Microplastic Beach Pollution

Microplastic (plastics < 1 mm) pollution is a growing environmental concern. Primary sources of microplastics involve the direct release of microplastics into the environment, such as synthetic fibers released in washing machine effluent, microbeads in cosmetic products, and pre-production pellets that are spilled during transport. Secondary sources involve the breakdown of macroplastics into smaller particles. Microplastics are an environmental problem because they can carry persistent organic pollutants and can easily be mistaken as food and ingested by animals. Here we investigated the presence of microplastics in sediment samples from two Lake Michigan beaches—Oval Beach, Saugatuck, and North Beach, Ferrysburg. Samples (approx. 1.5 L each) were collected at 5 m intervals along a 20 m transect line placed along the beach’s storm strandline. Each sample was then fluidized in an elutriation column to separate out the lighter particles, which then underwent a density separation from the remaining sediment using NaI. The supernatant of this density separation was visually inspected using a dissecting microscope to quantify the amount of microplastic particles. While macroplastics were found in all 10 samples, only 9 out of the 10 contained microplastics, with abundances ranging from 0 to 25 particles/L. The average microplastic abundance for Oval Beach was 6 particles/L and the average abundance for North Beach was 14 particles/L. These preliminary results demonstrate that microplastic pollution is present along Lake Michigan beaches. Further research is needed in order to determine the recovery efficiency of the elutriation tower, which will help us better quantify the abundance of plastic at various beach sites.