scholarly journals INFLUENCE OF RUNOFF AND FLOOD REGIME ON QUALITY CHARACTERISTICS OF BREAM JUVENILES (ABRAMIS BRAMA ORIENTALIS L.) IN THE EASTERN AND WESTERN PARTS OF THE VOLGA DELTA

2019 ◽  
pp. 22-32
Author(s):  
Natalia Ivanovna Chavychalova ◽  
Sergey Vladimirovich Ponomarev ◽  
Olga Mikhailovna Vasilchenko
Keyword(s):  
Age Distribution ◽  
High Water ◽  
Middle Zone ◽  
Volga River ◽  
Spawning Grounds ◽  
Volga Delta ◽  
Stage Of Development ◽  
Natural Reproduction ◽  
Spawning Periods ◽  
Qualitative Characteristics

The paper presents the assessment results of the influence of hydrological conditions on the qualitative characteristics of bream juveniles in the Volga delta. The influence of factors (volume, hydrological characteristics of spring flood, temperature conditions) on the spawning periods of producers, duration of feeding of juveniles at spawning grounds, including viable ones, at the end of the hollow period has been traced. There have been presented the comparative data on the age, distribution and qualitative composition of larvae and juveniles obtained in the course of the research works at spawning grounds in different regions of the lower reaches of the Volga River in 2011-2017. The most favorable conditions for feeding on young bream have been found to form in the high-water years (2013 and 2016) and in the mid-water year (2017). Years 2011 and 2015 became critical for natural reproduction; years 2012 and 2014 were unfavorable. The highest size-weight characteristics of bream juveniles were observed by the end of the hollow period in the east of the delta in the arid and middle water years, and in high-water years they were found in the Volga-Akhtuba floodplain. The qualitative characteristics of bream in the east in low-water years were maximum in the upper zone, minimal - in the middle zone, in the western spawning grounds there was observed a reverse situation. In high-water years the highest values of bream juvenile size-weight parameters were observed in the middle zone in the east of the delta. In the mid-water year (2017) in the eastern part of the delta the maximum feeding results were observed in the lower zone, and in the spawning grounds of the western delta - in the middle zone. By the end of the feeding period in high-water years practically all bream juveniles (98.4%) reached the viable stage of development, and in arid years only 28.4% of bream juveniles reached the stage.

ON THE FEATURES OF NATURAL REPRODUCTION OF BREAM (ABRAMIS BRAMA ORIENTALIS, 1758) ON THE SPAWNING GROUNDS OF THE LOWer VOLGA IN THE HIGH-WATER YEAR OF 2013 AND LOW-WATER YEAR OF 2015

2017 ◽  
pp. 17-24 ◽  
Author(s):  
Olga Mikhailovna Vasilchenko ◽  
Sergey Vladimirovich Ponomarev
Keyword(s):  
High Water ◽  
Abramis Brama ◽  
Negative Consequences ◽  
Spawning Grounds ◽  
Volga Delta ◽  
Stage Of Development ◽  
Natural Reproduction ◽  
Bream Abramis Brama ◽  
Short Period ◽  
Wide Range

