Access to hydrocarbon resources has caused disputes between five Caspian littoral countries. Unequal transmittance of hydrocarbon resources increases the difference of the opinions about these oil areas. There are some conflicts on how to use the sea in a better manner. The Caspian Sea is important not only for the oil and gas but also for the materials such as coal, afferent, iron, chromium, titan, asbestos, and other minerals. These in turn would cause the concentration of many of the world trades (Simonett, 2006). Natural conditions in the Caspian Sea (except the South and West Coast) seem to be undesirable. Dry climate coupled with

high thermal changes in the summer and winter, very severe winter storm,s and lack of drinkable water make the survival of human life so problematic. Each activity has its own particular effect so that the environment is basically vulnerable to these effects. The exploitation of oil reserves or defects of the related installations has contaminated the surface and underground water. Sturgeon is regarded as a source of caviar and hence needs a healthy environment, while the Caspian environment has severe conditions with large water management projects such as irrigation, construction of dams for power plan electricity, exploitation of oil and gas areas, and sea transportation of oil by heavy tankers. The littoral states and the international community have to be deeply worried with regard to the destruction of the Caspian Sea. The international communities have to be always committed to the many issues and concerns faced in the Caspian area.

Ecosystem and environment of the Caspian sea

The Caspian Sea is the largest enclosed water body in the world and it is located on the border of Asia and Europe. The biological resources of the Caspian Sea include 800 species of fauna and 500 species of flora. Due to the presence of a very precious kind of fish called ‘sturgeon’, preserving the water quality in the Caspian Sea is of critical importance. Sturgeons of Caspian produce expensive high-quality caviar. There are three dominant sturgeon species in the Caspian Sea, namely; the Stellate, Beluga, and the Russian sturgeon. In the mid-1990s oil and Gas brought an influx of foreign investment in

energy development in the region. Oil and gas extraction, along with transportation and industrial production has been the source of soil, air, and water pollution in the Caspian region. There is no doubt that the development of the oil and gas industry does have significant impacts on the environment. The chemicals and pesticides are threats to the flora and fauna. Since 2000 due to pollution thousands of seals died in the Caspian Sea., the pollution has weakened their immune systems. The Caspian is an ecosystem under stress. Existing pollution has damaged marine terrestrial communities. The overfishing of Sturgeon has caused a dramatic decline in fish stocks., the number of commercial fish has considerably been reduced. Some fish species have been included in the red book (Simonett, 2006). Weak environmental laws and regulations and the ability to enforce them are affecting efforts to protect the Caspian’s environment. Without increasing cooperation by the littoral countries, the country of the environment in the Caspian Sea and surrounding areas will remain threatened.

The Caspian Sea and its catchment

The coastal plain is also a transit area for freshwater organisms. It usually consists of terrestrial, partly also from Caspianlimnic sediments predominantly Quaternary age. Rivers from the north reaching the Caspian sea is provided about 85 percent of river discharge, While the rivers leading to the southern Caspian Sea provided 60 percent of river sediment load into the Caspian Sea. Due to the passage of the river basin, South Caspian slope of the mountains filled with low vegetation, sedimentation rate of those rivers is denser. Hallmarks of most Caspian tributaries in Iran is a short, straightforward, and deeply incised course between source and mouth. The flow behavior of all the southern Caspian tributaries is characterized by a strong year-round water supply. The sea has 130 large and small tributaries mostly flowing from the northern and western coast. More than 90% of freshwater flowing into the Sea is provided by five large rivers in the region, that is, Volga, Kura, Terek, Ural, and Sulak. Iran is on the beach Sepidrud river that with an Average 4 Km3 discharge per year is one of the biggest rivers in the North of Iran. The general landscape ecology of the south Caspian lowlands under special consideration of ornithology was a newer representation of the Anzali wetland.

Climate conditions

Caspian Sea has a variety of weather conditions. It is surrounded by Volga river and Ural rivers in the North, dry and semi-dry plains of Kazakhstan and Turkmenistan in the East and Alborz mountains, and humid regions of the Caucasus in the South and the West. Climatic phenomena of the Caspian are linked to fluctuations of the North Atlantic (atmospheric air pressure fluctuations). Caspian Sea water’s mass mainly flows through the West Bank from north to south to Peninsula Abshuran and it is divided into two branches. One of them flows along with the West Bank and the other joins to the flow moving from south Caspian toward the north.

Chmical and biological pollutions

The sources of Caspian Sea pollution consist of water level rise, land-based sources, drilling in the sea bed, pollution in relation to ships activities, atmospheric and biological contamination (Simonett, 2006 Rodman1996). All these problems threaten the Caspian ecosystem. 

