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 cyprinids in the stream during their spring upstream migration

2020 ◽  
Vol 164 ◽  
pp. 07029
Author(s):  
Andrey Chemagin
Keyword(s):  
High Speed ◽  
Western Siberia ◽  
Fish Population ◽  
Upstream Migration ◽  
Low Velocity ◽  
Body Sizes ◽  
Velocity Characteristic ◽  
Irtysh River ◽  
Distribution Of Fish ◽  
Correlative Relationship

The researches were carry out by stationary and mobile hydroacoustic computerized complexes in the floodplain-riverbed complex of the Irtysh River (Western Siberia, Russian Federation). It was established that during the migration period during the spring flood, patterns of distribution of fish in the stream are observe due to the size-taxonomic characteristics of the fish population and the physiological capabilities of the organism of fish. With an increase in the flow velocity characteristic from the near bank part of the river to its midstream, the proportion of cyprinids in the watercourse decreases, and the proportion of fish with body sizes> 15 cm increases. The number of fish smaller at high-speed sections of the river increases with an increase in water temperature, which in turn indicates the increasing physiological capabilities of representatives of Cyprinidae family. Absolute numerical dominance of migratory fish and the largest proportion of cyprinids were observed in the low velocity section of the river, located closer to the shore. The indicator of the proportion of cyprinids have a direct strong correlative relationship with the temperature factor (0.70-0.73, P<0.05).

scholarly journals INFLUENCE OF ABIOTIC FACTORS ON FEATURES AND DISTRIBUTION DYNAMICS OF FISH IN SMALL TRIBUTARY OF IRTYSH RIVER

2020 ◽  
Vol 2020 (4) ◽  
pp. 66-80
Author(s):  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Water Level ◽  
Abiotic Factors ◽  
Open Water ◽  
Water Area ◽  
Fish Distribution ◽  
Fish Density ◽  
Water Turbidity ◽  
The North ◽  
Wind Events ◽  
Distribution Of Fish

The article focuses on the studies carried out in the flooded floodplain of the small river Varpak in the basin of the lower Irtysh during the spring flood (in May). The influence of abi-otic factors on the distribution of fish, including juveniles of cyprinids, percids and pike was analyzed. It was found that during the research period there was a direct correlation between the fish density and the temperature and water level, i.e. the fish density increased, as well as the mentioned indicators. There was found the regularity of decreasing the proportion of percids and fish density along with increasing water turbidity in the periods of the southern (S) and south-western (SW) winds, which is stipulated by the wind and wave fish set-down and their independent movement to the shallow areas of the flooded floodplain; In the periods of the north (N) and northeast (NE) winds the fish density increased along with water turbidity, i.e. the fish moved from the shallow water zones to the open water area. The investigated section of the Varpak River is open to the winds of the mentioned directions due of its location and relief. When considering the direction of the fish density distribution during the period of wind events S, SW, N and NE, there has been registered the similarity between the wind direction and the fish distribution in the water area of the floodplain. As a result of the analysis during the observation period the influence of the turbidity factor on the distribution of fish is noted; the greater turbidity, the greater the proportion of cyprinids and the lower the proportion of percids, which can be explained by the specific behavior of these groups of fish. Thus, there is a direct and indirect effect of a number of environmental factors (temperature and water level, wind phenomena and turbidity) on the characteristics and dynamics of fish distribution in the flooded floodplain of the river in the spring period

scholarly journals LOCALITY OF FORMING WINTERING RIVERBED DEPRESSION IN IRTYSH RIVER

2020 ◽  
Vol 2020 (4) ◽  
pp. 7-21
Author(s):  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Water Area ◽  
Taxonomic Composition ◽  
Fish Density ◽  
Endangered Fish ◽  
Rational Use ◽  
Biological Resources ◽  
Control Section ◽  
Irtysh River ◽  
Riverbed Depression ◽  
The Irtysh River

