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4. Apart from the extensive shallows of the northern part, the other two physical features that characterize the Caspian are the delta of the Volga and the Kara Bogaz Gol gulf.

5. The Volga Delta covers about 10.000km² and the apron has a width of about 200km. A feature of the delta region are the so-called Bear knolls, which are hillocks between 3-20m in height, formed by the action of onshore winds on the river sediments that are discharged into the delta at a rate of 8 million tones per year. Numerous small laces are found between the knolls, and there is a complex system of channels with many islets. The Volga – Caspian shipping canal traverses the delta, and is dredged to a minimum 2m depth.

6. The Kara Bogaz Gol is situated on the eastern coast of the Caspian and comprises a shallow depression with a surface area of 18.000km^2, annual precipitation between 75-100mm and over 1.000mm evaporation per year. As a result, under natural conditions, water flows the main Caspian into the Gol at a rate of about 18-25km³ per year. This significant volume of water moves through a 8km long channel at speeds of 50-100cm/sec and influences water levels of the Caspian by about 6-8cm. In 1980, in an attempt to stem the impact of dropping water levels, the channel was blocked by a permanent dam and the Gol lost its supply of Caspian water. Its volume shrank immediately and its physical characteristics changed. Some water (around 2km³) has been allowed to flow into the Gol again since 1984, and more recently a full and free flow has been restored.

7. The most salient physical characteristic of the Caspian from the human point of view is the continuous fluctuation in its surface level. Modern observations began in 1830, and for the next 100 years the water level was recorded as fluctuating within a range of 1.0m with a mean level of-25.83m below MSL. In 1930 the level began to fall abruptly, and by 1941 it had gone down 1.9m. The dropping level continued to the mid – 1950s and 1960s, probably as a result of the major reservoirs that were built then on the Volga, and an increase in the amount of water drawn for irrigation. Without this draw-off, the Caspian waters would probably have started to rise again. But by 1977, the levels went down to the lowest and reached over the past 500 years or so, -29.0m. However, from 1978 the trend was suddenly reversed, and the levels started rising again. By 1993 in had reached -27.0m, that is, it had gone up 2.0m in 15 years. In 1995, Caspian, water levels stood around – 26.5m and were still rising.

8. The long term changes in Caspian water level have a complex character and have aroused great interest in scientific and economic quarters. The calculations of long –term forecasts of water level is not thought reliable, and it seems more expedients to plan for a further rise in water level, bearing in mind the levels that prevailed in the early 1900s.

d) Biological resources

9. The Caspian region lies in the center of the Paleoarctic zoogeographical realm and is comprised of two major biomes – cold, continental deserts in the north and east, and warmer mixed mountain and highland systems with complex zonation in the south-west and south. There is also a small area around the Volga Delta in the west where the temperate grasslands biome is represented. Caspian living resources reflect the range of climatic conditions that prevail around its perimeter, resulting in a significant degree of biological diversity. This is further enhanced by the existence of extensive wetland systems such as the deltas of the Volga, the Ural and the Kura rivers, and the hyper saline Kara Bogas Gol.

10. The biodiversity of the Caspian aquatic environment is derived from the long history of the existence of the sea and its isolation, allowing ample condition. The number of endemic aquatic taxa, over 400, is very impressive. There are 115 species of fish, of which a number are anadromous and migrate from the Caspian up the rivers to spawn. The best known of these are the seven species and subspecies of sturgeon, which have provided a valuable economic resource for over a century. There is also a Caspian freshwater seal, one of only two species that occur worldwide, with the other one found in Lake Baical.