scholarly journals Meander reshaping – the formation process of a wintering riverbed depression of fish

2021 ◽  
Vol 29 (4) ◽  
pp. 380-386
Author(s):  
A. A. Chemagin
Keyword(s):  
Life Cycle ◽  
Research Work ◽  
Aquatic Organisms ◽  
Water Area ◽  
Average Density ◽  
Winter Period ◽  
Channel Processes ◽  
Siberian River ◽  
Riverbed Depression ◽  
Distribution Of Fish

The study of the spatiotemporal distribution of fish is an important and poorly studied aspect of the ecology of aquatic organisms. The research work was performed using the modern hydroacoustic method and geographic information systems. A section in the lower reaches of the Irtysh, a large transboundary Siberian river (in Western Siberia, Russian Federation), was studied. It has a strong development of meandering. The merging (i.e., reshaping of closely spaced meanders and erosion-accumulating channel processes) results in development of wintering riverbed depression, which is a critical “temporal bottleneck” during the winter period of the fish life cycle. The average density of fish in the study area in summer and autumn was 8,031 and 9,194 individuals per ha, respectively. Analysis of the distribution of fish showed that the distribution in the horizontal aspect had a more aggregated character in the autumn. In the vertical aspect, it had a more surface (pelagic) character. The ichthyofauna in the water area of the riverbed depression is mainly represented by cyprinids. The loop-shaped evolution of the channel formed a section of the river with multidirectional, circulating, and counter-current flows. It also created zones with depths exceeding 20 m and aggregations of fish. These features characterize the studied water area as a wintering riverbed depression of the fish of the Lower Irtysh. This section of the river should be included in the list of protected wintering biotopes of fish in the West Siberian fishery basin, which will ensure the conservation of fish at the critical stage of the life cycle.

scholarly journals FISH POPULATION OF GORNOSLINKINSKAYA RIVERBED DEPRESSION OF THE LOWER IRTYSH IN WINTER PERIOD

2018 ◽  
pp. 39-47
Author(s):  
Gleb Igorevich Volosnikov ◽  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Water Column ◽  
Fish Population ◽  
Water Area ◽  
Fish Distribution ◽  
Winter Period ◽  
Composition Control ◽  
Ecological Features ◽  
Hydroacoustic Survey ◽  
Riverbed Depression ◽  
Distribution Of Fish

Fish distribution was studied using sonar computerized complex in the deep part of the water column of Gornoslinkinskaya riverbed depression in winter. In the horizontal aspect there was estimated the number of fish registrations, in the vertical aspect the fish density was analyzed in three conditional horizons of the water column: surface, pelagic, bottom. Additionally, the bathymetric characteristics of the riverbed depression in the fish registration areas were evaluated. In the study period the depths were lower than 40 m. On the trajectory of the planned research route there were drilled holes in ice with a motor-drill (screw D=200 mm). Hydroacoustic survey was performed for each drilled hole. To control the species composition control fishing was carried out by gillnets. The hydroacoustic survey files were further processed in the laboratory using AsCor and Taxonomy applications for carrying out dimensional-taxonomic identification of fish. It has been established that fish inhabits the water area of the riverbed depression non-uniformly, both horizontally and vertically. The density of fish in the horizons of the investigated water area is distributed in descending order: pelagic - 105 sp./ha, bottom - 61 sp./ha, surface - 18 sp./ha. The features of the taxonomic distribution of fish are the following: in the surface horizon there are not found percid species and non-identified fish, their shares are decreasing from the bottom to pelagic horizons. The groups of cyprinids and whitefish-pike fish are registered throughout the water column of the riverbed depression: their shares increase from the bottom to the surface. The uneven distribution of different taxonomic fish groups in the investigated water area can be explained by the ecological features of different species in winter, as well as their trophic-defensive behavior.

scholarly journals Distribution of sturgeon in the River Irtysh

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
A. A. Chemagin
Keyword(s):  
Size Structure ◽  
Water Area ◽  
Fish Density ◽  
Low Velocity ◽  
Result Show ◽  
Body Sizes ◽  
Software And Hardware ◽  
And Control ◽  
Riverbed Depression ◽  
Distribution Of Fish

