COASTAL CAPTURE: QUANTIFYING MICROPLASTIC ACCUMULATION ON NATIVE ROCKWEED ASCOPHYLLUM NODOSUM

Global annual production of plastic is on a trajectory of exponential increase, with plastic waste not far behind. While much attention has been paid to larger macro-plastics, there is growing evidence that smaller plastics, such as microplastics (particles < 5 mm in size), may pose the greatest risk of harming the environment and the organisms that depend on it. Microplastics can be ingested, transferred, and bioaccumulate up the food web through trophic interactions. One recently proposed way by which microplastics do this is by adhering to the viscous mucosal layer of macroalgae at the base of the food web. To test this hypothesis, we compared the distribution of microplastics captured by Ascophyllum nodosum populations in five locations along the coast of Maine. A. nodosum populations located near Bigelow Beach, Portland Public Boat Ramp, and Searsport Public Pier show clear microplastic contamination. However, significant variability was observed within and between sites. This is especially true for Mosman Park and Searsport Public Pier, which are approximately fifty meters apart but showed distinct microplastic concentrations. Searsport Public Pier had higher concentrations which may have been associated with high port activity. Although microplastic:macroalgal associations have only recently been discovered, higher resolution spatial and temporal surveys of microplastic accumulation in impacted locations may clarify the drivers of local distribution patterns, specifically the roles of water circulation, shore exposure, land/water use, and changing population density.

Presentation Preference: Poster

Primary Presenter: Annabelle Warren, Colby College (annabelle.warren99@gmail.com)

Authors:

Annabelle Warren, Colby College  (annabelle.warren99@gmail.com)

Rachel Sipler, Bigelow Laboratory for Ocean Sciences  (rsipler@bigelow.org)