AKTAU, Kazakhstan — The concrete steps that led from Aktau’s seafront promenade into the water were built in the 1970s for bathers. Today they end on dry sand, and the sea begins about 140 meters farther out, past a line of rusted mooring rings that once held fishing boats.
The Caspian Sea, the largest enclosed body of water on earth, has fallen about 2.3 meters since 1995 and about 70 centimeters in the past five years alone, according to measurements published by Kazakhstan’s hydrometeorological service. The sea’s level is now about 29.5 meters below global sea level, the lowest since instrumental records began, and a study by scientists in Germany and Kazakhstan published in September projected a further decline of 9 to 18 meters by 2100 under moderate warming scenarios. The northern Caspian, which is shallow and lies mostly in Kazakh waters, would largely disappear.
The causes are a combination of reduced inflow from the Volga River, which supplies about 80 percent of the sea’s water and has been dammed and drawn down for irrigation across Russia, and rising evaporation as the region warms. Kazakhstan’s government formally declared the Caspian decline a national emergency in July and has created a commission to coordinate a response, though most of the inflow lies outside its control.
“We are an inland sea with five owners and one tap, and the tap is in another country,” said Dr. Bakhyt Zhumagulov, a hydrologist at the Caspian research institute in Aktau. “We can dredge. We can move ports. We cannot make it rain in Russia.”
The economic effects are already visible along the Kazakh coast. The port of Aktau, which handles the ferry route across the Caspian to Baku that has become central to the so-called Middle Corridor trade route between China and Europe, has spent about 14 billion tenge, or $27 million, on dredging in the past three years and has had to restrict the loading of rail ferries so they draw less water. Oil terminals near Kuryk have extended their jetties twice. Farther north, the Ural River delta, once a sturgeon fishery, has become reed marsh and then steppe; the town of Atyrau is now about 45 kilometers from open water.
The Caspian seal, found nowhere else, has lost most of the ice sheets in the northern shallows on which it breeds, and the population, estimated at a million a century ago, is now put at about 70,000. Mass die-offs have been reported on the Kazakh and Russian shores in each of the past four winters.
The decline has created an unlikely boom in Aktau: land. The city’s administration has begun leasing exposed seabed along the former shoreline for cafes and parking, and a developer has proposed a resort on what was, in 2010, a sandbar. “Twenty years ago I rented pedal boats from this spot,” said Aigerim Nurlanova, 47, who now runs a cafe on the reclaimed sand. “Now I rent umbrellas. The customers walk farther every summer.”
The government has proposed a Caspian summit of the five littoral states for next year to discuss water flows, and has asked for the sea’s decline to be included on the agenda of the U.N. climate conference. Dr. Zhumagulov was not hopeful. “Everyone agrees it is a problem,” he said. “It is just that for four of the five, it is someone else’s shore.”
A version of this article appears in print on Oct. 12, 2026, Section A, Page 6 of the European edition with the headline: The Caspian Is Retreating, and Kazakhstan’s Port City Is Watching the Sea Walk Away.
