The seasonal distribution characteristics of microplastics on bathing beaches along the coast of Qingdao, China

Fenglei Gao; Jingxi Li; Jun Hu; Baolu Sui; Chuanxing Wang; Chengjun Sun; Xianguo Li; Peng Ju

doi:10.1016/j.scitotenv.2021.146969

The seasonal distribution characteristics of microplastics on bathing beaches along the coast of Qingdao, China

Sci Total Environ. 2021 Aug 20:783:146969. doi: 10.1016/j.scitotenv.2021.146969. Epub 2021 Apr 8.

Authors

Fenglei Gao¹, Jingxi Li², Jun Hu³, Baolu Sui⁴, Chuanxing Wang⁴, Chengjun Sun⁵, Xianguo Li⁶, Peng Ju²

Affiliations

¹ Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Laboratory of Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology, Qingdao 266071, China; Key Laboratory of Marine Eco-environmental Science and Technology, Marine Bioresource and Environment Research Center, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China.
² Key Laboratory of Marine Eco-environmental Science and Technology, Marine Bioresource and Environment Research Center, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China.
³ Research Vessel Operation Center, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China.
⁴ Qingdao University of Science and Technology, Qingdao 266042, China.
⁵ Laboratory of Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology, Qingdao 266071, China; Key Laboratory of Marine Eco-environmental Science and Technology, Marine Bioresource and Environment Research Center, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China. Electronic address: csun@fio.org.cn.
⁶ Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China. Electronic address: lixg@ouc.edu.cn.

PMID: 33866158
DOI: 10.1016/j.scitotenv.2021.146969

Abstract

Microplastics pollution in nearshore marine environment has become increasingly prominent and has received widespread attention. As a major leisure and entertainment place in coastal cities, bathing beaches not only provide an environment for microplastics to enter the ocean, but also provide a place for the retention of microplastics. In this paper, the distribution, composition and seasonal variation of microplastics in seawater and sediments of six bathing beaches along the coast of Qingdao were studied. The results showed that the average abundance of microplastics in the sediments of the Qingdao bathing beach was 91.11 ± 26.76 items/m² (13.77 ± 4.39 items/kg) in the winter and 147.78 ± 34.80 items/m² (21.98 ± 5.97 items/kg) in the summer. The microplastic abundance in the seawater in the summer (average: 567.50 ± 101.06 items/m³) was significantly higher than that in the winter (average: 326.11 ± 49.03 items/m³, p < 0.05). The abundance of microplastics at the six bathing beaches increased from east to west, consistent with the transport direction of coastal currents. The microplastic abundance in the sediment of non-swimming zone of the bathing beach was significantly higher than that in swimming zone (p < 0.05), and the microplastic abundance in the seawater of the swimming zone was slightly higher than that of the non-swimming zone but with no significant difference (p > 0.05). To an extent, it can reflect the correlation between the abundance of microplastics and human recreational activities. The microplastics detected at the bathing beaches were mainly lines (80.5%) and fragments (7.9%) with a size range of 100 to 1000 μm. Rayon (41.8%) and polyethylene terephthalate (PET, 16.9%) were the main polymer types. The microplastic characteristics showed significant seasonal differences, more diversity in summer than in winter. These results emphasized that the distribution and movement of microplastics in bathing beaches were affected by seasons, human activities and coastal currents.

Keywords: Bathing beaches; Coastal current transport; Distribution characteristics; Microplastics; Seasonal differences.