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42-446: The two lakes are the remains of a large lake or sea whose surface, according to Shamsutdinov (1983), once reached 2,400 km (930 sq mi) some 700,000 years ago. They are the largest soda lakes in the arid zone in the trans-Baikal region. They lie close to one another, connected by the Utochi channel, in a closed basin with no outlet to the sea. The size and volume of water in

84-903: A well-oxygenated upper layer ( epilimnion ) and an anoxic lower layer ( hypolimnion ), without oxygen and often high concentrations of sulfide . Stratification can be permanent, or with seasonal mixing. The depth of the oxic/anoxic interface separating the two layers varies from a few centimeters to near the bottom sediments, depending on local conditions. In either case, it represents an important barrier, both physically and between strongly contrasting biochemical conditions. A rich diversity of microbial life inhabit soda lakes, often in dense concentrations. This makes them unusually productive ecosystems and leads to permanent or seasonal "algae blooms" with visible colouration in many lakes. The colour varies between particular lakes, depending on their predominant life forms and can range from green to orange or red. Compared to freshwater ecosystems, life in soda lakes

126-412: A lake to become alkalic, a special combination of geographical, geological and climatic conditions are required. First of all, a suitable topography is needed, that limits the outflow of water from the lake. When the outflow is completely prevented, this is called an endorheic basin . Craters or depressions formed by tectonic rifting often provide such topological depressions. There are exceptions to

168-422: A long evolutionary history of adaptation to these habitats with few new species from other environments becoming adapted over time. In-depth genetic surveys also show an unusually low overlap in the microbial community present, between soda lakes with slightly different conditions such as pH and salinity. This trend is especially strong in the bottom layer ( hypolimnion ) of stratified lakes, probably because of

210-606: A weight of 3.7 kg (8.2 lb) and a wingspan of 1.87 m (6.1 ft). The hooded crane breeds in south-central and south-eastern Siberia . Breeding is also suspected to occur in Mongolia . Over 80% of its population winters at Izumi , southern Japan . There are also wintering grounds in South Korea and China . There are about 100 hooded cranes wintering in Chongming Dongtan, Shanghai every year. Dongtan Nature Reserve

252-436: Is 13 km. The lake is round and has a single island, which turns into a peninsula when the water level is low. Lake Zun-Torey is mostly fed by the channel from Lake Baran-Torey, and does not dry as extensively or vary in extent as much as Lake Baran-Torey does. During the aridification of Zun-Torey lake, four stages of changes in the planktonic associations were identified; the phytoplankton decreased in abundance and biomass, and

294-460: Is carried out on a commercial scale with soda lake water. Hooded crane The hooded crane ( Grus monacha ) is a crane native to East Asia and a frequent migratory bird in Japan . It has a grey body. The top of the neck and head is white, except for a patch of bare red skin above the eye. It is one of the smallest cranes, but is still a fairly large bird, at 1 m (3.3 ft) long,

336-714: Is everywhere, but the environment selects"). Photosynthesis provides the primary energy source for life in soda lakes and this process dominates the activity at the surface. The most important photosynthesizers are typically cyanobacteria , but in many less "extreme" soda lakes, eukaryotes such as green algae ( Chlorophyta ) can also dominate. Major genera of cyanobacteria typically found in soda lakes include Arthrospira (formerly Spirulina ) (notably A. platensis ), Anabaenopsis , Cyanospira , Synechococcus or Chroococcus . In more saline soda lakes, haloalkaliphilic archaea such as Halobacteria and bacteria such as Halorhodospira dominate photosynthesis. However, it

378-407: Is fed by two rivers. The Ulz River (Uldza River or Ulz Gol) flows into the lake from the south and forms a large estuary. The Imalka River flows into the lake from the west. When the water level reaches 596.1 m in elevation, Barun-Torey water starts running off into Zun-Torey lake via the Utochi channel. Once the surfaces of the two lakes are levelled up, the wind and other factors induce changes in

420-515: Is not clear whether this is an autotrophic process or if these require organic carbon from cyanobacterial blooms, occurring during periods of heavy rainfall that dilute the surface waters. Below the surface, anoxygenic photosynthesizers using other substances than carbon dioxide for photosynthesis also contribute to primary production in many soda lakes. These include purple sulfur bacteria such as Ectothiorhodospiraceae and purple non-sulfur bacteria such as Rhodobacteraceae (for example

462-494: Is often completely dominated by prokaryotes , i.e. bacteria and archaea , particularly in those with more "extreme" conditions (higher alkalinity and salinity, or lower oxygen content). However, a rich diversity of eukaryotic algae, protists and fungi have also been encountered in many soda lakes. Multicellular animals such as crustaceans (notably the brine shrimp Artemia and the copepod Paradiaptomus africanus ) and fish (e.g. Alcolapia ), are also found in many of

