Microplastic contamination in Rupsha River of Bangladesh and its impacts on fish species

Abstract

Microplastics have emerged as a significant environmental concern, with their ubiquitous presence and potential adverse impacts on aquatic ecosystems. Microplastics (MPs) are constantly increasing, including aquatic food and aquatic animals. Therefore, this study aimed to assess the extent of microplastic contamination in a segment of Rupsha River, Bangladesh, and its impacts on the fish species that eventually enter the human food cycle. The 18-kilometer stretch of the Rupsha River showed concerning results in the concentration of microplastic ranging from 0.67 ± 0.38 to 8.67 ± 0.38 particles per liter. Microplastics of various shapes, sizes, and colors were detected. Four fish species were tested (Rohu, Mystus, Singhi, Taki) according to the abundance and human consumption, which revealed microplastic ranged from 5.00 ± 0.54 to 7.90 ± 0.95 particles per fish, with Rohu the highest (7.90 ± 0.95 particles per fish) number and Mystus the lowest (5.00 ± 0.54 particles per fish) and 38.61 ± 4.77 to 125.34 ± 13.80 particles per kilogram of fish respectively. These results pointed out a correlation between fish mass and microplastic concentration for pooled samples. Fourier Transform Infrared (FTIR) spectroscopy was used to identify types of microplastic and revealed polypropylene, polyethylene, polyvinyl chloride and nylon. This study highlights the emergence of microplastic hazards in the Khulna Region of Bangladesh, which has a vast resource of rivers and fish.