Aral Sea

The Aral Sea was once the fourth-largest body of freshwater on Earth. Located in the desert of the central Asian republics of Kazakhstan and Uzbekistan, its waters once supported productive fisheries. However, as a result of unwise water management practices, the Aral Sea has since lost about 60 percent of its surface area, is saltier than the world’s oceans, and has markedly changed the local climate and ecology.

Overview

Tectonic movements during the Tertiary period (from about 65 million years to about 3 million years ago) formed large basins in parts of central Asia. In time, these basins filled with water. As the climate and rainfall varied over millions of years, the number and sizes of these water-filled basins also varied. The Caspian Sea and Aral Sea (both actually large freshwater lakes) are remnants of much larger, ancient bodies of water. The Aral Sea formed in a depression in the Earth’s surface at the beginning of the Pleistocene epoch (the last Ice Age) about 1.6 million years ago.

Aquatic vegetation eventually established a presence in the water-filled basins. The nearby wetlands supported lush plant growths to form extensive, highly productive marshes. Farther back from the marshes, shrubs and trees developed into riparian forests. Beyond the influence of the waters, shrubby grasslands and sparse vegetation gave way to near-desert conditions.

Flocks of migratory waterfowl, including ducks, geese, and egrets, fed among the lush vegetation, nested, and raised their young. Deer, wild pigs, muskrats, and a host of small mammals also occupied the extensive wetlands and meadows. Fertilized by the abundant aquatic vegetation, shoals of sturgeon, carp, roach, pike, perch, bream, and other fish provided a ready supply of food for humans from the time they first ventured into the area.

Human Development

During the early decades of the twentieth century, human settlement around the shores of the Aral Sea increased, as did the harvest of the rich fisheries. In addition to the catch consumed by local populations, large volumes of fish were packed and shipped across the continent. To satisfy the demand for Aral Sea fish as food, the waters yielded an annual harvest of fifty thousand tons of fish. Trawlers, some as long as fifteen meters, plied the lake waters, gathering the Aral’s fish.

In addition, cattle grazed on the lush grasslands surrounding the Aral Sea, and crops were grown and harvested to feed the local human population. Although the region was surrounded by sparse vegetation and desert, the availability of water from the Aral Sea and its riverine systems made agriculture possible.

The area surrounding the Aral Sea enjoyed what has been described as a desert-continental climate, with cold winters, hot summers, and sparse rainfall. The climate was moderated somewhat by the heat capacity of the volume of water in the Aral Sea. During the summer, the waters absorbed heat from the air and slowly released it in the winter. This had the effect of reducing the extremes of seasonal temperatures. Although the Aral Sea never became a popular resort area, its waters were used by villagers around its shores for swimming and boating during the warm season.

In addition, the Aral Sea and the rivers that supplied it, the Amu Darya and the Syr Darya, were important sources of potable water and water for domestic and farming uses. Both humans and livestock, as well as the region's abundant wildlife, depended on these waters for life.

Cotton at a Price

Following World War I, Kazakhstan and Uzbekistan were absorbed into the Soviet Union, and the Communist authorities developed a plan to make the new nation self-sufficient in cotton. The program, which involved irrigating vast near-desert regions in central Asia and planting and growing cotton, began in the mid-1920s and appeared successful. By the 1950s, vast volumes of water were being diverted from the two rivers that fed the Aral Sea. The waters flowed through hundreds of kilometers of canals that extended from the rivers to the surrounding desert to irrigate the new cotton fields. Poor or hasty planning led to constructing canals open to the Sun's searing heat, resulting in significant water losses due to evaporation. In addition, the canals were unlined, and much water was lost by percolation into the sandy desert soils.

Despite these problems, the irrigated cotton project yielded rich dividends, and the Soviet Union joined the United States and China as a world leader in cotton exports. However, the ecological backlash of the project became apparent during the early 1960s. The first sign of trouble was the shrinking of the Aral Sea as billions of liters of water were diverted from the feeder rivers to irrigate the cotton crops. Between 1950 and 1988, irrigated cotton fields were expanded to cover more than seven million hectares of land. The fishers and cattle workers in the Aral Sea region were forced to become cotton pickers.

Loss of Water Volume

The impact of the massive withdrawal of water from the feeder rivers of the Aral Sea soon became apparent as an increasing amount of sea bottom was exposed. Details about the dismal state of the Aral Sea were largely unknown outside the Soviet Union. The Communist government maintained a wall of silence about what many eventually called one of the world’s worst environmental disasters, perhaps second only to the nuclear power plant accident at Chernobyl in 1986. However, in the mid-1980s, under the principle of glasnost (openness) practiced by Soviet President Mikhail Gorbachev, the world soon learned the truth about the Aral Sea.

What had been the world’s fourth-largest lake—slightly bigger than Lake Huron in North America—had, by the 1980s, lost 80 percent of its volume. This loss was largely caused by evaporation. With its riverine input diverted to irrigate cotton, there was insufficient water to resupply the lake basin. More than three million hectares of seabed, now exposed to the drying sunlight and wind, became an expanse of white salt. The mineral content of the remaining Aral Sea waters increased dramatically until they had three times the salinity of the world’s oceans. The resulting brine concentration killed off all twenty-four of the Aral Sea’s native fish species. With the collapse of the once-thriving fisheries and related economic adversities, one hundred thousand workers were displaced.

