Ganges River ecosystem

Category: Inland Aquatic Biomes.

Geographic Location: Asia.

Summary: The lifeline of India, the Ganges River supports massive and diverse habitats but is threatened by climate change and pollution.

The national river of India, the Ganges, originates at Gaumukh as a stream called Bhagirathi, in the Gangotri glacier in the Himalayan mountains at an altitude of 13,451 feet (4,100 meters) above mean sea level. The first town in the course of the Ganges, Gangotri, is 14 miles (23 kilometers) from its source of origin. The main stream of the river flows through the Himalayas until another two streams—the Mandakini and the Alaknanda—join it at Devprayag, the point of confluence. The river is also known as Ganga Ma, Mother Ganges, and may be called Ganges or Ganga.

The river takes its course through the Himalayan valleys until it reaches the plain at the town of Haridwar. From there, the Ganges flows southeast through the Indian states of Uttar Pradesh, Bihar, Jharkhand, and West Bengal. At Allahabad, the Yamuna River joins the Ganges. The main tributaries of the Ganges are the Yamuna, Ram Ganga, Gomati, Ghaghara, Son, Damodar, and Sapt Kosi Rivers. The largest tributary, the Ghaghara, meets the Ganges in Bihar near Patna. Another important Himalayan tributary is Gandak, which flows from Nepal. The Upper Ganges supplies water to extensive irrigation works.

The Ganges flows through some of the most populous cities in India, such as Kanpur, Allahabad, Varanasi, Patna, and Kolkata. At Bhagalpur, it meanders past the Rajmahal Hills and changes its course southward. At Pakaur, the Ganges has its first distributary, the Bhagirathi River, followed by the river Hoogly. In central Bangladesh, the Brahmaputra and Meghna Rivers join the Ganges. These three rivers combined are called the Padma River, which forms a delta 220 miles (354 kilometers) wide when it empties into the Bay of Bengal. The delta is also called Sundarbans; its plains are among the most fertile and densely populated regions of the world.

The Ganges River basin covers 332,590 square miles (861,400 square kilometers) and encompasses 26 percent of the land area of India, as well as parts of Nepal, China, and Bangladesh. The annual flow of the river is subject to local variations. The predominant water-flow pattern, however, is a low-flow dry season from January to May and a wet season from July to November, with peak flows usually occurring in August. The waters of the Ganges River carry one of the world's highest sediment loads, at a mean annual total of 1.8 billion tons (1.6 billion metric tons), compared with 0.5 billion tons (0.4 billion metric tons) for the Amazon River.

Biodiversity

The Ganges supports a rich variety of flora and fauna, including the endangered Ganges River dolphin or Susu (Platanista gangetica). The Ganges River dolphin is one of only four freshwater dolphins found throughout the world, and is considered threatened; pollution and changes to its habitat from dams and human activity have caused the Ganges River population to drop to a quarter of what it was a mere 15 years ago. Nine other species of aquatic mammals, and three species of crocodiles including the mugger crocodile and the gharial, also call the Ganges home. There are 11 species of freshwater turtles and one minor lizard as well.

The riparian zone supports many plant species of ecological and economic importance. Many crops are grown along the banks of the Ganges River, including staple crops such as rice, sugarcane, potatoes, cotton, wheat, oil seeds, and various legumes. Among the flora of the region are approximately 450 medicinal plants used in Ayurvedic medicine, India's system of traditional healing.

The river has the richest diversity of freshwater fish anywhere in India. Fish are an important part of life here, providing sustenance for people, animals, and birds living near the sacred river. Among the fish in this biome are featherbacks (Notopteridae family), common to the Bengal region; barbs (Cyprinidae); the walking catfish (Clarias batrachus); and others. The Ganges shark (Glyphis gangeticus) is critically endangered.

Parrots, crows, myna birds, kites, patridges, and various types of waterfowl such as ducks and snipes find refuge along the Ganges River, but there are no endemic (found nowhere else on Earth) birds in the upper Gangetic Plain. Many birds cross the Himalayas to reach the Ganges and migrate to wetland areas. Among the bird species found along the Ganges River, there are two threatened species: the great Indian bustard (Ardeotis nigriceps) and lesser florican (Sypheotides indicus).

Common mammals found along the Ganges River include deer, boars, wildcats, foxes, wolves, and jackals. At the Ganges Delta in Bangladesh, the clouded leopard (Neofelis nebulosa), the Indian elephant (Elephas maximus indicus), and the endangered Bengal tiger (Panthera tigris tigris) may be found.

Mythology and Human Activity

According to Hindu mythology, the Ganges River is believed to have come down to Earth from the heavens. The river symbolizes purification to millions of Hindus, who believe that drinking its water before death or bathing in the river at least once will lead to salvation. The river has been the final resting place for many Hindus, whose cremated ashes or partially burned corpses are placed in the river for spiritual rebirth.

