Quantification of plastic pollution in Gulf of Mannar Marine Biosphere Reserve: Risk assessment and management strategies

Abstract

Worldwide, plastic pollution constitutes a significant environmental issue, currently recognized as a major threat to marine biodiversity. Enhancing our knowledge of the pathway of plastic accumulation in a particular site is crucial for litter management. Hence this study aimed to examine macro, meso, and microplastics (MPs) for their abundance and characterization along the beaches of Dhanushkodi, Kundukal, Pudumadam, and Valangapuri in the Gulf of Mannar Biosphere Reserve Region, Southern India towards suggesting possible management solution. A total of 1083 numbers, 58 kg of macro litter found in 2464 m². The average abundance of meso litter and range of MPs was 11.08 ± 16.65 items/m² and 28.2 ± 5.9–60.8 ± 23.3 particles/50 g respectively. Plastic (86 % in numbers and 71 % in weight) was found to be the most common type of macro litter. The Clean Coast Index (CCI), Plastic Abundance Index (PAI), Microplastics Pollution Index (MPPI), Pollution Load Index (PLI), Polymer Hazard Index (PHI), and Coefficient of Microplastics Impact (CMPI) revealed that the beaches ranged from moderately clean to dirty, with moderate to high plastic abundance, corresponding to Hazard Level I and a high hazard score. The backshore area accumulated a majority of the macro litter than the intertidal region. Public and fishing activities could be the main sources of plastic litter. Given that the study area is a significant biosphere reserve and a popular pilgrimage site, plastic contamination can affect biodiversity and beach tourism drastically. The study recommends stringent enforcement of a total ban on single-use plastics in this area, systematic monitoring, and appropriate training for fishermen on the proper disposal of waste, especially fishing gear would be highly effective.