View source for Selenga

{{Short description|River in Mongolia and Russia}}
{{Infobox river
| name               = Selenga
| native_name        = {{native name list |tag1=ru|name1=Селенга |tag2=mn|name2=Сэлэнгэ}}
| name_other         = Selenge
| name_etymology     =
| image              = Selenga2.jpg
| image_size         =
| image_caption      = Selenga River in Russia
| map                = Selengerivermap.png
| map_size           =
| map_caption        =
| pushpin_map        =
| pushpin_map_size   =
| pushpin_map_caption=
| subdivision_type1  = Country
| subdivision_name1  = [[Russia]], [[Mongolia]]
| subdivision_type2  =
| subdivision_name2  =
| length             = {{convert|992|km|mi|abbr=on}}
| width_min          =
| width_avg          =
| width_max          =
| depth_min          =
| depth_avg          =
| depth_max          =
| discharge1_location= [[Kyakhta|Ust-Kyakhta]]
| discharge1_min     = {{convert|23|m3/s|cuft/s|abbr=on}}February
| discharge1_avg     = {{convert|284|m3/s|cuft/s|abbr=on}}
| discharge1_max     = {{convert|601|m3/s|cuft/s|abbr=on}}August
| source1            = [[Delgermörön]]
| source1_location   =
| source1_coordinates=
| source1_elevation  =
| source2            = [[Ider River|Ider]]
| source2_location   =
| source2_coordinates=
| source2_elevation  =
| source_confluence  = Olon Golyn Bilchir
| source_confluence_location = [[Khövsgöl Province|Khövsgöl]], [[Mongolia]]
| source_confluence_coordinates = {{coord|49|15|40|N|100|40|45|E|display=inline}}
| source_confluence_elevation =
| mouth              = [[Lake Baikal]]
| mouth_location     =
| mouth_coordinates  =
| mouth_elevation    =
| progression        = {{RLake Baikal}}
| river_system       =
| basin_size         = {{convert|447000|km2|abbr=on}}
| tributaries_left   =
| tributaries_right  = [[Uda (Selenga)|Uda]]
| custom_label       = Basin coordinates
| custom_data        = 46-52 degrees N 96-109 degrees E
| extra              = {{Infobox mapframe |wikidata=yes |zoom=5 |height=250 | stroke-width=1.5 |coord {{WikidataCoord|display=i}}}}
}}
[[File:Bridge over the Selenga River in Ulan-Ude.jpg|thumb|Bridge over the Selenga River in Ulan-Ude]]
The '''Selenga''' or '''Selenge''' ({{IPAc-en|s|ɛ|l|ɛ|ŋ|ˈ|g|ɑː}}<ref>[http://www.dictionary.com/browse/selenga?s=t "Selenga", Dictionary.com]</ref> {{Langx|mn|Сэлэнгэ мөрөн|translit=Selenge mörön}}; {{langx|bua|Сэлэнгэ гол / Сэлэнгэ мүрэн|translit=Selenge gol / Selenge müren}}; {{langx|ru|Селенга́}}, {{IPA|ru|sʲɪlʲɪnˈɡa|IPA}}) is a major river in [[Mongolia]] and [[Republic of Buryatia|Buryatia]], [[Russia]]. Originating from its [[River source|headwater]] [[Tributary|tributaries]], the [[Ider River|Ider]] and the [[Delgermörön|Delger mörön]], it flows for {{convert|992-1024|km|mi|abbr=}}<ref>H. Barthel, ''Mongolei-Land zwischen Taiga und Wüste'', Gotha 1990, p.34f</ref><ref>{{cite web|title=Сэлэнгэ мөрөн|url=http://www.medeelel.mn/index.php?page=land&sm=73&s=1345|work=www.medeelel.mn|url-status=dead|archive-url=https://archive.today/20121205104032/http://www.medeelel.mn/index.php?page=land&sm=73&s=1345|archive-date=December 5, 2012|access-date=July 16, 2007}}</ref><ref>{{GSEn|100947|Селенга}}</ref> before draining into [[Lake Baikal]]. The Selenga therefore makes up the most distant headwaters of the [[Yenisey]]-[[Angara]] river system.
