Microplastics in the surface waters of the South China sea and the western Pacific Ocean: Different size classes reflecting various sources and transport

Yaozong Cui; Mengyang Liu; S Selvam; Yongcheng Ding; Qianqian Wu; V Stephen Pitchaimani; Peng Huang; Hongwei Ke; Haowen Zheng; Fengjiao Liu; Bojun Luo; Chunhui Wang; Minggang Cai

doi:10.1016/j.chemosphere.2022.134456

Microplastics in the surface waters of the South China sea and the western Pacific Ocean: Different size classes reflecting various sources and transport

Chemosphere. 2022 Jul:299:134456. doi: 10.1016/j.chemosphere.2022.134456. Epub 2022 Mar 29.

Authors

Yaozong Cui¹, Mengyang Liu², S Selvam³, Yongcheng Ding⁴, Qianqian Wu², V Stephen Pitchaimani³, Peng Huang⁵, Hongwei Ke⁶, Haowen Zheng², Fengjiao Liu⁷, Bojun Luo², Chunhui Wang², Minggang Cai⁸

Affiliations

¹ State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China; Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen, 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
² College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
³ Department of Geology, V.O. Chidambaram College, Tuticorin, 628008, Tamil Nadu, India.
⁴ Coastal and Ocean Management Institute, Xiamen University, Xiamen, 361102, China.
⁵ College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China; College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China.
⁶ Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen, 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
⁷ College of Chemistry, Chemical Engineering and Environment, Minnan Normal University, Zhangzhou, 363000, China.
⁸ State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China; Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen, 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China; Coastal and Ocean Management Institute, Xiamen University, Xiamen, 361102, China; College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China. Electronic address: mgcai@xmu.edu.cn.

PMID: 35364074
DOI: 10.1016/j.chemosphere.2022.134456

Abstract

Microplastic transport in the marginal seas is a key process influencing their ultimate fate in the open oceans. In the present study, we collected seawater samples from the western Pacific Ocean (WP) and the South China Sea (SCS) to investigate the distribution, transport, and possible sources for microplastics. Generally, the range of microplastic levels were 187-1816, 146-1563, and 34.2-622 particles/m³ (averaged in 797 ± 512, 744 ± 330, and 201 ± 134 particles/m³) for the northern SCS, the western SCS, and the WP, respectively. Based on the size distribution, the highest value (390 ± 288 particles/m³) was found for 100-200 μm, followed by 200-500 μm (131 ± 155 particles/m³), and 500-1000 μm (29.7 ± 39.2 particles/m³), with the lowest for 1-5 mm (13.6 ± 14.2 particles/m³). Granule, yellow, and size <1000 μm were their most prevalent characteristics. The main polymer types of microplastics were polyester, rayon, and nylon. A negative correlation between microplastic proportion and particle size was observed in the SCS and the WP. Furthermore, the main sources of microplastics in the northern SCS probably came from the Pearl River. Surface currents and the vertical mixing processes might be two different mechanisms that affect microplastic transport from the WP and the SCS. Future comparison to measured particle size distributions data allows us to explain size-selective microplastic transport in the marine environment, and probably provide guidance on microplastic longevity.

Keywords: Microplastics; Size distribution; South China Sea; Surface seawater; Western Pacific Ocean.

MeSH terms

China
Environmental Monitoring
Microplastics*
Oceans and Seas
Pacific Ocean
Plastics
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Water Pollutants, Chemical