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504-474: Is strewn with temporary freshwater pools fed by groundwater and precipitations, even though that groundwater is not necessarily freshwater. These pools are alkaline, with a pH around 8.2 – 9.0; they are oligohaline (0.5–1.0 g × l-1), rather warm (26 to 30°С), most are muddy (TR = 0.1–0.3 m). Those at the western shore of the lake are fed by groundwater discharge through a geological fracture . In periods of high water level, Barun-Torey lake and Zun-Torey lake have

546-597: Is the largest natural wintering site in the world. In December 2011, a hooded crane was seen overwintering at the Hiwassee Refuge in southeastern Tennessee, well outside its normal range. In February 2012, one was seen at Goose Pond in southern Indiana, and is suspected to be the same bird, which may have migrated to North America by following sandhill cranes ( Antigone canadensis ). In March 2020, seven hooded cranes ( Grus monacha ) were seen in Siargao , Philippines where it

588-623: The red-crowned crane ( Grus japonensis ), white-naped crane ( Grus vipio ), swan goose ( Anser cygnoides ), great bustard ( Otis tarda ), and relict gull ( Ichthyaetus relictus ). The lakes are located on East Asian–Australasian Flyway , and millions of birds pass through the Torey Lakes and nearby wetlands in spring and autumn. The lakes provide migratory habitat for the critically endangered Siberian crane ( Grus leucogeranus ) and threatened hooded crane ( Grus monacha ). Traditional agriculture, fishing, and animal husbandry are important to

630-418: The "no outlet" rule: both Lake Kivu and Lake Tanganyika have outlets but also have the characteristics of soda lakes, and Lake Tanganyika even grows microbialites . The high alkalinity and salinity arise through evaporation of the lake water. This requires suitable climatic conditions, in order for the inflow to balance outflow through evaporation . The rate at which carbonate salts are dissolved into

672-965: The bacterial community of the lake with the highest salinity was characterized by a higher recent accelerated diversification than the community of a freshwater lake, whereas the phylogenetic diversity in the hypersaline lake was lower than that in a freshwater lake. Culture-independent surveys have revealed that the diversity of microorganisms in soda lakes is very high, with species richness (number of species present) of individual lakes often rivaling that of freshwater ecosystems. In addition to their rich biodiversity, soda lakes often harbour many unique species, adapted to alkalic conditions and unable to live in environments with neutral pH. These are called alkaliphiles . Organisms also adapted to high salinity are called haloalkaliphiles . Culture-independent genetic surveys have shown that soda lakes contain an unusually high amount of alkaliphilic microorganisms with low genetic similarity to known species. This indicates

714-421: The direction of the current in the channel. When the water level falls, the shallower Barun-Torey lake dries up quicker and the water in the Utochi channel flows from Zun-Torey lake to Barun-Torey lake. As the lake level falls and during the initial refilling of the lake, three stages of changes in the planktonic associations have been identified; the plankton communities increase in species richness and abundance in

756-750: The equator. In general, the microbial biodiversity of soda lakes is relatively poorly studied. Many studies have focused on the primary producers, namely the photosynthesizing cyanobacteria or eukaryotic algae (see Carbon cycle ). As studies have traditionally relied on microscopy , identification has been hindered by the fact that many soda lakes harbour poorly studied species, unique to these relatively unusual habitats and in many cases thought to be endemic , i.e. existing only in one lake. The morphology (appearance) of algae and other organisms may also vary from lake to lake, depending on local conditions, making their identification more difficult, which has probably led to several instances of taxonomic confusions in

798-430: The high pH prohibits the release of hydrogen sulfide (H 2 S) in gas form. Genera of alkaliphilic sulfur-reducers found in soda lakes include Desulfonatronovibrio and Desulfonatronum . These also play important an ecological role besides in the cycling of sulfur, as they also consume hydrogen , resulting from the fermentation of organic matter. Sulfur-oxidating bacteria instead derive their energy from oxidation of

840-461: The high pH. This can hinder nitrification , in which ammonia is "recycled" to the bio-available form nitrate . However, ammonia oxidation seems to be efficiently carried out in soda lakes in either case, probably by ammonia-oxidizing bacteria as well as Thaumarchaea . The following table lists some examples of soda lakes by region, listing country, pH and salinity. NA indicates 'data not available': Many water-soluble chemicals are extracted from

