Editing Ganges (section)

==Ecology and environment==

[[File:Bangladesh tmo 2011313.jpg|thumb|''Ganges from Space'']]
Human development, mostly agriculture, has replaced nearly all of the original natural vegetation of the Ganges basin. More than 95% of the upper Gangetic Plain has been degraded or converted to agriculture or urban areas. Only one large block of relatively intact habitat remains, running along the Himalayan foothills and including [[Rajaji National Park]], [[Jim Corbett National Park]], and [[Dudhwa National Park]].<ref name=wwf0166>{{WWF ecoregion|id=im0166 |name= Upper Gangetic Plains moist deciduous forests|access-date=6 May 2011}}</ref> As recently as the 16th and 17th centuries the upper Gangetic Plain harboured impressive populations of wild [[Asian elephant]]s (''Elephas maximus''), [[Bengal tiger]]s (''Panthera t. tigris''), [[Indian rhinoceros]] (''Rhinoceros unicornis''), [[gaur]]s (''Bos gaurus''), [[barasingha]]s (''Rucervus duvaucelii''), [[sloth bear]]s (''Melursus ursinus'') and [[Indian lion]]s (''Panthera leo leo'').<ref name=wwf0166/> In the 21st century there are few large wild animals, mostly deer, [[wild boar]]s, [[wildcat]]s, and small numbers of [[Indian wolf|Indian wolves]], [[golden jackal]]s, and [[Red fox|red]] and [[Bengal fox]]es. Bengal tigers survive only in the [[Sundarbans]] area of the Ganges Delta.<ref name=Britannica/> The Sundarbands freshwater swamp ecoregion, however, is nearly extinct.<ref name=wwf0162>{{WWF ecoregion|id=im0162 |name= Sundarbans freshwater swamp forests|access-date=6 May 2011}}</ref> The [[Heritiera fomes|Sundarbans mangroves]] (''Heritiera fomes'') also grow in the Sundarbans area of the Ganges Delta.<ref>{{Cite web |last=Centre |first=UNESCO World Heritage |title=The Sundarbans |url=https://whc.unesco.org/en/list/798/ |access-date=2022-06-24 |website=UNESCO World Heritage Centre |language=en |archive-date=8 December 2023 |archive-url=https://web.archive.org/web/20231208015435/https://whc.unesco.org/en/list/798/ |url-status=live }}</ref> [[Threatened species|Threatened]] mammals in the upper Gangetic Plain include the tiger, elephant, sloth bear, and [[four-horned antelope]] (''Tetracerus quadricornis'').<ref name=wwf0166/>

[[File:Florican, 1781.jpg|upright|thumb|[[Lesser florican]] (''Sypheotides indicus'')]]

Many types of birds are found throughout the basin, such as [[myna]], ''[[Psittacula]]'' parakeets, [[crow]]s, [[Kite (bird)|kites]], [[partridge]]s, and [[fowl]]s. [[Duck]]s and [[snipe]]s migrate across the Himalayas during the winter, attracted in large numbers to wetland areas.<ref name=Britannica/> There are no [[Endemism|endemic]] birds in the upper Gangetic Plain. The [[great Indian bustard]] (''Ardeotis nigriceps'') and [[lesser florican]] (''Sypheotides indicus'') are considered globally threatened.<ref name=wwf0166/>

The natural forest of the upper Gangetic Plain has been so thoroughly eliminated it is difficult to assign a natural vegetation type with certainty. There are a few small patches of forest left, and they suggest that much of the upper plains may have supported a [[Tropical and subtropical moist broadleaf forests|tropical moist deciduous forest]] with sal (''[[Shorea robusta]]'') as a [[climax species]].<ref name=wwf0166/>

A similar situation is found in the lower Gangetic Plain, which includes the lower Brahmaputra River. The lower plains contain more open forests, which tend to be dominated by ''[[Bombax ceiba]]'' in association with ''[[Albizzia procera]]'', ''[[Duabanga grandiflora]]'', and ''[[Sterculia vilosa]]''. There are early [[seral]] forest communities that would eventually become dominated by the climax species sal (''Shorea robusta'') if forest succession was allowed to proceed. In most places forests fail to reach climax conditions due to human causes.<ref name=wwf0120>{{WWF ecoregion|id=im0120 |name= Lower Gangetic Plains moist deciduous forests|access-date=6 May 2011}}</ref> The forests of the lower Gangetic Plain, despite thousands of years of human settlement, remained largely intact until the early 20th century. Today only about 3% of the ecoregion is under natural forest and only one large block, south of Varanasi, remains. There are over forty protected areas in the ecoregion, but over half of these are less than {{convert|100|km2|sqmi}}.<ref name=wwf0120/> The fauna of the lower Gangetic Plain is similar to the upper plains, with the addition of a number of other species such as the [[smooth-coated otter]] (''Lutrogale perspicillata'') and the [[large Indian civet]] (''Viverra zibetha'').<ref name=wwf0120/>

===Fish===
[[File:Catla catla India.jpg|thumb|The [[catla]] (''Catla catla'') is one of the Indian carp species that support major fisheries in the Ganges.]]