Carrying {{convert|935|m3/s|cuft/s}} of water into [[Lake Baikal]], it makes up almost half of the riverine inflow into the lake, and forms a wide delta of {{convert|680|km2|mi2}} when it reaches the lake.
Periodic annual floods are a feature of the Selenga River. The floods can be classified as “ordinary”, “large” or “catastrophic” based on the degree of impact. Of the twenty-six documented floods that occurred between 1730 and 1900, three were “catastrophic”. The three “catastrophic” floods were the floods of 1830, 1869 and 1897.
The Selenga River basin is a semi-arid region that is {{convert|280000|km2|mi2}} in area. It is part of the [[Arctic Basin|Arctic Ocean Basin]] and is located in northern Mongolia. Stone implement artifacts found on the Selenga River at the end of the 19th century have been used to form a link between Native Americans and their ancestors in East Asia. The climate of the Selenga basin is influenced by a powerful Siberian anti-cyclone. The weather consists of harsh winters and warm summers, with the river freezing from November to April.
The Selenga River delta is a [[Ramsar site]], surrounded by marshlands. Found in the administrative region of the Republic of Buryatia, the wetlands are the habitat of a large number of threatened and endemic species, including the Siberian [[Baikal sturgeon]] and over 170 species of birds. The Selenge-Orkhon forest steppe includes the areas of the Orkhon and Selenge river basins. The region has scattered forests and extensive mountain ranges.
River modifications like the [[Irkutsk Hydroelectric Power Station]] have affected the environment of the Selenga Delta, causing it to become waterlogged. Activities including mining, agriculture, breeding and dumping of wastewater have also affected the environment of the river. There has been an observed degradation of water quality from these anthropogenic factors. Natural factors like erosion processes and weathering have also contributed to the decline in water quality.
The proposed Shuren Hydropower Plant Project was protested against by environmental groups because of the potential ecological ramifications it would have on the Selenga Delta. The reasons cited included potential disruption to the flow of the river and the breeding grounds of endemic fish species in Lake Baikal.
== Name ==
The name Selenge comes from Mongolian ''seleh'', which means "to swim". 'Selenga' is the [[Russification|russified]] version of the same.
An alternate source believes the name originated with the [[Evenki language|Evenki]] word ''sele'' ("iron") to which the possessive ''nge'' suffix was added.<ref>E. M. Pospelov, Географические названия Мира (''Geograficheskie nazvaniya mira'', Moscow: Russkie slovari, 1998), p. 378.</ref>
The [[Selenge Province]] of Mongolia is named after the river.
<gallery mode="packed" heights="165">
File:The bridge across the Selenga River in the city of Ulan-Ude.jpg|Automobile bridge over the Selenga River in the city of [[Ulan-Ude]]
File:Selenga River bridge.jpg|Railway bridge over the Selenga River outside of [[Ulan-Ude]], Russia
</gallery>
== History ==
=== Archaeology ===
At the end of the 19th century, evidence of Paleolithic culture was discovered in the Selenga River basin. The artifacts found were collections of stone implements.<ref name=":1">{{Cite journal|last1=Okladnikov|first1=A. P.|author2-link=Chester S. Chard|last2=Chard|first2=Chester S.|date=April 1961|title=The Paleolithic of Trans-Baikal|url=http://dx.doi.org/10.2307/278736|journal=American Antiquity|volume=26|issue=4|pages=486–497|doi=10.2307/278736|jstor=278736 |s2cid=163736250 |issn=0002-7316}}</ref>
During 1928 and 1929, G. P. Sosnovskii, under the purview of the Academy of Sciences of the U.S.S.R., directed an archaeological Stone Age study in the Selenga Valley near Kiakhta.<ref name=":1" /> In this expedition, Sosnovokii discovered remains of local Paleolithic culture in an area that stretched from "the valley of the Selenga River from the Mongolian Frontier down to [[Selenginsk]]."<ref name=":1" />
