Оценка экологического состояния р. Малиновка г. Ижевска по организмам макрозообентоса и содержанию тяжелых металлов в донных отложениях
The assessing of the river Malinovka`s environmental status on macrozoobenthos organisms and heavy metals in the sediments in Izhevsk
The Izhevsk pond is one of the source of drinking water of the city. Since 2003 citizens of Izhevsk feel the unpleasant smell of water from the Izhevsk pond. The reason of this smell is the mass reproduction of cyanobacterium in the pond. So now the environmental statement of the Izhevsk pond is an ecological and social problem. To evaluate and track the dynamics of change of water quality in Izhevsk pond, it is important to know the state of the catchment area and the rivers flowing into the pond. Malinovka River is the right tributary of the Izhevsk reservoir river.
The purpose of the work is to assess the environmental state of the river on organisms of macrozoobenthos and the content of heavy metals in bottom sediments.
The objectives of the research are:
- to assess the content of heavy metals in bottom sediments of the river Malinovka and to compare them with Belgian standards
- to assess the percentage of organic matter in bottom sediments
- to identify the samples of macrozoobenthos and to define the dominant species of benthos
- to define the number and the biomass of benthos
-to implement the bioindication of the river Malinovka with the index of Woodiwiss and the saprobic index
- to assess the environmental state of the river using the results of chemical analysis of bottom sediments and bioindication.
The studies were conducted in June and in August 2015 with standard methods of hydrobiological studies. 5 research stations were founded where 20 samples of macrozoobenthos were selected - 10 qualitative and 10 quantitative and 8 samples of bottom sediments. In the sampling points the following characteristics were measured: flow rate, water temperature, transparency, depth, type of soil. The biomass of individual species of macrozoobenthos was determined by weighing on torsion balance of BT-500. The content of organic matter in the sediments was determined by incineration in a muffle furnace in the laboratory of experimental and theoretical chemistry UdSU. Determination of heavy metals was carried out in the laboratory of "Izhstal". We determinated 4 metals: Mn, Cu, Zn, Ni. In assessing the state of the river bottom communities Malinovka we used Woodiwiss biotic index, and the index Mayer saprobity by Pantle and Buku in Sladecheka modification. In identifying indicator type saprobic index we used atlas of saprobic organisms (1977) and G.H.Scherbina's articles (2010). We calculated Spearman rank correlation (rs) in the program Statistica 6.0 ® for Windows to analyze the data rates. Pre-processing of the data and descriptive statistics were calculated in Microsoft EXCEL 2010 spreadsheet application.
- The results of chemical analysis showed that Belgian standards of copper and nickel are exceeded.
- In august the percentage of organic matter in bottom sediments was less than in June. The content of organic matter increased from springhead to estuary
- During the research we found there 88 species and taxons of macrozoobenthos from 44 families, 14 orders, 6 classes, 3 types.
- The dominant groups of benthos were diptera and gastropods.
- The number of species, the total number and the average biomass of benthos increase from springhead to estuary.
- The biotic index of Woodiwiss showed that the river Malinovka is moderately polluted. According to the saprobic index the river belonged to the third class of water, it is b-mezosaprobic zone.
- Chemical analysis and biotic indexes showed that Malinovka is moderately polluted and belonged to the third class of water, it is β-mezosaprobic zone. This class of water can be used for drinking supply after the purification and for fishfarming and irrigation.