Organic compounds in snow, ice, and sub-ice waters from the mouth of the Severnaya Dvina River and the Kandalaksha Gulf (White Sea)

The paper reports data on concentrations of organic compounds (organic carbon, lipids; aliphatic hydrocarbons, and polycyclic aromatic hydrocarbons) in snow, ice, and sub-ice waters from the mouth of the Severnaya Dvina River in March 2005-2007 and the Kandalaksha Gulf (Chupa Bay) in March 2004. It was established that organic compounds are accumulated in snow and the upper ice layer near Archangelsk city. Distribution of molecular markers indicates that pollutions were mainly caused by local fallouts. In the Chupa Bay organic compounds are concentrated in the lower ice layer; it is typical for Arctic snow-ice cover. High contents of organic compounds in the snow-ice cover of the White Sea are caused by pollution of air and water during the winter season.

Dinoflagellate cysts analyses from sediment cores of the Po River discharge plume over the last two centuries

To obtain insight into the natural and/or human-induced changes in the trophic state of the distal portion of the Po River discharge plume over the last two centuries, high temporal resolution dinoflagellate cyst records were established at three sites. Cyst production rates appear to reflect the natural variability in the river's discharge, whereas cyst associations reflect the trophic state of the upper waters, which in turn can be related to agricultural development. The increased abundances of Lingulodinium machaerophorum and Stelladinium stellatum found as early as 1890 and 1920 correspond to the beginning of the industrial revolution in Italy and the first chemical production and dispersion of ammonia throughout Europe. After 1955, the increased abundances of these species and of Polykrikos schwartzii, Brigantedinium spp. and Pentapharsodinium dalei correspond to agriculturally induced alterations of the hypertrophic conditions. A slight improvement in water quality can be observed from 1987 onward.

(Table) Content of organic compounds in the bottom sediments of the Volga River estuary

Materials from different spheres of the Earth are ultimately delivered to bottom sediments, which serve as a natural recorder of the functioning of other spheres and originate as a result of the accumulation of their substances. Sedimentary material and species of river-transported elements are subjected to dramatic reworking in marginal filters, where river and sea waters are mixed. These processes are most important for the Caspian Sea, where runoffs of rivers (especially the Volga River) and the intense development and transportation of hydrocarbon fuel by tankers and pipelines (related to the coastal petroleum industry in the Sumgait and Baku ports, Apsheron Peninsula) are potential sources of hydrocarbon pollution. Previously obtained data showed that the total content of hydrocarbon fraction (i.e., the sum of aliphatic hydrocarbons (AHC) and polycyclic aromatic hydrocarbons (PAH)) in bottom sediments varied within 29-1820 µg/g. The content of petroleum hydrocarbons in the northeastern Caspian region varied from 0.052 to 34.09 µg/g with the maximum content in the Tengiz field. The content of six polyarenes in the Volga delta sediments was no more than 40 ng/g. To determine the recent HC pollution of bottom sediments and trends in the functioning of the Volga marginal filter, in summer of 2003 and 2004 we analyzed bottom sediments (58 samples) in the river waterway; Kirovsk channel; Bakhtemir and Ikryanoe branches; tributaries of the Kizan, Chagan, and other rivers; and the Caspian seashore.