The Aral Sea, once the world’s fourth-largest inland body of water, was a vast, landlocked lake situated between Kazakhstan and Uzbekistan. In 1960, the sea covered approximately 68,000 square kilometers, supporting a unique regional ecosystem and a thriving local economy. Over the following decades, this massive body of water began to vanish at an unprecedented rate, shrinking to less than ten percent of its original size by 2007. The rapid desiccation of the Aral Sea is one of the most significant human-induced environmental catastrophes in modern history. The cause was not climate change, but a deliberate, massive-scale engineering project that redirected the sea’s only water sources.
Engineering the Collapse: River Diversion and Irrigation
The disappearance of the Aral Sea began in the 1960s due to Soviet-era central planning decisions. These plans aimed to transform the arid Central Asian plains into productive agricultural land for water-intensive crops like cotton and rice. This policy was implemented without regard for the long-term environmental consequences for the sea.
The Aral Sea relied almost entirely on the inflow from two major rivers: the Amu Darya in the south and the Syr Darya in the north. To irrigate the new farmlands, vast networks of canals were constructed to divert water from these rivers hundreds of kilometers into the desert. By the early 1980s, the cumulative effect of these diversions meant that little to no water from either river reached the Aral Sea for long periods.
A significant portion of the diverted water never reached the crops due to poor engineering and management practices. The irrigation canals were often unlined, allowing massive amounts of water to leak directly into the porous desert soil. High rates of evaporation from the open canals and poorly managed flood irrigation systems also contributed to the loss. Estimates suggest that between 25% and 75% of the water diverted was lost through seepage and evaporation.
Despite the accelerating drop in the sea’s water level, the expansion of irrigated land and cotton production continued well into the 1980s. This persistent focus on agricultural output starved the Aral Sea of the inflow required to balance its natural rate of evaporation. The volume of water entering the sea plummeted from around 58.8 cubic kilometers in 1960 to barely 4.3 cubic kilometers by 1989. The massive diversion of the Amu Darya and Syr Darya effectively signed the ecological death warrant for the Aral Sea.
The Immediate Aftermath: Ecological and Socioeconomic Disaster
The reduction in water volume led to a series of environmental and human disasters across the region. Since the rivers no longer delivered fresh water, the remaining body of water became increasingly concentrated with salt. The salinity level rapidly increased from about 10 grams per liter to over 100 grams per liter in some areas, making it three times saltier than typical ocean water.
This extreme increase in salinity proved fatal to most of the sea’s aquatic life, including the 20 native fish species. The once-thriving fishing industry, which employed tens of thousands of people, collapsed completely by the late 1980s. Former port cities, such as Moynaq, were left stranded dozens of kilometers from the new shoreline, their harbors filled with the rusted remains of a fishing fleet.
As the water receded, a vast new landmass emerged: the Aralkum Desert, covering over 60,000 square kilometers of exposed seabed. This dried lakebed is laced with highly concentrated salts and toxic residues from decades of agricultural runoff, including pesticides and fertilizers. Strong winds lift this toxic mixture into the atmosphere, creating frequent dust storms that carry contaminated material across Central Asia.
The resulting public health crisis in the surrounding regions, particularly in the Uzbek province of Karakalpakstan, has been severe. The inhalation of the toxic dust has been linked to abnormally high rates of:
- Respiratory illnesses.
- Cancers.
- Anemia.
- Birth defects among the local population.
Economically, the collapse of fishing and the degradation of soil due to salt deposition led to mass unemployment and migration, devastating local communities.
Partial Restoration: Saving the Northern Aral Sea
The massive inland sea fragmented into several smaller, isolated water bodies, primarily the Northern Aral Sea (Small Aral) and the Southern Aral Sea (Large Aral). To stabilize the Northern Aral Sea, which is fed by the Syr Darya River, the government of Kazakhstan undertook a major remediation project. The cornerstone of this effort was the construction of the Kokaral Dam, completed in 2005 with funding from the World Bank.
The Kokaral Dam is a 13-kilometer-long structure built to separate the Northern Aral Sea from the dried Southern basin, trapping the Syr Darya’s inflow. This intervention led to a successful partial recovery of the Northern Aral Sea. By 2008, the water level had risen by 12 meters, recovering to a height last seen in the 1980s.
The increased volume of water successfully reduced the salinity of the Northern Aral Sea, dropping it from approximately 30 grams per liter to about 8 grams per liter. This drop in salt concentration allowed many native freshwater fish species, such as pike-perch and bream, to return and thrive. The local fishing industry has seen a significant revival, with annual catches increasing substantially since the dam’s completion.
The situation in the Southern Aral Sea remains dire, considered unsalvageable due to the continued diversion of its main water source, the Amu Darya. The eastern lobe of the Southern Aral Sea dried up completely in 2014, leaving behind the vast Aralkum Desert. While the Northern Aral Sea offers a powerful example of successful ecological restoration, the fate of the southern basin serves as a reminder of the magnitude of the original catastrophe.