Abundances and characteristics of microplastics in core sediments of the Persian Gulf coast, Iran

Abstract

The presence of microplastics in tidal sediments is a growing ecotoxicological concern for sea and benthic health. This investigation was designed to record and characterize the vertical prevalence of microplastics (MPs) in intertidal sediments of the Persian Gulf (around Bushehr city, Iran). Sediments of three depths (0-10 cm, 10-20 cm, and 20-30 cm) were sampled during low tide in six sites along the coastal zone of Bushehr, Iran. MP particles were found in all evaluated areas and sediment depths. The average abundance of MPs in all of the sediment samples was 117.96 ± 97.75 particles kg−1 dry sediment. No differences were found in the MPs number among the sites. The most dominant microplastics in surface sediments were 2-5 mm in size. In all areas, fibers and fragments were more abundant. Particles in higher depths (0-10 cm) were often colorless (white, and transparent). Raman spectroscopy indicated the presence of polystyrene, polyethylene, polyvinyl chloride, polyethylene terephthalate, and polypropylene in the samples. Further research is required to evaluate the possible interaction between MPs and layers of sediments. Waste management and proper wastewater disposal are critical to control MPs pollution in intertidal ecosystems around coastal cities.

Keywords

• Microplastics
• Sediments
• Raman analysis
• Pollution
• Intertidal zone