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 ECOLOGICAL RISK OF A SAND QUARRY EXCAVATION IN THE RIVERBED

2018 ◽  
pp. 7-16
Author(s):  
Andrey Stepanovich Aldokhin ◽  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Water Quality Assessment ◽  
Biological Indicators ◽  
Fish Population ◽  
Water Area ◽  
Taxonomic Composition ◽  
Fish Density ◽  
Negative Consequences ◽  
Sturgeon Species ◽  
Size Groups ◽  
Taxonomic Groups

The article describes the potential negative consequences of hydraulicking a sand quarry in the Irtysh channel: vibration and noise impact on fish and hydrobionts, changes in the bathymetric and hydrological characteristics of the riverbed, increased turbidity, secondary pollution of water and bottom sediments, and deterioration of the hydrochemical regime. The projected quarry will be located in the riverbed of the Irtysh in the Tobolsk District of the Tyumen Region, at a distance of 5 and 10 km upstream from two wintering holes - Nizhne-Filatovskaya and Nadtsinskaya, which are of great importance for preserving the aquatic biological resources. To prevent possible negative consequences for the fish population, including sturgeon species, it has been proposed to conduct monitoring studies. There is given a list of physical, chemical and biological indicators that should be monitored during the quarry operation: fish density, proportion of fish taxonomic groups and size groups, content of oxygen dissolved in water, content of heavy metals and oil products in water and sediments, turbidity, bathymetric characteristics. Using Horiba, a multi-parameter system of water quality assessment, and AsCor and PanCor hydroacoustic complexes there have been studied the initial indicators of water turbidity and fish density in the water area adjacent to the site of the projected quarry, as well as taxonomic composition of the fish population. Additionally, in order to minimize damage to fisheries, it has been proposed to limit the period of quarry operation by the time of its drying in the period of low water - from 2d decade of August to October.

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 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.

Characterization of Western Painted Turtle Bycatch in Fyke Nets During Freshwater Fish Population Assessments

2015 ◽  
Vol 7 (1) ◽  
pp. 222-230 ◽  
Author(s):  
Tyrel S. Moos ◽  
Brian G. Blackwell
Keyword(s):  
Sex Ratio ◽  
Freshwater Fish ◽  
Significant Relationship ◽  
Annual Variation ◽  
Size Structure ◽  
Fish Population ◽  
Painted Turtle ◽  
Nontarget Species ◽  
Catch Rates ◽  
Fyke Nets

Abstract In fisheries management, fish populations are assessed using various net types that invariably also capture nontarget species. Although the bycatch of turtles tends to be a common occurrence, data describing the bycatch of turtles during freshwater fish sampling are lacking. To improve the available knowledge base concerning the bycatch of turtles during fish sampling, we characterize the dynamics of western painted turtle Chrysemys picta bellii bycatch in unbaited modified fyke nets used in fish population sampling in northeastern South Dakota. We collected data from June to September during fish population assessments in 39 lakes and nine impoundments between 2007 and 2012. We characterize western painted turtle bycatch relating to water type (lake and impoundment) including catch rates (number of turtles/net night), size structure, and sex ratio. Catch rates were higher in impoundments than lakes. Total mean annual catch rates ranged from 1.07 to 3.28 for lakes and from 0.70 to 6.63 for impoundments and the variation among years was significant for both water types. We observed no annual variation in water surface area or mean depth, precluding either from explaining the variation in annual catch rates. We observed a significant relationship between mean depth and catch rate for lakes, but not impoundments. We observed no significant relationship relating surface area to catch rate for lakes or impoundments. Catch rates differed significantly from June to September for lakes but not impoundments. Annual variation in catch rates was best explained by the previous winter precipitation for both water types. The sex ratio was skewed toward males and differed significantly from June to September for lakes but not impoundments. The size structure was skewed toward large turtles. Understanding bycatch dynamics during fish population assessments is a critical first step to understanding the impact of biological sampling on nontarget species and may prove useful in minimizing future bycatch of western painted turtles.

