Microplastics in seafood as an emerging threat to marine environment: A case study in Goa, west coast of India

The present study exhibits the occurrence of MPs in different matrices (water, sediment and biota) from the Sal estuary, Goa, situated on the central west coast of India. The average numbers of MPs in the water column and sediment were 48 ± 19 MP particles/L (MPs/L) and 3950 ± 930 MP particles/kg (MPs/kg), respectively. In shellfish (whole soft tissue), the average concentrations of MPs were 4 ± 2 (Crassostrea sp.), 3.2 ± 1.8 (Perna viridis) and 0.7 ± 0.3 (Paphia malbarica) MPs/g body weight (bw), respectively. The highest MPs were recorded in finfish (gastro-intestinal tract) (Mugil cephalus)7.8 ± 4, followed by (Gerres filamentosus) 5.3 ± 4.9, (Arius jella) 4.6 ± 2.6, and (Etroplus suratensis)1.4 ± 0.3 MP/g bw. MP fibres were predominant in all matrices. Interestingly, a dominance of small sized (10-300 μm) MPs was recorded in biota. Among the 37 polymer types identified by μ-FTIR, the most prevalent ones were, polyacrylamide (PAM) , polyacetylene, ethylene vinyl alcohol (EVOH), polyvinyl chloride (PVC) and polyamide (nylon). Notably, the polymers dominant in the gut of finfish and in whole shellfish were equally prominent in sediment and the water column. This study highlights the presence of MPs in commercially important shellfish and finfish samples from the Sal estuary. This study clearly shows the presence of MPs in various types of marine organisms in the Sal estuary. As shellfish is locally consumed as a delicacy and plays a major role in the seafood industry, the MPs may pose a hazard for human health. There is also an ecological risk as MPs are also found in water and sediment and in the digestive tract of finfish.