The "Buriat-Mongol Archaeological Expedition from the Institute for the History of Material Culture, Academy of Sciences of the U.S.S.R and the Institute of Culture of the Buriat-Mongol A.S.S.R",<ref name=":1" /> undertook a Paleolithic study in the Trans-Baikal region from 1947 to 1958.<ref name=":1" /> Directed by A. P. Okladnikov, the study uncovered 30 new sites, including one that covered the area from Selenginsk to the Selenga River mouth, which provided evidence of a Paleolithic-type culture.<ref name=":1" /> Among these 30 sites was one called Ust-Kyakhta-3.<ref name=":1" /> While Ust-Kyakhta-3 was discovered in 1947, it was only later excavated in 1976 and 1978, yielding "more than 40,000 stone artifacts [and] abundant faunal remains".<ref name=":2">{{Cite journal|last1=Yu|first1=He|last2=Spyrou|first2=Maria A.|last3=Karapetian|first3=Marina|last4=Shnaider|first4=Svetlana|last5=Radzevičiūtė|first5=Rita|last6=Nägele|first6=Kathrin|last7=Neumann|first7=Gunnar U.|last8=Penske|first8=Sandra|last9=Zech|first9=Jana|last10=Lucas|first10=Mary|last11=LeRoux|first11=Petrus|date=June 2020|title=Paleolithic to Bronze Age Siberians Reveal Connections with First Americans and across Eurasia|journal=Cell|volume=181|issue=6|pages=1232–1245.e20|doi=10.1016/j.cell.2020.04.037|pmid=32437661 |issn=0092-8674|doi-access=free}}</ref> Further archaeological work in 2012 at the site found two human tooth fragments.<ref name=":2" />
In a study published in volume 181 of the journal ''[[Cell (journal)|Cell]]'', the link between Native Americans and their ancestors in East Asia was established using one of the tooth fragments found at the Ust-Kyakhta-3 site.<ref name=":2" /><ref>{{Cite web|last1=Price|first1=Michael|date=2020-05-20|title=Oldest cousin of Native Americans found in Russia|url=https://www.science.org/content/article/oldest-cousin-native-americans-found-russia|access-date=2022-05-20|website=Science {{!}} AAAS}}</ref>
=== Floods ===
Periodic floods are characteristic of the Selenga River, with small flooding events observed annually.<ref name=":3" /> There have been four periods of high-flooding: 1902-1908, 1932-1942, 1971-1977 and 1990-1998.<ref name=":10">{{Cite journal|last1=Kadetova|first1=Alena V.|last2=Radziminovich|first2=Yan B.|date=2020-05-11|title=Historical floods within the Selenga river basin: chronology and extreme events|url=http://dx.doi.org/10.1007/s11069-020-04001-z|journal=Natural Hazards|volume=103|issue=1|pages=579–598|doi=10.1007/s11069-020-04001-z|s2cid=218592869 |issn=0921-030X}}</ref> The floods of the Selenga River can be classified based on the degree of impact.<ref name=":10" />
"Ordinary" floods are floods accompanied by little damage, with maximum outcomes including river overflowing, floodplain flooding and small structural instability.<ref name=":10" />
"Large" floods are those that cover a substantial section of the river and lead to flooding of territories. The maximum outcomes of "large" floods include flooding of settlements and agricultural land damage.<ref name=":10" />
"Catastrophic" floods refer to floods that cover the majority of the river basin and cause flooding of whole settlements.<ref name=":10" /> These floods included the possibility of human casualties, and are estimated to occur 3-4 times per century.<ref name=":10" />  Twenty-six floods occurred between 1730 and 1900, and of these 26, three floods were "catastrophic".<ref name=":10" />
==== Flood of 1830 ====
The flood of 1830 in the Selenga River is the first flood that was recorded in some detail.<ref name=":10" /> On August 1, 1830, the Selenga River and its tributaries, the Chikoy, Dzhida, Khilok and Temnik Rivers, burst their banks.<ref name=":10" /> The flood plains and the islands in the Selenga River were completely flooded.<ref name=":10" /> On August 16, Verkhneudinsk, the city now known as Ulan-Ude, was flooded and the water level in the city reached {{convert|420|cm|in}}.<ref name=":10" /> The flood destroyed fifty-four buildings in Selenginsk. After the flood, the town was moved to higher ground on the left bank of the Selenga River.<ref name=":10" /> There were also heavy losses in agriculture, with the flood making some pastures and hayfields unusable for an extended period after the flood.<ref name=":10" /> The river retreated to its banks by September 27.<ref name=":10" />
