Caspian Sea 2011

State of the Environment of the Caspian Sea

cies and thus found only in the deltas of big rivers (the Volga, Ural, Kura and Terek). There are 24 bi- valve species in the Caspian Sea. Invasion of three species was either intentional or accidental. The introduction of Abra ovata and Mytilaster lineatus has had a considerable impact on the benthic com- munity. Three endemic bivalve species have not been found for 20 years and might be extinct. Gastropods in the Caspian Sea are usually small animals. This group is very diverse and includes freshwater species from deltas as well as many marine species. In general, their bio- mass is not high compared to Mytilaster and Abra. There are many endemic species of mollusks in the Caspian Sea. There are 13 endemic species and 16 endemic subspecies of Bivalves (88%). There are 83 marine gastropods in the Caspian Sea, 74 of which are endemic. There are only 10 species of Bryozoans in the Caspian Sea and no endemic species. One spe- cies — Conopeum seurati — is a possible invader. Cyclostomes and fishes In the Caspian Sea and surrounding low deltas, there are 110 native species belonging to 50 gen- era. Some species are represented by two or more subspecies. Another 24 species moved into the Caspian Sea in the 20th century. Most fish - 58 native species and 8 introduced species - can be found both in the Sea and in the contributing riv- ers during the different stages of their life cycles. Some of these fish live only in the sea – 28 aborig- inal species and two introduced species of mul- let. The number of endemic species is very high in the Caspian Sea. One lamprey species inhabits the Caspian Sea: it is endemic and belongs to an endemic genus. Six species of sturgeon live in the Caspian Sea. Five of them are anadromous: the Great sturgeon, the Russian sturgeon, the Persian sturgeon, the Stellate sturgeon and the Fringebar- bel sturgeon. All of these species are fished com- mercially. All sturgeon species also inhabit the Black Sea. All 11 species of the herring family are endemic to the Caspian Sea. A very special group is the 36 species of Caspian gobies, 24 of which

are endemic. Another 10 gobie species inhabit the Black Sea but the subspecies are endemic to the Caspian Sea. Caspian Sea marine fish include 23 endemic species and 3 endemic subspecies. In total, 37 endemic species and 19 endemic sub- species can be found in the Caspian Sea. Taking into account fish from the lower delta areas, the total number of endemic species increases to 46 species and 22 subspecies. Nineteen species and subspecies of fish in the Caspian Sea are listed in the IUCN and some Na- tional Red Data Books. There are 15 species of Amphibians in the Caspian Sea region, but only five or six of them are connected to the Sea through coastal habi- tats and river deltas. No species have been identified in the open Caspian Sea. Only one species is endemic ( Batrachuperus persicus ), in- habiting small mountain creeks on the Iranian coast. Along the northern coast only three to five species were identified (Genera Rana, Bufo, Pelobates, and Bombina), while 10 species were identified on the Iranian coast. There are many Reptile species along the coast of the Caspian Sea, but only a few of them have habitats connected with water. In the Cas- pian Sea region, there are only two tortoise spe- cies ( Mauremys caspica and Emys orbicularis ) and two snakes ( Natrix natrix and Natrix tessellata ). All four species are common. There are more than 300 species of nesting, mi- grating and wintering Birds along the coast of the Caspian Sea. The Caspian Sea plays a significant role as one of the great migration routes. During the migratory season, the presence of many mil- lions of birds is an amazing sight. Many species spend winter in the wetlands along the coast of the mid and the South Caspian Sea. Approxi- mately 94 waterfowl species nest around the Cas- pian Sea: 35 of them spend winter in the region, while 22 species arrive and spend winter only in northern regions. Forty five species of waterfowl can be observed on their migration route – they


Made with FlippingBook - Online catalogs