Spatiotemporal distribution of microplastic debris in the surface beach sediment of the southeastern coast of Bangladesh

Jarin Tasnim; Md Kawser Ahmed; Kazi Belayet Hossain; Muhammad Saiful Islam

doi:10.1016/j.heliyon.2023.e21864

Spatiotemporal distribution of microplastic debris in the surface beach sediment of the southeastern coast of Bangladesh

Heliyon. 2023 Nov 17;9(11):e21864. doi: 10.1016/j.heliyon.2023.e21864. eCollection 2023 Nov.

Authors

Jarin Tasnim¹, Md Kawser Ahmed^{1

2}, Kazi Belayet Hossain^{3

4

5}, Muhammad Saiful Islam⁶

Affiliations

¹ Department of Oceanography, Faculty of Earth & Environmental Sciences, University of Dhaka, Dhaka, 1000, Bangladesh.
² International Centre for Ocean Governance (ICOG), Faculty of Earth & Environmental Sciences, University of Dhaka, Dhaka, 1000, Bangladesh.
³ Coastal and Ocean Management Institute, Xiamen University, Xiamen, 361102, China.
⁴ College of Environment and Ecology, Xiamen University, Xiamen, 361102, China.
⁵ State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China.
⁶ Fiber and Polymer Research Division, BCSIR Laboratories Dhaka, Bangladesh Council of Scientific and Industrial Research, Dhaka, 1205, Bangladesh.

Abstract

This study undertakes a spatiotemporal analysis of microplastic pollution in surface beach sediments, covering 7 coastal beaches in Bangladesh and two seasons-monsoon and winter. The concentration of microplastics extracted from the surface beach sediment is 242.86 particles/kg dw. The results showed both significant seasonal (p value = 0.001) and spatial (p value = 0.004) variation. The abundance and polymer types were significantly higher (57 %) in winter than in the monsoon season (43 %). Touristic and commercial beaches showed higher levels of microplastic pollution than the non-touristic beaches. Polyethylene (28.8 %) and Polypropylene (27.6 %) were the most abundant polymer. The most dominant coloration of microplastics was white (42.6 %). The majority of the microplastics were fibers (33.5 %). Smallest particles measuring <1 mm constituted nearly half of the total microplastics load (48.5 %). This baseline data can be useful in terms of coastal zone management for the southeastern coastal beaches of Bangladesh.

Keywords: Beach sediment; FT-IR; Marine pollution; Microplastics; SEM; Spatiotemporal analysis.