Features of the formation of zooplankton of the upper Ob in the conditions of the influence of the megapolis

Journal: Рыбоводство и рыбное хозяйство №8 2021, №8, 2021 Based on the data obtained in the study of some hydrobiological sections of the Ob River, located above and below the city. The qualitative and quantitative characteristics of the zooplankton community were considered, and the saprobity index was calculated. The species composition is represented by 34 species from three systematic groups, of which 12 are rotifers (Rotifera), 14 are branchial crustaceans (Cladocera), and 10 are copepods (Copepoda). The highest species diversity was observed above the city — 34 taxa, the lowest below the city — 14. The average number of zooplankton above the city of Novosibirsk is insignificant and reached 761 copies/m³ per year. Most (49%) were copepods (Copepoda). The number of rotifers (Rotifera) was 34% of the total. In the summer, the number of zooplankton was slightly higher than the annual one and amounted to 871 copies/m³. The average annual biomass of zooplankton had low values and was 35.0 mg/m³. The maximum summer values reached 180 mg/m³. In the study area of the Ob River below Novosibirsk, the average number of zooplankton increases to 2,4 thousand copies/m³. The group of oar-footed crustaceans dominated in number, its share reached 91%. The number of branchiform crustaceans was 7%. The average annual zooplankton biomass in the river below the city limits was 99.53 mg/m³. The value of the saprobity index in the area above Novosibirsk was 1.6, which indicates the presence of weak organic contamination and corresponds to beta-mesosaprobic conditions. In the zone below Novosibirsk, the saprobity index was 2.0, which indicates an increase in organic pollution and corresponds to beta-mesosaprobic conditions. An increase in the level of eutrophication contributes to a change in the structure of zooplankton. This is reflected in a significant decrease (2.4 times) in the species diversity of zooplankton and a significant increase in quantitative indicators: abundance — 3.2 times, biomass — 2.8 times.

BIOINDICATIVE, ECOLOGICAL AND ANALYTICAL SPECIFICATIONS OF MINOR STREAMS UNDER THE INFLUENCE OF HAZARDOUS MAN-MADE OBJECTS

Water bodies are the most vulnerable mean in terms of human-made impact, and the collection of monitoring information on the state of biota and the hydrochemical regime is mandatory per the recommendations of the Water Framework Convention. The paper deals with the necessary arrangements for integrated monitoring and analysis of hydrobiological and environmental analytical databases for prognostic and remediation purposes at water observation points affected by human-made chemically hazardous technogenic object (chemical weapons). The purpose of this paper was to present data of hydrobiological and hydrochemical monitoring of rivers in the area of hazardous human-made objects (chemical weapons) as recommended by the Water Framework Convention for a comparative description of the reactions of European aquatic biota to stress effects. The use of hydrobiological indices and indices of biological diversity to record the anthropogenic impact on water has been validated. The features of environmental analytical data for additional analysis of monitoring specifications dynamics have been identified. The scale parameters of hydrobiological monitoring with the calculation of α-diversity, Shannon index, saprobity index should be based on a complete examination of aquatic and semi-aquatic vegetation and flora. The analysis of the anthropogenic impact of a chemically hazardous human-made object in the Bryansk region (Russian Federation) on aquatic ecosystems over a long period of time using bioindication method (which consists in the assessment of species diversity, calculation of the Shannon index and water saprobity index) revealed that the technogenic component of the impact of reference points on watercourses is minimal.

Biological method in monitoring small rivers of the Oka River basin

The Oka basin is characterized by serious environmental problems associated with the depletion of water resources. Communities of aquatic organisms are the first to respond to negative changes in the aquatic environment, such communities are used as indicators in biological monitoring. The aim of the work was to assess the ecological state of the small river of the Oka basin by bioindication. The quality of the water in the reservoir was assessed by chemical indicators - biogenic and technogenic elements. The saprobity index of the reservoir was determined by the species diversity of periphyton. The results revealed technogenic and organic pollution of the small river. According to the results of biological monitoring, the value of the saprobity index is 2.85, which corresponds to class 4 of the reservoir quality, and the water is assessed as polluted. Monitoring the degree of pollution of the small river by the biodiversity of the periphyton community allows you to determine the degree of water pollution quickly.

To the question of the relationship between the diversity index and the saprobity index in algae and invertebrates

A description is given of the process of creating an empirical model of the functioning of aquatic ecosystems, its indicators, and the limits of the parameters related to progressive succession stages when considering the effects of pollution. In addition to the previously used data for autotrophs, the parameters of the diversity of consumers are included in the model. The overestimation of impact assessments based on the second trophic level is discussed. Based on the data of the private allotment of water bodies of Ukraine, a conclusion is drawn on the conformity of estimates regardless of the geographical location of water bodies and on the suitability of interpretations for water ecosystems of a wide ecological spectrum.

