10,000 Metric Tons of Plastic Pollute Great Lakes Annually
Tracking the amount of plastic that enters the Great Lakes has led researchers from the Rochester Institute of Technology (RIT) to conclude that almost 10,000 metric tons of plastic from the United States and Canada pollute these bodies of water.
Publishing his findings in the Marine Pollution Bulletin as the lead author, Matthew Hoffman from RIT's School of Mathematical Sciences used computer simulations to follow the volume of plastic debris moving across state and international boundaries. "Most of the particles from Chicago and Milwaukee end up accumulating on the eastern shores of Lake Michigan, while the particles from Detroit and Cleveland end up along the southern coast of the eastern basin of Lake Erie," Hoffman shared. "Particles released from Toronto appear to accumulate on the southern coast of Lake Ontario, including around Rochester and Sodus Bay."
The study made use of mathematical modeling to extend the scope of the problem over time and spatial scales, going beyond the measures utilized by prior observational studies that concentrated on plastic pollution in the open water, tributaries and along the shorelines.
Hoffman and his coauthor, assistant professor of public policy Eric Hittinger from RIT, were able to trace that 5,000 metrics tons or half of the plastic pollution entering the Great Lakes went into Lake Michigan. Lake Erie would receive 2,500 metric tons of plastic while Lake Ontario ended up with 1,400 metric tons of plastic. Lake Huron got 600 metric tons of plastic and Lake Superior got 32 metric tons each year.
Hoffman noted that the plastic in the Great Lakes are carried by persistent winds and lake currents to the shore and could turn up in another country or state. This new inventory method is able to give full mass estimates on the entire connected lake system and is finally able to map plastic debris moving between lakes and across interstate and international borders. "This study is the first picture of the true scale of plastic pollution in the Great Lakes."