scholarly journals BIODIVERSITY OF OBJECTS OF AQUATIC BIORESOURCES OF THE VOLGA-CASPIAN FISHERY AREA

2017 ◽  
pp. 49-60
Author(s):  
Arsen Vyacheslavovich Mirzoyan ◽  
Raisa Pavlovna Khodorevskaya
Keyword(s):  
Caspian Sea ◽  
Sea Water ◽  
Natural Populations ◽  
Water Area ◽  
Commercial Fishing ◽  
Ecological Groups ◽  
The Caspian Sea ◽  
Sea Level Fluctuations ◽  
The North ◽  
Caspian Seal

In the course of the study there has been carried out the analysis of the data (both first-hand research and literature data), which characterize different species of fish, Caspian seal, river and crayfish and lobsters of the Volga-Caspian fishery basin. There have been listed families and species composition of the water biological resources on the water area of the Volga-Caspian fishery basin - 125 species and subspecies of fish (only 35 species are used in commercial fishing), belonging to 21 families. They have been divided into ecological groups according to spawning zones, preferred habitats and types of nutrition. Main features of ecological changes happened in the Caspian Sea for the last 65-70 years and resulted in drastic drop of fish catch volumes including sturgeons have been considered. In the populations of all sturgeon species there is a marked trend to dominating the young fishes - up to 80%. Increase in the number and improved biological characteristics was registered only in anadromous herring ( Alosa kessleri kessleri ) sires. Caspian seal retains the number of population on the level of the average annual figures, which is related to the favorable conditions for fattening and absence of critical epizootic situations. Materials on the long-term changes in the level of the Caspian Sea have been analyzed. The correspondence of sea level fluctuations and the size of commercial catches has been studied. The recommended measures for maintaining and development of the fishery complex in the Russian area of the Caspian basin (the Russian region) have been listed. The preservation of natural populations of all fish species, especially sea fish, anadromous fish of the Caspian Sea seems to be possible only if there are coordinated actions of all littoral states for preventing sea water pollution in the process of exploration and extraction of raw hydrocarbons, providing international inspections over preventive measures and creating the preserve zone in the North of the Caspian Sea (Russia, Kazakhstan).

scholarly journals STATE OF POPULATION OF PIKE PERCH OF THE LOWER FLOW OF THE URAL RIVER

2018 ◽  
pp. 83-89
Author(s):  
Sergey Vladimirovich Kuzmenko ◽  
Arkadii Fedorovich Sokolsky ◽  
Alexander Nickolaevich Nevalennyy ◽  
Nikolay Nikolayevich Popov
Keyword(s):  
Caspian Sea ◽  
Fishing Ground ◽  
Commercial Fishing ◽  
The Caspian Sea ◽  
Foreign Markets ◽  
North East ◽  
The North ◽  
Pike Perch ◽  
Exploration And Production ◽  
Commercial Species

In domestic and foreign markets a great demand for pike perch is caused by the fact that its meat is a digestible and dietetic product. Due to growing scales of exploration and production of oil, as well as of poaching in the last years pikeperch and other species suffer from anthropogenic load. In 1990 spike perch catches reached 4.49.000 tons and made 1/3 of total catch of semi anadromous and river fish. During the last decade pike perch catches have decreased in the Ural-Caspian region up to 380 t, according to data of 2016. The study of pike perch populations on fishing zones of the Ural (delta, Malaya Dambinskaya fishing ground) covered the data obtained in 2010-2016. There have been studied migrating periods of pike perch to the spawning grounds. Since 2011 there has been stated a drastic decrease of sire number and a much less catch of pike perch per one casting in autumn, which was caused by the permission for fishing in the coastal part of the Caspian Sea. According to the research data, there have been given size-weight parameters of pike-perch producers in the Ural river during 10 years (2006-2016). The tendency to juvenation of spawning pike perch species is stated due to increasing share of the first spawning species, as well as due to decreasing number of male species in the catches as their age increased. Fultin and Clark’s condition coefficients are shown. Importance of pike perch as a commercial species in the ecosystem of the Ural-Caspian fishery zone contributes to define the following recommendations on saving and restoring pike perch population: to reduce commercial catches in the estuarine area of the Ural; to forbid commercial fishing in the coastal area of the north-east part of the Caspian Sea; to intensify fishery inspection in the Urals.

