Microplastics in farmed and wild prawn (Macrobrachium rosenbergii) from aquatic environments in Bangladesh

Abstract 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 farmed and wild prawns from 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 farmed prawns (8.91 ± 1.38 items/individual) and wild prawns (5.87 ± 1.07 items/individual), indicating a higher likelihood of MP ingestion in farmed 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 farmed prawns, whereas other MP characteristics were positively correlated in both groups. A cluster analysis showed that the sources of MPs were similar for both farmed and wild prawns. The Polymer Hazard Index (PHI) for polyvinyl chloride (PVC), determined to be 102.02, indicates potential toxicological effects on ecosystems and human health. This study emphasises the importance of raising awareness of MP pollution and provides insight for governments and agencies to develop effective mitigation strategies to protect the safety and sustainability of prawn farming in Bangladesh.