Accumulation of Plastics and Trace Elements in the Mangrove Forests of Bima City Bay, Indonesia

Abstract

Pollution with microplastics (MPs), nanoplastics (NPs) and trace elements (TEs) remains a considerable threat for mangrove biomes due to their capability to capture pollutants suspended in the water. This study investigated the abundance and composition of plastics and TEs contained in the soil and pneumatophores of Avicennia alba sampled in experimental areas (hotel, market, river mouth, port, and rural areas) differentiated in anthropopressure, located in Bima Bay, Indonesia. Polymers were extracted and analyzed with the use of a modified sediment isolation method and Fourier transform infrared spectroscopy. Trace elements were detected by inductively coupled plasma optical emission spectrometry. The lowest and highest quantities of MPs in soil were recorded in rural and hotel areas, respectively. The rural site was characterized by distinct MP composition. The amounts of sediment-trapped MPs in the tested localities should be considered as high, and the recognized polymers partly corresponded with local human activity. Concentrations of seven plastic types found in plant tissues did not entirely reflect sediment pollution with nine types, suggesting a selective accumulation (particularly of polyamides and vinylidene chloride) and substance migration from other areas. Very low concentrations of non-biogenic TEs were observed, both in sediments and pneumatophores. The results highlight the relevance of environmental contamination with plastics.

Multifaceted Aquatic Environmental Differences between Nanoplastics and Microplastics: Behavior and Fate

“…When plastic particles are acting as adsorbates, the main substances that can adsorb MPs and NPs in the aquatic environment are suspended substances and sediments, with clay minerals, carbonate particles, as well as organic and inorganic matter in the substrate being the most important adsorption carriers. , Studies have shown that MPs are the major contamination problem in the sediments of Bima City Bay, Indonesia, and similarly, the abundance of MPs in the sediments of the Ma River in Vietnam was relatively high (i.e., 1328.3 ± 1925.5 items/kg dry weight), while the abundance of MPs in the surface water was relatively low (i.e., 57.3 ± 55.8 items/m 3 ) . Under simulated seawater conditions, researchers observed strong heterogeneous aggregation of PSMPs with silicate clay minerals (kaolinite, bentonite, illitic and kaolinitic soil clays) and iron oxide minerals (hemeatite, goethite) .…”