The water volume loss caused immediate and long-term problems for the Aral Sea, the surrounding region, and the local people. The fish were gone, and the sea environment became inhospitable to birds and other wildlife. Deer and small mammals deserted the sea edges where growing layers of crusting salts had replaced the lush grasses and shrubs. The cotton harvest slowly declined, with the plants producing fewer and smaller bolls. The shrinking of the Aral Sea, which formerly had moderated the local climate, resulted in a harsher climate, a shorter growing season, and frequent dust storms. The salts and chemical residues blowing off the dry seabed reduced the soil’s fertility.

The long-term impact on human populations in the Aral Sea region has extended well beyond the loss of fisheries and jobs. Many of the people in the region have said that they fear they are slowly being poisoned. Runoff from the irrigation system supplies the local drinking water, which has become a brew of pesticides, defoliants, and fertilizers. Worse, domestic sewage only partially treated in the old, Soviet-era equipment is also part of the drinking water supply. The frequent wind storms blow clouds of salt, dust, and agricultural chemicals from the exposed, dry seabed, resulting in a high incidence of respiratory problems. The wind-borne pollutants, coupled with the contaminated drinking water, have been blamed for many digestive upsets, cases of typhoid and dysentery, and congenital disabilities. Populations close to the Aral Sea report infant mortality rates as high as one hundred deaths per one thousand births (10 percent), the highest in the former Soviet Union. Further, life expectancy at birth tends to be lower than the average in more economically developed countries.

IIn 2005, the government of Kazakhstan built the Kok-Aral dike and dam to alleviate some of the damage and save small parts of the sea. The dam separated the sea into northern and southern parts, allowing the northern water levels to rise at the expense of those in the south. This project led to a slight rise in water levels in the North Aral Sea.

Significance

The story of the Aral Sea is not unfamiliar. Those who elevate the need for economic gain above sound environmental planning have induced a number of environmental disasters. Some of those disasters have come about simply because the needed information was not available, while others have occurred because available information was ignored by planners.

The Aswan High Dam across the Nile River in Egypt was built in the early 1960s to provide electricity to the city of Cairo and to furnish irrigation water to the lower Nile basin. The completion of the dam caused several ecological backlashes. Nutrient-rich silt, which provided annual enrichment of the local farmland, was suddenly trapped behind the dam and could no longer flow downriver. The silt had also enriched the nearby waters of the Mediterranean Sea, thereby boosting its productive sardine fishery. Deprived of this natural fertilizer, farmers were forced to import chemical fertilizers at great expense. The sardine fisheries collapsed. Furthermore, Lake Nasser, the reservoir that formed behind the Aswan Dam, provided a habitat for snails carrying the organism that causes schistosomiasis, a disease with a significant fatality rate in humans.

Other examples of environmental backlash include the unregulated dumping of organic household waste (sewage) in many communities, which often results in the pollution of drinking water; the introduction of non-native species to new areas, which sometimes causes the extinction of native plants and animals; and the widespread use of agricultural insecticides, which may accumulate in food chains and lead to the deaths of larger animals that prey on the target insects.

The restoration of the Aral Sea may prove to be beyond human technology and capabilities. In the long run, the most feasible course of action may be inaction to allow the natural processes of ecological succession to eventually restore the area to some semblance of its natural state. Indeed, the most significant benefit to be gained from the example of the Aral Sea is that of a lesson learned. While it is difficult, if not impossible, to foresee all or most of the consequences of human action in the natural environment, at least as much attention should be paid to a soundly produced environmental impact plan as is paid to engineering and economic plans.

In the mid-2020s, only 10 percent of the original Aral Sea remains. In its place lays the massive Aralkum Desert. The region suffers from vast ecological problems, including land degradation, water scarcity, loss of biodiversity, and toxic dust storms, which cause chronic health problems for the region’s inhabitants. Once profitable fishing and agricultural industries from the Aral Sea collapsed, various socioeconomic issues were left in their place. While Kazakhstan’s Kok-Aral Dam has brought some relief to fishing industries, its impact has been minor. Other efforts include Kazakhstan’s International Fund for Saving the Aral Sea, which has implemented programs like the Aral Sea Basin Program-4 and the Regional Environmental Protection Program for the Sustainable Development of Central Asia. Still, in the twenty-first century, the Aral Sea’s situation remains dire, and as global climate change has accelerated, its future looks bleak. 

Principal Terms

climate moderation: a change in the climate or average weather of a region that reduces the extremes of heat and cold

ecological backlash: the unanticipated ecological effect of what appears, at first, to be a harmless activity

irrigation: the relocation and application of water using ditches or pumping as an aid to crop production

salinity: a measure of the quantity of dissolved salts in water

water equilibration: a condition in a lake or other body of water in which the water lost by evaporation is equal to the water added by rainfall or runoff

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