scholarly journals CURRENT STATE OF FISHERIES AND ASSESSMENT OF FISH STOCKS IN THE WESTERN MIDDLE OF THE CASPIAN SEA. PROSPECTS FOR THE USE OF THE FISH RESOURCES

2016 ◽  
Vol 11 (2) ◽  
pp. 70-83
Author(s):  
A. S. Abdusamadov ◽  
S. A. Guseinova ◽  
L. A. Dudurkhanova
Keyword(s):  
Caspian Sea ◽  
The Caspian Sea ◽  
Fish Stocks ◽  
Fish Resources ◽  
Current State

scholarly journals Contribution of the researchers of the Department of Ichthyology and Hydrobiology of Saint-Petersburg State University to the conservation of the Caspian sturgeon population

2019 ◽  
Vol 323 (4) ◽  
pp. 498-505
Author(s):  
R.P. Khodorevskaya
Keyword(s):  
Caspian Sea ◽  
Physiological State ◽  
Biological Indicators ◽  
Commercial Fishing ◽  
Caspian Basin ◽  
State University ◽  
The Caspian Sea ◽  
Saint Petersburg ◽  
Current State ◽  
Artificial Breeding

The paper deals with the main historical moments of the Caspian sturgeon population dynamics and the formation of their stocks. The participation of researchers of the Department of Ichthyology and Hydrobiology of Saint-Petersburg State University in creating the concept of sturgeon conservation in the Caspian Sea and the specialized institute of sturgeon farming in Astrakhan was highly appreciated. The materials on the contribution of the Department’s researchers to the study of the physiological state of sturgeon producers, improving their quality, survival and safety in the conditions of artificial breeding of these species are presented. The data on the reduction of the sturgeon abundance reared and released into the Caspian Sea by the Caspian littoral states are presented. A description of the current state of the sturgeon of the Caspian basin is given. The data on changes in stocks, the structure of the spawning part of the population and reproduction of the beluga, Russian sturgeon and stellate sturgeon in the Volga-Caspian basin under the conditions of the prohibition of their commercial fishing are analyzed. It was shown that during the years of the ban, the abundance and stocks of sturgeon and biological indicators of breeding migrants to spawn in the Volga continued to decrease and the proportion of females among them, which is associated with the illegal catch of sturgeon, comparable in scale to the commercial fishery before the ban was introduced. Reduced natural (up to its complete cessation in the Beluga) and artificial reproduction of sturgeons are stated. Only observing the moratorium on sturgeon fishing in all the Caspian littoral states, strengthening the protection of fish at feeding grounds and spawning migrations can preserve and restore their unique Caspian populations.

TO STUDY THE BIOECOLOGY OF CASPIAN SHRIMPS

2021 ◽  
pp. 98-102
Author(s):  
Kais M. Guseynov ◽  
Aysha Sh. Gasanova ◽  
Marina V. Khlopkova
Keyword(s):  
Caspian Sea ◽  
Regression Equations ◽  
The Caspian Sea ◽  
Macrobrachium Nipponense ◽  
The North ◽  
Current State ◽  
Palaemon Elegans ◽  
Near Future ◽  
The Relationship ◽  
Shrimp Population

Only two species of shrimps live in the Caspian Sea: Palaemon elegans and P. adspersus (Crustacea, Decapoda: Palaemonidae), which were introduced to the Caspian Sea in 1931-1934 during the introduction of mullets. Data on the biology of these species of shrimps are reflected only in the works by E.N. Kudelina (1950) and M.P. Marochkina (1980). This determines the relevance of research on the current state of the Caspian shrimp population. The material was collected in various areas of the Middle Caspian Sea in the summer-autumn period. Both species live up to five meters deep. P. elegans prefer coastal underwater objects with dense thickets, P. adspersus - open shallow waters with sandy-muddy soil. To the north of Makhachkala, P. elegans predominates, to the south, the number of both species is the same, and to the east, P. adspersus dominates. The characteristics of breeding females are presented, and the dependence of fecundity on the length of egg-bearing females is revealed. The absolute fecundity increased with the increase in the size of the females. Regression equations reflecting the relationship between fecundity and length of egg-bearing females of P. elegans and P. adspersus are calculated, expressed by power equations, respectively: E = 0.044947 · L265356 and E = 2.323 · L17.4, where: E - fecundity, L-length. In October 2017, in May and October 2018, several specimens of the subtropical freshwater shrimp Macrobrachium nipponense were found downstream of the Terek River. Probably, in the near future, the species composition of the Caspian shrimp will be replenished with another species.

scholarly journals Retrospective analysis and current state of walleye stocks and fishery on the Dagestan coast of the Caspian Sea

