UW oceanography senior finds microplastics, likely from fabrics, widespread on beachs

A University of Washington (UW) undergraduate has discovered a problem much closer to home: nearly invisible bits of plastic on Puget Sound beaches, along the northwestern coast of the US state of Washington.


As a year-long project toward a UW bachelor's degree, Frances Eshom-Arzadon visited 12 beaches around Puget Sound to tally the number of microplastics, generally classified as fragments between 0.3 and 5 millimeters, or 1/100 to 1/5 of an inch, or smaller than a grain of rice.

As part of her senior thesis project, the oceanography major, who graduated in June, visited each location once at the same time along the Seattle and Everett shorelines in the tidal cycle between November and February, scraped sediment from an area just below the wrack line, the line of debris left by the high tide.

Back in the lab, Eshom-Arzadon dried the samples, then used chemicals and weight-based techniques to separate the plastic from sand and other material.

Her results show that small plastics are widespread along the shore of Puget Sound. All 12 samples contained microplastics, at an average of 1,776 pieces per 3-foot-square, or nearly 0.28-square-meter, sampling plot.

The highest concentration of plastics by number was at Howarth Park in Everett, followed by Carkeek Park and Alki Beach Park in Seattle.

The cleanest beaches, according to a recent posting on the university's website, were found to be at Mukilteo Lighthouse Park and Edmonds Marina Beach, both situated on points of land near ferry terminals.
   [Xinhua/globaltimes.cn]
9/7/17