Aquatic Species and Their Environments - Water Diversion—the Aral Sea

The Aral Sea is bounded by Uzbekistan and Kazakhstan, and was once the fourth-largest lake in the world. However, over the past 30 years, the lake has lost 60 percent of its water and shrunk to half its original area. This is due to the long practice of diverting water from the Amu-Darya and the Syr-Darya, two rivers that feed the lake, for irrigation and agriculture. With water loss, the lake has also increased in salinity—from 10 percent salt content to 23 percent salt content in 1999. Aral Sea habitats have been utterly destroyed. The Aral Sea was once a thriving fishery, with a total catch of 26,000 tons in 1957. Thousands of fishermen were once employed at the sea, and commercial species included carp, pike-perch, and roach. Commercial fishing in the Aral had ceased entirely by 1982.

The destruction of the Aral Sea has had numerous other consequences as well. Exposure of the lakebed has resulted in dust storms and air pollution, which affect much of the human population living around the Aral Sea. In the last 15 years, liver disease, kidney disease, and chronic bronchitis have increased 30-fold, and incidence of arthritic disease has increased by a factor of 60. The loss of the lake has also affected regional climate patterns, so that summers are now hotter and drier and winters are longer and colder. Agriculture in the region has also been severely impaired, both by the shortening of the growing season and the degradation of soil, which is prone to high salinity and erosion.