SOURAV BAR, JHUMPA MAJHI, SOUMIK DHARA AND SUDIPTA KUMAR GHORAI
Abstract
Microplastic contamination was assessed in the air-breathing sea slug Peronina tenera (Stoliczka, 1869), collected from the Subarnarekha estuary in the northeastern Bay of Bengal. This study aimed to evaluate the abundance, size, colour, and polymer composition of microplastics in the tissues of these estuarine organisms. Ten specimens were sampled from Talsari, Odisha (21°36â2.29âN, 87o27â13.9âE) in April 2024. The concentration of microplastics ranged from 3.72 to 13.51 particles per gram of tissue, with an average of 6.47 particles. Among the different size classes, smaller microplastics (50-500 ?m) were the most abundant, and blue-coloured microplastics were the most commonly observed. Raman spectroscopy analysis identified five polymer types: polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), and polyethylene (PE), all of which are widely used in packaging, textiles, and industrial applications. The pollution load index (PLI) averaged 1.29, indicating significant contamination levels in this estuarine environment. The presence of these microplastics suggests multiple potential sources, including the degradation of plastic waste from fishing nets, ropes, and gear discarded by the fishing industry, as well as synthetic fibers from textile washing and the breakdown of single-use plastic packaging. The accumulation of these microplastics in P. tenera highlights their bioavailability in estuarine food chains, raising serious ecological concerns about trophic transfer, bioaccumulation in higher organisms, and potential long-term impacts on aquatic biodiversity.