Volga River Delta - A Global Ecoregion
One of the world's largest and most important temperate deltas
Snapshot: Ecoregion 157
Size:
86,000 sq. km (34,000 sq. miles)
Habitat type:
Large River Deltas
Geographic Location:
Western Asia: Kazakhstan and Russia
Conservation Status:
Critical/Endangered
Quiz Time!
Is there any such thing as "living fossils"?
Answer:
Yes! Meet the sturgeons - fossils that can swim. Often called "living fossils," sturgeons evolved 250 million years ago, when dinosaurs roamed the Earth. Individuals live a long time, too: some can reach an age of 150 years.
About the Area
The Volga River starts in the Valday Hills of northwestern Russia and flows 2,300 miles (3,700 km) before creating this delta and pouring into the Caspian Sea.
Water entering the Volga delta separates into more than 500 channels, arms, and rivulets and spreads out onto the adjacent floodplain forming shallow lakes. These flows also carry many nutrients from upstream into the delta making it one of the world's most productive areas for fish, particularly sturgeon.Local Species
About 400 vertebrates, including 127 species of fish and 260 species of birds (including swans, ducks, herons, terns, and ibis), as well as 850 aquatic invertebrates, 430 different plants, and more than a thousand species of insects can be found in the delta.
Sturgeon species found in the delta are the Russian (Acipenser gueldenstaedti), Beluga (Huso huso), Sterlet (A. ruthenus), and Stellate (A. stellatus) sturgeons, in addition to migratory species such as Whitefish (Salmonidae) and Herrings (Clupeidae). White-eyed bream (Abramis sapa) and the endemic Volga lamprey (Caspiomyzon wagneri) are some of the rare fishes found in this ecoregion.
The ecoregion has the distinction of being named a Wetland of International Importance because it provides habitat for many migratory birds. Among the unusual birds found here are the Dalmatian pelican (Pelecanus crispus), Great white egret (Egretta alba), and Penduline tit (Remiz penduculinus).
Threats
Dams upstream have altered the natural flow regime of the river thus negatively affecting the productivity of the delta and its fauna. Planned impoundments, water diversions, industrial, agricultural, and domestic pollution further threaten the health of populations dependent upon the delta ecosystem. Cyanobacterial blooms and deoxygentation have increased in recent years.
Resources
• NationalGeographic.com