882-504: The internal nitrogen cycle very important for their ecological functioning. One possible source of bio-available nitrogen is diazotrophic cyanobacteria , which can fix nitrogen from the atmosphere during photosynthesis . However, many of the dominant cyanobacteria found in soda lakes such as Arthrospira are probably not able to fix nitrogen. Ammonia , a nitrogen-containing waste product from degradation of dead cells, can be lost from soda lakes through volatilization because of

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924-451: The isolated character of such environments. Diversity data from soda lakes suggest the existence of many endemic microbial species, unique to individual lakes. This is a controversial finding, since conventional wisdom in microbial ecology dictates that most microbial species are cosmopolitan and dispersed globally, thanks to their enormous population sizes, a famous hypothesis first formulated by Lourens Baas Becking in 1934 ("Everything

966-488: The lake water also depends on the surrounding geology and can in some cases lead to relatively high alkalinity even in lakes with significant outflow. Another critical geological condition for the formation of a soda lake is the relative absence of soluble magnesium or calcium . Otherwise, dissolved magnesium (Mg ) or calcium (Ca ) will quickly remove the carbonate ions, through the precipitation of minerals such as calcite , magnesite or dolomite , effectively neutralizing

1008-452: The lakes varies greatly with the region's multi-decadal rainfall and climate cycles. These interdecadal cycles last from 27 years to 35 years; they depend on variations in atmospheric moistening: relatively moist and very cold periods alternate with dry and relatively warm periods. For example, Barun-Torey lake completely dried up in summer 2009, and started refilling in 2013; Zun-Torey lake dried up in autumn 2017. The dry bed of Barun-Torey lake

1050-764: The less extreme soda lakes, adapted to the extreme conditions of these alkalic and often saline environments. Particularly in the East African Rift Valley , microorganisms in soda lakes also provide the main food source for vast flocks of the lesser flamingo ( Phoeniconaias minor ). The cyanobacteria of the genus Arthrospira (formerly Spirulina ) are a particularly preferred food source for these birds, owing to their large cell size and high nutritional value. Declines in East African soda lake productivity due to rising water levels threaten this food source. This may force lesser flamingos to move north and south, away from

1092-428: The local population. An area of 172,500 ha (426,000 acres), including both lakes and adjacent wetlands and uplands, was designated a Ramsar Site on September 13, 1994. The RAMSAR site comprises 65% lakes, 22% terrestrial steppe ecosystems, 7% river, 5% arable land, and 1% human settlements and roads; its altitude goes from 591 m to 769 m. The Daursky Nature Reserve or Zapovednik-Daursky state biosphere reserve

1134-438: The most extreme aquatic environments on Earth. In spite of their apparent inhospitability, soda lakes are often highly productive ecosystems , compared to their (pH-neutral) freshwater counterparts. Gross primary production ( photosynthesis ) rates above 10 g C m day (grams of carbon per square meter per day), over 16 times the global average for lakes and streams ( 0.6 g C m day ), have been measured. This makes them

1176-513: The most productive aquatic environments on Earth. An important reason for the high productivity is the virtually unlimited availability of dissolved carbon dioxide . Soda lakes occur naturally throughout the world (see table below ), typically in arid and semi-arid areas and in connection to tectonic rifts like the East African Rift Valley . The pH of most freshwater lakes is on the alkaline side of neutrality and many exhibit similar water chemistries to soda lakes, only less extreme. In order for

1218-467: The outcome of diversity studies, since only about one in a hundred organisms can be cultured using standard techniques. For microorganisms, the phylogenetic marker gene small subunit (SSU) ribosomal RNA is typically targeted, due to its good properties such as existence in all cellular organisms and ability to be used as a "molecular clock" to trace the evolutionary history of an organism. For instance, 16S ribosomal RNA gene clone libraries revealed that

1260-527: The pH of the lake water. This results in a neutral (or slightly basic) salt lake instead. A good example is the Dead Sea , which is very rich in Mg . In some soda lakes, inflow of Ca through subterranean seeps, can lead to localized precipitation. In Mono Lake , California and Lake Van , Turkey, such precipitation has formed columns of tufa rising above the lake surface. Many soda lakes are strongly stratified , with

1302-477: The primary producers, results in one-carbon (C1) compounds such as methanol and methylamine . At the bottom of lakes (in the sediment or hypolimnion , methanogens use these compounds to derive energy, by producing methane , a procedure known as methanogenesis . A diversity of methanogens including the archaeal genera Methanocalculus , Methanolobus , Methanosaeta , Methanosalsus and Methanoculleus have been found in soda lake sediments. When