State of populations and fishing of semi-anadromous fish in the North-Eastern Caspian sea

2021 ◽  
pp. 22 (87)-30 (94)
Author(s):  
Askarbay Kadralievich Kamelov
Keyword(s):  
Caspian Sea ◽  
Water Area ◽  
The State ◽  
Anthropogenic Factors ◽  
Anadromous Fish ◽  
The Caspian Sea ◽  
The North ◽  
Natural Reproduction ◽  
Pike Perch ◽  
North Eastern

Semi-anadromous fish (roach, bream, pike-perch, asp) are the main objects of fishing in the coastal zone of the North-Eastern part of the Caspian Sea. The state of the populations of these fish changes significantly under the influence of natural and, especially, anthropogenic factors, which have increased in recent years. The aim of this work was to study the current state of populations of semi-anadromous fish in the NorthEastern Caspian Sea. Based on the materials of three years of research (2016, 2018, 2020), with the involvement of literary sources, long-term changes in the size-weight and, age indicators, nutritional status of fish and the sex ratio in populations are considered. It has been established that the state of the semi-anadromous fish populations in the North-Eastern Caspian remains tense at the present time. All populations are characterized by general negative patterns of state change. There are tendencies of decrease in size, weight and age indicators, the number of populations and fish catches are decreasing. These changes were least of all manifested in bream (whose state is relatively stable) and were most pronounced in pike perch. The depressive state of the populations is explained by a decrease in the scale of natural reproduction in recent years, due to a decrease in the water content of the Ural River and the number of spawners allowed to spawn on the river. Marine fisheries in the North-Eastern Caspian are concentrated in shallow waters, which increases the fishing load on semi-anadromous fish and prevents their passage to spawning. It is necessary to reduce the pressure of fishing by reducing the number of nets used in the shallow water area of the North-Eastern Caspian and strict observance of the rule of the forbidden pre-estuary space of the river Ural. English version of the article on pp. 87-94 is available at URL: https://panor.ru/articles/state-of-populations-and-fishing-of-semi-anadromous-fish-in-the-north-eastern-caspian-sea/64076.html

scholarly journals TSUNAMI HAZARD ASSESSMENT IN THE CASPIAN SEA

2019 ◽  
Vol 47 (5) ◽  
pp. 74-88
Author(s):  
E. A. Kulikov ◽  
A. Yu. Medvedeva ◽  
I. V. Fine
Keyword(s):  
Hazard Assessment ◽  
Caspian Sea ◽  
Water Area ◽  
Tsunami Hazard ◽  
Estimation Of Parameters ◽  
The Caspian Sea ◽  
Tsunami Waves ◽  
The North ◽  
Tsunami Hazard Assessment ◽  
Run Up

The article describes the tsunami hazard assessment for the coast of the Caspian Sea, in particular for the Absheron Peninsula. Due to the high socio-economic load on the coast of this region by electric power and oil production industries requirements, it is necessary to take into account risks even for such extremely rare natural phenomena like tsunamis. An earthquake with M = 8 ± 0.2 can occur throughout the Caspian Sea region, including land, once every 216 years, while for the water area the frequency of occurrence of such an event is 1620 years. The article presents the results of a tsunami hazard assessment based on a deterministic approach for the Absheron Peninsula. This approach of the tsunami hazard assessing of an arbitrary part of the coast consists of selecting of the strongest observed (or hypothetical) tsunami event from a neighborhood and from a distant zone, of the subsequent estimation of parameters for model sources and, finally, of the numerical modeling of tsunami generation and propagation from these sources. It was obtained that with the propagation of tsunami waves from the north to the coast of the Absheron Peninsula, its height can reach 3‒4 m for some parts of the coast with run-up 500‒1500 m.

