Caspian Sea is situated on the junction of two continents – Europe and Asia. It contains 44 % of the total water volume of all lakes and land-locked seas in the world.

Caspian Shelf is a vast inhabitation place for tremendous number of flora and fauna species, including rare species inserted in Red Books of literal states.

Stemmed from segregation of Caspian Sea from World Ocean, it has high level of endemic. Major groups of organisms of the earth are broadly represented in the sea and its coasts. Sturgeons, the most ancient phylogenetic group, are represented by five species and two sub-species (more than anywhere in the world). It makes more than 85% of existing world sturgeon stocks. Fish resources of the Caspian Sea have enormous economic value at a market.

Caspian Sea possesses unique variety of dwelling places. They are represented by vast river systems and mouths with their rich dewy plains, huge areas covered by reeds, vast shallow waters, waters with salinity variations, from fresh to brine water in Gara-Bogaz-Gola.

On-land biota species include salt-endurable desert plants, enormous population of coastal birds and few on-land mammals. Migratory types of fishes adapted to wide range of environmental conditions live in the sea. There is a great variety of birds and their population is very big. Some of the species are classified as rare and endangered birds.

The Caspian Sea is the biggest land-locked reservoir on our planet. It occupies territory of about 380 thousands sq.km. The length of Caspian Sea from the north to the south is 1030 km, from the west to the east ranges from 196 km to 435 km. Meridian direction of the sea defines variety of climatic conditions, coastal landscapes and biological species. There is a change from acutely continental desert climate in the north-eastern part till subtropical climate to the south-west.

The depth of Caspian Sea varies from 1025 m., in the deepest southern part of the sea, till average depth of 4.4 m. in the eastern part of the northern part of Caspian Sea. The northern part of Caspian Sea is shallow watered shelf zone, where the main part of fresh flows outlet. That stipulates its high biological productivity.

Coastal line in the northern part of the sea is tortuous, and in the remaining part of the sea is comparably steady. Eastern coast of the Northern Caspian Sea has small inclination. It has dewatering zones formed under effect of wind tides and wave movements and high dynamic of coastal line caused by sea level fluctuation.

In connection with insulation of Caspian Sea from World Ocean, it formed conditions for evolvement and existence of endemic forms of fauna and flora. Vegetation of only Caspian plain is represented by 945 species belonging to 371 types and 88 families. 357 species of high plants belonging to 185 types and 35 families relates directly to coastal flora.

Migratory flows of flora formed in Caspian nether lands allochthonous flora framework. Younger indigenous flora core consists of caspian and aral-caspian species, such as Suaeda salsa, S. Kossinskyi, Corispermum laxiforum, C.aralo-caspicum. Endemics of Kazakhstan are represented by 25 species (7%), 6 types are included in Red Books of Kazakhstan and CIS countries.

There are 64 species of sediment algae in Caspian Sea, out of which 12 were brought from Black Sea, after opening of Volga-Don channel.

Phytoplankton of Caspian Sea is represented by 449 species and sub-species. Out of which 414 forms exist in the northern part of Caspian Sea, 225 in the middle part and 71 in southern part. Most numerous of them are blue-green (102), diatomic (163) and green (139) algae.

Species content of animal plankton of Caspian Sea is comparably poor, but origin of species varies. Here, there are arctic, Mediterranean and endemic species. In total, about 100 species of animal plankton are described, among which 61 is mainly fresh water inhabitants, 20- sea, 5 – euryhalinic and 9 with unidentified ecology. Out of these species, approximately 35 belong to Rotiferas, 32 to , 18 to , 9 to Mysydacea, 6 species are ichthyoplanktons.

379 species of benthic organisms live in Caspian Sea. They pertain to 4 fauna complexes: 1 - indigenous caspian complex (310 species), mainly remaining of tertiary fauna, which perceived change of hydrological regime of the sea; 2 – mediterranean-atlantic complex (29 species): species which have been brought to Caspian Sea at different time; 3 - fresh water complex (31): species which comparably recently have been brought into Caspian Sea by rivers flowing into it; 4 – arctic complex (9 species).

