Presenter(s): Ellie Jones
Faculty Mentor(s): Craig Young & Alan Shanks
Poster 55
Session: Sciences
Recent calculations estimate there are currently 5.25 trillion plastic particles afloat in the world’s oceans. Many of these plastics are characterized as microplastics < 5 mm in diameter. Studies within the past few decades show that no ecosystem is exempt from plastic contamination. This study examined sediment samples from Norfolk Canyon off the coast of Virginia, the Coos Bay Estuary in Oregon, and headlands along the Oregon shoreline to characterize the abundance of microplastics within various marine sediments. Box core sediment samples were taken from within Norfolk Canyon and from the adjacent continental slope. Plastics were removed by density differentiation using a saturated salt solution. Nineteen pieces of plastic were found from the nine samples within the canyon, while only eight pieces were found from the seven samples on the continental slope. This suggests that canyons can be accumulation zones for microplastics due to strong down-canyon currents. Next, box core and Poner grab sediment samples were taken from within the Coos Bay Estuary and the adjacent continental shelf. Plastics were removed by density differentiation, and the majority of plastics were found within the mouth of the bay. This suggests that plastics can become concentrated in areas where fronts are created between two bodies of water (in this case, the ocean and the estuary.) To analyze shoreline sediment, belt transects were taken during January and February on the northern and southern sides of Yaquina Bay Head, Cape Perpetua, and Cape Blanco. The majority of plastics were found on the southern side of each headland. This suggests that microplastics are carried onshore by winds, which are blowing onto southern-facing beaches on Oregon’s coast during the winter. Knowing where plastics settle in the ocean can influence mitigation and management decisions. Therefore, it is important to determine possible places for microplastic accumulation to manage and conserve natural resources.