Using the modern hydroacoustic methods and the computerized software and hardware complex “AsCor”, the features of the distribution of fish of the Acipenseridae family in the lower reaches of the large transboundary river the Irtysh (Western Siberia) have been investigated: in the water area of the riverbed depression (turbulent flow) and control sections (laminar flow). The identification of sturgeon was carried out by the echometric method according to the shape of the swim bladder. It is shown that in the water area of the riverbed depression, increased density of fish is formed, the share of sturgeons being 4.9–5.8%. Among other fish species, the group of cyprinids always dominates. The significant excess of the average fish density in the riverbed depression, in contrast to the control, was 6–30 times. In the water area of the riverbed depression, the average fish density was 4,524, in the control sections 245–2,091 individuals/ha. The size structure of the group of sturgeon in the control sections was represented by individuals with body sizes less than 25–30 cm, and in the riverbed depression – by individuals of different sizes and ages with a body length to 35 cm. The water area of the riverbed depression is located in the meandering section of the river and is characterized by intense vertical vortex structures (whirlpools) and the presence of malfunctioning currents. Features of the hydrological characteristics of the riverbed depression are factors in the formation of aggregations of fish, since fish can use the energy of discrete vortices, low-velocity areas, and as a result, show preference for certain turbulence regimes.

scholarly journals DISTRIBUTION OF FISH IN THE PREDATOR-PREY SYSTEM IN THE RIVERBED DEPRESSION OF THE LOWER IRTYSH

2017 ◽  
pp. 76-84
Author(s):  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Water Area ◽  
Bottom Surface ◽  
Predator Prey ◽  
Prey System ◽  
Irtysh River ◽  
Riverbed Depression ◽  
Distribution Of Fish ◽  
The Irtysh River

The article presents are features of the horizontal and vertical distribution of fish in the water area of the Kondinskaya riverbed depression in the lower reaches of the Irtysh River (Tyumen region, Russia). There have been considered horizons of the water column from the surface to the bottom: surface-pelagic horizon (< 10 m), 1st pelagic horizon (10-20 m), 2nd pelagic horizon (20-30 m), and bottom-pelagic horizon (> 30 m). Hydroacoustic survey was conducted using a software and hardware complex "AsCor" on board a small ship that moved in tacks (zigzags). The recorded information, including the GPS track, processed with special application software "AsCor". Taxonomic belonging to the families was determined remotely - by the type of the reflected sound. According to the data of echometric sensing, main part of fish population on the studied water area was presented by carp species (Cyprinidae) - 66.81%, perch species (Percidae) - 23.77%, cisco species (Coregonidae) - 5.60%, unrecognized species (sturgeon (Acipenseridae)), eelpout species (Lotidae), pike species (Esocidae)) - 3.82% of the registered plurality of fish. All fish groups of the registered mass in terms of abundance have been distributed predominantly in the surface and 1-st pelagic horizons of the water column of the riverbed depression. The difference in the distribution of registered taxonomic fish groups in the vertical aspect from the surface to the bottom is different: in planktivorous fishes more than 190 times, in predatory fishes from 10 to 27 times. A more even distribution of predatory species reduces their aggressive interaction - interspecific and intraspecific competition. There has been revealed a tendency to decrease the percentage of planktivorous species (Cyprinidae) in each succeeding horizon in direction from the surface to the bottom; for Percidae and Coregonidae species and a group of unrecognized fishes it was established, vice versa, in the direction from the bottom to the surface. Due to the wedge-shaped decrease of the living space in the riverbed, the general tendency of a decrease in the number of fish has been registered in the direction of deeper horizons. There has been noted the statistical reliability of differences in the vertical distribution for all registered fish groups. The features of the fish distribution in the predator-prey system on the Irtysh river section with heterogeneous conditions of the aquatic environment (intensive ascending currents and funnels, significant depth changes) characterize it as a "window of antipredation".

scholarly journals DIEL AND INTER-SEASONAL DYNAMICS OF SPATIAL DISTRIBUTION OF FISH IN WATER AREA OF WINTERING RIVERBED DEPRESSION

2021 ◽  
Vol 2021 (3) ◽  
pp. 55-68
Author(s):  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Spatial Distribution ◽  
Dark Period ◽  
Water Area ◽  
Light Period ◽  
Diurnal Dynamics ◽  
Entire Observation Period ◽  
Prey Escape ◽  
Riverbed Depression ◽  
Distribution Of Fish ◽  
Observation Period

