Historical behaviors of microplastic in estuarine and riverine reservoir sediment

Zhixin Cheng; Ye Ma; Xiaoxue Fan; Qian Wang; Yue Liu; Zaijin You

doi:10.1016/j.marpolbul.2024.116331

Historical behaviors of microplastic in estuarine and riverine reservoir sediment

Mar Pollut Bull. 2024 Apr 9:202:116331. doi: 10.1016/j.marpolbul.2024.116331. Online ahead of print.

Authors

Zhixin Cheng¹, Ye Ma², Xiaoxue Fan³, Qian Wang³, Yue Liu⁴, Zaijin You⁵

Affiliations

¹ College of Environmental Science and Engineering, Dalian Maritime University, 116026, China; Centre for Ports and Maritime Safety, Dalian Maritime University, 116000, China.
² College of Environmental Science and Engineering, Dalian Maritime University, 116026, China; Centre for Ports and Maritime Safety, Dalian Maritime University, 116000, China. Electronic address: ye.mawater@outlook.com.
³ College of Environmental Science and Engineering, Dalian Maritime University, 116026, China.
⁴ College of Science, Liaodong University, Dandong 118003, China.
⁵ Centre for Ports and Maritime Safety, Dalian Maritime University, 116000, China.

PMID: 38598928
DOI: 10.1016/j.marpolbul.2024.116331

Abstract

This study investigates the sedimentation behaviors of microplastics (MPs) within a typical meso-scale river estuary, the Yalu River Estuary (YRE) and its riverine reservoir. It analyzes sediment cores in two habitats of Yalu River, revealing changing MPs abundance over time. Results highlight significant differences in riverine and estuarine MPs deposition. Reservoir sample contains more MPs in fragments. Color variations are notable in estuarine samples but minimal in reservoir sample. After 1980, estuarine cores show an increase in coarser MPs, likely due to growth of aquaculture activities. Although sediment accumulates at 1/10 of the rate in reservoir compared to estuary, MPs in reservoir sediments exceeds estuarine level by over threefold. A possible mechanistic framework is then proposed to discuss the varying MPs behaviors in the two habitats, indicating reservoirs accumulate MPs at a higher rate due to the barrier effect of an upper-stream reservoir, stable hydrodynamics, and weak salinity-induced buoyancy.

Keywords: Coastal dynamics; Mesoscale Estuary; Microplastics; Reservoir; Sedimentation behavior.