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Fig.: Distribution of Polycyclic Aromatic Hydrocarbons (PAHs total, ng/g) in the bottom sediments of Northern and Medium Caspian in April-May 2009.
The Caspian Sea is particularly sensitive to pollution from land-based sources, oil spills, untreated sewage, etc.

Regular monitoring of its environmental state is important to make a sound marine policy and ensure a sustainable development.

In the spring time 2009 two expeditions aboard RV “Neptun” (17-29 April) and RV “Tantal” (22-30 May) were conducted in the shallow estuarine part of the Delta Volga in the Northern part of the Caspian Sea and around Dagestan coasts as well as in the deep region of the Medium Caspian.

The over aim was to study the actual pollution of the water column and bottom sediments. Focus was on a wide spectrum of anthropogenic pollutants.

Twenty individual Polycyclic Aromatic Hydrocarbons (PAHs) was analyzed in the bottom sediments. Total concentration of PAHs in the studied areas was strongly patchy distributed (Figure on right side).

Their concentration varied in wide range from the analytical zero to the 160.86 ng/g. The maximums were recorded close near the twon of Isberbash (160.86 ng/g) and the estuarine region of the river
Samur (129.84 ng/g). In the bottom sediments of
those areas the small dispersion fraction was prevalent
and a very high level of organic matter was observed.

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Fig.: Seasonal and interannual variability at three specific sites

Apart from the shore the concentration of PAHs was rather low except the deepest station at 122 m with large part of small muddy particles (53.50 ng/g). In general even the maximums not exceeds the Permitting Level of 1000 ng/g according the Neue Niederlandische Liste, Altlasten Spektrum 3/95.