Microplastics in Possession Sound

Plastic debris has been found in the marine environment around the world. In recent years, microplastics, which are synthetic polymers that are less than 5 mm, have been increasing in the water column. Emerging research is being conducted on the distribution of microplastic threads. Research has been conducted over the past five years in the Possession Sound estuarine system, a section of Puget Sound west of the Everett metropolitan area, by students from Ocean Research College Academy (ORCA), a dual enrollment running start program through Everett Community College. This research includes collection and analysis of plankton tows, including a vertical tow from 10-50 m with a 335 micron net and a horizontal plankton tow collected at the halocline with a 20 micron net. Archived plankton photographs show that microplastic threads have appeared in at least five out of twenty cruises. Two of the five threads were found in vertical tows, one at Mount Baker Terminal (MBT), which is near the Mukilteo site. The other three were found in horizontal tows, one was at MBT and the other was at Buoy, a site in between Jetty and Hat Island. The Snohomish River, Mukilteo, Whidbey Island, and Hat Island research sites were analyzed to determine how the influence of the river and the ferry terminal affect the microplastic fragments found in the surface layer. The working hypothesis is that there will be a spatial difference in the location of the microplastic fibers within the water column, where the sites near the mouth of the river and ferry terminal will have a lower concentration of microplastics on the surface compared to the sites on the east side of Hat and Whidbey Island.