Caspian Sea is characterized by the fact that, in comparison with regions having access to World Ocean, is has small number of fish species living in it: only 76 species and 17 families. Mostly they are carps (33%), gobies (28%), northern caspian (14%). Many species are indigenous including several representatives of mediterranean complex. We can identify 4 main groups of fishes:

Sea fishes. These fishes spend all their life cycle in the sea. This group consists of sprats, caspian shad and some types of gobies.

Anadromous fishes. These fishes live in the sea until their sexually mature, and for breeding, they migrate upstream the rivers to spawning places. Lamprey, salmon, sturgeons (except sterlets), black-backed shad, black sea roach and others.

Half-migratory fishes (living in sea water, spawning in fresh water). Flattering of these fishes occurs in fresh water of Caspian Sea and they spawn during floods in river basins. This group includes Caspian bream, roaches, carps, zander and others.

River and coastal species. These fishes live their entire life cycle in fresh water of nether river streams, mouths and adjoin coastal areas of the sea. This group includes carp, perch, red-eye and others. Out of all species living in Caspian Sea 40 have commercial importance.

Caspian Sea is an important spot of seasonal migration, molting and wintering of birds coming from almost all parts of former USSR and adjacent regions. About 10-12 millions of water-fowl individuals find interim asylum in the Caspian region on the way of their annual migrations. Approximately 3-3.5 millions birds spend winter in Caspian region. That makes 50% of all birds wintering on the territory of former USSR.

Major risk factors of biodiversity of Caspian region are:

• Sea level rise and the human activities responding on sea level rise
• Regulation of water discharge and water consumption
• Pollution of air, rivers, ground water and sea
• Intensive fish catch
• Eutrophication of the sea
• Biological settlement
• Desertification of coastal zones
• Anthropogenic impact on coastal ecosystems

Sea level rise has positive and negative aspects. From one hand it leads to increment of fresh water area of the sea, broaden the area of fattening for fishes, biological productivity of the reservoir also increases. The shallow water area also increases, which potentially might become inhabitation place for migratory and nestling birds. From another hand, sea level rise causes increase of water depths. At the same time, the square occupied by surface high level marine vegetation is reduced, which, in course of quick level rise, can not timely move towards see shore following water level rise. That leads to decline of the areas suitable for waterfowls nestling and deteriorates their living conditions. Creation of artificial structures, restricting sea submersions (dams, etc.) decrease the area of shallow water auspicious for inhabitation of waterfowls, what also adversely affects on their population.

Serious threat to biodiversity is regulation of river water outlet. Construction of Volga cascade of hydro power stations exacerbated path to traditional spawning place of sturgeons, inconnu, migratory herring, what jeopardized their existence. Similar effect is also observed in regulation of other rivers of Caspian basin. Being valuable commercial specie, Caspian salmon became rare specie.

Regulation of river outlet led to alteration of reviver hydrography, changed flood term, what negatively influenced reproduction of half-migratory fishes.

Water, air soil pollution is a particular danger. In 80s, stemming from sea pollution growth, mass morbidity of sturgeons occurred, dubbed cumulative polytoxicosis. It evolved in form of exfoliation of mussels tissues and disruption of the structure of caviar shell. At the same time, increased content of heavy metals and pesticides was observed in different sturgeon organs. Some, particularly contaminated areas became unsuitable for inhabitation of fishes and other aquatic life.

In conjunction with economic recess in 90s, the level of pollution of Caspian Sea and rivers flowing in it began to decrease. However, in connection with sea level rise, conserved oil wells and coastal oil fields began to get submerged, what have created potential possibility of sea pollution and threatens to biodiversity.

There is a separate problem of irrational utilization of biological resources of the sea. Primarily that affected on sturgeons population – most valuable fish specie in Caspian basin. Their mass illegal catch by poachers, which according to estimates exceeds sturgeon catch limits for more than 3 times, brought this one of the ancient fish specie under the threat of extinction. Even catch with permits, under condition of lack of rigorous control does not assure compliance of reporting data to actual.

In the condition of water volume growth of Volga and Ural rivers, observed increased discharge in the sea of biogenic elements and organic substances carried by rivers outlets and also their ingestion from flooded shores, led to increase of eutrophication of coastal waters. In the south-western part of Northern Caspian Sea, during summer, large zone of hypoxia appears, low oxygen content in sediment water layers makes them of little use for inhabitation of fishes during this season of a year. Local zones of eutrophication are observed in many coastal areas.

