- The Ganges river system is the second largest plastic-polluting watershed in the world and is one of 14 continental rivers into which more than a quarter of the world’s waste is discharged.
- Some proposed solutions for dealing with plastic dumped in the river include researching and adopting alternatives to plastic, then tackling land-based sources and landfills, before tackling marine litter.
- Further research can help identify the main sources and pathways of microplastics to better design intervention measures.
Born at the confluence of the Alaknanda and Bhagirathi rivers, the Ganges traverses a distance of over 2,500 kilometers from the snow-capped Himalayas, through the vast alluvial plains of northern India, before meeting the Brahmaputra River and joining the sea.
As the Ganges, fed by its many tributaries, flows through some of the most densely populated swathes of India and Bangladesh, it is a vital water source for over 655 million people. Throughout history, religions have been born on the banks of the river – with temples still welcoming pilgrims from far and wide to worship its sacred waters. Imperial capitals and civilizations have risen, ebbed and flowed along its fringes.
For decades, the river has carried more than just prayers downstream: municipal garbage, untreated sewage, industrial chemical effluents, agricultural runoff, religious offerings and ghost fishing gear have polluted the waters, the plastic being the most widespread and persistent pollutant.
Along its course, the river accumulates plastic – macro, meso and micro, from various sources, and transports it to the sea. The Ganges network is the second largest catchment area of plastic pollution in the world, with more of 0.12 million tons of plastic discharged into marine ecosystems per year, and is one of the 14 continental rivers in which more than a quarter of the world’s waste is discharged.
The Ganges is one of the main contributors of land-based plastic pollution in the global oceans – the river serves as a conduit for land-based waste that ends up in marine ecosystems.
The upper Ganges area extends from the mountainous catchments of its two main tributaries, Alaknanda and Bhagirathi, to the alluvial plains of Uttar Pradesh, ending at the state’s administrative border with Bihar. The main stem of the Ganges begins where the Alaknanda and Bhagirathi rivers meet at Devprayag in the Garhwal district of Uttarakhand. Along its upper course, the Ganges is fed by numerous streams or springs such as Dhauliganga, Nandakini, Pindar, Mandakini, as well as the catchment areas of rivers such as Ramganga, Ghaghara, Gomti and Tons. On its journey it erodes and carries much sediment from higher elevations, depositing it downstream as rich, alluvial soil along the plains and has long been an essential lifeline for biodiversity, people, agriculture and civilizations of northern India.
To add to this, plastic pollution from ghost gear – any abandoned, discarded, lost or abandoned fishing gear in aquatic systems and urban centers – poses an additional threat to biodiversity and human well-being.
In February 2021, ghost gear sampling was carried out in cities like Bhola, Chandpur, Varanasi, Kannauj, Anupshahr, Rishikesh (Uttar Pradesh), Patna (Bihar), Sahibganj (Jharkhand), Rajbari (West Bengal).
In August 2021, the Convention on Migratory Species (CMS) and the United Nations Environment Program (UNEP) published a report as part of the CounterMEASURE II project, which documents the threats facing terrestrial migratory species, freshwater and avian in Asian and Asian habitats. The pacific. She concluded that plastic pollution has a disproportionate impact on migratory species, as they cover larger geographical areas and are more exposed.
The lower Ganges area begins at the administrative boundary of Uttar Pradesh and Bihar. From here, the river flows east past the Farakka Dam to meet the Brahmaputra, forming a massive delta of ever-changing mangrove-covered islands, before emptying into the Bay of Bengal.
Inland fisheries provide essential income and nutrition to people in the lower parts of the Ganges, and India and Bangladesh are two of the world’s leading producers of inland fisheries. Over 140 species of fish have been reported along the Ganges, with freshwater fish in the areas above Farakka Dam and estuarine species in the lower reaches.
Inland fisheries are threatened by urban and industrial waste, agricultural pesticides, heavy metal contamination, the construction of the Farakka dam, leading to a decrease in stocks. In turn, overexploitation by fishermen threatens the biodiversity along this stretch, and their ghost gear has far-reaching consequences for aquatic ecosystems.
Some proposed solutions include finding and adopting alternatives to plastic, then tackling land-based sources and landfills before tackling marine litter. Further research, such as that undertaken by the CounterMEASURE project, implemented by the Asia and the Pacific Section of the United Nations Environment Programme, funded by Japan, can help identify the main sources and pathways of microplastics to better design the intervention measures. Targeted and informed interventions will be crucial to ensure human health, biodiversity and ecosystems.
Text: Devayani Khare
Illustrations: Sumita Nanda
From the sea to the source: expedition on the Ganges
Qualitative analysis of microplastics along the Ganges, Toxic Links report, 2020.
Impacts of Plastic Pollution on Aquatic, Terrestrial and Freshwater Avian Migratory Species in the Asia and Pacific Region
Duncan, EM, Davies, A., Brooks, A., Chowdhury, GW, Godley, BJ, Jambeck, J., Maddalene, T., Napper, I., Nelms, SE, Rackstraw, C. & Koldewey, H. (2020) Message in a Bottle: Open Source Technology to Track the Plastic Pollution Movement. PloS One, 15(12), e0242459. https://doi.org/10.1371/journal.pone.0242459
Nelms, SE, Duncan, EM, Patel, S., Badola, R., Bhola, S., Chakma, S., Chowdhury, GW, Godley, BJ, Haque, AB, Johnson, JA & Khatoon, H. (2021 ) River plastic pollution from fishing: insights from the Ganges system. Total Environmental Science, 756143305. https://doi.org/10.1016/j.scitotenv.2020.143305
Sarkar, UK, Pathak, AK, Sinha, RK, Sivakumar, K., Pandian, AK, Pandey, A., Dubey, VK & Lakra, WS (2012) Freshwater fish aquatic entertainment in the River Ganga (India): evolution pattern, threats and conservation perspectives. Reviews in Fish Biology and Fisheries, 22(1), 251-272.
Biodiversity of freshwater fishes in the Ganges River (India): changing pattern, threats and conservation prospects https://doi.org/10.1007/s11160-011-9218-6
Napper, IE, Baroth, A., Barrett, AC, Bhola, S., Chowdhury, GW, Davies, BF, Duncan, EM, Kumar, S., Nelms, SE, Niloy, MNH and Nishat, B. (2021) The abundance and characteristics of microplastics in the surface waters of the transboundary Ganges. Environmental pollution, 274116348.
Sarkar, DJ, Sarkar, SD, Das, BK, Manna, RK, Behera, BK & Samanta, S. (2019) Spatial distribution of meso and microplastics in sediments of the Ganges in eastern India. Total Environmental Science, 694133712.