Microplastics in farmed and wild Prawn (Macrobrachium rosenbergii) from Diverse Aquatic Environments in Bangladesh

Microplastic (MP) contamination has become a global concern due to the widespread use of plastics, their environmental persistence, and associated health risks. To determine whether MPs are also present in the commercially important freshwater prawn Macrobrachium rosenbergii , gut, gills and muscles of prawns from both culture and capture in key prawn-producing districts of southwestern Bangladesh were examined. MP extraction involved tissue digestion, filtration, microscopic analysis, and polymer identification using ATR-FTIR spectroscopy. The results showed a significant difference (p < 0.05) in MP abundance between cultured prawns (8.91 ± 1.38 items/individual) and captured prawns (5.87 ± 1.07 items/individual), indicating a higher likelihood of MP ingestion in cultured prawns. In the tissues, MPs were most abundant in the gut, followed by the gills and muscles. The dominant types of MPs across all tissues were fibres, particles smaller than 0.5 mm, and black-coloured MPs. Among the identified polymers, polyvinyl stearate was the most common (40.82%), followed by polyethylene-propylene-diene (22.45%). Principal Component Analysis (PCA) showed that green-coloured MPs were negatively correlated with cultured prawns, whereas other MP characteristics were positively correlated in both groups. The sources of MPs were similar for both cultured and captured prawns, as determined by cluster analysis. The Polymer Hazard Index (PHI) for polyvinyl chloride (PVC), determined to 102.02, indicates potential toxicological effects on the ecosystems and human health. This study emphasises the importance of increased awareness of MP pollution and provides vital insights for governments and agencies to develop effective mitigation strategies to protect the safety and sustainability of prawn farming in Bangladesh.