Unauthorized release of biological objects in the Caspian Sea is a serious threat to conservation of biodiversity. Most probably they are carried by vessels entering to the Caspian Sea via Volga-Don channel from Black Sea or through Belomor-Baltic systems of channels from northern seas. They may occupy somebody else trophic niche, displacing its indigenous inhabitants.

Another threat is desertification of coastal territories. It happens because of many causes, connected with natural factors (climate change, droughts, frosts, sea level rise and consequently laying level of ground water) as well as anthropogenic factors (irrational nature utilization, extensive livestock pasture, pastures clogging, wood stock, uprooting of bushes, phytoamelioration, intensive of dry agriculture, regulation of river discharges, industrial and livestock pollution of territories, urbanization). Their consequences are soil contamination with oil, malfunctioning and unpredictability of the directions of formation of vegetation and top-soil, destruction of the environment of temporary asylum on the migration paths of birds and animals, soil erosion, secondary soil pickling, malfunctioning of flood-lands regime of soil and vegetation in deltas and water meadow of the rivers.

Under effect of human activity, destabilization of traditional nestling places and migration of many species of birds is ongoing, e.g. yellow Egyptian squacco, small white heron, brand geese and white forehead geese. Decrease of natural habitats and population density are observed. Near the borders of oil fields in the north-eastern part of Caspian Sea birds are observed 10 times less than in natural desert landscapes. As a result of mosaic human settlements, the integrity of nestling and forage areas breaks.

Possible causes of adverse impact on biodiversity are linked both with local factors and transboundary processes. Transboundary factors are pollution transfer, regulation of river outlets and irrational nature utilization.

From another hand, there is local impact on transboundary species of biota – fishes, birds, aquatic and land animals. Intervention into their inhabitation places, their poach extraction in huge volumes exceeding few times officially approved level, deterioration of conditions of inhabiting places lead to decline of total population and disappearance of some species.

Among many other problems of biodiversity preservation, priority transboundary and transnational problem is a problem of preservation of sturgeon as specie, preservation of inhabitation places of migratory and nestling birds, combating with desertification of coastal areas, prevention of contamination of Caspian Sea.

Priority issues on biodiversity preservation involve the whole set of problems.

First issue is intervention of entire biotic complex of Caspian Sea and coastal territories. Data available at the present time are unsystematic and describe separate areas of the sea with different comprehensiveness. It is necessary to determine all rare or endangered species of biota, supplement Red Books of some literal states. It is necessary to determine trends of ongoing biodiversity changes caused by effect of natural and anthropogenic factors. There is an acute need to detect all local and regional risk factors for biota and its inhabitation places.

Development of special measures aimed at sturgeons preservation is needed, including reduction of poaching activity, artificial reproduction and amelioration of spawning spots. It is necessary to undertake efforts for rehabilitation of population of valuable in the past, commercial fish species of caspian salmon and herring.

Rational water consumption and water discharge systems outgoing from water reservoirs consistent with natural river hydrography play an important role for provision with favorable environmental conditions for fishes spawning and birds nestling in deltas of the rivers.

It is essential to develop legal framework, defining priorities of water resources utilization for the sake of biodiversity preservation.

Existing protected territories play an important role in conservation of biodiversity on Caspian Sea. It is necessary to define the status of existing protected areas and inhabits, especially of those which have transboundary importance, consider need for increase of status of existing territories and creation of new territories.

For preservation of species variety of flora and fauna living in coastal areas, it is required to develop special programs for integrated management of coastal areas which will minimize anthropogenic destruction of inhabits, malfunctioning of soil, desertification of territories.

One of the factor facilitating biodiversity preservation is improvement of environmental education and propaganda in Caspian region, creation of inhabitants feel of responsibility for nature conservation.

Significant circumstance for biodiversity preservation is social and economic conditions. Their improvement will allow to develop alternative types of production and technologies enabling reduction of anthropological load on adjacent territories, more rational utilization of aquatic and coastal bioresources. At the same time, there should be developed and put into force economic impact levers aimed at reduction of pollution, rational nature utilization, encouragement of application of “clean technologies”. It is necessary to develop legal framework and standards which would be common for all riparian states, harmonization of existing legal acts with Convention on Biological Diversity, basic national law on nature protection.