==== Flood of 1869 ====
Water levels began to rise on July 24, 1869, but slowly decreased from August 5, 1869.<ref name=":10" /> The water level began to rise again on August 22, only beginning to decline from September 3.<ref name=":10" /> This flood was classified as a "large" flood. In Verkhneudinsk, the water level reached {{convert|386|cm|in}}, and in Lake Baikal, the water level rose by more than {{convert|2|m|ft}}.<ref name=":10" /> The water level in the Angara River also rose and did not return to its pre-flood levels by January 1870.<ref name=":10" />
==== Flood of 1897 ====
The flood of 1897 began on August 11, when water levels started to rise in the middle and lower reaches of the Selenga River and reached its peak on August 14.<ref name=":10" /> The water level then proceeded to decrease gradually over ten days.<ref name=":10" /> On the first day of the flood, the water level rose by {{convert|4|m|ft}} in three hours.<ref name=":10" /> The water level in the Selenga River was over {{convert|350|cm|in}} near Verkhneundinsk.<ref name=":10" />  The flood did not heavily impact settlements on the banks of the Selenga River, but there were reports of bridge and telegraph pole destruction between the towns of Selenginsk and Verkhneundinsk.<ref name=":10" />
==== Impact of flooding ====
The volume of water inflow into Lake Baikal during the 1897 flood is estimated to have been approximately {{convert|22.2|km3|mi3}}.<ref name=":10" /> Based on the observations of increased water level during floods, it has been deduced that flooding from the Selenge River can affect the environment of Lake Baikal. It can also cause an increase in runoff from the Angara River.<ref name=":10" />
== River course ==
The Selenga River is {{convert|1480|km|mi}} long and is formed from the convergence of the [[Ider river|Ider]] and [[Delger mörön|Delger]] rivers.<ref name=":0">{{Cite web|title=Selenga River {{!}} river, Asia|url=https://www.britannica.com/place/Selenga-River|access-date=2020-10-14|website=Encyclopedia Britannica}}</ref> It flows from Mongolia and into east-central Russia, acting as the main tributary of Lake Baikal.<ref name=":0" />
The Delger River flows from the Sangilen Mountains, "found on the border between Mongolia and the Russian republic of Tyva",<ref name=":0" /> while the Ider's headwaters are located in the Hangyn Mountains in central Mongolia.<ref name=":0" />
Upon the meeting of the Delger and Ider Rivers, the Selenga River moves northeast from Mongolia and joins with the Orkhon River at Suhbaatar.<ref name=":0" /> The river then continues north into Russia.<ref name=":0" />
Once in Russia, the river turns eastward towards Ulan-Ude, the capital of Buryatia and then goes northwards to Tataurovo.<ref name=":0" /> The Selenga proceeds to move westwards and then "flows through a delta into Lake Baikal."<ref name=":0" />
=== Climate ===
A powerful Siberian anti-cyclone is the major influence on the climate of the Selenga basin. It is formed in September and October and disappears in April and May.<ref name=":9">{{Cite journal|last1=Kasimov|first1=Nikolay|last2=Shinkareva|first2=Galina|last3=Lychagin|first3=Mikhail|last4=Kosheleva|first4=Natalia|last5=Chalov|first5=Sergey|last6=Pashkina|first6=Margarita|last7=Thorslund|first7=Josefin|last8=Jarsjö|first8=Jerker|date=2020-07-28|title=River Water Quality of the Selenga-Baikal Basin: Part I—Spatio-Temporal Patterns of Dissolved and Suspended Metals|journal=Water|volume=12|issue=8|pages=2137|doi=10.3390/w12082137|issn=2073-4441|doi-access=free}}</ref> Due to the anti-cyclone, the 448,000-km<sup>2</sup> river basin is prone to a climate of harsh winters,<ref name=":0" /> which consist of sunny days and low air temperatures,<ref name=":9"/> and warm summers.<ref name=":0" /> The river experiences "...extended summer floods and short occasional (event-driven) floods in the other seasons."<ref name=":9"/>
