Microplastic contamination in the sediments of the Saint Martin’s Island, Bangladesh

Abstract

Microplastic (MP) contamination has emerged as a global concern because of its ubiquitous nature and detrimental effects on the coastal environment and aquatic life. This study, for the first time, intends to account for the extent of the abundance and types of microplastics (MPs) in intertidal sediments in the only coral island of Bangladesh, St. Martin’s Island. Extraction of MPs was done from 12 surficial sediment samples collected along the coastline of the island through the sieving and density separation method. Visual identification of the MPs was conducted using a stereomicroscope. Microplastics were identified in all samples, with mean concentrations of 20.8 items 100 g−1, mostly white and ranging in size from 0.5–1 mm. The majority of the detected MPs were fibrous (< 1 mm), accounting for approximately half of the total microplastics. The prevalent types were fibers > films > fragment > foam. Using the (ATR-FTIR) Attenuated total reflectance-Fourier transform infrared spectroscopy, associated types of polymers have been detected. Rayon, nylon, and polyethylene have been found to be the most detected polymers in the selected regions. Microplastic concentration is higher in the Uttar Para areas compared to the Dakhin Para which can be linked to the growth of unplanned industrialization, emerging tourism, and urbanization. Microplastic pollution on St. Martin’s Island possess a potential threat to marine and coastal environments. This study might be used as a valuable reference to better understand the microplastic contamination status in the southeastern coastal region of Bangladesh.