2021 ◽  
Vol 699 (1) ◽  
pp. 012053
Author(s):  
A K Alieva ◽  
B M Nasibulina ◽  
T A Abdusamadov ◽  
T F Kurochkina ◽  
A D Guseynov
Keyword(s):  
Retrospective Analysis ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Current State

scholarly journals STATE OF FISHERIES IN SOUTH REGION OF VOLGO-CASPIAN FISHERIES BASIN

2021 ◽  
Vol 2021 (3) ◽  
pp. 7-17
Author(s):  
Pavel Aleksandrovich Balykin ◽  
Raisa Pavlovna Khodorevskaya
Keyword(s):  
Annual Runoff ◽  
Southern Region ◽  
The Caspian Sea ◽  
Volga River ◽  
Total Allowable Catch ◽  
Fish Resources ◽  
The North ◽  
Current State ◽  
Pike Perch ◽  
North Western

The paper presents the generalized materials on the current state of fisheries in the Northern part of the Caspian Sea (southern region of the Volga-Caspian fisheries basin). It is shown that catches in the North-Western and Tersk-Caspian subdistricts varied in the opposite way: an increase in production in one subdistrict was accompanied by a decrease in the other. The decreasing or increasing catches is due to semi-anadromous (roach, brim, zander, carp) and freshwaterfish species (cat-fish, pike-perch, small size ordinary fish). There have been found the significant relationships between the size of catches in the North-Western and Tersk-Caspian subdistricts with the annual runoff and the volume of spring flooding of the Volga river, which allows to conclude that fish resources are redistributed between these regions depending on the natural conditions of a particular year. In order to more fully develop the fish resources of the southern region of the Volga-Caspian fisheries basin, it is recommended to abandon the division of quotas into parts for the North-Western and Tersk-Caspian subdistricts and to allow the fishing organizations to work at the expense of the total allowable catch

scholarly journals Current State and Economic Value of Astacofauna in Certain Areas of the Eastern Shelf of the Caspian Sea

2020 ◽  
Vol 15 (1) ◽  
pp. 28-36
Author(s):  
V. B. Ushivtsev ◽  
S. V. Vostokov ◽  
G. A. Akhmedova ◽  
M. L. Galaktionova ◽  
S. A. Kotenkov
Keyword(s):  
Comparative Analysis ◽  
Caspian Sea ◽  
Dominant Species ◽  
Economic Value ◽  
The Caspian Sea ◽  
Current State ◽  
Cluster Density ◽  
Eastern Shelf ◽  
Survey Protocol

Aim. The purpose of this work was to assess the current state of crayfish populations in their habitats on the eastern shelf of the Caspian Sea (Alexander Bekovich‐Cherkassky Bay).Material and Methods. Fieldwork was based on underwater research methods using light diving equipment. Collection of research material was carried out according to an established crayfish survey protocol using fixed grid sites of 100 square metres. Collected crayfish were identified by species, measured and weighed, fecundity of females and the condition of crayfish shells were recorded. Crayfish were then released back into the sea. Calculation of numbers was carried out on the basis of determination of cluster density (ind/m2) with a further assessment of useful biotype areas. Calculation of commercial stocks based on crayfish length. The research synthesized information derived from comparative analysis of modern research results and archival data from the 1970s to 1990s.Results. Analysis showed that significant changes in the composition of populations had occurred. The dominant species recorded was Caspiastacus pachypus Rathke which has substantially displaced from the biotopes Pontastacus eichwald  Воtt. which was previously the dominant species here.Conclusion. Comparative analysis of the modern state of the astacofauna on the eastern shelf and historical data indicates significant changes in the structure of populations of Caspian crayfish. The resilient C. pachypus has become the dominant species. Its small commercial size has significantly reduced the economic value of crayfish stocks. In general, however, commercial stocks of these crayfish make it possible to develop these marine biological resources.

scholarly journals The current state of commercial stocks and reserves of the Caspian Sea fishery

Trudy VNIRO ◽  
2018 ◽  
Vol 171 ◽  
pp. 141-156
Author(s):  
A. V. Mirzoyan ◽  
◽  
V. A. Kalmykov ◽  
S. V. Kanatiev ◽  
R. P. Khodorevskaya ◽  
...  
Keyword(s):  
Caspian Sea ◽  
The Caspian Sea ◽  
Current State

scholarly journals Biology and current state of anchovy kilka (Clupeonella engrauliformis Borodin)