The article describes a new locality of the formed wintering riverbed depression discovered in the erosion zone of the isthmus of conjugate meanders of the Irtysh river for the rational use and effective protection of aquatic biological resources in places of their concentration in the Irtysh river basin (Western Siberia, the Russian Federation. The morphology of the riverbed depression was mapped (relief and bathymetric maps). The maximum depths in the channel depression exceeded 27 m. The channel depression and 4 control river sections were studied. The analysis of hydroacoustic surveys showed that in the wintering riverbed depression there is, according to the statistical data, higher fish density compared to the control areas: in the water area of the riverbed depression the average fish density made 4 524 species/ha, in the control sections 245-2091 sp./ha. The cluster analysis based on the fish density and the size-taxonomic composition of the ichthyofauna has revealed that the riverbed depression is being separated into a cluster, but at the same time goes to the control section No. 4, which is located downstream, where further erosion of the river channel is registered. In this regard, the minimum protection zone of the wintering channel depression should include the water area of the channel depression and the water area of control section No. 4. In the water areas of the riverbed depression and control sections in the spring period, cyprinids dominate - up to 65% of the total number of fish, percids are represented to a lesser extent - 36.76%, coregonids and pikes - up to 18.18, sturgeons - up to 9.31%. The given locality of the wintering riverbed depression must be included in the list of protected river sections of the Fishing Rules for the West Siberian fishery basin for developing the effective strategy for the protection, restoration and rational use of aquatic biological resources, including rare and endangered fish species of the Irtysh River and the whole Ob-Irtysh basin

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 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 The effect of vortex structures in the river bed on the concentration and size differentiation of the fish population

2018 ◽  
Vol 26 (2) ◽  
pp. 139-144 ◽  
Author(s):  
A. A. Chemagin
Keyword(s):  
Size Structure ◽  
Fish Population ◽  
Water Area ◽  
Additional Element ◽  
Vortex Zone ◽  
Technological Complex ◽  
River Bed ◽  
Taxonomic Groups ◽  
Distribution Of Fish ◽  
River Fish

On the basis of recent hydroacoustic method with using “PanCor” computerized program-technological complex, research was conducted on the distribution of fish of different taxonomic groups in the water area of Irtysh, a large trans-border river on the bend (meander) with a vortex zone. A hydroacoustic complex allows one to conduct remote size-taxonomic identification of fish. It is demonstrated that on the examined area of the river, fish of different taxonomic groups and sizes concentrate in the zones of increased turbidity and intense whirlpools (vortices) which form as a result of opposite currents at the river meander. The largest concentrations of fish form in the deepest zone of the examined water area and in front of it – vortex zone. It was determined that in the zone of recorded vortices, the number of fish of different taxonomic groups (Cyprinidae, Percidae, Coregonus, Esocidae, Sturgeon, burbot) is on average 2.14–2.61 times reliably higher compared to the observations at the studied part of the river with no vortices at comparable parameters of depth. The size structure of the fish was dominated by small individuals (<10 cm) in the vortices, and large fish out of these zones, which can be an additional element of the survival strategy. The peculiarities of the studied area of the river with vortices, on one hand, are the factors of formation of fish concentrations, and on the other hand – factors of differentiation by taxonomical and size parameter, related to inability of certain groups of organisms to resist the hydrodynamic force of the vortex structure.

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

Abstract 302: The PAT Ratio is Reduced by Beta-blockers

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Ueda Tomohiro
Keyword(s):  
Brachial Artery ◽  
Beta Blocker ◽  
Vascular Function ◽  
Beta Blockers ◽  
Multivariable Analysis ◽  
Control Group ◽  
Peripheral Arterial Tonometry ◽  
Result Show ◽  
Peripheral Arterial ◽  
And Control

Background: Flow-mediated dilatation (FMD) of the brachial artery and Peripheral arterial tonometry (PAT) are both methods for assessing endothelial vascular function. FMD measures predominantly nitric oxide mediated vasodilation whereas PAT measures a more complex range of mechanisms. The recent study showed that the sympathetic nervous system plays a significant role in this response. Methods: The study involved 176 subjects (mean age66 ±12 years). Based on the medication of beta-blockers, they were divided into 2 groups: beta-blocker group (n=37) and control group (n=139). Flow mediated vasodilatation (FMD) and nitroglycerine-induced vasodilatation (NID) in the brachial artery was measured by using UNEXEF18G (UNEX CO, Japan), and nitroglycerin mediated vasodilatation (NMD) was used as a control test for FMD. At the same time, PAT ratio was measured by using Endo-PAT 2000 (Itamar Medical, Israel) Results: PAT ratio was significantly impaired in beta-blocker group compared to that in control group (1.5±0.4% vs. 1.9±0.6%, respectively; P<0.05). However, FMD and NMD had no deference in both groups. Multivariable analysis revealed that blood sugar and medication of beta-blockers were independent variables for PAT ratio. Conclusion: These result show that beta-blockers is associated with a tendency towards reduced PAT ratio. PAT needs to be further studied, including the assessment of non-endothelial factor

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