Three species of fish that evolved in the Aral and went extinct when it dried. Museum specimens show they had evolved extreme salinity tolerance in just 10,000 years.
Kessler, Public domain, via Wikimedia Commons
An Ocean of Salt in the Desert
Before the 1960s, the Aral Sea was the fourth-largest lake on Earth, a vast, brackish body of water with a salinity of about 10 grams per liter. It supported a massive fishing industry that employed around 40,000 people and produced one-sixth of the Soviet Union's fish. this environment contained over 20 native fish species, including some found nowhere else on the planet.
Among its inhabitants were the Aral trout (Salmo trutta aralensis) and the Syr Darya sturgeon (Pseudoscaphirhynchus fedtschenkoi). These species, along with others, had adapted perfectly to the Aral's specific conditions over millennia. The Aral trout was a subspecies of brown trout that spawned in the tributary rivers before migrating back to the sea. The Syr Darya sturgeon was a small, ancient fish endemic to the Syr Darya river basin and the Aral Sea itself. This species had seen no sightings since the 1960s and is now considered possibly extinct.
How to Kill a Sea
The destruction of the Aral Sea began in the 1960s. Soviet planners diverted the two rivers that fed the sea, the Amu Darya and the Syr Darya, to irrigate immense cotton and rice fields in the desert. This massive water diversion starved the sea. From 1961 to 1970, the sea's level fell by an average of 20 centimeters per year; by the 1980s, this rate accelerated to 80-90 centimeters annually.
As the volume of water plummeted, the salinity skyrocketed. By 1989, the average salinity had tripled to 30 g/L, and the sea split into the smaller North Aral and the larger South Aral. By 2004, the salinity in parts of the South Aral exceeded 100 g/L, far saltier than any ocean. For the native fish, this was an extinction-level event. The 20 native species, adapted to low salinity, died off. The commercial fishery completely collapsed by 1987. Even saltwater-tolerant flounder, introduced in an attempt to revive the fishery, could not survive the hypersaline conditions of the South Aral by the late 1990s. The Aral trout became functionally extinct by the early 1990s. The once-thriving ecosystem had collapsed in just a few decades.
💡Fun Facts
The exposed seabed, now called the Aralkum Desert, is the world's newest desert and a source of toxic dust storms carrying salt and agricultural chemicals.
The Syr Darya sturgeon (*Pseudoscaphirhynchus fedtschenkoi*) belonged to a genus of "living fossils" restricted to the Aral Sea basin.
The port city of Moynaq, once a bustling fishing center employing 30,000 people, now lies over 90 kilometers from the water, its harbor filled with rusting ships in the sand.
A dam built in 2005 has helped partially restore the North Aral Sea in Kazakhstan, lowering salinity and allowing the return of 22 fish species, though not the extinct endemics.
The former seabed and the "ship graveyard" at Moynaq are accessible by 4x4 vehicles. The terrain is a flat, sandy desert. Guided tours are highly recommended.
Aral Sea endemic fish extinctionKarakalpakstan, Uzbekistan
