Thursday, 23 August 2012

Aral Sea Is Dying

The Aral Sea is an endorheic saline lake in Central Asia located between Kazakhstan and Uzbekistan. Since the 1960s its level and its amount of water are promptly decreasing due to drawing of water from main feeding rivers – the Amu Darya and the Syr Darya. Before the shallowing the Aral Sea was the fourth biggest lake in the world.

By today the drying Aral Sea has moved 100 km away from its former coastline near Muinak, Uzbekistan.

Along centuries it repeatedly happened that the riverbed of the Amu Darya moved aside from the Aral Sea (to the Caspian Sea) what made the Aral Sea size smaller. However it always gained its big size back. Today the considerable part of water from both rivers is spent for irrigation of rice and cotton fields what results in drastic reduction of water coming back to their deltas and consequently to the Aral Sea itself.
Worsening of the sea condition was kept secret in the USSR for dozens of years till 1985 when M. Gorbachev eventually made the ecological catastrophe public known. In the end of the 1980s the water level dropped so much that the sea divided into two parts: Northern Small Aral and Southern Big Aral.

By 2007 in the southern part there formed a deep western and a shallow eastern basins, also remains of a little separate firth. Big Aral decreased from 708 to 75 km3 only and the water salinity raised from 14 to 100 g/l. With the collapse of the USSR in 1991 the Aral Sea turned to be divided between the newly formed states: Kazakhstan and Uzbekistan.

The drying of the Aral Sea had terrible aftermath. Due to the drastic drop of the rivers flow stopped the spring floods providing the Amur Darya and the Syr Darya with fresh water and fertile sediments. Number of fish inhabiting the sea dropped from 32 to 6 due to high salinity of the water, loss of spawning ground and feeding areas.

In 1960 fish capture reached 40 thousand tons but by the mid of the 1980s capture fishing just ceased to exist and consequently 60 thousand of working positions were lost.

Navigation also stopped because the water moved many kilometres away from the main local ports.



There are hundreds of ship skeletons on the coastline.

The Aral Sea is impossible to restore. The only way out that would let make the situation better is to stop irrigation of the fields that demands 92% of the withdrawal. However 4 of 5 republics near the basin of the Aral Sea intend to only increase irrigation of the farmlands to feed the growing population.

Other large basins of the world trace the sad destiny of the Aral Sea:  for example Chad lake in Central Africa or Salton Sea in the south of an American state California.












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