Accumulation of microplastics in river basin sediments of Kuala Rompin, Malaysia
(a)Nur Izzati Razak, (a)Sabiqah Tuan Anuar, (a)Yusof Shuaib Ibrahim, (a*)Maisarah Jaafar

(a) Microplastics Research Interest Group (MRIG), Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia

Abstract

Kuala Rompin is well-known for hosting annual world-class fishing competitions and for its plentiful supply of freshwater prawns and clams. However, the accumulation of microplastics in freshwater sediment can pose a hazard to aquatic organisms and enter the food chain. Thus, this study was undertaken to investigate the accumulation of microplastics in Rompin river sediment samples collected from 6 stations along a 20-kilometer stretch from the river to the open sea. 24 sediments were collected with a ponar grab and extracted with zinc chloride (1.63 g/cm3) and hydrogen peroxide (30%) before being physically sorted under stereomicroscope for shape, colour, and size identification. Microplastic abundances ranged from 213 to 455 particles/g, with particle sizes ranging from 30 to 300 microns. The most common shape and colour were fibres (90%) and transparent (68%) microplastics, respectively. The surface morphology of selected microplastics was cracked, with pit holes and irregular surface texture, indicating that the microplastic had weathered and may have interacted with other pollutants in the environment. Micro-Fourier Transform Infrared was used to confirm the polymer types of microplastics in selected samples, which can be linked to the local human anthropogenic sources. A high accumulation of microplastics in sediments could potentially affecting aquatic organisms, particularly filter feeders like clams, raising concerns about food safety when consumed.

Keywords: Microplastic, Sediment, Kuala Rompin, food, South China Sea

Topic: Aquatic Pollution and Ecotoxicology