scholarly journals Hydrology-hydrochemical researches of the Caspian Sea in July-August 2019

Trudy VNIRO ◽  
2020 ◽  
Vol 180 ◽  
pp. 174-178
Author(s):  
N. I. Torgunova ◽  
N. V. Arzhanova ◽  
A. S. Hursanov ◽  
O. A. L’vova
Keyword(s):  
Hydrogen Sulfide ◽  
Organic Carbon ◽  
Caspian Sea ◽  
Vertical Structure ◽  
Nitrate Nitrogen ◽  
Distribution Patterns ◽  
Summer Season ◽  
Research Information ◽  
The Caspian Sea ◽  
Sulfide Layer

Comprehensive research information on hydrology-hydrochemical structure of the Middle Caspian Sea in July-August 2019 on board of R/V “Issledovatel’ Kaspiya” is presented in the article. Data on dissolved oxygen, hydrogen sulfide, basic nutrients (ammonium, nitrite and nitrate nitrogen; mineral phosphorus) and dissolved organic carbon were obtained in four quasi-latitudinal sections using the probing complex SBE19 plus Sea Bird, equipped with a series of sensors and twelve Niskin bathometers. It is shown, that the distribution patterns of determined elements and vertical structure correspond to average annual values of the summer season. Despite the sea level decline, the thickness of hydrogen sulfide layer of the Caspian Sea hasn’t decreased.

Stable Isotopic Composition of Particulate Organic Carbon in the Caspian Sea

Oceanology ◽  
2018 ◽  
Vol 58 (1) ◽  
pp. 45-56 ◽  
Author(s):  
M. D. Kravchishina ◽  
A. A. Klyuvitkin ◽  
L. A. Pautova ◽  
N. V. Politova ◽  
A. Yu. Lein
Keyword(s):  
Organic Carbon ◽  
Isotopic Composition ◽  
Particulate Organic Carbon ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Stable Isotopic Composition ◽  
Stable Isotopic

scholarly journals Spatio-temporal variability of organic matter contents in the waters of the Caspian Sea

2019 ◽  
Vol 46 (1) ◽  
pp. 70-81
Author(s):  
A. I. Agatova ◽  
N. I. Torgunova ◽  
E. A. Serebryanikova ◽  
L. K. Dukhova
Keyword(s):  
Organic Matter ◽  
Hydrogen Sulfide ◽  
Caspian Sea ◽  
Vertical Mixing ◽  
Qualitative Change ◽  
Border Region ◽  
The Caspian Sea ◽  
Sea Levels ◽  
The North ◽  
Spatio Temporal

We analyzed spatio-temporal changes in concentrations and elemental compositions of dissolved organic matter in the waters of the Caspian Sea over the period 2010–2015. These studies showed that over the past 5 years of lowering of sea levels, mean concentrations of Corg and Norg remained virtually unchanged, whereas concentrations of Porg decreased more than three-fold, suggesting a qualitative change in organic matter. Based on data averages, concentrations of Corg, Norg, and Porg in Southern waters were slightly higher than in the North and Middle-Caspian waters during the monitoring period. In deep areas at the border region of hydrogen sulfide occurrence, concentrations of Corg, Norg, and Porg increase. Hence, the presence of hydrogen sulfide in the deep waters of the Derbent and South Caspian basins, and the corresponding increase in organic matter contents, indicates no radical improvement of vertical mixing of the sea in these areas during the eight years of our regression model. Moreover, according to the carbohydrate distribution, organic substances of petroleum hydrocarbons contribute considerably to a common pool.

Resumption of hydrogen sulfide contamination of the water column of deep basins in the Caspian Sea

2013 ◽  
Vol 453 (1) ◽  
pp. 1094-1099 ◽  
Author(s):  
M. V. Ivanov ◽  
A. S. Savvichev ◽  
A. A. Klyuvitkin ◽  
A. L. Chul’tsova ◽  
E. E. Zakharova ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Water Column ◽  
Caspian Sea ◽  
The Caspian Sea

scholarly journals Analysis of the Content of Hydrogen Sulfide in the Air of the City of Atyrau

2021 ◽  
Vol 16 (3) ◽  
pp. 479-483
Author(s):  
Mansiya Yessenamanova ◽  
Zhanar Yessenamanova ◽  
Anar Tlepbergenova ◽  
Gaukhar Batyrbayeva
Keyword(s):  
Hydrogen Sulfide ◽  
Caspian Sea ◽  
Maximum Permissible Concentration ◽  
Air Pollutant ◽  
Oil Refinery ◽  
The Caspian Sea ◽  
Atmospheric Air ◽  
The North ◽  
The Republic ◽  
The City

This study is aimed at analyzing the content of hydrogen sulfide in the air of the city of Atyrau, located in the northern part of the Caspian Sea of the Republic of Kazakhstan. The analysis was carried out on the basis of monitoring the indicators of the Republican State Enterprise "Kazhydromet" from 8 points located in different directions from the Atyrau oil refinery. Measurements of atmospheric air pollution are made by the GANK-4AR gas analyzer designed for continuous automatic measurement of concentrations of pollutants in the atmospheric air. Hydrogen sulfide was selected as an indicator air pollutant. Atyrau oil refinery is the main object of pollution of the territory of the city of Atyrau, located in the western part of the Republic of Kazakhstan, on the shore of the Caspian Sea. The results obtained show that the content of hydrogen sulfide in the territory of the city of Atyrau in most places shows an excess of the maximum permissible concentration. Especially the excess is observed in the north-western part up to 4-8 maximum permissible concentrations. At two points (in the north-eastern and western parts), the content of hydrogen sulfide did not exceed the maximum permissible concentration.

