Microplastic contamination in water and organs of Deveximentum insidiator (Ponyfish) from a potential fishing zone off Mangalore, southeastern Arabian Sea

This study investigates microplastic (MP) contamination in Deveximentum insidiator (pony fish or silverbellies), a commercially important species in the Indo-West Pacific, with samples collected from a Potential Fishing Zone (PFZ) in the Southeastern Arabian Sea on February 20, 2024. A total of 51 fish specimens and corresponding water column samples were analyzed to assess the prevalence and characteristics of MPs. The results revealed an average of 28.21 ± 17.73 MPs per individual and 2.97 ± 3.02 MPs per litre of water. Organ-specific accumulation showed the highest MP load in the gut (31.8 %), followed by the muscle (25.71 %), gills (23.83 %), and gonads (18.62 %). In fish, fibres dominated (99.32 %), while fragments (52.10 %) were most abundant in water. MPs in fish were predominantly 11-100 μm in size, indicating bioaccumulation potential, whereas larger MPs (1000-3000 μm) were more common in water (37.81 %). Polypropylene was the major polymer detected in both fish and water samples. Potential human health risks were assessed through estimates of MP intake via fish consumption. Adults may ingest approximately 20.57 MPs/day (7505 MPs/year), and children 9.80 MPs/day (3577 MPs/year). Risk assessment indices indicated low ecological risk (PLI: fish = 2.41, water = 1.55-2.27), but moderate toxicity risk based on the Polymer Hazard Index (PHI: fish = 9.68; water = 10.89). This study provides the first documented evidence of MP presence in D. insidiator in this region, highlighting the species' exposure to MPs and the associated potential health risks for seafood consumers. These findings underscore the need for species-specific assessments to inform marine conservation strategies food safety management in Potential Fishing Zones.