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 QUANTITY AND DISTRIBUTION OF CASPIAN ROACH, BREAM AND PIKE PERCH UNDERYEARLINGS IN THE NORTH-WEST OF THE CASPIAN SEA IN CONDITIONS OF THE VOLGA HIGH WATER AND LOW WATER RUN OFF

2018 ◽  
pp. 74-82
Author(s):  
Ljubov’ Aleksandrovna Belogolova ◽  
Tatyana Anatolievna Solokhina
Keyword(s):  
Caspian Sea ◽  
High Water ◽  
Water Area ◽  
The Caspian Sea ◽  
Volga River ◽  
North West ◽  
The North ◽  
Run Off ◽  
Pike Perch ◽  
Caspian Roach

The article presents the comparative analysis of quantity and the distribution of Caspian roach, bream and pike perch underyearlings in western part of the northern Caspian in the current context of the Volga river high water and low-water run-off in 2013-2016. It has been shown that, depending on conditions of each year, the quantity of the three species underyearlings varies too much. The biggest number of Caspian roach and bream in the period under review was observed in 2013 and 2016, and the biggest pike perch quantity - in 2016. In spite of certain variability, the quantity of Caspian roach and pike perch underyearlings stays low today. Bream quantity in some years increased up to the level of middle yielding generations. In spite of low quantity, Caspian roach underyearlings almost completely developed feeding territories of western part of the north Caspian in both high water and in low-water years. The foraging area of bream and especially of pike perch underyearlings is smaller than Caspian roach one. They spread to the maximum upon the water area of the Caspian Sea in 2016, that year was the most favorable in salinity for generative freshwater fish for the last few years. Caspian roach underyearlings generally gained weight in waters with salinity over 8‰, bream - in desalinated areas with salinity up to 5‰. Pike perch underyearlings stayed in desalinated areas during the high water years; they were found across the studied spectrum with low (0-5‰), high (>10‰) and moderate water salinity (5-8‰) during the low-water years.

ICE CONDITIONS IN THE NORTH-WESTERN PART OF THE CASPIAN SEA IN THE MODERN PERIOD

2020 ◽  
Vol 19 (6) ◽  
pp. 4-17
Author(s):  
Nepomenko Leonid ◽  
◽  
Popova Natalia ◽  
Zubanov Stepan ◽  
Ostrovskaya Elena ◽  
...  
Keyword(s):  
Caspian Sea ◽  
The Caspian Sea ◽  
The North ◽  
Modern Period ◽  
Ice Conditions ◽  
North Western

scholarly journals DISTRIBUTION AND NUTRITION OF RUSSIAN STURGEON JUVENILES ( АCIPENSER GUELDENSTAEDTII, АCIPENSERIDAE) IN THE NORTH-WESTERN PART OF THE CASPIAN SEA

2019 ◽  
Vol 20 (3) ◽  
pp. 326-338
Author(s):  
S.V. Shipulin ◽  
◽  
S.V. Kanat’ev ◽  
I.N. Lepilina ◽  
E’.Ju. Tikhonova ◽  
...  
Keyword(s):  
Caspian Sea ◽  
Russian Sturgeon ◽  
The Caspian Sea ◽  
The North ◽  
North Western

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.

scholarly journals Current state of bacterioplankton in Northern Caspian

2021 ◽  
Vol 0 (4) ◽  
pp. 31-38
Author(s):  
Svetlana Aleksandrovna Dyakova ◽  
Olga Borisovna Soprunova ◽  
Ecatherina Rafaelevna Galyautdinova ◽  
Anna Vitalievna Menkova ◽  
Dinara Gaidarovna Baubekova ◽  
...  
Keyword(s):  
Annual Runoff ◽  
Total Abundance ◽  
The North ◽  
Current State ◽  
Maximum Value ◽  
Simultaneous Decrease ◽  
Positive Correlations ◽  
Research Period ◽  
Number Of Bacteria

Microbiological monitoring of the Northern Caspian proved that for the research period in 2013-2018 the average annual value of the total number of bacteria (TBN) was 1.35 million cells/ml. The TBN maximum value (1.46 million cells/ml) was recorded in 2013, the minimum (1.19 million cells/ml) - in 2014. Concentration of saprotrophic bacteria in the waters of the Northern Caspian during the research period varied from 50.94 thousand CFU/ml in 2013 to 1.66 thousand CFU/ml in 2014. The concentration of saprotrophic bacteria remained practically unchanged within 2014-2018. The values of the ratio of the total abundance of microorganisms and saprotrophic bacteria show the eutrophication of the waters of the North Caspian in 2013 and in 2016, in other periods the water quality corresponded to the readings of an oligotrophic reservoir. The maximum number of oil-oxidizing bacteria (OOB) (8.28 thousand CFU/ml) in the waters of the Northern Caspian was recorded in 2013, the minimum (0.21 thousand CFU/ml) - in 2014. Starting from 2015 there was recorded an increasing number of OOBs and its stabilization until the end of the research period. The ratio of NOB and saprotrophs in water varied from 16.47 to 52.47%. Analysis of microbiological and hydrological-hydrochemical indicators revealed positive correlations of TBN and annual runoff (r = + 0.77), TBN and the content of mineral forms of nitrogen (r = + 0.60), the number of saprotrophic bacteria and nitrogen (r = + 0.83), the amount of NOB and mineral nitrogen and silicon (r = + 0.81). In the long-term aspect, an improvement in the microbiological situation was recorded against the background of a growing total number of bacterioplankton under a simultaneous decrease in the number of saprotrophic and oil-oxidizing bacteria.

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.

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

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