," Mary Balcer, director of the Lake Superior Research Institute at University of Wisconsin-Superior, told the Associated Press via The Duluth News Tribune.

The plastic can also absorb toxic chemicals, turning the fragments into endocrine-disrupting sponges. The plastic "sponges" are the perfect size for small fish to mistake them for food and gobble them up. Some of the plastic is so small that it is invisible to the naked eye. The majority of the particles are about the size of the scrubbing beads found in certain hygienic products.

"I was thinking at first, 'Oh, it is just a little microplastic, but then when I observed the sample under the microscope, we found thousands of micro bits and microplastic," Lorena Rios-Mendoza, assistant professor of chemistry at the University of Wisconsin-Superior, a leader of the study, told WDIO.

The particles are so small that they won't get filtered out in watersheds, which means humans that rely on the Great Lakes for drinking water could be ingesting the bits of plastic.

A research team dragged mesh nets through the water's surface, and were troubled by what they found. In Lake Superior, the particles were found in the sediment as well as floating freely through the water, the AP reported.

"It was very shallow where they were found, but they were in the sediment," Mendoza told the AP.

Lake Erie was found to contain the highest concentration of the harmful plastic, most likely because it sits downstream from the other lakes.

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