Kuibyshev Reservoir Research Articles

Microplastic in Abiotic and Biotic Parts of the Mesha Bay of the Kuibyshev Reservoir (Republic of Tatarstan)

The study of microplastic content in water, sediments, gills and gastrointestinal tract of bream (Abramis brama) at the mouth of the Mesha River, the right tributary of the Kama River, was conducted. The content of microplastics in water was found at the level of 20.5 ± 22.3 units/m3, in bottom sediments 44.7 ± 41.8 units/kg, in fish gills 12.3 ± 8.4 units/example, in the gastrointestinal tract 14.5 ± 11.5 units/example. Fibers dominated in water samples, in the gills and gastrointestinal tract of fish, fragments dominated in the sediment. Correlation analysis showed the presence of a negative relationship between the content of microplastics in the gills, gastrointestinal tract and biologic indicators of studied fish. In terms of the frequency of occurrence and content of microplastics in the gills and gastrointestinal tract, the contamination of the studied fish is at a high level compared to literature data, which is associated with the feeding behavior of bream.

Long-term dynamics of the heterоtrophic bacterioplankton development in the mouth of the Usinsky bay of the Kuibyshev reservoir

Data of our long-term observations of the bacterioplankton development in the mouth section of the Usinsky bay (the Kuibyshev reservoir) during the summer–autumn periods are presented. The total abundance of heterotrophic bacterioplankton varied within (1.61–7.44)×106 cells/mL, the biomass was 39.01–249.53 µgC/L, which corresponds to III–V water quality classes. Between 2010 and 2017 the total abundance of heterotrophic bacterioplankton was nonmonotonically decreasing, and since 2021 its significant increase is recorded. Among heterotrophic bacteria, single freefloating cells predominated, mainly cocci and coccobacilli, and the proportion of rod-shaped cells increased during cyanobacterial bloom. Picocyanobacteria and picodetritus particles were almost always present in plankton, but their average contribution to the total organic carbon of picoseston was insignificant.

The current state of the pike population of the Kuibyshev reservoir

Pike Esox lucius is one of the key fishing objects in the Kuibyshev reservoir. The article presents materials from various years of research of the pike in the Kuibyshev reservoir and notes the changes that have occurred in its population. The dynamics of the species stock, its role in fishing and influence of individual environmental factors are analyzed.

Microplastics in Abiotic and Biotic Parts of the Mesha Bay of the Kuibyshev Reservoir (Republic of Tatarstan)

Microplastics in Abiotic and Biotic Parts of the Mesha Bay of the Kuibyshev Reservoir (Republic of Tatarstan)

ДИНАМИКА ЗАГРЯЗНЕНИЯ ПОВЕРХНОСТНЫХ ВОД РЕКИ ВОЛГИ ФЕНОЛОМ

Phenols are priority pollutants of the natural environment and enter water sources through wastewater treatment plants of industrial enterprises. They pose a certain threat to the human body, since many of them are highly toxic and belong to the first class of danger. Organochlorine derivatives of phenol exhibit particularly high toxicity; under conditions of water disinfection with chlorine-containing preparations, they can form polychlorinated dibenzo-n-dioxins, which are classified as super-ecotoxicants and have a negative effect on the genetic code of the human body. As a result of the studies, the surface waters of the Volga river basin of the Kuibyshev reservoir in the water area of the city of Kazan were analyzed for the content of phenol and its derivatives using gas-liquid chromatography. When analyzing phenols in the aquatic environment, it was established that the maximum permissible concentrations norms for ortho-, meta-, para- chlorophenols, which are characterized by high toxicity to the human body and wildlife, were exceeded. The dynamics of seasonal changes in the concentration of phenol and its derivatives in the surface waters of the Volga river has been established, which are associated with the intensification of redox processes in the summer, occurring under the influence of temperature factors involving dissolved oxygen.

