Microplastics in the western Pacific and South China Sea: Spatial variations reveal the impact of Kuroshio intrusion

Mengyang Liu; Yongcheng Ding; Peng Huang; Haowen Zheng; Weimin Wang; Hongwei Ke; Fajin Chen; Lihua Liu; Minggang Cai

doi:10.1016/j.envpol.2021.117745

Microplastics in the western Pacific and South China Sea: Spatial variations reveal the impact of Kuroshio intrusion

Environ Pollut. 2021 Nov 1:288:117745. doi: 10.1016/j.envpol.2021.117745. Epub 2021 Jul 6.

Authors

Mengyang Liu¹, Yongcheng Ding², Peng Huang³, Haowen Zheng⁴, Weimin Wang⁴, Hongwei Ke⁴, Fajin Chen⁵, Lihua Liu⁶, Minggang Cai⁷

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 Coastal and Ocean Management Institute, Xiamen University, Xiamen, 361102, China.
³ College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China; College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China.
⁴ College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
⁵ College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China.
⁶ CAS Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, 510640, China.
⁷ 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. Electronic address: mgcai@xmu.edu.cn.

PMID: 34243083
DOI: 10.1016/j.envpol.2021.117745

Abstract

Surface currents play an essential role in the worldwide distribution of microplastics in the coastal seas and open oceans. As a branch of the western boundary currents (WBCs), Kuroshio changes seawater properties and pollutant levels of the South China Sea (SCS) during its intrusion process. To study the impact of Kuroshio intrusion on microplastics, we conducted field observations on surface water from the western Pacific (WP) and SCS. Microplastic abundances in the surface water of WP (0.02-0.10 particles m^-3) were generally lower than those in the SCS (0.05-0.26 particles m^-3). Fragments and granules dominated their apparent characteristics, and showed spatial classifications in different areas. The abundance of fragment, granule and foam showed a similar unimodal trend, as they peaked when the Kuroshio fraction was 0.1, implying the effect of Kuroshio intrusion was a combination of the dilution and biogeochemical influence. The polymer types of microplastics, dominated by polypropylene (PP), polyethylene (PE), polyester (PES), polymethacrylate (PMA) and phenoxy resin (PR), showed complicated compositions in the northern SCS, and Kuroshio intrusion was not the dominant influencing factor. Further study is needed to discover the comprehensive effect of Kuroshio intrusion on the fate of microplastics and is expected for the whole WBC system.

Keywords: Kuroshio intrusion; Microplastics; Oceanic transport; South China Sea; Western Pacific.

MeSH terms

China
Environmental Monitoring
Microplastics*
Plastics
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Water Pollutants, Chemical