It may not be an exaggeration to say that ever since humans started settling on its banks, the mighty river has steadily moved toward degeneration. The Aryans settled on the Gangetic plains around 1200 b.c.e. In the subsequent 3,200 years of human occupancy, the landscape of the Gangetic Plain has been exploited and transformed by agricultural and industrial activities. The Ganges River accounts for around 32 percent of India's annual usable water resources for agriculture, aquaculture, hydroelectric power generation, and industry, and it supplies water for an area composing more than one-third of the country's population.

The exploitation of the river by the human settlements along the river has eroded the quality of the river's waters. The populous and industrial towns, through their overextraction and water-diversion activities, have intensified the problem of river pollution at various points. About 30 cities and more than 60 towns thrive along the banks of the Ganges.

Besides sewage that is often untreated—as much as 264 million gallons (1 billion liters) per day—industrial discharges from pharmaceuticals factories, electronics plants, textile and paper industries, tanneries, fertilizer-manufacturing units, and oil refineries produce an additional load. The hazardous components of the effluents include hydrochloric acid, mercury and other heavy metals, and polychlorinated biphenyls (PCBs). There is much room for modernization of water treatment and filtration systems.

Pollution is not the only threat. A report by the Intergovernmental Panel on Climate Change warned that if the current trends of climate change continue, the size of the Himalayan glaciers could be reduced by as much as 80 percent by 2030. These glaciers are the ultimate source of the Ganges River, along with rainfall, and any changes in the rate at which these glaciers melt will impact the waters of the Ganges. Higher seasonal water levels followed by a drop in the water levels of the river may be disastrous for all living near these waters, reducing the supply of freshwater at some times, and generating uncontrollable erosion at others.

Conservation Efforts

The Ganga Action Plan (GAP) was initiated in 1984 by the government of India, supported by the Netherlands, the United Kingdom, and some voluntary organizations. The principal aims of the GAP were to reduce pollution load on the river immediately and to establish self-sustaining treatment plants.

The Indian government has declared the 84-mile (135-kilometer) stretch of the Ganges between Gaumukh and Uttarkashi to be an eco-sensitive zone, seeking specific activities to save the rich biodiversity of the region. As a result, three hydroelectric projects that were proposed to be initiated along the river—Bhaironghati, Pala Maneri, and Loharinag Pala—were discontinued. In April 2011, the Cabinet Committee on Economic Affairs approved a river-cleaning project to be implemented by the National Ganga River Basin Authority (NGRBA). The central and state governments of Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, and West Bengal agreed to share the expenses.

The pilot study conducted at Chandernagore Municipality by Birol and Das in West Bengal reveals that it would be economically viable to invest in infrastructure that would treat higher quantities of wastewater to create higher quality. The pilot experiment stated that all households, regardless of their income levels, showed willingness to pay higher taxes to ensure the full capacity of the sewage treatment plant for primary treatment and to upgrade the technology needed to enable secondary treatment. The results of the study can be adapted to similar municipalities along the Ganges with the use of the benefits-transfer method. The results support enhanced investments to improve the water quality of the Ganges River in order to reduce the environmental hazards and health risks currently threatening the sustainability of ecosystems across the biome.

The Union Ministry of Environment and Forests has asked the Indian Institute of Technology to prepare a work plan for the NGRBA. A carefully designed environmental policy may help prevent a great deal of environmental damage and associated cleanup costs in the future, as well as save the Ganges from shrinking in the face of global warming and glacier contraction.

Bibliography

Birol, Ekin and Sukanya Das. “Estimating the Value of Improved Waste Water Treatment: The Case of River Ganga, India.” Journal of Environmental Management 91, no. 1 (2010).

Butler, Stuart. "The Ganges: River of Life, Religion, and Pollution." Geographical, 20 Jan. 2022, geographical.co.uk/culture/the-ganges-river-of-life-religion-and-pollution. Accessed 4 Aug. 2022.

International Institute for Environment and Development. “Up in Smoke? Asia and the Pacific.” 2007. http://pubs.iied.org/10020IIED.html.

Markandya, Anil and Maddipati Narasimha Murty. “Cost-Benefit Analysis of Cleaning the Ganges: Some Emerging Environment and Development Issues.” Environment and Development Economics 9, no. 1 (2004).

Ministry of Environment and Forests, Government of India. “Annual Report 2011–12.” 2012. http://moef.nic.in/report/report.html.

Qadri, Altaf. "Ganges River Flows with History and Prophecy for India." Earthbeat, 18 Aug. 2020, www.ncronline.org/news/earthbeat/ganges-river-flows-history-and-prophecy-india. Accessed 4 Aug. 2022.