Sanitary and biological condition of open sources is a determining factor in the reconstruction of elements of water supply systems

The results of the analysis of monitoring data of the Kuibyshev reservoir, as a source of domestic and drinking water supply, for the period 2000-2018 are presented. It has been established that in summer, during the period of massive development of cyanobacteria, biological pollution of the reservoir is observed, the quality of water deteriorates in terms of smell, color, pH, and dissolved oxygen content. During the period of deterioration in the quality of water in the water supply source in large Volga cities, problems arise in purifying natural water to meet the requirements of the drinking water supply of the population. To solve the problem, recommendations have been developed to improve the technological scheme for purifying Volga water from organic and toxic substances.

Reconstruction of the currents structure in the Kuibyshev Reservoir using satellite data and field measurements

This paper is devoted to a series of the first field subsatellite experiments conducted in the waters of the Kuibyshev Reservoir (Kama estuary) in 2023. Simultaneously with ship-based measurements of current and wind fields, as well as chlorophyll-a concentration, two high-spatial-resolution satellite scanners surveyed the study area of the reservoir. From sequential images, current fields were reconstructed using the standard maximum cross-correlation (MCC) method, which were then compared with measurements from the Acoustic Doppler Current Profiler (ADCP). In certain parts of the water area, satisfactory agreement was obtained between the reconstructed currents and direct measurement current data. And in those parts of the water area where a significant discrepancy between the ADCP and MCC data was recorded, the possible reasons for the discrepancies were analyzed. Preliminary estimates of the parameters that have a significant impact on the possibility of reconstructing currents using the MCC method in inland eutrophicated water bodies have been made, and some limitations of the MCC method as a whole have been identified. Possible ways of further development of the method are analyzed.

Influence of weather conditions on the dynamics of summer phytoplankton in the Kuibyshev reservoir

Based on observation data in the summer of 2019 and 2021, an assessment was made of changes in abiotic characteristics and chlorophyll (Chl) content in the Kuibyshev Reservoir. Regular observations were carried out at the outlet section of the reservoir (Zhigulevsky hydroelectric complex) under conditions of complete mixing of water masses. The main goal of the study is to assess the influence of abiotic factors on the chlorophyll content and the mass development of cyanobacteria. It has been established that the main influencing factors are thermal regime and weather conditions. 2019 is characterized as “cold”. The total number of days with water temperatures above 22 °C was only 11. The degree of favorability was low (23 °C ˃ t ˃ 22 °C). 2021 characterized as “warm”. The total number of days with water temperatures above 22 °C was 72. The degree of favorability varied widely: from low (23 °C ˃ t ˃ 22 °C) to extreme high (t ˃ 26 °C). The most favorable year for the mass development of cyanobacteria was 2021, when the Chl content over the summer period was 7.2 μg/dm3. The least favorable year was 2019, when the Chl content was 1.4 μg/dm3. Seasonally, the temperature optimum was observed annually in July. The Chl content in July 2021 was 12.6 μg/dm3, and in July 2019 – 1.8 μg/dm3. Significant variability in chlorophyll content is due to synoptic cyclicity and changing weather conditions. The established influence of thermal regime and weather conditions on the content of chlorophyll suggests that in conditions of global warming, the process of mass development of cyanobacteria is expected to intensify, which will negatively affect the ecological state and water quality of the Kuibyshev Reservoir.

Parameters of the temperature optimum for cyanobacteria in the Kuibyshev reservoir

