By: Grace Ruiter
Microplastic pollution in the Great Lakes has garnered its fair share of media coverage since a 2012 study found that, on average, there are 43,000 microplastic particles per square kilometer in the lakes. But little attention has been given to one of the probable sources of this pollution: rivers, including West Michigan’s own Grand River, which eventually flows into Lake Michigan.
The rivers that flow into the oceans are responsible for 80 percent of the plastic pollution in the oceans. University of Michigan professor Melissa Duhaime, who is leading a team of researchers trying to find out how the plastic impacts the ecosystem in the lakes, believes that the statistics are similar for the Great Lakes. Since the rivers are smaller bodies of water, the plastic levels may be even higher in the rivers than the lakes.
University of Michigan engineering professor Laura K. Alford, who is a member of Duhaime’s research team, hopes that Michigan will take a more active role in combatting microplastic pollution in lakes and rivers.
“I’d love to see [Michigan] become a leader in this,” she said. “We’re surrounded by Great Lakes. We need to get out ahead of the pack on legislation to protect the lakes in all manners.”
Researchers are starting to look at microplastic levels in Lake Ontario, and there are plans to study pollution in Lake Erie. However, it will probably be years before anyone takes a look at the Grand River, or any of the other rivers that flow into Lake Michigan. That means that we may not know how severe the plastic pollution problem is in the Grand River until the damage has already been done.
Scientists worry the microplastic particles are being mistaken for food by fish and birds. Since plastic is absorbent in water, it is possible that the plastic is soaking up dangerous toxins in the lakes and rivers. If fish and birds eat the plastic, they could introduce those toxins into the food chain. Ingesting the plastic may also fool fish and birds into thinking they are full, leading them to stop eating real foods.
Despite these alarming possibilities, Duhaime says there is no need to panic yet. Research on the ecosystem impact of microplastic is still in its early stages, and the current theories do not yet have significant evidence to back them up. Duhaime says it is even possible that microplastic particles have a positive impact on the fish that ingest them.
“If a fish is already contaminated [by chemicals] and it ingests a piece of plastic, it could even end up cleaning the fish’s tissue,” she explained.
Whatever the ecosystem impact, Duhaime’s research so far suggests fish are eating the plastic. Every fish her team has looked at so far has had plastic-looking particles in its stomach. Larissa Sano, one of the researchers on the team, will still need to confirm them as plastic using a spectroscopy.
Sherri Mason, an associate professor of chemistry at the State University of New York and the coauthor of the 2012 study, has gotten similar results in her research. So far, she has found an average of nine particles of plastic in the stomachs of perch from the Great Lakes. She also recently analyzed her first bird. It had 120 plastic particles in its gastrointestinal tract.
One of the main sources of plastic pollution is thought to be microbeads, which are small beads common in cosmetics products. Other culprits include nurdles — small plastic pellets used in manufacturing — and larger pieces of plastic, such as water bottles, that get broken down into small plastic pieces over time.
Some states are already taking legislative action to ban microbeads. Illinois recently became the first state to pass legislation banning them. A similar bill has been drafted in Michigan but has yet to pass through Lansing.
Researchers like Alford are also looking for solutions to the microplastic problem. In fact, Alford already has an idea for a wastewater treatment plant that could stop microbeads and nurdles in their tracks.
Microbeads and nurdles get into the lakes through wastewater treatment plants because they are too small for the plants to catch. Alford has submitted a proposal for an undergraduate research project that would see students work with her to develop a prototype for a self-cleaning wastewater treatment system capable of capturing the microplastic pieces:
“The problem is that the plastics are such tiny things that the filter would get clogged really easily, so we need something that would constantly clean itself. We’re thinking to make a prototype out of stock parts using current technology. We want to show people that you don’t have to reinvent wheel to find a solution.”