Date of Award
Campus Access Thesis
Master of Science (MS)
Marine Sciences and Technology
Plastic accounts for 70-80% of the marine debris on earth and has been recorded in marine organisms at various levels of the food chain. Plastic in the environment begins to degrade into smaller particles known as microplastics. Microplastics, less than 5 mm in size, have been discovered in the most remote island regions, which are particularly vulnerable to environmental stressors because of their physical insularity (isolation). Nantucket Island, off Cape Cod, Massachusetts has a rich maritime history and an economy largely dependent on seasonal tourism. The management of plastic waste on the island is already challenging, and this intensifies with the increase of waste from tourism. I evaluated the occurrence of microplastics on the island in 2019 and 2020 through the analysis of seawater and intertidal beach sediments from three beaches. Nantucket Harbor Town Pier Beach, Madaket Beach at Warren’s Landing, and Surfside Beach were selected for their varying geomorphology and land-uses to examine the influence of both anthropogenic activity and environmental conditions on microplastic concentrations. Sampling took place during months of the island’s off-season (fall/winter) and peak summer season to determine if the increased human activity results in higher microplastic pollution. To determine if microplastics were entering the marine food chain, samples of the eastern oyster (Crassostrea virginica), bay scallop (Argopecten irradians), and gray seal (Halichoerus grypus) scat were also analyzed for microplastics. Finally, I developed and implemented a science education lesson plan on microplastic pollution for middle school students to create awareness of the issues related to plastic pollution. Results from this unit showed that students learned what microplastics were and the lesson helped increase their awareness of microplastic pollution. This is the first-ever study to research the prevalence of microplastics on Nantucket Island, and results showed that total microparticles were present in all types of samples collected, with microfiber particles accounting for ~80-90% of the total microparticles. Seawater and beach sediment total microparticle (TMP) concentrations ranged from 1-25 TMP/L and 8-500 TMP/kg, respectively, and varied significantly between beaches and sampling times. Microparticles were identified in 100% of oyster and gray seal scat samples and in 95% of bay scallop samples suggesting that microplastics are being ingested by species that are economically and culturally important to Nantucket.
Hogan, Shannon Marie, "Plastic Pollution on Nantucket Island: Occurrence of Microplastics in Marine Seawater, Intertidal Sediments, and in Ecologically Important Organisms, Bay Scallops (Argopecten Irradians) and Gray Seals (Halichoerus Grypus)" (2022). Graduate Masters Theses. 724.