scholarly journals DISTRIBUTION OF CASPIAN SPRATS IN THE NORTH-WESTERN PART OF THE CASPIAN SEA (BASED ON RESULTS OF HYDROACOUSTIC RESEARCH IN NOVEMBER 2018)

2019 ◽  
pp. 41-50
Author(s):  
Tatiana Vasilievna Pomogaeva
Keyword(s):  
Caspian Sea ◽  
Water Surface ◽  
Bottom Layer ◽  
Water Area ◽  
Middle Part ◽  
Average Density ◽  
Layer By Layer ◽  
The Caspian Sea ◽  
The North ◽  
Study Results

Since Caspian sprat today is a reserve fishery object, hydroacoustic studies are the main purpose of solving the problem of estimating concentrations, areas and terms of the organization of the Russian marine fishery. A promising fishing area is the region of the middle part of the Caspian Sea, off the Dagestan coast, which has been studied since 2011. As it was found during previous studies, the densest sprat schools form in the autumn period in the bottom layer. The present research focuses on Caspian sprat distribution in the western part of the Middle Caspian in November 2018. Hydroacoustic tacks covered a water area of 630 NM. The echo recordings of hydroacoustic surveys covering the water area at the depths 20-60 m were analyzed. The recordings were studied considering the response of sprat to the day and night light. Processing of hydroacoustic data was carried out in several stages: analytical viewing of echograms purposed to identify specific features of sprat; recording minimum and maximum values of echo intensity depending on the depth; data post-processing in SIMRAD BI-60 program. The distribution of Caspian sprats is represented totally from the water surface to the ground, and layer by layer, in layers of 10 meters from the water surface. It has been stated that in the surface layer there are practically no sprat schools. The maximum value of the average density (8.7 t / mile2) was registered in the bottom layer (40-50 m). The study results can be used in organization of Russian sprats fishing in the Caspian Sea.

Intraannual and interannual variability of storm surges in the North Caspian Sea

2020 ◽  
Vol 3 ◽  
pp. 42-57
Author(s):  
A.V. Pavlova ◽  
◽  
V.S. Arkhipkin ◽  
S.A. Myslenkov ◽  
◽  
...  
Keyword(s):  
Sea Level ◽  
Caspian Sea ◽  
Storm Surges ◽  
Western Coast ◽  
Coastal Zones ◽  
The Caspian Sea ◽  
Sea Level Fluctuations ◽  
The North ◽  
Inundation Area ◽  
Flooded Area

The article presents the results of hydrodynamic modeling of sea level fluctuations in the Caspian Sea using the ADCIRC model for the period from 1979 to 2017. Surges are simulated using an irregular triangulation computational grid with a changing cell size, that easily adapts to changes in shoreline and depth and, therefore, more accurately describes coastal zones. It is found that the seasonal variability of surges is characterized by a maximum in winter and spring and by a minimum in summer. On the western coast of the North Caspian Sea, the maximum sea-level fluctuations are observed in December-February, and on the northern and eastern coasts – in February and March. The areas of inundation of the coastal territory of the Russian sector of the sea are identified. For the surge on March 12–16, 1995, that was one of the most catastrophic ones in terms of its consequences, the inundation area made up 53% of the possible flooded area, and the inundation area for the surge registered on March 27–April 1, 2015 made up 71 %. The more severe consequences of the surge in 1995 are associated with the fact that the mean annual sea level, that determines the possible flooded area, in 1995 was much higher than in 2015. Keywords: ADCIRC, Caspian Sea, unstructured grid, storm surge, sea level, numerical modeling Fig. 11. Ref. 15.

scholarly journals Contemporary ecological state of waters of the Caspian Sea during development of oil and gas deposits

