|Location||Kazakhstan, East-Kazakhstan region|
|Central coordinates||84o 38.00' East 47o 49.00' North|
|IBA criteria||A1, A4i|
|Altitude||382 - 397m|
|Year of IBA assessment||2006|
Summary Following the construction of the hydroelectric power complex on the Bukhtarma river about half a century ago, there have been gradual changes in the natural layout of the vast Chyorny (Black) Irtysh delta. As a result, the wetland network of previously seasonally flooded areas have been completely inundated, while a new delta structure has emerged in the higher section of the Chyrony Irtysh, submerging the previously dry tracts of the Zaisan Hollow. Presently, the delta extends, in its widest parts, up to 40 km east to west, and 30 km north to south.
Site description The Chyorny (Black) Irtysh delta makes up an appreciable part of area fringing the eastern shore of Lake Zaisan. The total area can be split notionally into 3 major subdivisions: the southern delta – the water complexes of the Kendyrlyk branch; the central part – the segment of the Chyorny Irtysh proper, with numerous subsiduary channels branching from the main channel; and and north-western delta including the branches of the Stary (Old) Irtysh and Zhankarasu rivers and all intervening areas. All of the channels follow extremely tortuous routes, often re-entering the main waterbody not far from the spot of initial meandering. The southern delta comprises vast expanses of dense reed alternating with the stretches of open waters. The shoals are covered by mature beds of reed mace (Typha sp.), and every sheltered backwater contains well-developed communities of water-plants including Potamogeton sp., Nuphar lutea, Trapa sp. and Polygonum amphibium. Further east, the typical landscape of the delta gradually gives way to a swampy congregation of alluvial banks eventually becoming boggy terrain with an intricate system of sandy islands separated by waterlogged areas and marshes. The archipelago-like component of this wetland area is actually the upper part of the deluged portion of the sandy ridges and dunes of the neighbouring desert. The islands are frequently fringed by a mixed border of reed, cattail and scarce willow beds. The line of the Kenderlyk branch consists of innumerable branches, many often terminating in clogged impasses, and frequently changing their courses as the result of flooding. Upstream of the delta, a distinct shoreline only appears in the middle section of the Kendyrlyk channel, with scattered patches of trees gradually turning into small groves of Salix and Populus at the further reaches of delta. The central part of the delta is bisected by the main stream of the Chyorny Irtysh which also consists of an intricate complex of open water channels. This section of the area supports frequent stands of riverine Populus-Salix groves. In the upper reaches tree growth is substantial forming a dense forest with an underlying maze of half-overgrown channels with water-logged banks. Beneath the trees there are prolific growths of tall meadow grasses or feeble reeds. The understoey is mainly Halimodendron argenteum and Rosa sp. The banks of the main stream have the appearance of a low cliff (1-1.5 m high) of sand-clay subject to continuous erosion. Owing to its tortuous nature the main course is full of spits, shoals and bays with placid water. The north-western part of the delta is made up by a network of two major branches - the Old Irtysh and Zhankarasu. These areas are slightly higher than the rest of the area which means that the highest areas often excape regular seasonal flooding. There are lush grass and herb flood meadows fringed, in most areas, by forest belts. Such areas are the main moulting areas of geese (Anser anser). These parts of the site are subject to the major impacts of human industrial activities. The rustic and agricultural interests of the Markakol district population are concentrated on the cattle raising industry. Therefore, a significant portion of the north-western delta, with the most promising herbage, is used extensively for cattle raising, dairy farming and extensive hay mowing. Annually, considerable areas of dead reed are burnt to create additional winter grazing. The flood-forest areas are often subject to wood cutting and much of the area is now crossed by roads and tracks. The final part of the delta is where the system of Chyorny Irtysh naturally ends in Lake Zaisan. Here there are huge patches of tall reed that are often submerged when laid flat by the strong and frequent easterly winds driving across the expanse of the lake. This area is generally avoided by any large number of birds.
|Species||Season||Period||Population estimate||Quality of estimate||IBA Criteria||IUCN Category|
|Swan Goose Anser cygnoides||passage||2005||3 individuals||medium||A1||Vulnerable|
|Dalmatian Pelican Pelecanus crispus||breeding||2006||1,000 individuals||good||A1, A4i||Vulnerable|
|Great Cormorant Phalacrocorax carbo||breeding||2006||3,000 individuals||good||A4i||Least Concern|
|IUCN habitat||Habitat detail||Extent (% of site)|
|Grassland||Humid; Steppes & dry calcareous||20%|
|Desert||Desert & semi-desert - sandy||5%|
|Wetlands (inland)||Rivers & streams; Standing fresh water; Water-fringe vegetation||45%|
|Artificial - terrestrial||Arable land; Other urban & industrial areas||5%|
|Land-use||Extent (% of site)|
Other biodiversity In Lake Zaisan and the low reaches of the Chyorny Irtysh there are modest populations of rare fish included in the Red Data Book of Kazakhstan: Inconny (Stenodus leucichthys nelma) and Taimn trout (Hucho taimen P.). Sus scrofa is very common in the thickets of the delta. In all of the higher areas adjacent to the delta there are substantial numbers of Ellow lemming (Lagurus luteus E.), which constitutes an important food component in the diet of local avian and mammal predators. Nationally protected species also occur.
Acknowledgements Appreciation for the valuable information provided by local naturalist A.I. Karamyshev.
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Recommended citation BirdLife International (2014) Important Bird Areas factsheet: Cherniy (Black) Irtysh Delta. Downloaded from http://www.birdlife.org on 15/03/2014
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