2020 ◽  
Vol 2020 (2) ◽  
pp. 45-51
Author(s):  
Vjacheslav Petrovich Razinkov ◽  
Yuriy Aleksandrovich Paritskiy ◽  
Yulia Nikolaevna Grozesku
Keyword(s):  
Survival Rate ◽  
Caspian Sea ◽  
Small Fish ◽  
Way Of Life ◽  
The Caspian Sea ◽  
Dynamics Of Abundance ◽  
Current State ◽  
Beroe Ovata ◽  
The Relationship ◽  
A New Species

In the Caspian Sea sprats is the name of the numerous small fish of herring family (Clupeonella). One of Clupeonella representatives is anchovy sprat. It differs from other types of kilka not only in appearance, but also in its way of life. A brief biology of the species and the state of ecosystem of the Caspian pelagic zone has been described. Anchovy kilka has been a leading targeted fish for over 50 years. Invading the Caspian Sea by ctenophore-mnemiopsis has undermined the stocks of anchovy sprats and caused the crisis of anchovy kilka fishing. Recently, there has been observed a slight increase in the number of the species. The survey materials confirm the increase in the number of juveniles in the studied catches. There are presented the materials from the last six years (2014–2019) of observations (eight research runs), shown the dynamics of abundance, biomass, spawning females, and total fertility of the population. Spawning efficiency and survival rate in early ontogenesis are analyzed. The relationship between kilka survival rate and the number of emerging generations is stated. Recommendations on restoring the stock of anchovy kilka are given. To restore the ecosystem of the Caspian Sea there has been proposed the invasion of a new species – ctenophore-beroe (Beroe ovata), which, due to the structure of its mouthparts eats only jelly-skinned (ctenophore-mnemiopsis, exceptionally) and can significantly reduce the number of ctenophore-mnemiopsis

scholarly journals Species Composition of the Benthic Macroinvertebrates on the Coastline Vegetated Rocky Substrates of the Southern Caspian Sea

2015 ◽  
Vol 16 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Amir Faraz Ghasemi
Keyword(s):  
Caspian Sea ◽  
Benthic Fauna ◽  
The Caspian Sea ◽  
Additional Food ◽  
Fish Stocks ◽  
Balanus Improvisus ◽  
Palaemon Elegans ◽  
Potential Interactions ◽  
Mytilaster Lineatus ◽  
Southern Caspian Sea

Abstract For studying benthic macrofaunal composition associated with seagrass rocky beds of the southern Caspian Sea, two time samplings were carried out along the coast line in the winter and summer of 2013. In total, 1,286 specimens of the five species were identified: Pontogammarus maeoticus, Balanus improvisus, Mytilaster lineatus, Palaemon elegans and Alitta succinea. The total recorded abundance was 5,675 and 755 ind./m2, with a biomass of 147,271 and 31,238 mg/m2 in the winter and summer respectively. The collected species in this study are generally non-indigenous (except P. maeoticus) and could potentially have an effect on native benthic fauna, as an additional food source could facilitate the commercially exploited fish stocks. Thus further studies are required to monitor their potential interactions on the Caspian Sea fauna

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.

CURRENT STATE FOR FOOD SUPPLY OF BENTHOPHAGIC FISH IN THE URAL RIVER DELTA AND THE NORTH PART OF THE CASPIAN SEA

2017 ◽  
pp. 54-61
Author(s):  
Leila Kamidullaevna Seydalieva
Keyword(s):  
Caspian Sea ◽  
Hediste Diversicolor ◽  
The Caspian Sea ◽  
The North ◽  
Current State ◽  
Chironomidae Larvae ◽  
North Part ◽  
Average Biomass ◽  
June July ◽  
Made In

The paper presents the results of the research held in spring-autumn, 2014. In the course of the research there were used complex field observations. There was determined qualitative composition of zoobenthos of the lower reaches and the delta of the Ural (13 taxons) and the North part of the Caspian Sea (33 taxons, main groups: crustaceans, molluscas and worms), quantity and biomass of main species and groups of zoobenthos. In the lower reaches of the Ural Oligochaeta worms made the largest group, Chironomidae larvae made a smoller group. In August average biomass of zoobenthos in the delta of the Ural made 16.66 g/m2. In the North part of the Caspian Sea maximum domination index belonged to Oligochaeta - 12.5; Hypanis vitrea vitrea had 7.1; Chironomidae larvae - 6.4. Corophiidae were numerous , with domination index 6.3; Balanus improvisus had 6.2; Hediste diversicolor - 4.7. Domination index of other bottom organisms didn’t exceed 3.8. Average biomass of bottom organizms in the North Part of the Caspian Sea made: in June - July 20.48 g/m2, in September 9.212 g/m2. Stern zoobenthos took (without taking into account large molluscas and barnacles) 8.14 and 3.8 g/m2, respectively. The data obtained can be used for determining methods of saving and stable use of fish resources in the Ural-Caspian Sea basin.

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