To study the dynamics of the spatial distribution of fish under ice cover the research was carried out in the water area of the riverbed depression located in the lower reaches of the Irtysh River (Western Siberia, Tyumen region). The research was conducted by using the hydroacoustic method based on a computerized hydroacoustic software-hardware complex. It was found that, in the diurnal aspect, throughout the entire observation period (December - April), the number of fish in the riverbed increases during the dark period of the day, and during the light period it decreases. The dominant groups of fish change with the change of the period of the day: December - cyprinids prevail in the dark period of the day, in March and April - in the light period of the day, the rest of the time the group of percids predominated. With an increase in water temperature from December to April from 3.7 to 6.5 °C, it was noted that the density of fish decreases from 184 to 8 sp/hect. in the daytime and from 2157 to 91 sp/hect. at night (dark period), respectively. Fish explore the horizons of the water column of the riverbed depression during the day and night from the surface to the bottom with the highest density indicators near the surface, except - the daytime in December. With increasing density of fish at nightfall at the same time, there was an increase used water area of riverbed depression. In the vertical aspect, cyprinids avoid predators (pike, in-connu, burbot) in the diurnal dynamics; the distribution of cyprinids has a significant negative cor-relation with the distribution of the second group of fish. Thus, the features of the vertical and hori-zontal distribution of fish in the diurnal dynamics throughout the entire observation period are the strategy of their survival: for prey - escape from predators, for predators - search for food objects

scholarly journals DIMENSIONAL AND TAXONOMIC STRUCTURE OF FISH POPULATION OF THE KONDINSKAYA RIVERBED DEPRESSION

2018 ◽  
pp. 25-32
Author(s):  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Research Work ◽  
Fish Population ◽  
Water Area ◽  
Taxonomic Structure ◽  
Sonar System ◽  
Size Groups ◽  
Hydroacoustic Survey ◽  
Riverbed Depression

On the basis of modern hydroacoustic techniques the article presents features of the dimensional-taxonomic structure and vertical distribution of fish in the water area of one of the largest riverbed depressions in the lower reaches of the Irtysh river - Kondinskaya (Khanty-Mansiysky district, Tyumen region, Russia). There have been analyzed the conditioned water column horizons: from the surface to the bottom < 10 m, 10-20 m, 20-30 m, > 30 m. Maximum depth of the riverbed in the studied period exceeded 43 m. Research work was done by software-hardware sonar system AsCor. To perform hydroacoustic survey from the small boat in the investigated water area there were made displacements on a grid of transects (in zigzags). Recorded information of the hydroacoustic survey was processed in the laboratory using special software programs AsCor and Taxonomy which enable remote dimensional-taxonomic identification of fish with calculation of their density and number. It has been established that in each subsequent depth horizon the proportion of planktivorous fish (Cyprinidae) decreased in direction from the surface to the bottom; the proportion of predatory fishes (Percidae, Coregonidae, Esocidae), and a group of unidentified fishes (Acipenseridae, Lotidae), on the contrary, increased. The features of vertical distribution and taxonomic structure in the water column of the riverbed depression is an element of the survival strategy, primarily for juveniles of planktivorous species. More than 90% of fish from the total recorded population are concentrated at depths up to 20 m. In the research period among the fish population of the riverbed depression cyprinids dominated, in the size groups there prevailed individuals with body lengths up to 15 cm.

Life Cycle Development of Successful Women-owned Enterprises

2020 ◽  
Vol 3 (4) ◽  
pp. 142-152
Author(s):  
Mohammad Waliul Hasanat ◽  
Kamna Anum ◽  
Ashikul Hoque ◽  
Mahmud Hamid ◽  
Sandy Francis Peris ◽  
...  
Keyword(s):  
Life Cycle ◽  
Data Collection ◽  
Research Work ◽  
Primary Data ◽  
Small Scale ◽  
Data Collection Process ◽  
Theoretical Finding ◽  
Successful Women ◽  
Two Phases ◽  
Life Cycle Development

In developing countries, the role of women in the business sector is continuously improving. As a result, female enterprises have also been encouraged in Pakistan. This study is based on life cycle development phases from which women-owned enterprises have to go through in order to become successful. As a primary data source, face-to-face interviews with owners of successful women-owned enterprises were preferred. The data collection process was divided into two phases i.e. Phase-I and Phase-II. After data collection, qualitative analysis has been performed using NVIVO. Findings provide both generic and specific factors involved in life cycle development of women-owned enterprises. This study provides a detailed view of life cycle development model followed by successful women enterprises. The outcome of this research work is a theoretical finding which can be utilized by entrepreneurs owning small scale enterprises to improve their level of performance. Findings can also be helpful for potentially talented women interested in setting up their own business.