The article presents data on spawning sires and feeding the young of bream ( Abramis brama orientalis , 1758) taken in the period from April to July 2013 and 2015 in the spring floods of the Volga delta: in the west - around the Main, Kirovsky and Gandurino banks; in the east - around Vasiljevsky and Belinsky banks. It has been found that all the components of spring flood lay the foundations of a wide range of reasons influencing primarily the efficiency of natural productivity of the species. The article presents data on distribution of bream larvae and juveniles in the eastern and western parts of the Volga delta, in the lower part of the Volga-Akhtuba flood-lands and in the kultuks. The efficiency of natural reproduction of bream depending on changes of hydrological regime has been estimated. More favorable conditions for bream sire reproduction took place in the high-water year of 2013, when the total number of fry on the spawning grounds of the lower part of the Volga-Akhtuba flood-lands and the Volga delta made 3.1 times more than in the low-water year of 2015. In 2013 the highest productivity of bream fry was registered in the eastern spawning grounds in the middle part; in 2015 due to late flooding of spawning grounds and early run of the fry from the spring floods and from the channel banks, the fry number grew in the kultuks. At the end of the flooding the average length of the fry fishes made 11.7 mm, mass - 18.5 mg, which was 2 and 14 times less than in 2013, correspondingly. The main reason of juvenile bream abundance reducing in 2015 was unfavorable hydrological conditions resulting in reduced spawning areas in the Volga delta. Bream fry had no time to grow over a short period of staying in the spring floods and had to run into kultuks of the North Caspian at the unviable stage of development, which lead to negative consequences of survival and productivity of bream species.

The role of anthropogenic impact and natural habitat conditions in the reproduction of semi-passable and mass river fish of the lower reaches of the Volga River according to retrospective data

2021 ◽  
pp. 34-46
Author(s):  
Natalia Ivanovna Chavychalova ◽  
Dina Germanovna Taradina ◽  
O.M. Vasilchenko ◽  
Raigul Sadyakhovna Mukhanova
Keyword(s):  
Water Content ◽  
River Flow ◽  
Juvenile Fish ◽  
Natural Habitat ◽  
Hydrological Regime ◽  
High Water ◽  
Food Competition ◽  
Volga River ◽  
Spawning Grounds ◽  
River Fish

A retrospective review of the main factors that caused the decline in the reproduction of semi-passable fish in the lower reaches of the Volga River is given. Long-term data on the yield of juvenile semi-passable and river fish are presented, on the basis of which the current state of natural reproduction of roach, carp is estimated as low; bream, bluefin and perch — satisfactory; crucian carp, gaster and rudd — safe. Overregulation of the Volga River flow near Volgograd violated the natural conjugacy of water and temperature regimes. In the regulated period, the timing of the onset of spawning temperature in most cases is ahead of the flooding of the strips. The lag of the delta spawning grounds begins when the runoff is less than 120 km³ and reaches the maximum values (up to 27 days) in years with extremely low water content. The delay in flooding of spawning grounds in conditions of unsatisfactory water content leads to the accumulation of producers in limited areas of strips and simultaneous spawning of fish with different ecology. This leads to increased food competition of the larvae and reduced survival. After the flow was regulated, the rates of rise and fall of the hollow waters increased by 2 times, the hatching of the larvae, as a rule, coincided with the onset of the flow of the hollow waters. The mass removal of larvae into the delta watercourses at the early stages of ontogenesis, due to their lack of viability in river conditions, leads to a decrease in the productivity of spawning grounds. In the modern period (2003– 2019), due to the predominance of unfavorable hydrological regime, the duration of high water and flooding of the poloi years, and in order to clarify the yield of juvenile fish in the lower reaches of the Volga, its accounting was carried out not only in the poloi of the delta, but also in the coastal watercourses (where a large number of larvae and fry that rolled off the poloi and from local spawning), in the kultuch zone and on the poloi of the lower zone of the Volga-Akhtuba floodplain.

THE NUMBER AND QUALITATIVE CHARACTERISTICS OF FRY FISH IN SHALLOW COASTAL WATERS OF THE VOLGA IN THE SUMMER-AUTUMN PERIOD OF 2012

2017 ◽  
pp. 65-73
Author(s):  
Edward Vladimirovich Nikitin
Keyword(s):  
Fish Species ◽  
Coastal Waters ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Volga River ◽  
Commercial Fish ◽  
Autumn Period ◽  
Fish Juveniles ◽  
Qualitative Characteristics ◽  
Shallow Coastal Waters