Ecological changes

Caspian Sea water level has been swing in the middle of geology and trough the centuries. Between 1880 and 1977, water level decreased up to 4 m and became 29 m below the free seas level (Simonett, 2006). During 1900 to 1929, sea level was relatively stable and its maximum value was between 25.6 and 26.6 m below the ocean level in 1929. The area of the Caspian Sea was 422000 km2 in that year. From 1929 to 1977, the water level of the Caspian Sea has decreased by 2 m. Decreasing water level in that period displaced coastal line 180 km because of low water level in eastern and northern coasts. Problems of the Soviet Union caused some actions to prevent the reduction of water level:

1) Diverting water of rivers dropping to the Arctic Ocean to the south-Caspian Sea.

2) Closing water input path to KaraBogaz-Gol-Gulf with 12000 km2 area whose water level is 4-5 m below the surface of Caspian Sea. This gulf is next to the Kara-Bogaz-Gol-Gulf desert and is connected to the Caspian Sea by a narrow strait and its evaporation rate is very high.

. Approximately 10-12 m3 of water drops to this gulf from the Caspian Sea each year and most of them evaporate. A dam was constructed in 1980 between the Caspian Sea and the entrance of the gulf.

The aim of construction was to alleviate the negative effects of water flowing from the Caspian Sea to this gulf because this increased 2-3 cm per year of the water level of the sea. After daming Kara-Bogaz-Gol-Gulf Straits, the activity of the Gulf as a natural hydraulic system for keeping low salt amounts was stopped. This increased the salt in the southern part of the Caspian, equal to 15 g/l, and resulted in a catastrophic consequence for the population of beluga. The dam was opened in 1984 for the same reason and in spring 1992, Turkmenistan destroyed the dam due to the dimensions of the disaster. On the basis of this, the relationship between the sea and the Gulf was established again. Until 1970, scientists were concerned about reducing the level of the Caspian Sea whereas the water surface was 29 m below sea level in 1977. Caspian Sea water level started rising mysteriously and this caused many problems in 1988. The sea level increased about 2.5 m and this process is now continuing with a warning speed of approximately 15 cm annually. Simultaneously, the water rise of the Caspian Sea has led to huge amounts of mud smeary oil and chemicals washed and are drawn toward the most sensitive parts of the sea.

It is estimated that annual rainfall accounts for 130 km3 of seawater. Reducing of water through penetration into the ground is less than 5 km3 and the amount of waters that flow into the KaraBogaz-Gol-Gulfis are about 18 km3 since the destruction of the dam. It is estimated that 350-375 km3 of seawater reduces due to evaporation each year. Total water input is estimated at something like 440 km3, and wasted water is estimated at 373 km3. So the water level of the Caspian Sea should have an increase trend now.

Biological damage

The biodiversity of the flora and fauna of the Caspian sea is unique on Earth. The approximate number of plant and animal species native to the Caspian Sea, The fauna and flora of

the Caspian have been seriously threatened by increasing the Caspian oil trade. Among fish species, 3 of them are under extreme extinction: Fringebarbel sturgeon (Acipenser nudiventris), Caspian salmon (Salmo trutta caspius), Caspian Barbel (Barbus brachycephalic caspius) (Alizade, 2004). Jellyfish (Mnemiopsis leidyi) is an eager consumer of zooplankton. This species is an invasion in the Caspian Sea and belongs to the Ctenophora phylum. The fish larva appeared in the second decade of the 90th year. It adopted well with the Caspian Sea ecosystem (in terms of salinity, temperature, and range of foods) and reproduces faster than native species. Because the available food is shared with native species, they have caused a severe impact on the native population and changed the entire food chain. . Commercial fishing industry including; anchovy / kilka (Clupeonella grimmi), sturgeon for instance Acipenser

brevirostrum , Acipenser sturio , Husu husu and Caspian seals (Phoca caspica) and other valuable species are seriously impacted by the jellyfish. . This comb jellyfish has been seen at the coast of Azerbaijan, Turkmenistan and Russia in a large individual in 2001. In a short period, Clupeonella grimmi supply has sharply decreased in the given areas. Studies show that between the years 1998- In a short period, Clupeonella grimmi supply has sharply decreased in the given areas. Studies show that between the years 1998- 2000, fishing Clupeonella grimmi by Iranian fishermen have reduced by almost 50% and this made a washout at least equal to $ 20 million per year (Simonett. 2006). Caspian Environment Program gave a high priority to combating this organism.

Caviar production was about 360 tons between 1984 and 1985 in Iran, but it reached about 44 tons in 2004. 

In addition to chemical and biological pollutions, the negative impact of water changes, lack of legal regime, excessive illegal hunting, and non-principle-oriented exploitation, led to diminishing fish supplies of the Caspian Sea.

The Caspian Sea has always played a significant role in relation to the life of human societies. Environmental pollutions of the Caspian Sea not only have a negative impact on the sea but also influence the population of all neighboring countries. Protection of this valuable Sea has a direct connection with the security and national stability of the coastal countries. Conflicts and disputes in the current management of natural resources of the coastal countries can make the deeper gap and hence leading to hostility among them in the near future.

By Sanjida Jannat