It has been estimated that about 350 fish species live in the entire Ganges drainage, including several [[Endemism|endemics]].<ref>{{cite book |editor1=Allen, D.J. |editor2=S. Molur |editor3=B.A. Daniel  | title=The Status and Distribution of Freshwater Biodiversity in the Eastern Himalaya | year=2010 | publisher=IUCN | page=23 | isbn=978-2-8317-1324-3 }}</ref> In a major 2007–2009 study of fish in the Ganges basin (including the river itself and its tributaries, but excluding the Brahmaputra and Meghna basins), a total of 143 fish species were recorded, including 10 non-native [[introduced species]].<ref name=Sarkar2012>{{cite journal |author1=Sarkar |author2=Pathak |author3=Sinha |author4=Sivakumar |author5=Pandian |author6=Pandey |author7=Dubey |author8=Lakra  | title=Freshwater fish biodiversity in the River Ganga (India): changing pattern, threats and conservation perspectives | year=2012 | journal=Rev Fish Biol Fisheries | volume=22 |issue=1 | pages=251–272 | doi=10.1007/s11160-011-9218-6 |bibcode=2012RFBF...22..251S |s2cid=16719029 }}</ref> The most diverse orders are [[Cypriniformes]] (barbs and allies), [[Siluriformes]] (catfish) and [[Perciformes]] (perciform fish), each comprising about 50%, 23% and 14% of the total fish species in the drainage.<ref name=Sarkar2012/>

There are distinct differences between the different sections of the river basin, but [[Cyprinidae]] is the most diverse throughout. In the upper section (roughly equalling the basin parts in Uttarakhand) more than 50 species have been recorded and Cyprinidae alone accounts for almost 80% those, followed by [[Balitoridae]] (about 15.6%) and [[Sisoridae]] (about 12.2%).<ref name=Sarkar2012/> Sections of the Ganges basin at altitudes above {{convert|2400-3000|m|ft|abbr=on}} above sea level are generally without fish. Typical genera approaching this altitude are ''[[Schizothorax]]'', ''[[Tor (fish)|Tor]]'', ''[[Barilius]]'', ''[[Nemacheilus]]'' and ''[[Glyptothorax]]''.<ref name=Sarkar2012/> About 100 species have been recorded from the middle section of the basin (roughly equalling the sections in Uttar Pradesh and parts of Bihar) and more than 55% of these are in family Cyprinidae, followed by [[Schilbeidae]] (about 10.6%) and [[Clupeidae]] (about 8.6%).<ref name=Sarkar2012/> The lower section (roughly equalling the basin in parts of Bihar and West Bengal) includes major floodplains and is home to almost 100 species. About 46% of these are in the family Cyprinidae, followed by Schilbeidae (about 11.4%) and [[Bagridae]] (about 9%).<ref name=Sarkar2012/>

The Ganges basin supports major fisheries, but these have declined in recent decades. In the [[Prayagraj]] region in the middle section of the basin, catches of carp fell from 424.91 metric tons in 1961–1968 to 38.58 metric tons in 2001–2006, and catches of catfish fell from 201.35 metric tons in 1961–1968 to 40.56 metric tons in 2001–2006.<ref name=Sarkar2012/> In the [[Patna]] region in the lower section of the basin, catches of carp fell from 383.2 metric tons to 118, and catfish from 373.8 metric tons to 194.48.<ref name=Sarkar2012/> Some of the fish commonly caught in fisheries include [[catla]] (''Catla catla''), [[golden mahseer]] (''Tor putitora''), [[tor mahseer]] (''Tor tor''), [[rohu]] (''Labeo rohita''), [[walking catfish]] (''Clarias batrachus''), [[pangas catfish]] (''Pangasius pangasius''), [[Bagarius|goonch catfish]] (''Bagarius''), [[Snakehead (fish)|snakeheads]] (''Channa''), [[bronze featherback]] (''Notopterus notopterus'') and [[milkfish]] (''Chanos chanos'').<ref name=Britannica/><ref name=Sarkar2012/>