The section of the Selenga River from Suhbaatar to its mouth is ice-free from May to October.<ref name=":0" /> Travel across the river is possible during this period.<ref name=":0" /> From November to April, the river is covered with ice.<ref name=":0" /> The ice drift lasts from 3–6 days.<ref name=":9"/> From May to September, in spring and early summer, snowmelt enables maximum discharge.<ref name=":9"/>
For 80–90 days, starting in mid-June, the basin area experiences the summer season with precipitation totaling {{convert|250| - | 300|mm|in}}.<ref name=":8">{{Cite web|title=Central Asia: Northern central Mongolia, stretching slightly into southern Russia {{!}} Ecoregions {{!}} WWF|url=https://www.worldwildlife.org/ecoregions/pa0816|access-date=2020-11-02|website=World Wildlife Fund}}</ref>  This is in contrast to autumn and winter, in which rainfall is typically {{convert|150| - |200|mm|in}}. In mid-September, autumn begins, lasting for about 65 days.<ref name=":8" />
==Tributaries==
The largest tributaries of the Selenga are, from source to mouth:
{{div col|colwidth=15em}}
* [[Ider River|Ider]] (right)
* [[Delger mörön]] (left)
* [[Khanui River|Khanui]] (right)
* [[Egiin Gol]] (left)
* [[Orkhon River|Orkhon]] (right)
* [[Dzhida (river)|Dzhida]] (left)
* [[Chikoy (river)|Chikoy]] (right)
* [[Khilok (river)|Khilok]] (right)
* [[Uda (Selenga)|Uda]] (right)
{{div col end}}
== Watershed ==
=== Selenga River basin ===
The Selenga River basin is part of the larger international Arctic Ocean Basin and is located in northern Mongolia.<ref name=":4">{{Cite web|title=AQUASTAT - FAO's Information System on Water and Agriculture|url=http://www.fao.org/NR/water/aquastat/countries_regions/Profile_segments/MNG-WR_eng.stm|access-date=2020-11-02|website=www.fao.org}}</ref> A semi-arid region, the basin is 280,000&nbsp;km<sup>2</sup><ref name=":5">{{Cite journal|last1=Ma|first1=X.|last2=Yasunari|first2=T.|last3=Ohata|first3=T.|last4=Natsagdorj|first4=L.|last5=Davaa|first5=G.|last6=Oyunbaatar|first6=D.|date=2003|title=Hydrological regime analysis of the Selenge River basin, Mongolia|url=http://dx.doi.org/10.1002/hyp.1442|journal=Hydrological Processes|volume=17|issue=14|pages=2929–2945|doi=10.1002/hyp.1442|bibcode=2003HyPr...17.2929M |s2cid=128740185 |issn=0885-6087}}</ref> and is Mongolia's largest basin.<ref name=":4" />  The basin has two main rivers: the Selenga and the Selenga's tributary, the Orkhon.<ref name=":4" />  The "major sub-basins are the Egiin, Ider, Orkhon and Tuul river basins"<ref name=":4" /> with Lake Baikal occupying 47% of the Selenga River basin.<ref name=":4" /> The terrain of the basin is dominated "by forest or grassland and is underlain by permafrost" according to an article published in 2003 by Ma ''et al''.<ref name=":5" />
=== Selenga River delta and the delta wetlands ===
Lobate shaped and 40&nbsp;km wide, the Selenga River delta is surrounded by marshlands. The formation of the delta is dependent on the sediment load carried by the river, with the lake tides having little impact in terms of geographical change.<ref name=":6">{{Cite web|date=2011-11-28|title=Snowfall on the Selenga River Delta, Russia|url=https://earthobservatory.nasa.gov/images/76521/snowfall-on-the-selenga-river-delta-russia|access-date=2020-11-02|website=earthobservatory.nasa.gov}}</ref> The sediment balance of the delta is dependent on physical processes, and this, in turn, affects the geochemical barrier functions of the area. During the period of the Irkutsk dam construction (1950–56), there was "increased sediment delivery to the delta" according to an article published in 2017 by Chalov ''et al''.<ref>{{Cite journal|last1=Chalov|first1=Sergey|last2=Thorslund|first2=Josefin|last3=Kasimov|first3=Nikolay|last4=Aybullatov|first4=Denis|last5=Ilyicheva|first5=Elena|last6=Karthe|first6=Daniel|last7=Kositsky|first7=Alexey|last8=Lychagin|first8=Mikhail|last9=Nittrouer|first9=Jeff|last10=Pavlov|first10=Maxim|last11=Pietron|first11=Jan|date=October 2017|title=The Selenga River delta: a geochemical barrier protecting Lake Baikal waters|url=http://link.springer.com/10.1007/s10113-016-0996-1|journal=Regional Environmental Change |volume=17|issue=7|pages=2039–2053|doi=10.1007/s10113-016-0996-1|s2cid=32043451 |issn=1436-3798}}</ref>
