As a child growing up in Rudsar on Iran’s northern coast, environmental journalist Maryam spent most of her free time at the water’s edge. She remembers the Caspian Sea rising and falling — occasional floods in the 1990s even left some relatives homeless — and those shifts felt ordinary. On a recent visit after many years away, however, the shoreline no longer looked familiar.
“I kept walking farther from the shore, but the water only reached my knees,” Maryam said, asking that her real name not be used for security reasons. For someone raised beside the Caspian, the new landscape was alarming.
Her experience reflects a wider, accelerating trend. The Caspian Sea — the world’s largest inland body of water, bordered by Iran, Russia, Azerbaijan, Turkmenistan and Kazakhstan — has been shrinking rapidly. Although the basin has a history of natural fluctuations, scientists warn the current decline, which began in the 1990s, is unlikely to reverse and could intensify this century. Some models project drops up to around 21 meters (about 70 feet).
Simon Goodman, an evolutionary biologist at the University of Leeds, highlights the scale of such losses: an 18-meter fall, for example, would exceed the height of a six‑story building, with far-reaching consequences for ecosystems, human health, livelihoods and local economies.
What’s causing the drop?
Multiple factors are at play. Roughly 80% of the Caspian’s freshwater enters from the north via the Volga River, and decades of dams, irrigation and other water management across the Volga basin have reduced inflows. On top of that, climate change is increasing evaporation from the sea’s surface while decreasing regional precipitation and runoff — meaning more water is being lost than replaced.
Already visible effects
The changes are most evident in the shallow northern basin along Russia and Kazakhstan. Many ports now require extensive dredging to keep shipping channels open, a problem scientists expect to worsen in the next five to 10 years. Fishing communities are under strain: wetland loss and falling fish stocks have hollowed out markets and altered coastal businesses. A café that once fronted the water now sits several meters inland.
If levels fall another 10 meters, large areas of the northern basin could dry out entirely, potentially removing nearly a third of the sea’s surface. Sites that once supported tens of thousands of seals during spring molting have already become dry land, a sign of habitats being lost.
Risk of an Aral-style outcome
Researchers warn the Caspian may be entering a trajectory similar to the Aral Sea disaster, where upstream water diversion largely desiccated a once‑vast lake, destroying livelihoods and creating polluted dust storms. Goodman says the northern Caspian’s exposed seabed could change the regional climate and release dust that carries contaminants, compounding ecological and public health risks.
Policy and cooperation challenges
Because five countries share the Caspian’s coastline, effective responses require coordinated policies and long-term investment. Scientists and local communities need sustained support for research, adaptation planning and measures that address both ecological restoration and economic resilience. As Goodman puts it, policy action must keep pace with the speed of environmental change.
Without faster, cooperative intervention, the sea Maryam knew as a child may continue to retreat, reshaping ecosystems and human lives across the region.