Dried Aral Sea bed (Aralkum) and Karakalpakstan

In the 1960s Soviet irrigation projects diverted the Amu Darya and Syr Darya, the rivers that fed the lake. Between 1960 and 1998 its area shrank by 60% and its volume by 80%; salinity went from 10 to about 30 g/L by 1990. By 2007 the lake had split into four bodies of water and by 2009 the south-eastern basin had disappeared (Wikipedia). The fishery that employed ports such as Muynak is gone.

To keep cotton yields up, growing quantities of pesticides were used from the 1960s, HCH and DDT among them, and drainage canals carried them to the lake; Wikipedia also mentions PCBs and metals from industry and residues of weapons testing. As the water receded, concentrations rose both in the remaining water and in the dry beds, and dust storms spread salt and residues over fields and settlements.

Bartrem and colleagues (2025) collected 140 soil, water and sediment samples at 79 locations in Karakalpakstan. Besides organochlorine pesticides in every water sample, 30% exceeded reference levels for hexavalent chromium; dissolved solids ranged from 563 to 3,852 mg/L and the salt content of soil and sediment reached 8.7%. Halophytic pioneer plants such as Suaeda acuminata grow on the exposed bed; their rhizosphere has been studied along a gradient of 5, 10 and 40 years since desiccation (Wicaksono et al. 2022).