Saad_Sajid — A team of researchers from the Bangladesh Agricultural University (BAU) has detected the presence of microplastics in native small fish species collected from the Arial Beel.
The study reveals that microplastic contamination affects five different fish species, with the highest concentrations found in the climbing perch (koi).
The comprehensive study was led by Dr. Md. Shahjahan, a professor in the Department of Fisheries Management at BAU.
To conduct the research, water, sediment, and fish samples were collected across five distinct locations within the Arial Beel—Gadighat, Basurola Denga, Sagar Denga, Boraikhali, and Alampur. Samples were gathered across three specific seasons: the monsoon season of 2024, the winter season of 2024–25, and the dry season of 2025.
The targeted fish species under investigation included climbing perch (koi), bata (bata), meni (bheda/nandina), gulsha tengra, and punti.
The findings indicate that contamination levels vary depending on the species’ feeding habits and environmental exposure:
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Climbing Perch (Koi): Due to their omnivorous feeding nature, koi fish accumulated the highest amount of microplastics. Across all three seasons (monsoon, winter, and dry), an average of roughly one microplastic particle was found in the muscle tissue of koi. Furthermore, an average of 1.70 to 1.90 particles were found in their guts, and 1.30 to 1.40 particles were detected in their gills.
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Bata Fish: Following koi, herbivorous bata fish showed significant accumulation, with an average of up to 1.50 microplastic particles found in their guts during the monsoon season, while muscle tissue maintained a steady level across all three seasons (0.80 to 0.90 particles).
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Meni and Gulsha Tengra: Meni fish showed relatively higher plastic particle counts in their guts during winter and dry seasons, though muscle tissue concentrations stayed between 0.60 and 0.70 particles. Gulsha tengra displayed a similar trend, peaking at 1.30 particles in the gut during winter.
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Punti Fish: Small omnivorous punti fish recorded the lowest overall microplastic presence, with only 0.50 to 0.51 particles detected in their muscle tissues.
Environmental samples from the study area revealed 11 to 31.67 microplastic particles per liter of water and 12.33 to 127.33 particles per kilogram of sediment, with water pollution peaking during the monsoon season.
Fourier Transform Infrared (FT-IR) spectroscopy testing showed that 34% to 63% of the identified particles were microfibers originating primarily from laundry wastewater, household sewage, and discarded plastic fishing nets.
Chemical analysis further identified polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polycarbonate (PC)—polymers commonly used in packaging, plastic bags, bottles, and household goods.
Addressing the potential health implications, lead researcher Dr. Md. Shahjahan emphasized the need for awareness rather than panic:
“There is currently no clear evidence of immediate health risks from consuming these fish. However, if such particles continue to accumulate in the body over a long period, the impact may appear in the future—perhaps not in five or ten years, but after 25 to 30 years or even in the next generation,” stated Dr. Shahjahan.
He further stressed that rather than panicking, the focus must shift toward controlling plastic pollution directly at its source, noting that the presence of microplastics in both the guts and muscle tissues of Arial Beel fish makes this a critical public health concern.
While immediate health threats from consuming these fish have not been established, the BAU study highlights the pervasive spread of microplastics in local aquatic ecosystems.
The findings underscore an urgent long-term challenge for food safety and environmental management in Bangladesh.