Microplastic hotspots in the Snake and Lower Columbia rivers: A journey from the Greater Yellowstone Ecosystem to the Pacific Ocean - PubMed (original) (raw)

Microplastic hotspots in the Snake and Lower Columbia rivers: A journey from the Greater Yellowstone Ecosystem to the Pacific Ocean

Kirsten J Kapp et al. Environ Pollut. 2018 Oct.

Abstract

It is widely understood that microplastics (MPs) are ubiquitous in the marine environment yet less is known about MP abundance in freshwater rivers, particularly those of the western United States. This study documents MP pollution along the Snake River (∼1735 km) and from its confluence with the Columbia River to the Pacific Ocean. Grab and plankton net samples (mesh size 100 μm) were collected from the top 25 cm of surface water every 80.5 river km. MPs were identified if they met visual criteria and were verified with the hot needle test. A small representative subset of MPs from the net samples (16.7%) were selected based on appearance for micro-Raman spectroscopy in effort to provide examples of polymer types found in this study. Seventy-five percent of grab samples and 92.8% of net samples contained MPs, with concentrations ranging from 0 to 5.405 MP L-1 and 0 to 0.014 MP L-1 (0 to 13.7 MP m-3), respectively. The majority of fragments, films and beads were between 100 μm and 333 μm. This study identifies potential hotspots of MP pollution along the Snake and Lower Columbia rivers and prioritizes areas where more intensive sampling is needed. Sites with low flow or those further down river had higher numbers and the top two hotspots were located in areas with low population density but high agricultural use. Monitoring MP abundance in freshwater systems is important for establishing baseline levels of MP pollution and can direct laboratory toxicology studies in using more environmentally relevant concentrations for a better indication of how MP pollution affects ecosystems.

Keywords: Emerging contaminant; Freshwater pollution; Microfibers; Microplastics; Rivers.

Copyright © 2018 Elsevier Ltd. All rights reserved.

PubMed Disclaimer

Figures

Fig. 1.

Fig. 1.

Percent MPs (100μm – 5mm) by category in grab and net samples.

Fig. 2.

Fig. 2.

Percent of each MP type observed in grab (top) and net (bottom) samples at each site. No MPs were found in the two sites located in Grand Teton National Park (sites −01 and 00). Site 07 was repeated one year later and is included as 07B.

Fig. 3.

Fig. 3.

Sampling location, site number, and number of MPs L−1for grab samples. Sites 7 and 22 contained the highest MPs. Two samples were collected at site 7, which explains the presence of two points at this site.

Fig. 4.

Fig. 4.

Sampling location, site number, and MPs m−3 for net samples. Sites 14 and 12 contained the highest MPs.

Similar articles

Cited by

References

    1. Avio CG, Gorbi S, Regoli F, 2017. Plastics and microplastics in the oceans: From emerging pollutants to emerged threat. Mar. Environ. Res. 128, 2–11. 10.1016/j.marenvres.2016.05.012 - DOI - PubMed
    1. Baldwin AK, Corsi SR, Mason SA, 2016. Plastic Debris in 29 Great Lakes Tributaries: Relations to Watershed Attributes and Hydrology. Environ. Sci. Technol. 50, 10377–10385. 10.1021/acs.est.6b02917 - DOI - PubMed
    1. Barrows APW, Neumann CA, Berger ML, Shaw SD, 2017. Grab vs. neuston tow net: a microplastic sampling performance comparison and possible advances in the field. Anal. Methods 9, 1446–1453. 10.1039/C6AY02387H - DOI
    1. Barrows APW, Cathey SE, & Petersen CW 2018. Marine environment microfiber contamination: Global patterns and the diversity of microparticle origins. Environ Pollut 237, 275–284. 10.1016/j.envpol.2018.02.062 - DOI - PubMed
    1. Beer S, Garm A, Huwer B, Dierking J, Nielsen TG, 2017. No increase in marine microplastic concentration over the last three decades - A case study from the Baltic Sea. Sci. Total Environ. 10.1016/j.scitotenv.2017.10.101 - DOI - PubMed

MeSH terms

Substances

LinkOut - more resources