Assessment of watercourses of Astrakhan by hydrobiological and microbiological indicators

The paper focuses upon the control over environmental pollution of water bodies by human waste products in urban areas, which can be carried out by monitoring hydrobiological indi-cators. In the course of study undertaken in May 2017 and 2018 there was assessed the ecological and sanitary status of the Volga and Kutum rivers that flow on the territory of Astrakhan. Samples were taken at four stations; the choice of station location was determined by the presence of pollutant sources: proximity of the city market or the power plant. Quantitative and qualitative indicators of the state of phytoplankton were used as hydrobiological indicators; the total number of bacteria and the total content of coliform bacteria were evaluated as microbiological indicators. During the study period the ecological and sanitary state of water was rated as satisfactory. The number of algae taxa increased insignificantly (by 3 units), diatoms predominated in the number of genera and number. Despite the presence of 4-5 species of pure water representatives in the investigated waters, the sanitary and bacteriological situation at all the studied stations was found unfavorable; the water was characterized as polluted and dirty. In 2018, there was registered deterioration of water quality compared to 2017, while the calculated saprobity index in the Kutum river indicates the water quality improvement downstream. The increasing value of the water saprobity index in the Kutum river indicates a tendency toward the growing level of organic pollution and necessitates a comprehensive analysis of hydrobiological indicators for systematic monitoring the aquatic environment.

Reliability estimation of reconstructions on the basis of bioindication methods unification (diatom analysis)

The work is devoted to the unification of bioindication techniques based on diatom analysis. A new method for calculating the numerical values of pH and temperature in time was proposed. The calculation of the saprobity index (S) is used as a methodological principle of unification. Approbation of the method was carried out for lakes from different landscape and climatic zones of the European part of Russia and the results of paleoreconstructions were found to be reliable and informative.

Determination of anthropogenic impact on the Siret River and its tributaries by the analysis of attached algae / Określenie antropogenicznych oddziaływań na rzekę Siret i jej dopływy poprzez analizę osiadłych glonów

The article is devoted to the determination of anthropogenic impact on the Siret River and its tributaries (the Sukhyj, the Mikhidra and the Malyj Siret Rivers). The taxons of attached algae were determined in this case. Then they were distributed in the saprobity groups and the correlation of each group was found. It was necessary to identify the stage of ecological regress on each site of the researched basin. The data about the ecological regress can be used as primary information on the aquatic ecosystem state for conducting the further researches. The next step of the investigations was counting of the saprobity index by Pantle and Bukk in Sladechek modification for classification of quality status of water in the researched basin.

INFLUENCE OF WASTEWATERS OF MUNICIPAL BIOLOGICAL WATER TREATMENT PLANTS ON THE CONDITION OF BENTHIC CENOSES IN THE BELAYA RIVER

The article reports on the results of the study of the Belaya rivers ecological condition in the area of wastewater ejection from the biofeedback in Ufa by analyzing the condition of benthic animals community. The degradation of benthic cenoses in the area of wastewater ejection is noted. The ecological condition becomes better 500 m lower the ejections, saprobity index of river waters decreases to the value minor pollution, however the number and biomasses of macrozoobenthos stays lower here than background values.

Hydrobiological study of the middle course of the Bečva River

The present work gives the results of the hydrobiological research of the middle course of the Bečva River in the river section between Valašské Meziříčí and Přerov, carried out in the years 2004 to 2007. Altogether, 65 taxa of macrozoobenthos were determined in the period 2000-2007 in the middle course of the Bečva River : Coelenterata (1 taxon), Oligochaeta (5 taxa), Hirudinea (3 taxa), Gastropoda (4 taxa), Isopoda (1 taxon), Amphipoda (2 taxa), Hydracarina (1? taxon), Ephemeroptera (7 taxa), Plecoptera (1 taxon), Odonata (3 taxa), Heteroptera (1 taxon), Megaloptera (1 taxon), Trichoptera (9 taxa), Coleoptera (3 taxa), Diptera (23 taxa). The number of zoobenthos taxa fell in the period 2004–2007 in comparison to period 2000–2002 from 51 taxa to 40 taxa. The decline of zoobenthos taxa was registered on study localities, as follows : Choryně (from 28 to 23 taxa), Hustopeče (from 27 to 25 taxa), Rybáře (from 35 to 28 taxa), Grymov (from 31 to 25 taxa). Average saprobity index of benthic community of the middle course of the Bečva River was 2.35. Average saprobity indices of monitored localities towards downstream were as follows: Choryně 2.41; Hustopeče 2.25; Rybáře 2.40; Grymov 2.34.