No abstract

The results of microbiological monitoring of the rivers with the various nature and intensity of anthropogenic load in the Middle Ob basin carried out from 2002 to 2019 is presented. The programme of monitoring included following parameters: the number of bacteria of 5 ecological-trophic groups, gram-staining and morphology of isolated bacteria study, testing of bacterial resistance to antibiotics and phenols. Also coefficients of mineralization and Water quality indexes were calculated. On the base of calculated values, the self-purification potential of the rivers was estimated. Studied rivers were categorized into 5 classes of water quality. In the most rivers on unpolluted and urban area G+ and coccus forms of bacteria were predominant in the microbial community. In the rivers within oilfields the proportion of G– and rod-shaped bacteria was increased considerably. Seasonal and spatial distribution of resistant bacteria over the rivers allows to apply them as markers of the nature and intensity of the anthropogenic load.

The Middle Ob is the part of the Ob river reach running through the central part of Western Siberia within Khanty-Mansi Autonomous Okrug, and brings its waters through the territory of Yamalo-Nenets Autonomous Okrug to the Gulf of Ob of the Arctic Ocean. The data on hydrochemical characteristics of the Middle Ob river and its anabranches during 2003-2008 and 2014-2018 in aspects of transboundary transfer is presented in the article. Composition of salt, organic compounds, heavy metals, petroleum hydrocarbons, biogenic ions in water and bottom sediments are described. The influence of oilfields and urban territories in water catchment area of the Middle Priobie is revealed. The main pollutants of the Middle Ob river are phenols, hydrocarbons, iron, manganese, chrome, cooper, phosphate-ions from technogenic and natural originating. We investigated that the level of the Middle Ob river water pollution was increased from 2003-2008 till 2014-2018.

This article is part of the special series "Environmental Monitoring on Global and Local Scales." The series documents cases of the current state of environmental assessment and tracking using different approaches: in situ monitoring, geoinformation modeling, and risk-based assessment. The work was originally presented at the conference "Ecological Monitoring: Methods and Approaches," held September 2021 in Krasnoyarsk, Russia, and co-organized with the European and Russian-Language Branches of Society of Environmental Toxicology and Chemistry.

Assessing the quality of environmental objects, identifying the causes of pollution and predicting the future state is an urgent and important task, since it is the quality of natural objects that largely determines the state of human health. This paper presents results of the statistical analysis of the data of water quality monitoring in the rivers within oil fields of the Khanty-Mansi Autonomous Okrug Yugra during 20182019. The correlation analysis (according to Pearson) was carried out to identify the relationships between the samples of hydrochemical parameters and the number of microorganisms of various ecological-trophic groups. As a result of the correlation analysis of the relationship between the indicators of the chemical composition of water, a direct and inverse correlation was obtained for the following indicators: total iron, anionic surfactants, nickel, phenols, copper, sulfates, ammonium ions, lead, phosphates, manganese. The maximum value of the correlation coefficient is observed for Ni and Cr concentrations. For total iron and manganese, a significant positive correlation is also revealed. The distribution of chemical compounds in the rivers doesnt have a pronounced correlation dependence, which is probably due to the heterogeneity of the composition of the waters, as well as to the increasing impact on the environment of the oil and gas complex.