The shrinking Caspian Sea: eco-hydrological responses to human and climate pressures

Duku, Jesse; Tourian Mohammad J.; Azarderakhsh, Marzi; Abbasov, Rovshan; Mehran, Ali; Torabi, Haghighi Ali; Xenarios, Stefanos; Boschee, Azara; Babagiray, Salih; Sadegh, Mojtaba; Shokri, Nima; Nazemi, Ali; Farahmand, Alireza; Ashraf, Samaneh; Khujanazarov, Temur; Hassanzadeh, Elmira; Najib, Dalal; Placht, Daniel; Mashtayeva, Shamshagul; Rets, Ekaterina

doi:https://doi.org/10.15480/882.17326

The shrinking Caspian Sea: eco-hydrological responses to human and climate pressures

Citation Link: https://doi.org/10.15480/882.17326

Basic Data Publication

Publikationstyp

Journal Article

Date Issued

2026-06-05

Sprache

English

TORE-DOI

10.15480/882.17326

TORE-URI

https://hdl.handle.net/11420/63527

Publisher Version

Journal

Earth's future

Volume

14

Issue

6

Article Number

e2025EF008028

Citation

Earth's Future 16 (6): e2025EF008028 (2026)

Publisher DOI

10.1029/2025EF008028

Scopus ID

2-s2.0-105040975609

Publisher

Wiley-Blackwell

Abstract

The Caspian Sea, the Earth's largest inland water body, faces water level decline, drawing comparisons to the collapse of the Aral Sea. Unlike the Aral Sea, the relative roles of climatic variability, hydrological changes, and anthropogenic pressures on the Caspian Sea remain poorly understood. Here, we integrate satellite observations, in situ hydrological records and reanalysis data to examine recent drivers of the Caspian water loss. We show that total river inflow to the Caspian Sea has declined significantly, primarily due to reduced discharge from the Volga River. At the same time, precipitation over the basin has remained broadly stable, while evaporation over the sea has shown a modest upward trend. These findings point to compound anthropogenic and climatic influences on the regional water balance. We also detect a long-term increase in chlorophyll-a concentrations in the shallow Northern Caspian, signaling growing ecological stress associated with ongoing hydrological change. Avoiding further ecological disruption requires coordinated international action and policies to mitigate shrinkage by optimizing water allocation and environmental releases, as well as prioritizing long-term ecosystem resilience. Without urgent intervention, the Caspian Sea risks following the trajectory of other desiccating inland water bodies, with long-lasting ecological and socioeconomic consequences.

Content

Subjects

anthropogenic water use

Caspian Sea

climate variability

inland water bodies

water level decline

DDC Class

551: Geology, Hydrology Meteorology

Funding References

Funding(s)

United Nations University Hub on Engineering to Face Climate Change at Hamburg University of Technology

Files

Lizenz

https://creativecommons.org/licenses/by/4.0/

Publication version

publishedVersion

Download

Name

Earth s Future - 2026 - Duku - The Shrinking Caspian Sea Eco‐Hydrological Responses to Human and Climate Pressures.pdf

Type

Main Article

Size

1.58 MB

Format

Adobe PDF