Preliminary study on microplastic abundance and morphological diversity in beach sediments of Goa and their role as carriers of metals

Abstract

This study investigates the abundance and morphological diversity of microplastics (MP) in the sediments of eight beaches from Goa, India. Average MPs in the surface sediments ranged from 463 particles/kg (Miramar Beach) to 1978 particles/ kg (Calangute Beach). The sediments were dominated by fibres (55.52-77.68 percent), followed by films (18.05-25.38 percent) and fragments (4.26-19.08 percent). It was attributed to the release of fibrous material through laundry, washing machine waste, and input from fishing activities involving the usage of nets. Also, the prevalence of colourless MPs (91.97-97.58 percent) was greater than the coloured MPs (blue, red, black, green, and yellow). The presence of MPs with a wide colour range suggested their numerous sources in the coastal water and beaches of Goa. The Coefficient of Microplastic Impact (CMPI) classified fibre, film, and fragment types of MPs under the categories of maximum, average and minimum (largely) classes, respectively. Pollution Load Index (PLI) revealed MP pollution in the beach sediments. Additionally, an attempt was made to understand the potential of MPs as carriers of metals. The findings revealed that MPs hold a significant proportion of metals, viz., Zn and Cu, followed by Co and Ni and thus disclosed their potential for acting as carriers of metals in the beach sediments.