Shallow coastal waters of the Volga river is a flooded feeding area for fish juveniles of nonmigratory fish species. There takes place annual downstream migration of fluvial anadromous fish species from spawning grounds of the Volga river to the Northern Caspian Sea. The most important factors determining the number and qualitative characteristics of fry fishes are the level of the Caspian Sea (currently having a tendency to the lowering), hydrological and thermal regimes of the Volga river. Researches were carried out in definite periods of time. In the summer-autumn period of 2012 fry fishes were presented by 19 species (13 of them were commercial species), which belonged to 9 families. The article gives data on all the commercial fish species. In the first decade of July the maximum number of fry fish was registered in the western part of the Volga outfall offshore - in box 247 (19.86 mln specimens/km2), in the eastern part - in box 142 (20.4 mln specimens/km2). The most populous were roach, red-eye, silver bream and bream; size-weight characteristics were better in the areas remoted from the Volga delta. In the third decade of July the quantitative indicators of fry fish on these areas decreased, size-weight characteristics greatly increased. In the second decade of October in the western part of the seaside there were registered increased pre-wintering concentrations of fish juveniles, their qualitative indicators increased, which is evidence to favorable feeding conditions in 2012.

scholarly journals Demographic development of Khabarovsk krai: problems and prospects

POPULATION ◽  
2019 ◽  
Vol 22 (3) ◽  
pp. 30-46
Author(s):  
Ekaterina Motrich
Keyword(s):  
Far East ◽  
Demographic Development ◽  
Khabarovsk Krai ◽  
East Region ◽  
The Far East ◽  
Natural Reproduction ◽  
Demographic Processes ◽  
Qualitative Characteristics ◽  
External Migration

Currently, the socio-economic development of the country, any of its subjects is closely linked to the dynamics of demographic processes. The paper provides a traditional analysis of statistical data on the formation of the population of Khabarovsk krai, shows the current distribution of the population of the region on its territory. The study presents the results of the analysis of the processes of natural population movement and shows the role of migration flows (intraregional, interregional and international) in the formation of the dynamics, quantitative and qualitative characteristics of the population of Khabarovsk krai in comparison with the general Far East indicators. The paper identifies the main areas of migration attraction of the population of Khabarovsk krai. There is shown the dynamics of the population of Khabarovsk krai in comparison with other subjects of the Far East. The analysis of the natural reproduction of the population in Khabarovsk krai, presented in the paper, shows the dynamics of fertility and mortality in the region and their opportunities for formation of the demographic potential in the future. The article discusses the current and prospective age structure of the population of Khabarovsk krai, compares it with similar indicators for the Far East region as a whole. Analysis of the transformation of the population structure by age revealed the situation with the reduction of labor potential, which entails the necessity to attract labor using interregional and external migration. On the basis of the established trends in the dynamics of the population, an assumption is made about the possible risks of achieving the indicators provided for by the Concept of demographic policy in the Far East of Russia. The prospective population of Khabarovsk krai is offered for consideration in two variants, the need for implementation of the task to secure population is substantiated.

Some results of monitoring for the pink salmon hatchery stocks from the Aniva Bay (Sakhalin Island)

2015 ◽  
Vol 183 (4) ◽  
pp. 51-60
Author(s):  
Marina Yu. Stekol’Shchikova
Keyword(s):  
Pink Salmon ◽  
Wild Fish ◽  
Population Parameters ◽  
Sex Composition ◽  
Spawning Grounds ◽  
Fish Size ◽  
Natural Reproduction ◽  
Aniva Bay ◽  
Salmon Hatchery ◽  
Spawning Run

Several population parameters (length and dynamics of spawning run, size-sex composition, variability of morphological and physiological characteristics) are determined and indices of survival are calculated for the pink salmon hatchery stocks from the Aniva Bay of the 2008-2011 generations on the base of the cultured pink salmon differentiation by thermal marks on otoliths. The hatchery pink salmon begin their migration to the bay rivers in late July, together with the wild fish. Size-weight parameters of the fish and their variability are similar for the hatchery and wild stocks in this period, obviously because of low impact of hatcheries on natural reproduction and high portion of wild fish among the spawners used in the hatcheries (> 50 %). Mean portion of the hatchery-reared pink salmon on spawning grounds of the main rivers was 17.9 % in the 2010-2013, the coefficients of their return varied from 1.0 % to 6.4 % that was lower than for the wild fish.

