Driving aspects of microplastic uptake: Influence in the Bentho-Pelagic ecosystem and its associated ecological risks along the coast of Goa, India.

Microplastics (MPs) interference in bentho-pelagic system plays a crucial role in understanding its impact on marine health and ensuring seafood safety. This study was an initial attempt to understand the realistic perspective of how habitat and feeding behaviour of marine species can be the driving causes for MPs ingestion. A total of 251 individuals from 9 pelagic and benthic fish and shellfish species were studied in Goa's rich coastal ecosystem. Habitat wise higher MPs contamination was found in benthic realm (55 %) and sediment (2500 particles/kg d.w.) compared to pelagic realm (45 %) and water column (120 MP/L). Particularly, among finfish, Stolephorus indicus (8.8 ± 2.3 MPs/individual, pelagic) and Arius jella (10.1 ± 4.7 MPs/individual, benthic) emerge as prominent accumulators of MPs, while Meretrix meretrix showed the highest MPs concentration (3.3 ± 2.4 MP/g) among shellfish. Scrutinizing MPs in both gastrointestinal tract (GIT) and gills, MPs accumulated most in the GIT, indicating it as the primary ingestion pathway. High abundance of fibrous MPs (20-300 μm), mainly polyamide and polyester, indicated fishing activities and wastewater discharge could be the key pollution sources. In response to the risk assessment of MP's interference, Polymer Hazard Index (PHI >1000) were found considerably higher for certain polymers. Nutritional indices unveiled compromised Condition Index (CI) and Microplastic Index (MPI) in shellfish raising serious concerns due to their reduced nutritional values. Considering all possible factors contributing to MPs bioaccumulation, human consumption through shellfish was estimated to be ∼10,780 particles/person/year. Hence, this study provides insights on MPs contamination in seafood, highlighting its bioaccumulation, trophic transfer, and potential risks to coastal populations.