Investigation of Microplastic Accumulation in Two Freshwater Fish Species (Labeo rohita and Wallago attu) from Tanguar Haor, Bangladesh

In the present work, we aimed to extract and identify microplastics (MPs) in two different species of fish, namely, Rohu fish (Labeo rohita) and Freshwater Shark (Wallago attu), inhabiting the Tanguar Haor (wetland) that is a part of the Surma River, Bangladesh. Three different parts, namely, the stomach, intestine, and dorsal muscle of the corresponding fish samples, were digested with a 10% KOH solution. We conducted a qualitative assessment using FTIR, UV-visible, and SEM/EDS measurements to confirm the presence of MPs. The study identified various types of MPs, including Polypropylene (PP), Polyethylene (PE), Polyvinylchloride (PVC), Polyamide (PA), Polyethylene terephthalate (PET), and Polymethyl methacrylate (PMMA), in three different parts of the respective fish samples. Among the different portions of fish, the intestine contained the most diverse range of MPs, with six different types identified. In comparison, five types of MPs were found in the stomach, and only three types were observed in the dorsal muscle. The mean diameter of the identified MPs determined by SEM analysis revealed the smallest mean diameter of 570 nm in the dorsal muscle portion of the L. rohita and the largest mean diameter of 889 nm in the intestine part of W. attu, respectively. Thus, the outcome of this investigation sheds light on the possible presence of MPs in freshwater wetland ecosystems.