Anthropogenic litter on sandy beaches in Mumbai Coast, India: a baseline assessment for better management

Sandy beaches are coastal habitats with distinctive biodiversity that connects the land to the sea and sustain ecological processes and human livelihoods. Sandy beach ecosystems are experiencing severe threats by anthropogenic litter pollution, which has increased due to ineffective waste management. This study aims to assess the abundance, composition, diversity, and sources of litter on two sandy beaches along the Mumbai coast using three transects of 50 m in length. All visible pieces of litter having a size > 2.5 cm were collected and removed. A total of 52,770 litter items with 52,7267.97 g weight falling in 41 debris categories and nine major groups were collected. The mean abundance of marine litter recorded in Juhu on the count and weight basis was 1698 ± 838.29 items/50 m and 11,800 ± 4470.03 g/50 m, respectively, and that of Aksa was 407.43 ± 28.19 items/50 m and 6653.75 ± 665.50 g/50 m, respectively. The highest abundance of litter with low diversity and evenness was found in Juhu during October. The predominance of plastics with an average abundance of 618 ± 271.82 items/50 m and 2616.77 ± 989.19 g/50 m emphasizes a high risk to marine organisms. The Clean Coast Index classified Juhu as a dirty beach and Aksa as a clean beach. General-based sources contributed more to marine litter. The significant causes of litter abundance were beach usage for recreational and religious activities and deposition from the sea. The data gathered through this study can be used as reference values for future litter monitoring programs to identify the primary sources and to design effective mitigation measures.