Based on the results of hydrometeorological observations in the period 2016-2021, the parameters of the optimum temperature zone (TTO) for the process of mass development of cyanobacteria in the Kuibyshev reservoir were determined. Such parameters of the optimum zone as duration, intensity, upper and lower boundaries depend on the hydrometeorological conditions of a particular year. For the period 2016-2021, the average duration of the OST was 44 days, the longest - 72 days and was observed in 2021, and the shortest - 11 days and was observed in 2019. The highest intensity of OST was observed in 2021, when 10 days were characterized by low intensity, 15 days by moderate intensity, 23 days by strong intensity, 24 days by very strong intensity and 7 days by extreme intensity. The lowest intensity was observed in 2019, when 10 days were characterized by low intensity and 1 day by high intensity. The upper border of the WTO in 2021 was observed on June 21, and the lower border on September 1. In 2019, the upper limit was observed on June 23, and the lower limit on July 26. For the process of mass development of cyanobacteria, the most favorable year is 2021, and the unfavorable year is 2019. It was found that with the increase in air and water temperature, the duration and degree of intensity of the temperature optimum zone increased. Consequently, with a further increase in air temperature due to global warming, the duration and intensity of the optimum temperature zone will only increase, which will activate the process of mass development of cyanobacteria, which will negatively affect the ecological state and water quality of the Kuibyshev reservoir.

Diversity of planktonic pro- and microeukaryotes in water bodies of the Volga-Don basin during the period of cyanobacterial bloom according to metabarcoding data

The first data on the phylogenetic diversity of planktonic communities of pro- and microeukaryotes in different types of water bodies of the Volga-Don basin during the period of cyanobacterial bloom are presented. Aphanizomenon flos-aquae/Dolichospermum flos-aquae blooms were found mainly in the Kuibyshev Reservoir; Planktothrix agardhii bloom was observed in floodplain lakes of the majority of investigated rivers. Bloom of Raphidiopsis raciborskii was found in a lake on the Volga River terrace, and in a pond in the floodplain of the Samara River Anabaenopsis dominated anong Cyanobacteria. Among heterotrophic prokaryotes, Proteobacteria, Bacteroidota, Verrucomicrobiota, Planctomycetota and Actinobacteriota predominate in the number of sequences, and among protists - Ciliophora, Gyrista (mainly Chrysophyceae), Cryptista and Myzozoa. During the period of cyanobacterial bloom, the contributions of Proteobacteria (especially, Burkholderiales and Pseudomonadales) and Actinobacteriota slightly decrease, while Myzozoa, on the contrary, increase. Monodominant blooms of various species of cyanobacteria significantly change the composition and structure of microbial communities, both at the OTUs and higher taxa levels. The plankton of the pond with Anabaenopsis bloom is most peculiar. Communities with blooms of P. agardhii, R. raciborskii and A. flos-aquae/D. flos-aquae are more similar to each other.

Влияние погодных условий на процесс массового развития цианобактерий в Куйбышевском водохранилище

According to observation data in the summer period 2016-2021. The interannual variability of weather conditions, water temperature and chlorophyll (Chl) content in the Kuibyshev Reservoir was considered. Regular observations were carried out at the outlet section of the reservoir (Zhigulevsky hydroelectric complex) under conditions of complete mixing of water masses. It has been established that the main factors influencing the process of mass development of cyanobacteria (MDC) are thermal regime and weather conditions. With increasing water temperature, the interval and degree of favorable activity of cyanobacteria increases. Over a 6-year period, the average interval was 44 days, the largest was 72 days, and the smallest was 11 days. The degree of favorability varied widely: from low (23 °С ˃ t ˃ 22 °С) to extreme high (t ˃ 26 °С). The most favorable years for the MRC process were 2016 and 2021, when the Chl content during the summer period was 6.2 and 7.2 μg/dm3, respectively. The least favorable years were 2017 and 2019, when the Chl content during the summer period was 0.6 and 1.4 μg/dm3, respectively. Seasonally, the temperature optimum was observed annually in July. The Chl content in July 2021 was 12.6 μg/dm3, and in the cold July 2017 – 0.7 μg/dm3. Significant variability of the MRC process is due to synoptic cyclicity and changing weather conditions. The established influence of thermal regime and weather conditions on the content of chlorophyll suggests that in conditions of global warming, the process of mass development of cyanobacteria is expected to intensify, which will negatively affect the ecological state and water quality of the Kuibyshev Reservoir.