The wetlands of the Selenga River delta are classified as a [[Ramsar site]] and are found within the administrative region of the Republic of Buryatia.<ref name=":7">{{Cite web|title=Selenga Delta |url=https://rsis.ramsar.org/ris/682?language=en|access-date=2020-11-02|website=Ramsar Sites Information Service}}</ref> The wetlands support a large number of threatened and endemic species, including over 170 species of bird.<ref name=":6" /> The area has mean air temperatures of 14 degrees Celsius in July and -19.4 degrees Celsius in January, with floods often occurring in summer after heavy rains.<ref name=":7" />
=== Selenge-Orkhon forest steppe ===
The [[Selenge-Orkhon forest steppe]] is a palearctic ecoregion that is a medium between steppe and taiga.<ref name=":8" /> The region includes the Orkhon and Selenge river basins, and features scattered forests as well as extensive mountain ranges.<ref name=":8" />  The mean altitude of the landscape is 800-1200m, with flora like ''[[Rosa acicularis]]'' found at lower altitudes.<ref name=":8" /> The area has a dry and humid climate that is influenced by warm winds from the northeast steppe regions.<ref name=":8" />
== River modifications ==
=== Irkutsk Hydroelectric Power station ===
The construction of Irkutsk Hydroelectric Power station began in spring of 1950 and was completed on December 29, 1956.<ref name=":11">{{Cite web|title=WWW Irkutsk: History of construction of Irkutsk Hydroelectric Power Station|url=http://www.irkutsk.org/fed/ges.html|access-date=2020-11-19|website=www.irkutsk.org}}</ref> Built on the [[Angara|Angara River]],<ref name=":12">{{Cite web|title=Selenga River and Delta - Maps and Satellite Images|url=https://geology.com/articles/selenga-river-delta/#:~:text=Land%20use%20on%20the%20Selenga%20Delta&text=A%20hydro-electric%20power%20plant,level%20fluctuations%20in%20Lake%20Baikal.|access-date=2020-11-19|website=geology.com}}</ref> the station was designed to raise the water level of the Angara River to match the water level of Lake Baikal.<ref name=":11" /> It would then raise the water level of Lake Baikal by 1.5m.<ref name=":11" /> The power plant causes water-level fluctuations in Lake Baikal, which in turn causes part of the Selenga Delta to become waterlogged.<ref name=":12" /> The delta is drained in response to activities at the power station.<ref name=":12" />
=== Shuren Hydropower Plant Project ===
In 2015, Mongolia was reported to be planning the construction of a dam, named the Shuren Hydropower Plant, on the Selenga River.<ref name=":13">{{Cite web|last=Mackay|first=Anson|title=Lake Baikal: incredible ecosystem threatened by Mongolian dam and pipeline|url=http://theconversation.com/lake-baikal-incredible-ecosystem-threatened-by-mongolian-dam-and-pipeline-40025|access-date=2020-11-19|website=The Conversation|language=en}}</ref> Environmental groups protested this plan, as they were concerned with the potential ecological ramifications, building a hydroelectric plant on the Selenga River, would have on the ecosystem of Lake Baikal.<ref name=":13" /> Disrupting the flow of the river would disturb the breeding grounds of many endemic fish species in Lake Baikal.<ref name=":13" /> This would have a [[wikt:flow-on effect|flow-on effect]] on the rare birds and aquatic species that inhabit the area.<ref name=":13" /> The Shuren Hydropower Plant Project was proposed in 2013 and was under the review of a World Bank-funded environmental and social impact assessment.<ref name=":13" /> On September 27, 2017, the World Bank froze its tender process on the Shuren Hydropower Plant Project.<ref>{{Cite web|title=Friends Of Russia's Lake Baikal Mark Small Victory Over Dam Project, Vow To Fight On|url=https://www.rferl.org/a/russia-mongolia-baikal-dam-project-activists-environment-/28804304.html|access-date=2020-11-19|website=RadioFreeEurope/RadioLiberty|language=en}}</ref>
