Oil components in the mouth area of the Don R. and in the Sea of Azov: Results of many-year studies

The data given are the results of many-year studying the distribution of the concentrations of main oil components (hydrocarbons, surfactants, and asphaltene-tarry substances) in the water mass, vertically settling particulate matter, and bottom sediment cores taken from the section Lower Don-The Gulf of Taganrog-Russian sector of the Sea of Azov in summer and autumn periods in 2006–2011. Spatial and seasonal regularities in the distributions of the total concentration of oil components and the values of their ratios in water, as well as the spatial and annual features of their accumulation in bottom sediments have been established. Radiological methods have been used for layer-by-layer dating of bottom sediment cores and determine the thickness of the layer that had formed under the maximal anthropogenic impact on ecosystems. The presence of considerable amounts of hydrocarbons of modern biological origin has been revealed in all components of examined aquatic complexes.