2021 ◽  
Vol 16 (2) ◽  
pp. 98-107
Author(s):  
A. F. Sokolskiy ◽  
A. Sh. Kanbetov ◽  
N. N. Popov ◽  
B. A. Mutashev ◽  
N. I. Rabazanov
Keyword(s):  
Caspian Sea ◽  
Oil And Gas ◽  
Sea Water ◽  
Petroleum Products ◽  
Water Area ◽  
Gas Production ◽  
Biogenic Elements ◽  
The Caspian Sea ◽  
Marine Research ◽  
The Impact

Aim. This study was an attempt by the authors to identify the impact of oil production in the Caspian Sea on the quality of waters surrounding oil and gas-production platforms.Material and Methods. In 2018, by order of the Committee for Forestry and Wildlife of the Ministry of Agriculture of the Republic of Kazakhstan, Kazekoproekt carried out comprehensive marine research to assess the state of biological resources in the eastern part of the Caspian Sea. All studies were carried out according to standard methods accepted in international practice. Samples were collected in summer (July-August) 2018 and autumn (September) 2018.Results. An analysis of the materials of environmental studies carried out in the water area of the eastern part of the Caspian Sea in 2018 established the absence of biogenic concentrations in sea water in excess of the standard indicators. It was found that in the waters surrounding several stations in summer and autumn, concentrations of oil products were exceeded. The concentrations of pesticides in the waters of the northern Caspian Sea recorded in 2018 were not detected.Conclusion. It was found that in the eastern part of the Caspian Sea in 2018 there was no concentration of biogenic elements in sea water above the standard indicators. Of the heavy metals, an excess of maximum permissible concentrations was found only at one station - of copper in the summer over 159 sq. m and in the autumn over 121 sq. m. Of particular concern is the fact that at several stations in summer and autumn excessive concentrations of petroleum products were recorded. The concentrations of pesticides in the waters of the northern Caspian Sea recorded in 2018 were not detected.

scholarly journals DYNAMICS OF ZOOBENTHOS DEVELOPMENT WITHIN THE WATER AREA OF THE YURI KORCHAGIN FIELD IN THE NORT PART OF THE CASPIAN SEA

2018 ◽  
pp. 89-97
Author(s):  
Semen Nikolaevich Studnikov ◽  
Lyubov Vasilievna Malinovskaya ◽  
Alexey Vladimirovich Kuzin
Keyword(s):  
Population Density ◽  
Benthic Invertebrates ◽  
Caspian Sea ◽  
Water Area ◽  
The Caspian Sea ◽  
Survey Period ◽  
Gas Field ◽  
Field Development ◽  
The North ◽  
North Part

One of the main purposes of the monitoring studies is a long-term research of benthic communities of the north part of the Caspian Sea. Analysis of quantitative and qualitative characteristics is the only means to formulate main laws of the development of benthic biocenosis in terms of enhanced oil and gas field development, as well as to provide a forecast of the state of the fields and of the human impact on them. In the survey period, from 2014 to 2016, 43 species of benthic invertebrates, namely 2 species of Annelida, 32 species of Crustacea and 9 species of Mollusca, were identified as the result of zoobenthos development study. In that period, total average population density of the benthic fauna within the Yuri Korchagin field water area made 6 716 organisms per square meter, while the general average biomass constituted 77.324 grams per square meter. During the whole period of the research such zoobenthos species as Crustaceans and mainly Gammarids, including Ch. Ischnus and St. similis , dominated in terms of population density. As to biomass, the most abundant zoobenthos species were molluscs - Mediterranean species M. lineatus and A. ovata with D. protracta - a marine species - dominating in different years. Zoobenthos diversity, quantity fluctuations and dominance of given species in biomass and population density at certain stations of the studied water area were linked principally to the water salinity, type of soil and food resources availability. The study of benthic invertebrates showed that Yuri Korchagin field area in the north part of the Caspian Sea is characterized by a high development of euryhaline and marine benthic invertebrates.