== Natural history ==
=== Fish ===
''[[Leocottus kesslerii]] gussinensis'' and ''Leocottus kesslerii arachlensis'' are endemic subspecies of fish that are found in the Selenga River headwaters and the upper Khilok River.<ref name=":14">{{Cite web|title=Yenisei|url=https://www.feow.org/ecoregions/details/605|publisher=Conservation Science Program of World Wildlife Fund}}</ref> Lake Baikal is the habitat of the Siberian Baikal sturgeon.<ref name=":14" /> The Selenga river is a breeding ground for the sturgeon, with migration taking place within the river system.<ref name=":14" /> The fish has two migration periods, which occur during the warmer part of the year.<ref name=":14" /> The first migration period begins in the second half of April when the water temperature is 3-5 degrees Celsius and finishes in approximately mid-June.<ref name=":14" /> The second migration of the Baikal sturgeon is the main migration period.<ref name=":14" /> It coincides with the summer floods of the Selenga.<ref name=":14" /> When the water temperature begins to cool, this signals the end of  the migration.<ref name=":14" /> There is also a non-migrating species of sturgeon that inhabits the Selenga catchment.<ref name=":14" />
=== Birds ===
Large populations of migrating, breeding and moulting waterbirds assemble at the wetlands in the Selenga Delta,<ref name=":15">{{Cite web|title=Selenga Delta {{!}} Ramsar Sites Information Service|url=https://rsis.ramsar.org/ris/682?language=en|access-date=2020-11-20|website=rsis.ramsar.org}}</ref> which has been recognised as an [[Important Bird Area]] by [[BirdLife International]].
==== Migrating species that occur in the Delta ====
* Siberian crane, ''Grus leucogeranus''<ref name=":15" />
* Black stork, ''Ciconia nigra''<ref name=":15" />
* Bewick's swan, ''Cygnus bewicki''<ref name=":15" />
* Swan goose, ''Anser cygnoides''<ref name=":15" />
* Imperial eagle, ''Aquila heliacal''<ref name=":15" />
* Golden eagle, ''A. chrysaetos''<ref name=":15" />
* Peregrine falcon, ''Falco peregrinus''<ref name=":15" />
* Gyr falcon, ''F. gyrfalco''<ref name=":15" />
* Saker falcon, ''F. cherrug''<ref name=":15" />
==== Breeding species that occur in the Delta ====
* White-tailed eagle, ''Haliaeetus albicilla''<ref name=":15" />
* Snipe-billed godwit, ''Macrorhamphus semipalmatus''<ref name=":15" />
* Whooper swan, ''Cygnus Cygnus''<ref name=":15" />
* Spotbill duck, ''Anas poecilorhyncha''<ref name=":15" />
* Falcated duck, ''A. falcata''<ref name=":15" />
* Bittern, ''Botaurus stellaris''<ref name=":15" />
* Baillon's crake, ''Porzana pusill''<ref name=":15" />
* Water-rail, ''Rallus aquaticus''<ref name=":15" />
* Corncrake, ''Crex crex''<ref name=":15" />
* Short-eared owl, ''Asio flammeus''<ref name=":15" />
* Azure tit, ''Parus caeruleus''<ref name=":15" />
=== Other fauna ===
The Selenga delta also supports the following species:
* Baikal grayling, ''[[Thymallus arcticus baicalensis]] infrasubspecies brevioinnis''<ref name=":15" />
* Mongolian toad, ''Bufo raddei''<ref name=":15" />
* ''Rana terrestris''<ref name=":15" />
* Ikonnikov's bat, ''Myotis ikonnikovi''<ref name=":15" />
* Brown long-eared bat, ''Plecotus auritus''<ref name=":15" />
* Parti-coloured bat, ''Vespertilio murinus''<ref name=":15" />
* ''V. nilssoni''<ref name=":15" />
== Hydrology ==
=== Water quality of the Selenga River ===
