Identifying Microplastic Sources and Longitudinal Patterns in the Yakima River

Document Type

Poster

Campus where you would like to present

Ellensburg

Event Website

https://digitalcommons.cwu.edu/source

Start Date

18-5-2020

Abstract

People generate an estimated 275 million tons of plastic waste annually, with about 8 million tons entering oceans. Significantly more is known about the abundance and effects of microplastics in marine environments, but less than 4% of microplastic studies have been in freshwaters. Microplastic, one of the most prevalent forms of plastic pollution, presents a danger to wildlife and organisms since it can enter the circulatory systems and food web. In this study I investigated the abundance and type of microplastic in the Yakima River by collecting water column and sediment samples from Snoqualmie Pass to Benton City. Every water column sample contained microplastics, including samples collected near the Alpine Lake Wilderness Area, averaging 37 fibers and 1.2 fragments per liter. Although wastewater treatment plants are known sources of microplastics, there was no difference in fiber or particle abundance up or downstream of treatment plant outfalls (paired t-test, p=0.38, p=0.32 respectively). While reservoirs may either be a sink for plastics or an entry for aerially deposited plastic, there was no difference up or downstream of reservoirs for fibers or particles (paired t-test, p=0.17, p=0.74 respectively). We did not find an upstream to downstream trend in microfiber or fragment abundance, but we did find a positive correlation between microfibers and particles (regression, p=0.02). Although this research establishes that microplastics are present, but more research is needed to understand the sources and fates of microplastic in the Yakima River.

Faculty Mentor(s)

Clay Arango

Department/Program

Biological Sciences

Additional Mentoring Department

https://cwu.studentopportunitycenter.com/2020/04/identifying-microplastic-sources-and-longitudinal-patterns-in-the-yakima-river/

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May 18th, 12:00 PM

Identifying Microplastic Sources and Longitudinal Patterns in the Yakima River

Ellensburg

People generate an estimated 275 million tons of plastic waste annually, with about 8 million tons entering oceans. Significantly more is known about the abundance and effects of microplastics in marine environments, but less than 4% of microplastic studies have been in freshwaters. Microplastic, one of the most prevalent forms of plastic pollution, presents a danger to wildlife and organisms since it can enter the circulatory systems and food web. In this study I investigated the abundance and type of microplastic in the Yakima River by collecting water column and sediment samples from Snoqualmie Pass to Benton City. Every water column sample contained microplastics, including samples collected near the Alpine Lake Wilderness Area, averaging 37 fibers and 1.2 fragments per liter. Although wastewater treatment plants are known sources of microplastics, there was no difference in fiber or particle abundance up or downstream of treatment plant outfalls (paired t-test, p=0.38, p=0.32 respectively). While reservoirs may either be a sink for plastics or an entry for aerially deposited plastic, there was no difference up or downstream of reservoirs for fibers or particles (paired t-test, p=0.17, p=0.74 respectively). We did not find an upstream to downstream trend in microfiber or fragment abundance, but we did find a positive correlation between microfibers and particles (regression, p=0.02). Although this research establishes that microplastics are present, but more research is needed to understand the sources and fates of microplastic in the Yakima River.

https://digitalcommons.cwu.edu/source/2020/COTS/26