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1344-411: The resulting methane reaches the aerobic water of a soda lake, it can be consumed by methane-oxidizing bacteria such as Methylobacter or Methylomicrobium . Sulfur-reducing bacteria are common in anoxic layers of soda lakes. These reduce sulfate and organic sulfur from dead cells into sulfide (S ). Anoxic layers of soda lakes are therefore often rich in sulfide . As opposed to neutral lakes,

1386-414: The same hydrochemical parameters: oligohaline and alkaline. During high-water years, Barun-Torey lake has an area of 550 km (210 sq mi), with a volume of 1.4 km (0.34 cu mi); the average depth is 2.5 m, with a maximum depth of 4.3 m. In low-water years, the lake shrinks dramatically and can dry up completely. The southern end of the lake extends into Mongolia. Barun-Torey lake

1428-428: The scientific literature. Recently, a number of studies have used molecular methods such as DNA fingerprinting or sequencing to study the diversity of organisms in soda lakes. These methods are based on DNA extracted directly from the environment and thus do not require microorganisms to be cultured . This is a major advantage, as culturing of novel microorganisms is a laborious technique known to seriously bias

1470-502: The soda lake waters worldwide. Lithium carbonate (see Lake Zabuye ), potash (see lake Lop Nur and Qinghai Salt Lake Potash ), soda ash (see Lake Abijatta and Lake Natron ), etc. are extracted in large quantities. Lithium carbonate is a raw material in production of lithium which has applications in lithium storage batteries widely used in modern electronic gadgets and electrically powered automobiles. Water of some soda lakes are rich in dissolved uranium carbonate . Algaculture

1512-463: The species Rhodobaca bogoriensis isolated from Lake Bogoria ). The photosynthesizing bacteria provide a food source for a vast diversity of aerobic and anaerobic organotrophic microorganisms from phyla including Pseudomonadota , Bacteroidota , Spirochaetota , Bacillota , Thermotogota , Deinococcota , Planctomycetota , Actinomycetota , Gemmatimonadota , and more. The stepwise anaerobic fermentation of organic compounds originating from

1554-399: The sulfide reaching the oxygenated layers of soda lakes. Some of these are photosynthetic sulfur phototrophs, which means that they also require light to derive energy. Examples of alkaliphilic sulfur-oxidizing bacteria are the genera Thioalkalivibrio , Thiorhodospira , Thioalkalimicrobium and Natronhydrogenobacter . Nitrogen is a limiting nutrient for growth in many soda lakes, making

1596-400: The transient pools. Lake Zun-Torey lies east of Lake Barun-Torey. During high water, the lake has a surface area of 285 km and a volume of 1.6 km; but in 1999 its surface reached 301.6 km and in 2015 it reached 254 km. The average depth is 4.5 m, and the maximum depth (in the northern part of the lake, where the lake bed drops steeply from the shore) is 6.7 m; its length is 23 km and its width

1638-666: The unannounced construction. Soda lake A soda lake or alkaline lake is a lake on the strongly alkaline side of neutrality, typically with a pH value between 9 and 12. They are characterized by high concentrations of carbonate salts, typically sodium carbonate (and related salt complexes), giving rise to their alkalinity. In addition, many soda lakes also contain high concentrations of sodium chloride and other dissolved salts , making them saline or hypersaline lakes as well. High pH and salinity often coincide, because of how soda lakes develop. The resulting hypersaline and highly alkalic soda lakes are considered some of

1680-490: Was designated a UNESCO Biosphere Reserve in 1997, and covers an area of 2,277 km (879 sq mi). It is also part of the 2017 World Heritage Site " Landscapes of Dauria ". A 2020 satellite imagery showed Mongolian plans to build a dam on the Uldza River which would potentially disrupt the natural water cycle and harm the fine balance in the ecosystem. UNESCO World Heritage Committee has expressed its concern on

1722-674: Was dominated by green algae and diatoms; the number of zooplankton species decreased but zooplankton's total abundance and biomass increased as the number of individuals increased in some crustacean species. The lakes and their environs are home to 305 bird species (including 90 breeding species), 42 species of mammals, various reptile, amphibian, and fish species, and over 590 insect species. The lakes and surrounding wetlands are an important breeding, feeding and staging area for many species of migratory waterbirds, including several rare and threatened species. The lakes support significant breeding populations of several threatened bird species, including

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1764-568: Was recorded as the first encounter of the species, since then, they are frequently migrating in the country, mainly on the wetlands in the southern regions. The estimated population of the species is 11,600 individuals. The major threats to its survival are wetland loss and degradation in its wintering grounds in China and South Korea as a result of reclamation for development and dam building. Conservation activities have been taken since 2008. Local universities, NGOs and communities are working together for

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