scholarly journals Relief formation of the Selenga River delta in different periods of water content during the technogenic stage of development

2020 ◽  
Vol 163 ◽  
pp. 05004
Author(s):  
Elena Ilicheva ◽  
Maksim Pavlov ◽  
Eseniya Shchipanova ◽  
Anastasia Gavrilova
Keyword(s):  
River Flow ◽  
Model Development ◽  
River Mouth ◽  
High Water ◽  
Flood Plain ◽  
Channel Network ◽  
Selenga River ◽  
Stage Of Development ◽  
Relief Formation ◽  
Basic Level

The technogenic stage of relief formation of the river mouth systems of the Lake Baikal coast occurred during the rise of the basic level in the 50-70 years of the last century and continues to the present time. In the considered stage, there were at least 6 anomalies of river flow, which caused the onset of low-water and high-water periods in the Baikal basin. Changes in the basic conditions of formation of the Baikal coast were significantly reflected in the morphology of the largest river mouth system of the Selenga River, representing the protruding delta. The fluvial process is leading in delta-forming and is controlled by the level of the receiving reservoir, hydro-climatic events in the basin and seismotectonic manifestations in the coastal zone. During the mentioned period at the top of the Delta, there was a change of the type of channel process, the restructuring of the channel network, the formation of flood-plain terrace, channel meso – and microforms was noted. Morphometric analysis of cartographic data allowed building a hydrological and geomorphological model development of the relief of the Delta, as well as for the time sections corresponding to the periods of low water and high water.

scholarly journals New information about the mechanism of oil displacement from productive reservoirs using flow control technologies

2020 ◽  
Vol 177 ◽  
pp. 01012
Author(s):  
Rustam Mukhametshin ◽  
Gulnara Kvon
Keyword(s):  
Oil Recovery ◽  
Experimental Studies ◽  
High Water ◽  
High Viscosity ◽  
Oil Displacement ◽  
Low Viscosity ◽  
Stage Of Development ◽  
Wide Range ◽  
Production Wells ◽  
Control Technologies

The article is devoted to improving the efficiency of methods application to increase oil recovery of deposits that are at the final stage of development. This stage is characterized by a high degree of waterlogging of reservoirs and extracted products. From a wide range of chemical methods for increasing oil recovery in Russian oil deposits, flow-regulating (flow-deflecting) technologies have become widespread. The article analyzes the results of purposeful use of thickened water for the completion of reserves of already flooded sandstone layers. Experimental studies were performed on two specially created five-point elements in the experimental sections of the Romashkinskoye deposit. To monitor the process of low-viscosity and high-viscosity oil displacement the following methods were used: a) intake, monitoring and production wells, in which the interval of productive horizons are lined with fiberglass pipes; b) method of high-frequency resistivity (technology of "VNIIneftepromgeophysics" Institute). The studies performed in the monitoring mode showed that, along with the increase in reservoir coverage by flooding at the macro level, there is also a displacement of part of the capillary-trapped oil in the already flooded layers’ intervals, that is, at the level of micro-uniformity of the porous medium. The paper concludes on the effectiveness of using flow-regulating technologies in conditions of high water availability of development objects.

scholarly journals The Change of the Water Regime of the Volga River in the Area of the Protected Island Bakhilovsky

2020 ◽  
Author(s):  
Keyword(s):  
Water Content ◽  
Water Regime ◽  
High Water ◽  
Ecological State ◽  
Spring Flood ◽  
Volga River ◽  
High Water Period ◽  
Average Water ◽  
Annual Water

