Nationwide monitoring of microplastics in bivalves from the coastal environment of Korea

Youna Cho; Won Joon Shim; Mi Jang; Gi Myung Han; Sang Hee Hong

doi:10.1016/j.envpol.2020.116175

Nationwide monitoring of microplastics in bivalves from the coastal environment of Korea

Environ Pollut. 2021 Feb 1:270:116175. doi: 10.1016/j.envpol.2020.116175. Epub 2020 Dec 19.

Authors

Youna Cho¹, Won Joon Shim¹, Mi Jang¹, Gi Myung Han², Sang Hee Hong³

Affiliations

¹ Oil and POPs Research Group, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea; Department of Ocean Sciences, KIOST School, University of Science and Technology, Daejeon, 34113, Republic of Korea.
² Oil and POPs Research Group, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea.
³ Oil and POPs Research Group, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea; Department of Ocean Sciences, KIOST School, University of Science and Technology, Daejeon, 34113, Republic of Korea. Electronic address: shhong@kiost.ac.kr.

PMID: 33352481
DOI: 10.1016/j.envpol.2020.116175

Abstract

Bivalves are useful bioindicators of microplastic contamination in the marine environment for several reasons, such as extensive filter feeding activity, broad geographical distribution, and limited movement capability. This study conducted a nationwide monitoring of microplastic pollution along the Korean coasts using filter-feeding bivalves (including oyster, mussel, and Manila clam) as bioindicators to identify the national contamination level and characteristics of microplastics. Seawater sample was collected from the same sampling stations of oyster and mussel for comparison. Microplastics were widely distributed in both coastal bivalves and waters with mean concentrations of 0.33 ± 0.23 n/g (1.21 ± 0.68 n/individual) in oyster/mussel, 0.43 ± 0.32 n/g (2.19 ± 1.20 n/individual) in Manila clam, and 1400 ± 560 n/m³ in seawater. Despite the lack of significant relationship in the abundance of microplastics, their dominant features such as size, shape, color and polymer type were similar between bivalves and seawater. Fragments (69% for oyster/mussel, 72% for Manila clam, and 77% for seawater), particles smaller than 300 μm (96% for oyster/mussel, 83% for Manila clam, and 84% for seawater) and colorless (79% for oyster/mussel, 85% for Manila clam, 75% for seawater) were the dominant shape, size and color, respectively. The major polymer types were polypropylene, polyethylene, and polyester. The microplastic level in bivalves was relatively high in urbanized areas with a wide diversity of polymer types compared with those in non-urbanized areas, and the proportion of polystyrene in the Korean samples was abundant compared with other regions due to wide use of polystyrene products in Korea. Our result suggests that microplastic contamination is widespread in the Korean coastal environment, and bivalves can reflect the microplastic pollution characteristics of the surrounding waters where they live.

Keywords: Bioindicator; Biomonitoring; Bivalve; Coastal environment; Microplastic; Seawater.

MeSH terms

Animals
Environmental Monitoring
Microplastics*
Plastics
Republic of Korea
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Water Pollutants, Chemical