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Immediate action is essential to safeguard endangered species, public health, and regional industries affected by the decreasing water levels of the Caspian Sea, according to recent research from the University of Leeds.
The Caspian Sea, recognized as the largest enclosed inland body of water on the planet, is undergoing substantial reductions in water levels. This phenomenon is attributed to rising temperatures, which lead to higher evaporation rates than the inflow of freshwater. Projections suggest that even if global warming is limited to under 2°C, the sea could experience a drop in water levels between 5 to 10 meters. However, should temperatures escalate further, the decline could reach as much as 21 meters by the year 2100.
The University of Leeds research team has analyzed the potential hazards that this decline poses to both biodiversity and human infrastructure. Their findings have been published in Communications Earth & Environment on April 10.
The study indicates that approximately 112,000 square kilometers—an area greater than Iceland—could desiccate even under a favorable climate scenario predicting a 10-meter decline. Many ecologically and economically significant areas are situated in shallow waters, and this could severely impact both local biodiversity and the well-being of human populations in the region.
Home to the endangered Caspian seal and six sturgeon species, in addition to numerous fish and invertebrate species unique to this habitat, the Caspian Sea’s declining water levels threaten critical breeding grounds and access to vital spawning rivers, which could disrupt entire food webs and migratory paths for birds.
Over 15 million individuals reside along the Caspian coasts of Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan, relying on the sea for fishing, shipping, and trade. The Caspian also plays a crucial role in regulating Central Asia’s climate.
The research predicts that settlements, ports, and industrial sites in northern Caspian could be left stranded up to hundreds of kilometers away from the newly formed shorelines. The exposed seafloor might release airborne dust laden with industrial pollutants and salt, posing significant health risks reminiscent of the consequences seen from the Aral Sea’s desiccation.
To address these challenges, researchers emphasize the need for a proactive and evolving strategy in biodiversity conservation, suggesting that traditional protected areas with fixed perimeters may no longer be effective due to fast-changing water levels.
Dr. Simon Goodman from the University of Leeds’ School of Biology stated, “While some decline in water levels appears inevitable, there remains an opportunity to mitigate impacts on biodiversity and human interests. This timeframe, though seeming extended, highlights the necessity for immediate action given the complex political, legislative, and logistical hurdles that lie ahead.”
Biodiversity
The Caspian Sea spans roughly 1150 km by 450 km, covering an area of 387,000 square kilometers.
A 10-meter drop could lead to the complete disappearance of four out of ten unique ecosystem types in the Caspian, reducing existing marine protected areas by up to 94%.
Caspian seals bear their pups, recognized by their distinctive white coats, between mid-January and early March atop ice in northern Caspian waters. The research indicates that a 5-meter reduction could diminish these vital habitats by up to 81%, greatly stressing an already vulnerable population.
Classified as Endangered by the International Union for the Conservation of Nature (IUCN) in 2008, the Caspian seal is acknowledged as a species at risk of extinction across all five bordering nations.
Additionally, current haul-out sites where seals rest may become unreachable due to falling water levels. Although there may be the emergence of new islands, further investigation is necessary to evaluate their suitability for seal populations.
Sturgeons, an ancient lineage of large fish, are critically endangered largely due to overfishing for their meat and caviar. Their preferred habitats in shallower waters are expected to diminish by 25% to 45% due to drying waters, potentially obstructing their access to remaining spawning locations in adjoining rivers.
The Caspian Sea is crucial as a habitat for migratory birds traveling between Europe, Asia, and Africa; these birds depend on coastal lagoons and reed beds for rest and resources during their journeys. Consequently, with habitat loss looming, the ecological ramifications could prove detrimental.
The richness of biodiversity in the Caspian Sea is already under threat from overfishing, invasion by non-native species, and pollution. Current conservation efforts may be rendered ineffective, resulting in nearly complete loss of existing marine protected areas for most countries bordering the sea, with Kazakhstan potentially retaining only about 5% of its current zones.
Rebecca Court, a PhD researcher in the School of Earth and Environment at Leeds, expressed hope that this research enhances awareness of the implications of falling sea levels. The mapping of these potential risks is intended to assist policymakers and conservationists in preemptively addressing these multifaceted challenges.
Industry and Society
The research findings also forecast adverse conditions for industry, indicating that vital ports across neighboring countries will be affected. Ports like Baku (Azerbaijan), Anzali (Iran), and Aktau (Kazakhstan) are expected to face distances to shore extending by over one kilometer, while Turkmenbashi (Turkmenistan) and Lagan (Russia) could experience increases of 16 kilometers and 115 kilometers, respectively.
The Volga River remains the sole conduit linking the Caspian Sea to broader maritime networks, and a mere 5-meter decline could jeopardize this essential trade route.
The Kashagan (Kazakhstan) and Filanovsky (Russia) oil fields, key sources of hydrocarbon production within the northern Caspian, currently depend on offshore facilities and marine transport systems yet stand to become landlocked due to predicted declines of 5 to 15 meters in water levels.
Communities along the northern Caspian may suffer greatly as declines in fish stock erode income, while challenging climatic conditions complicate agricultural viability, thereby posing risks to social stability.
Desalination processes in some cities surrounding the Caspian for freshwater supplies are already being impacted by lower water levels, with operational disruptions noted in Aktau, Kazakhstan.
Additionally, the substantial loss of water from the Caspian could lead to shifts in the regional climate, potentially resulting in less rain and drier conditions throughout Central Asia, which would indirectly affect agriculture and food security.
The geopolitical significance of the Caspian’s energy resources means that the social, economic, and environmental instability induced by climate change could have far-reaching implications beyond the regional context.
Recommendations
It is imperative to balance the protection of biodiversity with the needs of human prosperity. The researchers recommend immediate, coordinated regional planning and international collaboration to address the anticipated impacts effectively.
Dr. Elchin Mamedov from Azerbaijan’s Ministry of Ecology and Natural Resources emphasized the importance of this study, underscoring the risks posed by climatic changes to both biodiversity and local communities, and advocating for enhanced cooperation at both the regional and international level to mitigate these challenges.
This international collaboration consisted of researchers from various institutions, including Technische Universität Braunschweig and Berlin in Germany, Kaspika Caspian Seals Conservation Agency in Russia, and others from Kazakhstan, Azerbaijan, Turkmenistan, and more, reflecting a comprehensive effort to understand and address the complexities surrounding the Caspian Sea.
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