Assessment of methane levels throughout a temperate reservoir area using remote sensing data

Aquatic ecosystems are significant methane (CH4) emitters, potentially surpassing direct anthropogenic sources. Despite the advantages of satellite monitoring, its application for assessing methane content over freshwater bodies is not commonly encountered in scientific publications. Therefore, this study aims to assess methane levels in the atmosphere in and around the temperate reservoir area (Kuibyshev Reservoir, Russia) using Sentinel-5P/TROPOMI remote sensing data. The spatial distribution of CH4 content across the study area was heterogeneous and exhibited a latitudinal dependence, with concentrations decreasing from south to north. Seasonal variability in methane levels is observed, with the lowest values in spring and the highest in autumn. The average CH4 concentration over the period 2019–2023 was 1860±13 ppb. Additionally, a consistent trend of increasing annual methane background levels has been observed (up to 1878±11 ppb in 2023). Differences in methane levels are noted across different land cover types, with higher values typically observed above anthropogenically transformed landscapes, while minimal ones are found over extensive forested areas and the waters of the Kuibyshev Reservoir.

The state of the main biological indicators of roach (Rutilus rutilus, Linnaeus, 1758) in the upper part of the Volga reach of the Kuibyshev reservoir

The size-age structure and weight of roach in catches in the autumn period of 2022-2023 are considered in the upper part of the Volga reach of the Kuibyshev reservoir. The correspondence of the biological indicators of roach to the characteristics inherent in the destabilization period of the ecosystem of the Kuibyshev reservoir was established.

Modelling of Kuibyshev reservoir shallow water depths by bathymetric surveys and multispectral UAV imagery data: A case study

This study investigates the potential of using multispectral Unmanned Aerial Vehicle (UAV) imagery to model the shallow water depths of the Kuibyshev Reservoir, Russia. Traditional methods like boom soundings and echo sounders, while accurate, are labor-intensive and costly. By leveraging multispectral data from UAVs, we aim to provide a more efficient and detailed approach to bathymetric mapping. Our methodology involved conducting bathymetric surveys with a Garmin GPS Map 178C and a Geoscan 401 Geodesy UAV equipped with a MicaSense RedEdge-MX camera. We performed correlation analysis and modelled depth using various regression techniques, identifying the Decision Tree Regressor as the top-performing model with an R² value of 0.98. Our findings suggest that UAV multispectral bathymetry is a viable alternative for local-scale shallow water mapping, with significant implications for reservoir management and ecological studies.

Microbial biodiversity as an indicator of anthropogenic pollution of aquatic ecosystems

It is important to study the level of anthropogenic pollution of rivers in order to maintain the health of ecosystems and provide the sustainable development of society. Surface water pollution is mainly caused by urbanisation, agriculture and industrial discharges. Here, we present the results of a three-year study of the chemical composition and bacterial diversity of samples collected from three rivers of the Kuibyshev Reservoir. Statistically significant differences between chemical parameters and alpha diversity indices were found. In addition, a negative correlation was between the Shannon index and manganese content, and the Chao1 index with nitrite ions.

Medieval Archaeological Sites of Semenovsky Island in Tatarstan: history of study and some results of research

The article is dedicated to the medieval sites of the 10th – beginning of the 15th centuries, located on Semenovsky Island in the Spassk district of Tatarstan. These are 5 burial grounds and 4 ancient settlements. Semyonovka I settlement was one of the early settlements of the Volga Bolgars in the Kazan Volga region and founded in the second half of the 10th century. At present, the cultural layer of the ancient settlements on Semenovsky Island is completely eroded by the waters of the Kuibyshev reservoir, as well as the necropolises belonging to them. A significant part of the materials from these sites has been published, except for ceramics. The researchers paid special attention to coins and items, made of non-ferrous metal. The analysis of the finds allowed us to assume that the settlement structure on Semenovsky Island developed without significant interruptions from the second half of the 10th century to the beginning of the 15th century, having undergone several crisis transformations at the end of the 11th – the first half of the 12th and the first third of the 13th centuries, connected in the first case with the invasions of the Kipchaks and in the second case with the Mongol conquest.

