Microplastic prevalence, diversity and characteristics in commercially important edible bivalves and gastropods in relation to environmental matrices

The study focuses on the abundance and characteristics of ubiquitous microplastic (MP) pollutants in different natural molluscan settling sites along the southwest coast of India. It assesses its bioavailability within the tissue of selected locally abundant edible bivalves and gastropods viz., Villorita cyprinoides, Paphia malabarica, Crassostrea madrasensis, Perna perna, and Babylonia spirata. The mean MP abundance was found to be 140.83±32.62 items/L in water, 270.56±102.48 items/kg in sediment and 15.33 ± 15.56 MP/g of the soft tissue of molluscan samples. Transparent and blue-coloured fibres of size >500 µm, primarily comprising polyethylene, polypropylene, polystyrene, low-density polyethylene, polyamide, polyester, polyvinyl chloride and polyethylene terephthalate, were the most dominant forms of MPs. Interestingly, except for Babylonia spirata, a negative correlation has been observed between MP abundance and different morphometric characteristics in all the studied species. Hence, pre-emptive measures are needed to reduce the MP load by employing effective bioremediations to ensure food safety.