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).

Macrozoobenthos response to environmental degradation in a heavily modified stream: Case study the Upper Elbe River, Czech Republic

Biologia ◽  
2010 ◽  
Vol 65 (3) ◽  
Author(s):  
Zdeněk Adámek ◽  
Claus Orendt ◽  
Georg Wolfram ◽  
Jan Sychra
Keyword(s):  
Water Quality ◽  
Size Structure ◽  
Habitat Characteristics ◽  
Macroinvertebrate Communities ◽  
Elbe River ◽  
Important Indicator ◽  
Natural Stream ◽  
River Bed ◽  
Macrophyte Community ◽  
The Impact

AbstractBenthic macroinvertebrates are an important indicator of river health. However, their response upon water quality development downstream the pollution outlets considerably depends on the environmental habitat characteristics. Three successive stretches, each of them providing three different mesohabitats in stillwater (S), torrential (T) and riparian (R) zones were selected for evaluation of the impact of altered metapotamal river bed morphology (channelization) and chemical determinants of water quality on the Upper Elbe River. In downstream direction, the stretches are separated by weirs and characterized as a low polluted low modified natural stream (N), a low polluted channelized stream (C) and a channelized polluted stream (CP). Altogether, 111 benthic macroinvertebrate taxa were recorded in the Pardubice hotspot between Němčice and Přelouč. Despite different levels of stream bed and water quality degradation, micro- and mesohabitat characteristics appeared to be the most important factors determining the diversity of macrozoobenthos in riffle (substrate size structure) and in shoreline (macrophyte community composition and structure) mesohabitats. The diversity of macroinvertebrate communities was highest in riparian mesohabitats compared to stillwater and torrential ones. Saprobic indices increased in downstream direction, thus indicating the decline of water quality.

Analysis of Prey of Mandarin Fish and Large Mouth Bass and Distribution of Fish Population in Lake Paro, Korea

2015 ◽  
Vol 29 (2) ◽  
pp. 210-220
Author(s):  
Jaeyong Lee ◽  
◽  
Kwang yeol Lee ◽  
Sungchul Park ◽  
Jaeseok Choi ◽  
...  
Keyword(s):  
Fish Population ◽  
Mandarin Fish ◽  
Distribution Of Fish

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 Oil hydrocarbons and total lipids in the coastal casts of Cystoseira barbata (Stackh.) C. Agardh in the littoral zone of Sevastopol (Black Sea)

2017 ◽  
Vol 2 (2) ◽  
pp. 49-54
Author(s):  
O. A. Mironov ◽  
I. P. Muraviova
Keyword(s):  
Coastal Waters ◽  
Anthropogenic Impact ◽  
Gravimetric Method ◽  
Hydrocarbon Composition ◽  
Water Area ◽  
Total Lipids ◽  
Secondary Pollution ◽  
Oil Hydrocarbons ◽  
Cystoseira Barbata ◽  
Taxonomic Groups

The coastal zone of Sevastopol, especially the recreational part, feels great anthropogenic impact due to hosting a large number of tourists, but also because of the urban and stormwater discharge, containing oil hydrocarbons in its composition. Brown algae Cystoseira barbata forms vast underwater thickets here. Cut off from the substrate algae are at the edge of the water, mixed with coastal casts, resulting in secondary pollution of both coastline and coastal waters. At the same time freshly detached plants are used by representatives of different taxonomic groups and are actively involved in the food chain. In this context, the aim of this work is to study the lipid-hydrocarbon composition of Cystoseira from the coastal storm casts. The amount of oil hydrocarbons was determined by gravimetric method and the amount of lipids by color reaction with phospho-vanillin reagent. The results obtained indicate higher levels of chloroform-extracted substances, total lipids and oil hydrocarbons in macrophytes of Kruglaya Bay in comparison with the levels in water area of Park Pobedy. Onshore casts of Cystoseira may be the source of secondary pollution of the coastal waters by oil hydrocarbons.

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