The Ganges basin is home to about 30 fish species that are listed as threatened with the primary issues being [[overfishing]] (sometimes illegal), pollution, water abstraction, [[siltation]] and [[invasive species]].<ref name=Sarkar2012/> Among the threatened species is the [[critically endangered]] [[Ganges shark]] (''Glyphis gangeticus'').<ref>{{cite web |url= http://www.fishbase.org/summary/SpeciesSummary.php?genusname=Glyphis&speciesname=gangeticus |title= Glyphis gangeticus, Ganges shark |publisher= [[FishBase]] |access-date= 7 May 2011 |archive-date= 28 March 2024 |archive-url= https://web.archive.org/web/20240328172528/https://fishbase.mnhn.fr/summary/Glyphis-gangeticus.html |url-status= live }}</ref> Several fish species [[Fish migration|migrate]] between different sections of the river, but these movements may be prevented by the building of dams.<ref name=Sarkar2012/>

===Crocodilians and turtles===
[[File:Gavialis gangeticus, ZOO Praha 045.jpg|thumb|The threatened [[gharial]] (''Gavialis gangeticus'') is a large fish-eating [[crocodilian]] that is harmless to humans<ref>{{cite web | title=Gharial biology | publisher=Gharial Conservation Alliance | url=http://www.gharialconservationalliance.org/?page_id=216 | access-date=12 September 2017 | archive-url=https://archive.today/20130414200745/http://www.gharialconservationalliance.org/?page_id=216 | archive-date=14 April 2013 | url-status=dead }}</ref>]]

The main sections of the Ganges River are home to the [[gharial]] (''Gavialis gangeticus'') and [[mugger crocodile]] (''Crocodylus palustris''), and the Ganges delta is home to the [[saltwater crocodile]] (''C. porosus''). Among the numerous aquatic and semi-aquatic turtles in the Ganges basin are the [[northern river terrapin]] (''Batagur baska''; only in the lowermost section of the basin), [[three-striped roofed turtle]] (''B. dhongoka''), [[red-crowned roofed turtle]] (''B. kachuga''), [[black pond turtle]] (''Geoclemys hamiltonii''), [[Brahminy river turtle]] (''Hardella thurjii''), [[Indian black turtle]] (''Melanochelys trijuga''), [[Indian eyed turtle]] (''Morenia petersi''), [[brown roofed turtle]] (''Pangshura smithii''), [[Indian roofed turtle]] (''Pangshura tecta''), [[Indian tent turtle]] (''Pangshura tentoria''), [[Indian flapshell turtle]] (''Lissemys punctata''), [[Indian narrow-headed softshell turtle]] (''Chitra indica''), [[Indian softshell turtle]] (''Nilssonia gangetica''), [[Indian peacock softshell turtle]] (''N. hurum'') and [[Cantor's giant softshell turtle]] (''Pelochelys cantorii''; only in the lowermost section of Ganges basin).<ref name=turtles>{{cite book |editor1=Rhodin |editor2=Pritchard |editor3=Dijk |editor4=Saumure |editor5=Buhlmann |editor6=Iverson |editor7=Mittermeier  | title=Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group |author1=van Dijk |author2=Iverson |author3=Rhodin |author4=Shaffer |author5=Bour  |s2cid=88824499 | chapter=Turtles of the World, 7th Edition: Annotated Checklist of Taxonomy, Synonymy, Distribution with Maps, and Conservation Status | year=2014 | publisher=IUCN | volume=5 | doi=10.3854/crm.5.000.checklist.v7.2014 | series=Chelonian Research Monographs | isbn=978-0965354097 }}</ref> Most of these are seriously threatened.<ref name=turtles/>

===Ganges river dolphin===
[[File:GangeticDolphin.jpg|thumb|The Gangetic dolphin in a sketch by Whymper and P. Smit, 1894.]]
The river's most famed faunal member is the freshwater [[Ganges river dolphin]] (''Platanista gangetica gangetica''),<ref name=wwf0166/> which has been declared India's [[List of national animals|national aquatic animal]].<ref>{{cite web | url= http://wildpolitics.net/2010/01/19/ganges-river-dolphin-declared-indias-national-aquatic-animal/ | archive-url= https://web.archive.org/web/20110902103154/http://wildpolitics.net/2010/01/19/ganges-river-dolphin-declared-indias-national-aquatic-animal/ | url-status= dead | archive-date= 2 September 2011 | title= Ganges River Dolphin Declared India's National Aquatic Animal | publisher= WildPolitics.net | access-date= 6 May 2011 }}</ref>

