Sorbulak Lake System (19950)
Kazakhstan, Central Asia
Site overview
KBA status: confirmed
Global KBA criteria: A1a, A1c, D1a
Year of last assessment: 2007
National site name: Sorbulak Lake System
Central coordinates: Latitude: 43.6667, Longitude: 76.6000
System: freshwater, terrestrial
Elevation (m): 550 to 750
Area of KBA (km2): 183.80757
KBA classification: Global
Legacy site: Yes
Site details
Site description: The IBA is a system of sewage reservoirs situated in natural depressions of the Karaoi plateau, in the semi-desert zone, 80 km north of Almaty. It includes Sorbulak lake itself (formed in 1975-1985) and the line of small lakes with semi-running water with dykes and channels in the Zhamankum hollow. The maximum length of Sorbulak lake is 35 km, width up to 15 km, depth 22 m. The total length of the small lakes in the Zhamankum hollow is about 25 km, maximum width up to 3 km, average depth about 2 m. The lakes have indented coastlines, with many capes, spits, coves and a number of islands of different size. The water is fresh, but with a very high concentration of nitrates. In the second half of the summer it becomes brackish due to evaporation and drying out. It is an IBA for breeding, migrating and wintering waterbirds.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Additional biodiversity: About 300 species of 18 orders have been recorded. Most typical are Anseriformes (28 species) and Charadriiformes (more than 50 species). In some years, the site held the largest SE Kazakhstan breeding colonies of the following species: Larus ridibundus - 8,000 pairs, Sterna nilotica - 2,500 pairs, Phalacrocorax carbo -5,000 pairs, Glareola pratincola - 140 pairs and Himantopus himantopus - 70 pairs. On the coast, Tadorna tadorna and T.ferruginea breed - up to 100 pairs or more. At the end of the summer moulting flocks of T.ferruginea number up to 20,000. On passage, large numbers of wildfowl have been recorded including Anas platyrhychos (up to 50,000), Anas acuta (35,000), Netta rufina (15,000) and Fulica atra (40,000). In some winters, Mergellus albellus numbers reach up to 12,000 and Anas platyrhynchos 20,000. During passage, large numbers of passerines - up to 50,000 or more - concentrate in the water fringe vegetation. These include Sturnus vulgaris, Sturnus roseus, Hirundo rustica, Hirundo rupestris, Motacilla sp etc. Non-bird biodiversity: Around the lakes, there is typical semi-desert vegetation with low bushes (Salsola, Calligonum, Rosa, Spirea etc.) and grass. In the lakes, there are up to 10 species of fish, the most common are Carassius auratus and Cyprinus carpio. There are two species of amphibians Rana ridibunda and Bufo viridis, 8 species of snake, and one tortoise Agrionemis horsfieldi. Of mammals, there are fox (Vulpes vulpes), desert fox (Vulpes corsac), wolf (Canis lupus), and a number of rodents, the most common being Spermophilus fulvus.
Habitats
Summary of habitats in KBA: 100% of the terrestrial part of the IBA is used by local farmers as grazing for sheep, goats, cows and horses. Some areas are used for vegetables. Fishing is widespread but mostly illegal - legal fishing is permitted on a small scale at Sorbulak lake only (for fish-meal for livestock).
Land use: agriculture (50%) | fisheries/aquaculture (50%) | water management (50%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Desert | 8 | |
| Grassland | 10 | |
| Artificial - Aquatic | 51 | |
| Wetlands(Inland) | 10 | |
| Shrubland | 1 | |
| Forest | 12 |
Threats
Summary of threats to biodiversity at KBA: During the last 10 years, the number of farms around the lakes increased by 4-5 times. The numerous cattle damage the coastal biotopes, and the number of breeding ducks has decreased sharply. Illegal fishing is a serious threat eg use of motor boats, nets, disturbance of birds, especially in winter when the extent of open water is reduced. Illegal hunting (there is no effective protection) and an unstable hydrological regime are also dangerous.
Additional information
References: Auezov, E.M., Khrokov, V.V. and Yerokhov, S.N. (1980) Sewage-reservoir Sorbulak - new place of breeding, moulting and wintering of water-birds in south-east of Kazakhstan. Economic activity and hunting fauna. V. 1. Kirov: 48-50. (in Russian). Shimov, S.V., Auezov, E.M. and Yerokhov, S.N. (1984) Visual observations at migrations of birds at Sorbulak lake. Migrations of birds in Asia. Issue 9. Tashkent: 62-64. (in Russian). Yerokhov, S.N. (1978) The number and sex-age composition of waders during autumn passage at Sorbulak lake. Proceedings of 2-nd All-Union Conference on Bird Migrations. Alma-Ata. Yerokhov, S.N. (1981) Wintering of waterfowl at Sorbulak lake. Ecology and protection of birds. Kishinev: 81. Yerokhov, S.N. (1984) The results of route accounts at Sorbulak lake in 1981. Migrations of birds in Asia. Issue 9. Tashkent: 65-68. (in Russian). Yerokhov, S.N. (1986) The forming and dynamic of ornithofauna of sewage water-reservoirs in desert zone of south-east Kazakhstan - on sample of Sorbulak lake, Alma-Ata region. Moscow: Union Institute of Nature Protection. (PhD. Thesis). (in Russian). Yerokhov, S.N. (1986) The forming of bird migration ways in desert zone of south-east Kazakhstan in connection with a change of ecological conditions. Migrations of birds in Asia. Issue 10. Novosibirsk: 24-32. (in Russian). Yerokhov, S.N. (1986) The influence of thermality of sewage water on terms of breeding of some water-birds. The study of birds of USSR, their protection and rational use. Part 1. Leningrad: 221. (in Russian). Yerokhov, S.N., Gavrilov, A.E. and Khrokov, V.V. (1978) New findings of waders in south-east of Kazakhstan. Proceedings of AS of KazSSR, series biological, 6: 22-24. Belyalov, O., and Karpov, F. (2005). [Ornithological observations at Sorbulak in 2004]. . Almaty: 58-63. (in Russian).