Initial Characterization of Microplastic Contamination in the Great Bay Estuary

Microplastics are plastic particles less than 5 millimeters in length and represent an emerging pollutant class. Microplastics are thought to play an important and undercharacterized role in impacting the environment and ecosystems. It is estimated that more than 2 trillion microplastic particles are present in the world’s oceans, with that number continuing to grow as time passes. Microplastics can transport pollutants and pathogens through the environment, are ingested by marine organisms, and travel up the food chain to larger mammals, including humans. Little research has been conducted in New Hampshire to quantify or characterize microplastics, despite the level of protection and importance of marine environments to our communities. To initially quantify microplastic contamination in the Great Bay, samples were collected and processed using a method developed and tested in this project. The method developed involved vacuum filtration to concentrate microplastic particles, potassium hydroxide digestion, hydrochloric acid neutralization, and nile red particle staining. Upon particle staining, the samples were quantified using a guava flow cytometer. Due to uncertainties within the method and a lack of adequate method confirmation, an exact particle estimation was not determined. However, after data analysis, the samples processed contained microplastic contamination within the same magnitude as wastewater effluent samples. At the conclusion of this research project, a method for measuring microplastic concentrations in surface water samples was developed, but still needs refinement. Also, a better understanding of the level of microplastic contamination in the estuary was obtained, which will be integrated into future research programs and actions to preserve the Great Bay