This dolphin used to exist in large schools near urban centres in both the Ganges and Brahmaputra rivers but is now seriously threatened by pollution, dam construction and improper fishing methods.<ref>{{cite news | url= https://news.mongabay.com/2023/01/banned-but-abundant-gillnets-pose-main-threat-to-bangladeshs-river-dolphins/ | title= Banned but abundant, gillnets pose main threat to Bangladesh's river dolphins | access-date= 14 April 2024 }}</ref> Their numbers have now dwindled to a quarter of their numbers of fifteen years before, and they have become extinct in the Ganges' main tributaries.{{efn|name=puttick|1= {{harvtxt|Puttick|2008}}<br />"Sacred ritual is only one source of pollution. The main source of contamination is organic waste—sewage, trash, food, and human and animal remains. Around a billion liters of untreated raw sewage are dumped into the Ganges each day, along with massive amounts of agricultural chemicals (including DDT), industrial pollutants, and toxic chemical waste from the booming industries along the river. The level of pollution is now 10,000 percent higher than the government standard for safe river bathing (let alone drinking). One result of this situation is an increase in waterborne diseases, including cholera, hepatitis, typhoid, and amoebic dysentery. An estimated 80 percent of all health problems and one-third of deaths in India are attributable to waterborne illnesses." (p. 247)<br />"There have been various projects to clean up the Ganges and other rivers, led by the Indian government's Ganga Action Plan launched in 1985 by Rajiv Gandhi, grandson of Jawaharlal Nehru. Its relative failure has been blamed on mismanagement, corruption, and technological mistakes, but also lack of support from religious authorities. This may well be partly because the Brahmin priests are so invested in the idea of the Ganges' purity and afraid that any admission of its pollution will undermine the central role of the water in ritual, as well as their own authority. There are many temples along the river, conducting a brisk trade in ceremonies, including funerals, and sometimes also the sale of bottled Ganga Jal. The more traditional Hindu priests still believe that blessing Ganga Jal purifies it, although they are now a very small minority given the scale of the problem." (p. 248)<br />"Wildlife is also under threat, particularly the river dolphins. They were one of the world's first protected species, given special status under the reign of Emperor Ashoka in the 3rd century BC. They're now a critically endangered species, although protected once again by the Indian government (and internationally under the CITES convention). Their numbers have shrunk by 75 per cent over the last 15 years, and they have become extinct in the main tributaries, mainly because of pollution and habitat degradation." (p. 275)
----}} A 2012 survey by the [[World Wildlife Fund]] found only 3,000 left in the water catchment of both river systems.<ref>{{cite web |url=http://wwf.panda.org/what_we_do/endangered_species/cetaceans/about/river_dolphins/ganges_river_dolphin/ |title=Ganges River dolphin |publisher=WWF |website=wwf.panda.org |access-date=4 July 2012 |archive-date=15 April 2018 |archive-url=https://web.archive.org/web/20180415221525/http://wwf.panda.org/what_we_do/endangered_species/cetaceans/about/river_dolphins/ganges_river_dolphin/ |url-status=live }}</ref>

The Ganges river dolphin is one of only five true [[freshwater dolphin]]s in the world. The other four are the [[baiji]] (''Lipotes vexillifer'') of the [[Yangtze River]] in China, now likely extinct; the [[Indus River dolphin]] of the Indus River in Pakistan; the [[Amazon river dolphin]] of the Amazon River in South America; and the [[Araguaian river dolphin]] (not considered a separate species until 2014<ref>{{Cite journal | last1 = Hrbek | first1 = Tomas| last2 = Da Silva | first2 = Vera Maria Ferreira| last3 = Dutra | first3 = Nicole| last4 = Gravena | first4 = Waleska| last5 = Martin | first5 = Anthony R.| last6 = Farias | first6 = Izeni Pires| editor1-last = Turvey | editor1-first = Samuel T.| title = A New Species of River Dolphin from Brazil or: How Little Do We Know Our Biodiversity| doi = 10.1371/journal.pone.0083623 | journal = [[PLOS One]] | volume = 9 | issue = 1| pages = e83623 | date = 22 January 2014| pmid =  24465386| pmc = 3898917| bibcode = 2014PLoSO...983623H| doi-access = free}}</ref>) of the [[Tocantins River|Araguaia–Tocantins]] basin in Brazil. There are several marine dolphins whose ranges include some freshwater habitats, but these five are the only dolphins who live only in freshwater rivers and lakes.<ref name=wwf0120/>

