"The massive production of plastic and inadequate disposal has made plastic debris an important and constant pollutant on beaches and in oceans around the world, and the Great Lakes are not an exception," Lorena M. Rios Mendoza of the University of Wisconsin-Superior told a meeting of the American Chemical Society in New Orleans.
Much of the plastic pollution in the oceans and Great Lakes goes unnoticed because it is so small, Rios said, noting that in samples her team collected in Lake Erie 85 percent of the particles were smaller than two-tenths of an inch and much of that was microscopic.
Fish often mistake these bits of plastic for food, and Rios said her analysis of fish stomachs confirms they are consuming the plastic particles.
"The main problem with these plastic sizes is its accessibility to freshwater organisms that can be easily confused as natural food and the total surface area for adsorption of toxins and pseudo-estrogens increases significantly," Rios said.
While the Great Lakes research is new the problem of plastic pollution in the oceans has been widely known since at least 1988, when the National Oceanic and Atmospheric Administration first described the "Great Pacific Garbage Patch" in the North Pacific Ocean where currents have concentrated plastics and other pollution.
The patch changes in size at different times, but estimates indicate it has been as large as twice the size of Texas, researchers said.