Estimation of hydrocarbon accumulation by hydrobionts in the estuary of the Northern Dvina River

Abstract

The article contains the results of the research of the content of a mass fraction of petroleum hydrocarbons in the bottom layer of water as well as in sediment and tissues of bivalves sampled in the estuarial of the Northern Dvina River during 2009–2016 in the seasons of the highest filtration activity of mollusks. Accumulation levels of petroleum hydrocarbons in water, sediments and tissues of bivalves in the Northern Dvina estuary were estimated. Dependence between petroleum hydrocarbons accumulation level in bivalves’ tissues and pollution level of their habitat was studied. Quantitation of petroleum hydrocarbons content in the tissues of bivalves, in the bottom layer of water and sediments was carried out by fluorometric method. It is found that the mass fraction of petroleum hydrocarbons in the tissues of bivalves didn’t exceed the level for relatively clean water in all studied areas of the river. Considering the mass fraction of petroleum hydrocarbons in bottom sediments of the Northern Dvina estuary, it can be attributed mostly to the uncontaminated and slightly contaminated areas, except for local areas of the river within the city limits. In the bottom layer of water in the studied region, the content of the mass fraction of the petroleum hydrocarbons exceeds the state standards in some sampling points. It is concluded that further comprehensive analysis of biotic and abiotic factors is needed to study complex environmental gradients.

Keywords

• estuary
• Northern Dvina River
• mass fraction of petroleum hydrocarbons
• bottom water layer
• sediment
• bivalves