Scientists warn that climate change and habitat degradation are accelerating water loss in the Caspian Sea.
The Caspian Sea is rapidly shrinking. A long-term decline in water levels has been documented through satellite observations supported by hydrological and climate research, showcasing a consistent downward trend since the mid 1990s.
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Along parts of Azerbaijan’s coastline, including low-lying areas of the Absheron Peninsula, a retraction is becoming increasingly visible. It’s clear that previously shallow coastal zones are exposed, and shoreline patterns are shifting.
Scientists have warned that climate change and habitat degradation are accelerating water loss across the region. The falling levels are increasingly affecting ecosystems, biodiversity and coastal communities along the Caspian shoreline.
Why is the Caspian Sea under pressure?
The Caspian Sea is a landlocked basin with no natural outlet, meaning its water level depends entirely on the balance between river inflow, precipitation and evaporation.
The Volga River is the main source of freshwater inflow, supplying the majority of water entering the system. Hydrological research shows that changes in river discharge, combined with rising regional temperatures, have increased evaporation and disrupted this balance. But what does this mean?
“Climate change is accelerating evaporation and disrupting the water balance of the Caspian Sea,” explains Dr Elnur Safarov, Caspian Sea studies expert at environmental organisation IDEA Public Union and coordinator of the Caspian Integrated Scientific Network (CASPISNET).
He adds that continued warming could intensify long-term decline and pressures across the basin.
The retreat is already altering coastal landscapes and ecosystems.
The Surakhani Museum Ship, a vessel that once floated offshore, now stands on shallow waters - a visible marker of shifting water levels.
These changes are mostly noticeable in coastal zones, where even small reductions in water level can lead to large areas of exposed seabed.
Shrinking habitats and ecosystem pressure
The Caspian seal is widely regarded as a key indicator of ecosystem health in the basin.
According to the International Union for Conservation of Nature (IUCN) assessments, the species is endangered and has experienced a long-term population reduction driven by multiple pressures.
“The population decline of the Caspian seal moves this already endangered species closer to extinction risk,” says Hasanov, highlighting combined pressures including habitat loss, reduced ice formation in northern areas, pollution and bycatch.
Environmental monitoring shows that falling water levels are affecting wetlands, reed beds and delta systems across the basin.
“Fish in the Caspian Sea, which include sturgeon and other endemic species, are losing their natural habitats,” says zoologist Dr Nijat Hasanov.
He notes that declining populations are becoming a concern “both from biodiversity and food security perspectives”.
He also points to wider ecosystem impacts, adding that the region provides “nesting, breeding and resting habitats for millions of birds”, including pelicans, flamingos and ducks, all dependent on stable coastal conditions.
The environmental shift is also reshaping human activity along the coast.
“They have to go deeper into the sea to catch the same amount of fish they used to catch nearby the shore,” says Farhad Mukhtarov, an expert on water governance at the International Institute of Social Studies, referring to fishing communities in Azerbaijan.
He notes that in some cases fishermen are now travelling significant distances offshore, and facing increased exposure to changing weather and sea conditions.
Mukhtarov adds that despite these pressures, coastal communities are adapting through cooperation and local resilience.
Regional cooperation under the Tehran Convention
Environmental cooperation across the basin is coordinated through the Tehran Convention, signed by Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan.
The framework supports cooperation on pollution prevention, biodiversity protection, and environmental monitoring.
According to Mahir Aliyev, Coordinator of the Secretariat of the Tehran Convention, the decline in water levels is a shared concern, with visible impacts already emerging on biodiversity, wetlands and coastal systems.
“The continued decline in the level of the Caspian Sea is a matter of serious concern for all five Caspian littoral states. As the world’s largest enclosed inland water body, the Caspian Sea is particularly sensitive to climate variability and human pressures. The combination of reduced inflows and increased evaporation linked to rising temperatures is altering the Sea’s delicate hydrological balance.”
He emphasises that coordinated regional action is essential to manage the environmental consequences across the basin.
A system under long-term climate stress
Climate and hydrological research consistently point to a persistent imbalance between inflow and evaporation in the basin.
Rising temperatures are increasing evaporation rates, while variability in river inflow has not been sufficient to offset long-term losses.
Experts describe this as part of a broader climate-driven shift affecting closed inland water systems.
Taken together, satellite observations, hydrological studies and ecological monitoring indicate that the Caspian Sea is undergoing a sustained decline in water levels.
The result is a gradual transformation of coastal geography, ecosystems and livelihoods across the region, with continuing pressure on habitats, biodiversity and communities dependent on the basin’s changing environment.
