Lake Balkhash Ecology
Lake Balkhash, located in east-central Kazakhstan, is one of Asia's largest lakes, distinguished by its unique composition of both freshwater and saltwater. The lake spans approximately 375 miles (605 kilometers) and exhibits significant variation in surface area and water levels, influenced by inflow from rivers like the Ili, Karatal, Aqsu, and Lepsi. Historically, the Ili River contributed about 90% of the lake's inflow, but this has diminished due to human activities, including agricultural and industrial usage. The lake's western region is shallow and freshwater-rich, while the eastern part is deeper and saltier, leading to ecological diversity that includes several endemic fish species and a variety of flora and fauna adapted to its conditions.
The surrounding area is characterized by arid grasslands and semi-desert environments, with diverse bird species, including at-risk populations such as the Dalmatian pelican. Despite its ecological importance and designated protections, Lake Balkhash is facing significant threats from water diversion, pollution, and climate change, which have led to declining water levels and habitat loss. Recent plans for a nuclear power plant nearby have raised concerns about further ecological degradation, putting the lake's rich biodiversity at risk. Conservation efforts continue, particularly in designated Ramsar sites that support critical wildlife habitats.
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Lake Balkhash Ecology
- Category: Inland Aquatic Biomes.
- Geographical Location: Central Asia.
- Summary: Lake Balkhash, one of the largest lakes in Asia and unique in having both freshwater and saltwater tributary rivers, is in danger from diversion of water and from overusage.
Lake Balkhash is located in east-central Kazakhstan in central Asia, in the deepest part of the Balkhash-Alakol depression, currently at about 1,222 feet (342 meters) above sea level. The Balkhash-Alakol depression was formed by the sloping trough of the Turan Plate during the Neogene-Quaternary Period, between 23 and 2.6 million years ago. Lake Balkhash is located within an endorheic basin, a closed drainage catchment that retains the water that flows into it without releasing any water through other rivers, lakes, or oceans.
Some 375 miles (605 kilometers) long from east to west, the surface area of Lake Balkhash varies from about 6,000 square miles (15,500 square kilometers) in dry years to as much as 7,300 square miles (19,000 square kilometers) during peak inflow years. Changes in the total area are accompanied by about a 10-foot (3-meter) change in the water level, depending on how much water is flowing into the lake.
Lake Balkhash contains both freshwater—mainly from the Ili River flowing in from the western end—and saltwater from the Karatal, Aqsu, and Lepsi Rivers flowing in from the east and southeast. Ili River water originates from melted snow coming off the glaciated Tien Shan mountains of China's Xinjiang region. Before the late 20th century, the Ili River had provided Lake Balkhash with as much as 90 percent of its total inflow; this proportion has decreased, in part due to municipal and industrial use, but the Ili still provides up to three-fourths of the inflow. From scouring minerals in the arid Balkhash-Alakol basin, the rivers to the east bring sufficient saline content to equate to salinity levels in eastern Lake Balkhash that reach up to eight times that of the western area of the lake.
The western freshwater part of Lake Balkhash is wide and shallow, with its depth not reaching further than 36 feet (11 meters). The saline, eastern part of the lake is more narrow and relatively deep, reaching up to 85 feet (26 meters). A narrow, shallow segment, Uzynaral Strait, and an associated peninsula help keep east-west exchange of water to a minimum. The depth here is approximately 21 feet (6.4 meters).
Winters tend to be harsh in Kazakhstan and around Lake Balkhash, with the whole lake actually freezing over from the end of November to the beginning of April each year. The region receives about 17 inches (43 centimeters) of precipitation per year, yielding an arid grassy plain or steppe in the surrounding area, as well as some semi-desert and desert stretches.
Over the decades, the water levels of Lake Balkhash have significantly receded due to water extractions and diversions.
Species and Human Impacts
Vegetation around the lake—much of it salt-tolerant—features such forest species as Schrenk's spruce (Picea schrenkiana), Manchurian ash (Fraxinus sogdiana), and Semenov's maple (Acer semenovii); scrub plants like honeysuckle (Lonicera hispida), barberry (Berberis heteropoda), sea-buckthorn (Hippophae rhamnoides), salt cedar or tamarisk (Tamarix ramosissima), and saxaul or suo suo (Haloxylon ammodendon); and herbaceous flora such as the Chinese medicinal herb Anabasis (Anabasis salsa), amaranths (Nanophyton erinaceum, Halocnemum strobilaceum), and sagewort (Artemisia terrae alba).
