Chapter 8 - Assessment of microplastic pollution in the Vembar estuarine environment, Southeast coast of India

Abstract

The specialty of plastics is strength and long life, approximated in the range of tens to hundreds of years, which have contributed to the notable rise in plastic pollution. The present study aims to evaluate and intermingle the deposition of MPs, monitoring, quantification, and color of MPs, morphological shape, and source of pollution in beach sand samples from the Vembar to Muthu Nagar Beach. Fieldwork and beach sand sampling were carried out in the Tuticorin District during September 2019, representing the monsoon season. Thirteen sand samples were collected from nine different locations. Beach samples were collected approximately 2kg from nine shoreline environments. The analysis involves sieving and floating methods for dry beach sand samples to 5mm and density separation using an aqueous NaCl solution for visual observation under a fluorescence microscope. The higher percentage of total microplastics in VMR is 2%–10.19%, Periyasamypuram 2%–10.19%, and MNB—9.22%, while the lowest percentage is recorded in PCP at 1%–2.91%. On the other hand, the primary source of plastics is deposited as debris in the shoreline environment. Macroplastics (MAPs) constitute 29.21% of the particles identified. Based on morphology, the occurrence is highest for fiber-shaped microplastics swept by the wind, followed by fragments, foams, and film, while pellets and microbead-shaped microplastics as the least contributory. Fibers were recorded in PSP and Kunjayapuram at 100%. Microplastic and MAP particles are multicolored in descending order as white > blue > red > yellow > green > pink > violet, followed by blue > white > yellow > pink > red > brown > black. A higher percentage of total MPs are indicated found in the fishing industry for livelihood and the beach for recreation. Lower percentages are deposited due to rural nondevelopment areas. Fibers are found in entire locations that look like nylon; nylon chiefly accounts as a pollutant on the coast through fishing nets and nylon ropes. This study indicates that sand samples from the Southeast coast, especially Tuticorin District beaches, are contaminated with MP particles. The primary source of marine debris is fishing materials and daily-use items. Polyethylene and polypropylene plastics were found to dominate in all locations in beach sand samples, indicating their higher global production and consumption rate.