Water quality of the Yenisei River based on hydrochemical and bioindicative parameters
A.V. ANDRIANOVA1, T.P. SPITSINA2, A.V. KHILYUK2
1Institute of Computational Modeling, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, Russia
2Reshetnev Siberian State University of Science and Technology, Krasnoyarsk, Russia
Keywords: pollutants, zoobenthos, bioindication, spatial dynamics, specific combinatorial water pollution index, river regulation
Abstract
The article presents the results of a comprehensive assessment of the ecological state of waters of the Yenisei River along the entire length, obtained using chemical and biological methods. Materials from Roshydromet, regional State reports on the state and protection of the environment, and the results of our own field research were used as the initial data. It was revealed that persistent pollutants in the Yenisei River include metals (ions of total iron, copper, aluminum, manganese, and zinc), petroleum products, phenols, and organic substances. The upper section of the Yenisei River is rich in biogenic elements; after the confluence with the Angara River, their concentrations significantly decrease due to both dilution and biological processes. However, while the content of organic and biogenic substances decreases, the concentrations of copper, zinc, and petroleum products increase from the middle reaches to the mouth of the river. According to the specific combinatorial water pollution index, the Yenisei water corresponds to categories ranging from “slightly polluted” (class 2) to “dirty” (class 4a). A steady trend of increasing pollution from the headwaters to the mouth of the river is observed. Communities of benthic animals, whose development in the Yenisei is not limited by high-velocity conditions, as compared to planktonic organisms, were used as bioindicators. All bioindicative parameters (13 indices and metrics) consistently demonstrated a trend of water quality deterioration from the headwaters to the lower reaches of the Yenisei, supporting the hydrochemical methods. After the confluence with the Angara River, due to a decrease in the concentrations of organic and biogenic substances, an improvement in water quality was noted according to a number of indices taking into account organisms sensitive to pollution. The reason for the water quality deterioration relative to natural conditions is the reduced self-purification capacity of the watercourse after the cascades of hydroelectric power plants and the high level of pollution from waste water of large cities. Biogenic elements and organic substance accumulate in the reservoir beds. The ecological water quality of the Yenisei River is influenced by both anthropogenic and natural factors, particularly by heterogeneous hydrological conditions and a network of large right tributaries.
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