According to the researchers, although there is no clear evidence of immediate health risks from eating these fish at present, in the long run it may have negative impacts on human health, aquatic ecosystem and food safety.
The chief researcher of the study and professor of the Department of Fisheries Management at BAU, Dr. Md. Shahjahan, said the research was conducted by collecting water, sediment and fish samples from Gadighat, Basurola Danga, Sagar Danga, Baraikhali and Alampur areas of Arial Beel during the monsoon of 2024, winter of 2024-25 and dry season of 2025.
The study found that due to omnivorous feeding habits, the highest amount of microplastics accumulated in koi fish. On average, about one microplastic particle was found in the muscle of koi fish in all three seasons. On average, 1.70 to 1.90 particles were detected in the intestines and 1.30 to 1.40 particles in the gills.
After koi, the highest amount of microplastics was found in bata fish, followed by meni and gulsha tengra. The lowest amount of microplastics was detected in puti fish. In the monsoon season, on average, a maximum of 1.50 particles was found in the intestines of bata fish. On the other hand, only 0.50 to 0.51 particles were detected in the muscle of puti fish.
The study also found 11 to 31.67 microplastic particles per litre of water and 12.33 to 127.33 particles per kg of sediment. The level of pollution in water was highest during the monsoon season.
Fourier Transform Infrared (FT-IR) spectroscopy analysis showed that 34 to 63 percent of the detected particles were microfibers. According to the researchers, synthetic fibers released during washing clothes, household wastewater and plastic fishing nets are the main sources of these particles. Besides, various types of plastics from broken plastic, polythene, foam and packaging materials were also detected.
Professor Dr. Shahjahan said rather than panic, the most urgent need now is to take effective steps to control plastic pollution. He said as microplastics have been found not only in the intestines but also in the muscles of fish in Arial Beel, the matter is important from a public health perspective. Although there is no evidence of direct harm currently, if such particles continue to accumulate in the body for a long time, their effects may appear in the future.