Before the turn of the millennium, the Selenga River and Lake Baikal had rich aquatic ecosystems nearly untouched by human influence.<ref name=":9"/> Since the collapse of the Soviet Union in the 1990s, the basin, which contains vast plains, has been affected by agricultural, climatic and economic factors.<ref name=":9" /> This includes changes like forest losses, urbanization and a growth in farming and mining activities.<ref name=":9" />
Factors that affect the water quality of the Selenga River can be classified as either anthropogenic or natural factors.<ref name=":3">{{Cite book|last1=Chu|first1=JangMin|title=Integrated water management model on the Selenge River basin.|last2=Lee|first2=ChangHee|last3=Janchibdorj|first3=Lunten|last4=Oktyabrevich Gomboev|first4=Bair|last5=Park|first5=SangYoung|last6=Mun|first6=HyunJoo|publisher=Korea Environment Institute|year=2010|isbn=978-89-8464-449-6}}</ref> Anthropogenic factors include mining activities, agriculture, breeding, dumping of wastewater into water bodies and water use.<ref name=":3" /> Natural factors include erosion processes and weathering.<ref name=":3" /> The escalation of anthropogenic factors can be correlated with pollution by "potentially toxic elements, including metals and persistent organic pollutants."<ref name=":9" />
Mongolia has had rapid growth in GDP since 1999, fueled by agriculture, mining and light industry.<ref name=":3" /> These activities, particularly mining, have threatened the surface water quality of the Selenga River and adjacent groundwater.<ref name=":3" />
A study published in volume 12 of the journal ''Water'', found that based on the Mongolian National Standard, "the main pollutants of the Selenga River are [[Zinc|Zn]] ... [[Arsenic|As]] ... and [[Lead|Pb]] ..."<ref name=":9" />  They also found that metal content in the river water was tens or hundreds of times higher in sites closer to urban and mining areas.<ref name=":9" /> Based on data observing toxicological and bioaccumulation effects on aquatic biota, the contamination has been shown to have an ecological impact.<ref>{{Cite book|last1=Batbayar|first1=Gunsmaa|title=Chemical Water Quality in Selenge River Basin in Mongolia: Spatial-temporal Patterns and Land Use Influence|last2=Kappas|first2=Martin|last3=Karthe|first3=Daniel|last4=Sauer|first4=Daniela|last5=Ruppert|first5=Hans|last6=Pfeiffer|first6=Martin|last7=Schlund|first7=Michael|publisher=[[Georg-August-Universität Göttingen]]|year=2018}}</ref>
== Economy ==
=== Uses of the river ===
The Selenga River has an influential role in managing the economic futures of Mongolia and Russia.<ref name=":3" /> It is used extensively for activities that include hay harvesting, mining, grazing, commercial and sport fishing.<ref name=":15" />
Many of these uses contribute to the degradation of the river’s water quality, with the main Mongolian sources of pollution, including the Zaamar gold placer, the Shar River gold mining, settlements and agriculture.<ref name=":3" />
There are ten large-scale wastewater treatment plants in the Selenge River basin in Mongolia.<ref name=":16">{{Cite book|last1=Zandaryaa|first1=Sarantuyaa|title=Water and Sanitation in Municipalities in the Selenge River Basin of Mongolia|last2=Davaa|first2=Basandorj|publisher=UNESCO|year=2013|location=Ulaanbaatar}}</ref> These wastewater treatment plants are located in the Mongolian cities of Tsetserleg, Bulgan, Darkhan City, Uliastai, Erdenet City, Arvaikheer, Sukhbaatar, Zuunmod, Murun and Ulaanbaatar.<ref name=":16" />
The city of Ulan-Ude uses the Selenga River as its primary source of water for its municipal water supply, using 60 wells with submersible pumps to withdraw water.<ref name=":3" /> The total pumped water in 2009 was {{convert|56.68|e6m3|e9gal|abbr=off}}.<ref name=":3" />
==See also==
*[[Baikal sturgeon]]
*[[Irkutsk Hydroelectric Power Station]]
*[[List of rivers of Mongolia]]
*[[List of rivers of Russia]]
*[[Selenga Highlands]]
* [[Ulaanbaatar]]
==References==
{{Reflist}}
{{Authority control}}
[[Category:Rivers of Mongolia]]
[[Category:Important Bird Areas of Mongolia]]
[[Category:Rivers of Buryatia]]
[[Category:International rivers of Asia]]
[[Category:Khövsgöl Province]]