Aral Sea

The Aral Sea (/ˈærəl/) is an endorheic salt lake lying between Kazakhstan to its north and Uzbekistan to its south, which began shrinking in the 1960s and had largely dried up into desert by the 2010s. It was in the Aktobe and Kyzylorda regions of Kazakhstan and the Karakalpakstan autonomous region of Uzbekistan. The name roughly translates from Mongolic and Turkic languages to "Sea of Islands", a reference to the large number of islands (over 1,100) that once dotted its waters. The Aral Sea drainage basin encompasses Uzbekistan and parts of Afghanistan, Iran, Kazakhstan, Kyrgyzstan, Tajikistan, and Turkmenistan.

Formerly the third-largest lake in the world with an area of 68,000 km² (26,300 sq mi), the Aral Sea began shrinking in the 1960s after the rivers that fed it were diverted by Soviet irrigation projects. By 2007, it had declined to 10% of its original size, splitting into four lakes: the North Aral Sea, the eastern and western basins of the once far larger South Aral Sea, and the smaller intermediate Barsakelmes Lake. By 2009, the southeastern lake had disappeared and the southwestern lake had retreated to a thin strip at the western edge of the former southern sea. In subsequent years occasional water flows have led to the southeastern lake sometimes being replenished to a small degree. Satellite images by NASA in August 2014 revealed that for the first time in modern history the eastern basin of the Aral Sea had completely dried up. The eastern basin is now called the Aralkum Desert.

In a Kazakhstani effort to save and replenish the North Aral Sea, the Dike Kokaral dam was completed in 2005. By 2008, the water level had risen 12 m (39 ft) above that of 2003, to 42 m (138 ft). As of 2013^[update], salinity dropped, and fish were again present in sufficient numbers for some fishing to be viable.

After the visit to Muynak in 2011, United Nations Secretary General Ban Ki-moon called the shrinking of the Aral Sea "one of the planet's worst environmental disasters". The region's once-prosperous fishing industry has been devastated, bringing unemployment and economic hardship. The water from the diverted Syr Darya river is used to irrigate about two million hectares (5,000,000 acres) of farmland in the Ferghana Valley. The Aral Sea region is heavily polluted, with consequent serious public health problems. UNESCO has added historical documents concerning the Aral Sea to its Memory of the World Register as a resource to study the environmental tragedy.

The Amu Darya river flowed into the Caspian Sea via the Uzboy Channel until the Holocene. Geographer Nick Middleton believes it did not begin to flow into the Aral Sea until that time.

Despite its former vast size, the Aral Sea had relatively low indigenous biodiversity. However, the Aral Sea basin had an exceptional array of endemic fish subspecies (including three endemic sturgeon species). Most of these still survive in the North Aral Sea, but some, such as the sturgeons, have been greatly reduced or even driven to extirpation by the lake's shrinkage. Native fish species of the lake included

All these fish aside from the stickleback lived an anadramous or semi-anadromous lifestyle.

The salinity increase and drying of the lake led to the local extinction of the Aral trout, ruffe, Turkestan barbel, and all sturgeon species, and dams now block their return and migration routes; the Aral trout and Syr Darya sturgeon (Pseudoscaphirhynchus fedtschenkoi) may be extinct due to their restricted range. All other native fish, barring the stickleback (which persisted during the lake's shrinkage and salinity increase), were also extirpated, but many have returned to the North Aral Sea following its recovery from the 1990s onwards.