=== Effects of climate change ===
The [[Tibetan Plateau]] contains the world's third-largest store of ice. Qin Dahe, the former head of the China Meteorological Administration, said that the recent fast pace of melting and warmer temperatures will be good for agriculture and tourism in the short term; but issued a strong warning:

{{blockquote|Temperatures are rising four times faster than elsewhere in China, and the Tibetan glaciers are retreating at a higher speed than in any other part of the world.&nbsp;... In the short term, this will cause lakes to expand and bring floods and mudflows&nbsp;... In the long run, the glaciers are vital lifelines for Asian rivers, including the Indus and the Ganges. Once they vanish, water supplies in those regions will be in peril.<ref>{{cite web|author=AFP  |url=https://www.google.com/hostednews/afp/article/ALeqM5g1eE4Xw3njaW1MKpJRYOch4hOdLQ |title=Global warming benefits to Tibet: Chinese official|date=17 August 2009 |access-date=28 November 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100123192540/https://www.google.com/hostednews/afp/article/ALeqM5g1eE4Xw3njaW1MKpJRYOch4hOdLQ |archive-date=23 January 2010 }}</ref>}}

In 2007, the [[Intergovernmental Panel on Climate Change]] (IPCC), in its Fourth Report, stated that the Himalayan glaciers which feed the river were at risk of melting by 2035.<ref>{{cite web |url=http://ipcc-wg2.gov/AR4/website/10.pdf |title=See s. 10.6 of the WGII part of the report at |access-date=28 November 2010 |url-status=dead |archive-url=https://web.archive.org/web/20101124044114/http://ipcc-wg2.gov/AR4/website/10.pdf |archive-date=24 November 2010}}</ref> The IPCC has now withdrawn that prediction, as the original source admitted that it was speculative and the cited source was not a peer-reviewed finding.{{efn|1= The IPCC report is based on a non-peer-reviewed work by the World Wildlife Federation. They, in turn, drew their information from an interview conducted by ''New Scientist'' with Hasnain, an Indian glaciologist, who admitted that the view was speculative. See: {{cite journal
| url         = https://www.newscientist.com/article/mg20527432.800-sifting-climate-facts-from-speculation.html
| title       = Sifting climate facts from speculation
| date        = 13 January 2010
| journal=New Scientist
}} and {{cite news
| url         = http://www.thaindian.com/newsportal/health/pachauri-calls-indian-govt-report-on-melting-himalayan-glaciers-as-voodoo-science_100301232.html
| title         = Pachauri calls Indian govt. report on melting Himalayan glaciers as 'voodoo science'
| date         = 9 January 2010
| publisher         = Thaindian News
| access-date         = 20 January 2010
| archive-date         = 28 January 2010
| archive-url         = https://web.archive.org/web/20100128104205/http://www.thaindian.com/newsportal/health/pachauri-calls-indian-govt-report-on-melting-himalayan-glaciers-as-voodoo-science_100301232.html
| url-status         = dead
}} On the IPCC statement withdrawing the finding, see: {{cite news
| url         = http://www.ipcc.ch/pdf/presentations/himalaya-statement-20january2010.pdf
| title         = IPCC statement on the melting of Himalayan glaciers
| date         = 20 January 2010
| publisher         = IPCC – Intergovernmental Panel on Climate Change
| access-date         = 20 January 2010
| archive-date         = 15 February 2010
| archive-url         = https://web.archive.org/web/20100215024454/http://www.ipcc.ch/pdf/presentations/himalaya-statement-20january2010.pdf
| url-status         = dead
}}
----}} In its statement, the IPCC stands by its general findings relating to the Himalayan glaciers being at risk from global warming (with consequent risks to water flow into the Gangetic basin). Many studies have suggested that [[climate change]] will affect the water resources in the Ganges river basin including increased summer (monsoon) flow, and peak runoff could result in an increased risk of flooding.<ref>{{Cite journal|title=Impact of climate change on the hydrological regime of the Indus, Ganges and Brahmaputra river basins: a review of the literature|first1=Santosh|last1=Nepal|first2=Arun Bhakta|last2=Shrestha|date=3 April 2015|journal=International Journal of Water Resources Development|volume=31|issue=2|pages=201–218|doi=10.1080/07900627.2015.1030494|bibcode=2015IJWRD..31..201N |doi-access=free}}</ref>