The ecological state of the protected Islands Seredysh and Shalyga (now Bakhilovsky island) depends on the water content and flow of the Volga River. We have analyzed the long-term changes in the water flow of the Volga River for the period 1958-2017 in the alignment Zhiguli dam, located 12 km upstream from the island. According to the average annual water consumption, there are three periods that differ from each other in water content: low-water period (1958–1976), high-water period (1977–1997) and the period of average water content (1998–2017), with extremely low-water (1967, 1973, 1975, 1976, 1977, 1996) and extremely high-water (1966, 1979, 1981, 1990, 1991, 1994) years. In highwater years, during the passage of the spring flood, the island is almost completely flooded, and in low-water years, during the summer low water, the area of the island increases and changes its configuration.

scholarly journals FEATURES OF GILL FORMATION IN ROACH FRY ON SPAWNING GROUNDS OF THE VOLGA DELTA

2019 ◽  
pp. 66-71
Author(s):  
Nadezhda Yurievna Terpugova ◽  
Maria Pavlovna Grushko ◽  
Nadezhda Nickolaevna Fedorova
Keyword(s):  
Environmental Changes ◽  
Morphological Changes ◽  
Histological Study ◽  
Physiological State ◽  
Aquatic Organisms ◽  
Respiratory Epithelium ◽  
Water Bodies ◽  
Spawning Grounds ◽  
Volga Delta ◽  
Larval Stages

The article focuses on the influence of anthropogenic load initiating multidirectional metamorphosis of biological processes in the aquatic organisms in the Volga delta. The gill apparatus responds primarily to the environmental changes. There has been carried out a histological study of the gill apparatus of carp species, actually, late larvae and early roach fry, which helps to identify and describe the ecological situation on the spawning grounds in the Volga delta. Various morphological changes in the gills indicating respiratory disturbances were revealed. The late roach larvae and fry have been found to obtain the overgrown respiratory epithelium on the lamella tops, proliferation of multilayered non-keratinizing epithelium, vasodilation, deformation and curvature of the cartilage plate and filaments, lack of lamellae, joining of the side surfaces and filament hemorrhage. It has been stated that in comparison with the larval stages of development, in the fry period the occurrence of the respiratory epithelium accretion increases. The changes found in the gill apparatus of the examined roach larvae and fry indicate the unsatisfied physiological state of the fish in some water bodies of the Volga delta. This is explained by the fact that the gills suffer from the direct impact of the negative factors of the aquatic environment including different pollutants in the flooded water bodies.

scholarly journals Justification of necessity to consider well interference in the process of well

2021 ◽  
pp. 77-87
Author(s):  
I.N. Khakimzyanov ◽  
◽  
V.Sh. Mukhametshin ◽  
R.N. Bakhtizin ◽  
A.V. Lifantyev ◽  
...  
Keyword(s):  
Early Stage ◽  
High Water ◽  
Oil Field ◽  
Pressure Differential ◽  
Field Scale ◽  
Stage Of Development ◽  
Well Pattern ◽  
Oil Flow ◽  
Scale Experiment ◽  
High Water Cut

The paper discusses results of the unique field-scale experiment on halving of active wells and increase of pressure differential at bottomholes of active wells in the Bavlinskoye oil field. With a view to assess the effect of well interference between shut-in and active wells, two scenarios of oil flow lines in the reservoir, shut-in scenario and do-nothing scenario, were modeled. The numerical computation demonstrated that increase of pressure differential at an early stage of development can maintain the obtained level of production with a less number of free-flowing wells. It was also found that an optimal well pattern has to be used at an early stage of development. In this case, oil losses are lower vs. infill drilling at the late stage of development. In the latter case, high water cut challenges economic production, which was the case with half of re-entry experimental wells. Keywords: free-flow production; increase of differential pressure; field-scale experiment; well pattern; well interference; oil flow paths.

Sign in / Sign up

Export Citation Format

Share Document