Estimation of microplastics in sediments at the southernmost coast of India (Kanyakumari)

Increasing urbanization and anthropogenic activities of the last couple of decades have left significant amounts of plastic debris in both coastal and marine ecosystems. In this study, we estimated the abundance of microplastics (particle size < 5 mm) in the beach sediments of southernmost India at Kanyakumari by collecting sediments from harbors, coastal fishing villages/residential beaches, tourist beaches, and undisturbed coastal areas along the Indian Ocean. We recovered 343 particles (67% fiber and 33% fragment) from eight different stations by evaluating 50 g dry sediments (d.s.) from each location. All of them were secondary microplastics and most of them (i.e., 331 out of 343 particles) were transparent. Tourist beaches had the highest concentration (150 particles/50 g d.s.), followed by the harbors (99 particles/50 g d.s.). The undisturbed beach contained the least amount of microplastics, representing only 4.3% of the total recovered particles. Our study relates the abundance of microplastics to different degrees of anthropogenic activities. Further research, however, is required to identify the mechanism that influenced their transport and deposition in the coastal sediments as well as to evaluate the possible interaction between microplastic particles and marine ecosystems.