An Emerging Threat to the Great Lakes

Photo Courtesy of 5 Gyres
Photo Courtesy of 5 Gyres

The Great Lakes are a unique ecosystem, home to thousands of plant and animal species and contain more than 20% of the world’s surface freshwater, which is less than 1% of all the water in the world. Also within the basin are more than 40 million people that rely on the lakes for water, food, and employment. As this relationship between people and the environment continues to evolve, there continue to be major alterations to the Great Lakes system. One major concern that has recently garnered more media attention is the presence of plastics pollution. The plastics that are quickly becoming more of a concern can be classified in two ways, macro-plastics ( greater than or equal to 5 millimeters in diameter) and micro-plastics (less than 5 millimeters in diameter). The materials are found in many of our everyday personal care products; face wash, body wash, and toothpaste, but can also come from larger pieces of plastic that have been broken down. These small particles are a concern for a few reasons the concentrations here are much higher than expected, these particles can be mistaken as food by forage fish, and recent research has shown that plastic beads can be vectors of transportation for toxins.

Sherri Mason from State University of New York (SUNY), partnered with 5 Gyres Institute and conducted the first study to evaluate plastics pollution in the Great Lakes. Since then other research has been conducted by other teams of scientists such as Dr. Lorena Rios Mendoza who worked on Lake Michigan. Inland Seas Education Association, a Great Lakes science education non-profit based out of Suttons Bay also collected some initial samples in the summer of 2013 for Mason and her team. In July of 2012, aboard ‘US Brig Niagara’, Mason and her team of 20 students collected twenty-one samples in Lakes Superior, Huron and Erie and found that the concentration of plastics in Lake Erie is greater than the oceans, “[w]e had two samples in Lake Erie that we just kept going back and rechecking the data, because the count, the number of plastic particles in the sample, was three times greater than any sample collected anywhere in the entire world.”

Photo Courtesy of Inland Seas Education Association
Photo Courtesy of Inland Seas Education Association

Another concern is the fact that these plastic beads are being ingested by fish. The forage fish (smaller fish such as minnows or juvenile fish) and zooplankton (microscopic animals)are at the most risk, because they could confuse the beads with phytoplankton (microscopic plants), on which their diets are based. This could prevent nutrient absorption, create a physical barrier within the gut as well as present a choking hazard. Preliminary investigations highlight the fact that fish could be consuming plastic that are covered with toxins. These chemical pollutants adhere to the surface of the plastic bead and can “hitch a ride” through the Great Lakes.

Photo Courtesy of the Times Dispatch, Richmond, VA
Photo Courtesy of the Times Dispatch, Richmond, VA
Photo Courtesy of 5 Gyres
Photo Courtesy of 5 Gyres

As this new area of research continues to evolve, the results of these studies will continue to shape policies. Many companies have already agreed to phase out the use of microbeads in their products, which will certainly help. Plastic materials don’t go away. They simply break down into smaller and smaller pieces. By being aware of your individual plastic use and committing to using less, we can begin to decrease the amount of plastic that ends up in the Great Lakes.

How will you commit to using less plastic?

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Although I was born and raised in central Indiana, my heart has always been in the pinky region and I moved here as soon as I got the chance! My regular gig is at Inland Seas Education Association where I am the Education & Volunteer Coordinator. I teach Great Lakes science education aboard the schooner Inland Seas. I love all things Michigan, particularly the lake, beer and food but not always in that order. Drop me a line anytime to chat about science, the Great Lakes or anything else.