There is a relative abundance, especially around the southwestern shores of Lake Balkhash, of common species of reeds (Phragmites spp.), cattails (Typha spp.), and Russian thistle (Salsola spp.). Such stands provide a refuge for fish, land animals, and birds, although the marshlands generally have receded as water flow and levels have receded over the past several decades.
Before the quality of the lake declined in the late 20th century—due mainly to spreading human agricultural, industrial, and climate-change impact—dozens of fish species thrived here, of which a handful were peculiar to the lake itself (endemic). Among the surviving endemic species are Balkhash perch (Perca schrenki), Balkhash marinka (Schizothorax argentatus), and plain stone loach (Nemacheilus labiatus). All three are economically important to the human fishery in Lake Balkhash. Other popular species have been introduced to the lake, including sturgeon, pike, eastern bream, and Aral barbell (Barbus brachycephalus).
In the vicinity of the lake, Canadian muskrat were introduced in the 1940s to spur the fur trade. This has since come to a halt due to the downsizing of the muskrat habitat areas. Another animal that used to live in the region along the southern shore was the Caspian tiger (Panthera tigris virgata), now extinct.
Reptiles and amphibians are represented here by the toad agama (Phrynocephalus guttatus), steppe agama (Agama sanguinolenta), gray monitor (Varanus griseus), central Asiatic frog (Rana asiatica balchaschensis), and semirechensk salamander (Ranodon sibiricus).
Mammals include several considered rare or endangered, such as the marbled polecat (Vormela peregusna), a rodent known as the five-toed dwarf jerboa (Cardiocranius paradoxus), and the goitered gazelle (Gazella subgutturosa).
The Lake Balkhash biome still supports many species of birds, ranging from the great egret (Casmerodius albus) to cormorants and pheasants. Some birds, however, are in danger, such as the Dalmatian pelican (Pelecanus crispus), whooper swan (Cygnus cygnus), and Eurasian spoonbill (Platalea leucorodia).
Along with municipal and agricultural uses, including hydroelectric dams and irrigation networks, Lake Balkhash waters are also consumed, diverted, or polluted by a copper mining and smelting industry that deposits lead and zinc into the lake, as well as copper residues. Dust storms are an increasing problem, as global warming seems to be decreasing regional rain averages and increasing evaporation in Ili river, resulting in less water reaching Lake Balkhash. Further, in 2023, Kazakhstan announced its plans to build a nuclear power plant (NPP) on the shores of Lake Balkhash. The population voted in favor of the construction of an NPP in October of 2024. Experts warn of lake degradation and risk to the survival of the ecosystem with the construction and operations of the project.
The Lake Balkhash biome has some protections, including a Ramsar-listed Wetland of International Importance: the Ili River Delta and South Lake Balkhash wetlands of some 3,735 square miles (968,000 hectares) in area. Considered vital for fish, birds, desert flora, and other wildlife, this Ramsar site is within three State Nature Reserves—the Balkhash, Karroy, and Kukan—and is administered by a state national nature park agency. This area is downstream from the Alakol-Sasykkol Lakes System wetlands, another Ramsar site in Kazakhstan that is also crucial for nesting, migratory birds, and several vulnerable mammal species. This upstream wetland area comprises some 3,530 square miles (915,000 hectares).
Bibliography
McGivering, Jill. "Kazakh 'National Treasure' Under Threat." BBC News, 28 Sept. 2005, news.bbc.co.uk/2/hi/asia-pacific/4286916.stm. Accessed 29 Oct. 2024.
Mitrofanov, V. P., and T. Petr. Fish and Fisheries in the Altai, Northern Tien Shan, and Lake Balkhash (Kazakhstan). Food and Agriculture Organization, 1999.
Nelson, Haley. "Kazakhstan's New Nuclear Problem: Lake Balkhash." Caspian Policy Center, 22 Feb. 2024, www.caspianpolicy.org/research/category/kazakhstans-new-nuclear-problem-lake-balkhash. Accessed 29 Oct. 2024.
Thorsberg, Christian. "HotSpots H2O: Kazakhstan's Lake Balkhash Is Disappearing, Continuing a Trend of Desiccation in Central Asia." Circle of Blue, 12 July 2021, www.circleofblue.org/2021/wef/hotspots-h2o-kazakhstans-lake-balkhash-is-disappearing-continuing-a-trend-of-desiccation-in-central-asia/. Accessed 29 Oct. 2024.
Zhatkanbayev, Altay Zhumakan-Uly. "Creating Protected Areas on Lake Balkhash and Ile River Delta in the Kazakhstan Republic." Waterbirds Around the World, edited by G. C. Boere et al., The Stationery Office, 2006, pp. 283-84.