Geology, geography and global energy

Scientific and Technical Journal

About content and genesis of hydrocarbons in the Caspian Sea

2014. №4, pp. 43-51

Karygina Natalya V. - Senior Researcher, Federal State Unitary Enterprise Caspian Fisheries Research Institute, 1 Savushkin st., Astrakhan, 414056, Russian Federation, kaspiy-info@mail.ru

The article presents potential danger for the ecosystem of the Caspian Sea, which connected with possible hit to marine environment by petrochemical products in the result of intensification of oil and gas fields on its shelf. Uncovered in the waters and bed silt of the Caspian Sea hydrocarbons can have both natural and anthropogenic origin. The optimal method of research, combining fluorescence and gas chromatography has been applied to assess the extent of oil pollution of the Caspian ecosystem components and detection of hydrocarbon Genesis. It is established that the concentration of the hydrocarbons in the waters of different parts of the Caspian Sea was changeable and highly variable. The highest rates were characteristic of the water area of the Middle and southern Caspian, the extreme values over lethal concentration of oil products to aquatic organisms met in these parts of the sea, respectively, in 13,7 and 10,8 % of cases. The oil pollution of bottom sediments was the most expressed in the Northern Caspian where the maximum values of toxicants were stably high. On the main oil markers as part of alkanes were highlighted several areas with a similar distribution of hydrocarbons. The dominance of boiling compounds with maximum peaks chromatograms on C -C pointed to the autochthonous origin of hydrocarbons in North-Western and Eastern parts of the sea. The prevalence of high molecular alkanes with maxima on C -C and a significant number of naphtheno-aromatic compounds testified about technogenic of hydrocarbons, which were founded in the border zone between the Northern and Middle Caspian sea, and also in the area of Derbent depression. Mixed Genesis was characteristic hydrocarbon the South-Eastern part of the Middle Caspian Sea, where a significant role in their synthesis played bacteria. Hydrocarbons contaminated bottom sediments of the Northern part of the sea basically had a dual nature of origin - biogenous and terrigenous. In the grounds of the Dagestan coast in the composition of alkanes were registered dominance even high-boiling homologues, having apparently anthropogenic Genesis.

Key words: углеводороды, содержание, состав, нефтяное загрязнение, поверхностные воды, донные отложения, алканы, маркеры, автохтонный, техногенный, hydrocarbons, content, composition, oil pollution, superficial water, bed silt, alkanes, markers, autochthonous, anthr

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