Monitoring of the development of blue-green algae in the Kuibyshev reservoir using remote sensing indices

The research presents the results of remote monitoring of blue-green algae of the Kuibyshev reservoir, leading to eutrophication of the reservoir. Multispectral images were taken by the European Space Agency’s Sentinel-2 remote sensing satellite and were processed by using QGIS software. Satellite images were processed using spectral indices. After using several spectral indices, the three most informative ones were selected: NDVI, NDWI and SIPI. The usage of processed images made it possible to define the boundaries of the distribution of blue-green algae more clearly, as well as the zones of the most intensive development of biomass. The use of several spectral indices made it possible to determine the most suitable data for the usage under adverse meteorological conditions. The analysis of the processed satellite images makes it possible to assess the intensity of the development of blue-green algae. This is the basis for the development of a forecast model of biomass changes in the reservoirs of the middle zone of the Russian Federation.

Influence of Hydrodynamic Conditions on the Bacteriobenthos Distribution in the Upper Reaches of the Zhiguli Hydroelectric Power Station of Kuibyshev Reservoir

Influence of Hydrodynamic Conditions on the Bacteriobenthos Distribution in the Upper Reaches of the Zhiguli Hydroelectric Power Station of Kuibyshev Reservoir

Stock dynamics and biological indicators of the main commercial fish species of the Kuibyshev reservoir for the period 2001–2021, their development by fishing

Based on materials from resource studies 2000–2021 a review of the dynamics of stocks and biological indicators of the main commercial fish species of the Kuibyshev reservoir was prepared. The data on their development by trade are given. The reserves of biological resources of this reservoir are shown. Recommendations on rational use are given: it is proposed to increase the catch of roach, silver bream, perch, crucian carp, blue breeze and other underutilized species, which will make it possible to obtain an additional 400 tons of high-quality fish.

Использование основных гидрохимических и гидробиологических показателей для определения инвариантного состояния Куйбышевского водохранилища и его притоков

The method of ecological modifications was used to determine the invariant state of aquatic ecosystems in the Middle Volga basin. Based on the analysis of long-term regime hydrochemical and hydrobiological information using the methods of mathematical statistics (cluster, hierarchical cluster analysis, ordination methods), the studied water bodies were grouped according to the chemical composition of water, highlighting the main indicators of natural and anthropogenic genesis. We highlighted the general indicators of the chemical composition of water (temperature, salinity, hardness, content of oil products, chromium ions) that affect the change in the qualitative and quantitative characteristics of hydrobiocenoses, as well as specific indicators (nitrogen-containing compounds, phosphates, chlorides, sulfates, copper and iron ions), negatively affecting the quantitative and qualitative characteristics of hydrobiocenoses. A group of ciliates – cilioplankton (qualitative and quantitative characteristics) was used to assess the invariant state. Cilioplankton in the ecosystem of the Kuibyshev reservoir is characterized by high species diversity, which indicates anthropogenic stress. The quantitative characteristics of cilioplankton in rivers are low, and the community changes are ecological modulations. The share of rotifers development in zooplankton indicates the elements of ecological regress in water bodies, as well as anthropogenic eutrophication with elements of ecological regress (in most of the Kuibyshev reservoir). The level of zoobenthos development and its size, as well as the oligochaetes relative proportion indicate anthropogenic stress in the ecosystem of most parts of the Kuibyshev reservoir. The elements of ecological regress are traced only in the area of Chistopol. The water ecosystem in Tetyusha area is characterized as a transition from background to anthropogenic stress. The Vyatka and Mesha rivers are characterized as background rivers with the transition to anthropogenic stress. Anthropogenic eutrophication with elements of ecological regress can be traced in the Kazanka River. The Stepnoy Zai, Noksa and Ilet rivers has elements of ecological regress. Hydrobiocenoses indicators statistically depend on hydrochemical composition.