CURRENT STATE OF CASPIAN SEAL POPULATION

2017 ◽  
pp. 35-45
Author(s):  
Vasilii Vladimirovich Kuznetsov
Keyword(s):  
Caspian Sea ◽  
Ecological Monitoring ◽  
Water Area ◽  
Fishing Effort ◽  
Winter Period ◽  
The Caspian Sea ◽  
Current State ◽  
Seal Population ◽  
Ship Route ◽  
Caspian Seal

The work presents Caspian seal study review. The study gives investigation results on the current state of Caspian seal population, as well as advanced techniques of determining the number of offspring and producing females. In February 2012 during reproduction period the instrumental air-accounting survey was carried out on ice-water area in the Northern part of the Caspian Sea. For the first time in the history of the air-accounting investigations of seals in the Caspian Sea scientists used thermovision camera survey IK-scanner "Malakhit-M" which helped specify the number of white-coat seals and greatly improve deciphering methods of the obtained materials. The authors discuss the drawbacks of the earlier air-surveys of the Caspian seals (made before 2012) carried out by a group of researches. The work gives characteristics of nutrient resources of the Caspian Sea and annual food necessity of Caspian seal population. The nutrient base of seals is sound and food stocks tend to grow in the future. The work gives the reasons of decrease of seal catch since 1967; it is associated with the reduction of the fishing effort and re-orientation in winter period by the method of marine fisheries. The article shows that ship route accounting alive and dead species in different parts of the Caspian Sea which was used for ecological monitoring of the population permits to effectively control the changes of seal number, including mass epizootics. In recent years ship-route accounting has shown the stable dynamics of average concentrations of seals in the Northern, Middle and Southern parts of the Caspian Sea. Ship-route accounting presents the up-to-date total number of the seal population.

scholarly journals SCENARIO FORECASTS OF THE CASPIAN SEA FLUCTUATIONS IN THE LEVEL UNDER CLIMATIC AND MAN-MADE IMPACTS ON THE SEA WATER BALANCE

2019 ◽  
Vol 47 (5) ◽  
pp. 130-148 ◽  
Author(s):  
A. V. Frolov
Keyword(s):  
Water Balance ◽  
Sea Level ◽  
Positive Feedback ◽  
Caspian Sea ◽  
Sea Water ◽  
Nonlinear Dependence ◽  
The Caspian Sea ◽  
Sea Level Fluctuations ◽  
Sea Area

The paper deal with the scenario method for predicting long-term fluctuations in the Caspian Sea level. The scenario forecasts are included: Model of the sea level fluctuations mechanism, Models of the main components of the sea water balance, Morphometric characteristics of sea, Dependence between the outflow of water into the Kara-Bogaz-Gol Bay and the sea level, Assessments of possible direct technogenic impacts on the sea water balance, for example, the withdrawals of water from the inflow into the sea. The Caspian Sea level long-term fluctuations are considered by us as the output process of a non-linear hydrological system. The mechanism of the Caspian level fluctuations contains two negative and one positive feedback. The dependences of the Caspian sea area and the outflow from the sea into the Kara-Bogaz-Gulf bay on the sea level form negative feedbacks. Positive feedback is formed by the nonlinear dependence of evaporation from the sea area on the sea level. Under certain conditions, the effect of this dependence can lead to the sea level bimodal probability distribution density. A necessary (but not sufficient) condition for bimodality is the absence of free seawater inflow from the sea into Kara-Bogaz-Gol. The results of scenario forecasts of the Caspian Sea level developed within the framework of the Caspian Federal Targeted Program (1994-95) are presented. The linear and nonlinear models of the sea level fluctuations used in scenario forecasts are discussed. Failure to take into account of any kind of the feedbacks leads to incorrect predictive estimates of the sea level fluctuations statistical characteristics.

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