Microplastics in the Bay of Bengal: A critical review of bioaccumulation and ecological impacts across Bangladesh

Abstract

Microplastics (MPs) exert a substantial threat to marine ecosystems, including the Bay of Bengal (BoB), due to their widespread presence and high potential for bioaccumulation in marine biota. This review aims to provide a comprehensive analysis of the bioaccumulation of MPs, their prevalence, and the potential pathways for these contaminants in the BoB. By systematically reviewing existing literature, we analyzed relevant studies and identified key findings. MPs were detected in various marine organisms, including finfish, shellfish, and plankton in the BoB. Demersal species were found to ingest more MPs than pelagic species, likely due to their proximity to MP-laden sediments. The concentration of MPs varied with body weight and length, with some species showing a positive correlation, while others exhibited a negative correlation. MP particle sizes ranged from <500 μm to 1000 μm, with black particles, fibers, and fragments being the most common forms. Polyethylene (PE) and polypropylene (PP) were identified as the dominant polymers. Major sources of MP pollution in the BoB include fisheries, industrial and sewage discharge, tourism, and agricultural runoff. The review also highlights the ecological implications of their accumulation and the potential health risks to humans through the consumption of contaminated seafood. Lack of information on deep-sea and cultured species, trophic transfer, and standard methods are some of the most important shortcomings. Researchers should use more advanced methods of discovery in future studies and look into the long-term effects on health and the environment. To reduce MP pollution in the BoB, policymakers should work on reducing the use of plastic, making waste management better, and walking biodegradable alternatives.