Road Salt Application in Highland Creek Watershed, Toronto, Ontario - Chloride Mass Balance

2010 ◽  
Vol 45 (4) ◽  
pp. 451-461 ◽  
Author(s):  
Nandana Perera ◽  
Bahram Gharabaghi ◽  
Peter Noehammer ◽  
Bruce Kilgour
Keyword(s):  
Mass Balance ◽  
Management Practices ◽  
Chloride Concentration ◽  
Aquatic Organisms ◽  
Terrestrial Ecosystems ◽  
Road Salt ◽  
Winter Period ◽  
Chloride Mass Balance ◽  
Creek Watershed ◽  
Chloride Concentrations

Abstract Occurrence of increasing chloride concentrations in urban streams of cold climates, mainly due to road salt application, has raised concerns on its adverse effects on aquatic and terrestrial ecosystems. Therefore, there is a need for a better understanding of processes associated with road salt application and subsequent discharge into the environment in order to develop management practices to minimize detrimental effects of chlorides. The chloride mass analysis for the Highland Creek watershed based on four years of hourly monitoring data indicates that approximately 60% of the chlorides applied on the watershed enter streams prior to subsequent salting period, 85% of which occurs during the period between November and March. Contribution of private de-icing operations on chloride mass input within Highland Creek watershed was estimated to be approximately 38%, indicating its significance in overall chloride mass balance. Salt application rates, as well as chloride output in the streams, vary spatially based on land use, influencing chloride concentrations in surface waters. The estimated groundwater chloride concentration of 275 mg/L indicates that some aquatic organisms in Highland Creek would potentially be at risk even outside the winter period under dry weather flow conditions.

scholarly journals HYDROBIOLOGICAL STUDIES OF PLANKTON COMMUNITIES OF MAKHACHKALA SEAPORT

2019 ◽  
pp. 12-18
Author(s):  
Magomed Magomedovich OSMANOV ◽  
Frangiz Shamilievna AMAEVA ◽  
Ayshat Abdulmajidovna ABDURAKHMANOVA
Keyword(s):  
Aquatic Organisms ◽  
Water Area ◽  
Acartia Tonsa ◽  
Anthropogenic Influence ◽  
The Caspian Sea ◽  
Spring Period ◽  
Brackish Water Species ◽  
Water Species ◽  
Plankton Communities ◽  
Planktonic Communities

The article presents data from spring hydrobiological studies in the Makhachkala l Seaport during the period of dredging. It is noted that plankton of the studied water area of the Caspian Sea is a typical community of the spring period, formed mainly by marine and brackish-water species of phytoplankton and zooplankton. Diatoms mainly dominate in phytoplankton, and Copepods in zooplankton, where the main dominant is the Azov-Black sea invader Acartia tonsa Dana,1843. The analysis of planktonic communities indicates a rather developed quantitative and qualitative community of aquatic organisms with a characteristic abundance of species inhabiting it in the spring, despite a significant anthropogenic influence. It is established that the ongoing dredging operations do not have a tangible effect on the productivity of planktonic organisms.

scholarly journals Study of episootic sıtuation at poultry farms for colibacteriosis and salmonellosis in Azerbaijan

2021 ◽  
Vol 23 (103) ◽  
pp. 56-59
Author(s):  
S. B. Abbasov
Keyword(s):  
Research Work ◽  
Winter Season ◽  
Winter Period ◽  
Bacteriological Examination ◽  
Spring Season ◽  
Autumn Period ◽  
E Coli ◽  
Poultry Farms ◽  
The Republic

The article refers to the research work carried out in recent years at the poultry farms of the Khachmaz region of the Republic of Azerbaijan, the influence of opportunistic microbes on the activities of the farm. The role of opportunistic microbes in the occurrence of certain diseases with deficiencies in the process of feeding and raising of birds, and the microclimate in poultry farms is shown. During the bacteriological examination of breeding eggs by seasons there were revealed the presence of infection in the winter season with E. coli, Salmonella, Staphylococcus and Streptococcus – with each infection separately 13.0 %, in the spring season with E. coli, Salmonella, Staphylococcus – with each infection separately 20.0 %, in the autumn period with E. coli 27.0%, Salmonella 40.0 %, Staphylococcus 13.0 % and Streptococcus 13.0 %. In the course of bacteriological examination of dead embryos, the presence of infection in the winter period with E. coli 20.0 %, salmonella 30.0 %, staphylococcus 25.0 % and streptococcus 25.0 %, in the spring  season with E. coli 30.0 %, salmonella 40.0 %, staphylococcus 15.0 % and streptococcus 15.0 %, in the autumn season with E. coli 45.0 %, salmonella 55.0 % was revealed. In the autumn period, infection with staphylococci and streptococci was not detected. When studying as a whole, pseudomoniasis and mold fungi were not found.

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