LAKE HURON—Low water levels, invasive species, pollution and the most recent thing to worry about in our Great Lakes? Plastics, specifically ‘microplastics.’
In a July study of the Great Lakes, Dr. Sherri Mason, a chemistry professor at the State University of New York at Fredonia in New York State has found that of all the Great Lakes she has sampled (Superior, Huron and Erie), each one contained high amounts of microplastics.
Originally from Texas, Dr. Mason told The Expositor the thought of doing such a study came to her during the summer of 2011 during her first sail on the Great Lakes with a boat full of environmental studies students. “While I was out there, I was immediately hit with thoughts of the ‘Great Pacific Garbage Patch,’ which is not a giant garbage patch like it sounds, but is full of microplastics,” she explained, adding that while the Great Lakes looked just like water, she questioned that with so many people living around their shores whether there were similarities between the lakes and the Pacific. It turns out she was right in her assumptions.
“I was shocked when I got back and found that there had been no research on this topic and the Great Lakes at all,” she said.
Thanks to a $10,000 grant from The Burning River Foundation (an organization whose mission is to maintain and improve regional freshwater resources), plus training and tools from the 5 Gyres Institute (which seeks to eliminate plastic pollution in the oceans), Dr. Mason was able to take 21 samples from three of the Great Lakes this July, eight of which came from Lake Huron. The samples taken closest to Manitoulin came from near St. Joseph’s Island, she noted, and these also showed the largest amounts of plastics in Lake Huron—up to 5,000 pieces of plastic per square kilometre.
“It’s not a huge cross-section of the lake,” she admitted, adding that she found, just as she suspected, that the concentration of plastics increased as the population did. Lake Superior had the smallest number of plastics in a sample, Lake Huron had more and Lake Erie had the most—up to 600,000 plastic particles per square kilometer in two of this lake’s samples.
“The majority of what we found are microplastics,” Dr. Mason said. The net used to take the samples can catch particles ranging from 0.333 microns to one millimetre. “We also did catch bigger pieces too, but the majority are microplastics. This was surprising and interesting.”
“Eighty percent of what they find in the ocean comes from land—the proverbial plastic bag that goes from being stuck in a tree to the ocean. As it journeys, it becomes smaller and smaller,” the professor continued.
She said that due to the dry summer with little rain and therefore little runoff, a wetter summer would probably add to the proliferation of plastics in the water. It’s this theory that is bringing Dr. Mason back to the Great Lakes, and specifically to Lake Erie, next May.
So where is it coming from, she asked. Was it from bigger pieces of plastic that have been degraded, or have they been released from industrial abrasives, exfoliants or cosmetics? “Facial cleansers use ‘exfoliating microbeads.’ They are so small they go right through the wastewater system,” she said. “We don’t know which is the case, and it’s probably a mixture of the two.” But these microbeads are plastic pieces just as are the pieces of the shredded plastic shopping bag or the pulverized plastic water bottles.
Dr. Mason said scientists could make the comparison to oceanographic studies that see these microplastics ingested by marine life.
During a talk on her findings at the Healthy Lakes conference in Cleveland this fall, Dr. Mason was told that it was a well known fact in the Great Lakes that there has been a steady decline in the smallest organism in the lakes, zooplankton. Perhaps, one professor ventured, this was due to the prevalence of microplastics in the Great Lakes.
Scientists who study microplastics in the ocean have also found that plastics attract very dangerous chemicals as cling-ons, such as DDT, PCBs and nonylphenols—all harmful to human health.
“The Great Lakes have historically been known as harbingers of these chemicals,” she added, saying that analysis of these samples is currently underway. “The next question is, ‘if a fish eats these particles, will they work their way into the fatty tissue of these animals and then higher up in the food chain’?” she asked.
Dr. Mason is hoping to do further studies on Lake Erie and plans to sample Lake Michigan in August.