scholarly journals Reproductive biology of Caspian vimba, Vimba vimba (L.), in the coastal waters of the southwestern Caspian Sea

2015 ◽  
Vol 23 (3) ◽  
pp. 171-180
Author(s):  
F. Tari J. Imanpour Namin ◽  
Abdolmalaki Shahram ◽  
M. Hadavi
Keyword(s):  
Frequency Distribution ◽  
Caspian Sea ◽  
Gonadosomatic Index ◽  
Distribution Patterns ◽  
The Caspian Sea ◽  
Size Frequency Distribution ◽  
Reproduction Biology ◽  
Spawning Time ◽  
First Maturity ◽  
Size At First Maturity

Abstract The reproduction biology of Caspian vimba, Vimba vimba (L.), was investigated on the southwestern coast of the Caspian Sea using 712 fish specimens collected at three fisheries catch stations located in Talesh, Anzali, and Kiashahr over a two-year period from April 2012 through June 2013. Seasonal changes in the gonadosomatic index, gonad histological status, size frequency distribution of oocytes, and the fecundity of the species were studied. The peaks of the gonadosomatic index (GSI) were observed both in females and males in June 2012 and May 2013 indicating the variable peak spawning time of this species. Histological examinations and oocyte frequency distribution patterns showed synchronous oocyte development in the Caspian vimba. Absolute fecundity ranged from 5873 to 35421 eggs. The size at first maturity for females was 120 mm FL. We concluded that the Caspian vimba is a total spawner with variable spawning dependent on environmental factors.

scholarly journals Authigenic Minerals of the Derbent and South Caspian Basins (Caspian Sea): Features of Forms, Distribution and Genesis under Conditions of Hydrogen Sulfide Contamination

Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 87
Author(s):  
Nina Kozina ◽  
Liudmila Reykhard ◽  
Olga Dara
Keyword(s):  
Hydrogen Sulfide ◽  
Bottom Sediments ◽  
Deep Water ◽  
Caspian Sea ◽  
The South ◽  
The Caspian Sea ◽  
Authigenic Minerals ◽  
Framboidal Pyrite ◽  
Magnesian Calcite ◽  
Authigenic Mineral

This paper presents the results of complex lithological, mineralogical, and geochemical studies of bottom sediments of deep-water basins of the Caspian Sea (Derbent and South Caspian Basins) in areas contaminated by hydrogen sulfide. In the course of complex studies, numerous manifestations of authigenic mineral formation associated with the stage of early diagenesis have been established. Authigenic minerals belonging to the groups of sulfates (gypsum, barite), chlorides (halite), carbonates (calcite, low Mg-calcite; kutnohorite), and sulfides (framboidal pyrite), as well as their forms and composition, have been identified by a complex of analytical methods (X-ray diffractometry (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS); atomic absorption spectroscopy (AAS); coulometric titration (CT)); the nature of their distribution in bottom sediments has been assessed. Carbonates and sulfates are predominant authigenic minerals in the deep-water basins of the Caspian Sea. As a part of the study, differences have been established in the composition and distribution of associations of authigenic minerals in the bottom sediments in the deep-water basins. These are mineral associations characteristic of the uppermost part of the sediments (interval 0–3 cm) and underlying sediments. In the Derbent Basin, in sediments of the interval 3–46 cm, an authigenic association is formed from gypsum, calcite, magnesian calcite, siderite, and framboidal pyrite. An association of such authigenic minerals as gypsum and calcite is formed in sediments of the 0–3 cm interval. In the South Caspian Basin, in sediments of the interval 3–35 cm, an association of such authigenic minerals as gypsum, halite, calcite, magnesian calcite, and framboidal pyrite is formed. The association of such authigenic minerals as gypsum, halite, calcite, magnesian calcite, kutnohorite, and framboidal pyrite is characteristic of sediments of the 0–3 cm interval. We consider the aridity of the climate in the South Caspian region to be the main factor that determines the appearance of such differences in the uppermost layer of sediments of the basins. Judging by the change in the composition of authigenic associations, the aridity of the South Caspian increased sharply by the time of the accumulation of the upper layer of sediments (interval 0–3 cm). Taking into account lithological, mineralogical and geochemical data, the features of the processes of authigenic mineral formation in the deep-water basins of the Caspian Sea under conditions of hydrogen sulfide contamination have been determined. Analysis of the results obtained and published data on the conditions of sedimentation in the Caspian Sea showed that hydrogen sulfide contamination recorded in the bottom layer of the water column of the deep-water basins of the Caspian Sea may affect the formation of authigenic sulfides (framboidal pyrite), sulfates (gypsum), and carbonates (calcite and kutnohorite) associated with the activity of sulfate-reducing bacteria in reducing conditions.

scholarly journals Specialty of vertical water exchange of the Caspian sea on the basis of distribution of transient tracers

2019 ◽  
Vol 46 (5) ◽  
pp. 496-502
Author(s):  
V. S. Brezgunov
Keyword(s):  
Deep Water ◽  
Surface Waters ◽  
Caspian Sea ◽  
Large Scale ◽  
Water Exchange ◽  
Vertical Structure ◽  
Gravitational Convection ◽  
The Caspian Sea ◽  
Structure Of Water ◽  
Geochemical Studies

The analysis of the reliability of different scenarios for the formation of the vertical structure of the waters of the Caspian Sea, obtained from the distribution of transient tracers (CFC-11, CFC-12, 3H and 3He) at the deep-water stations of the Middle and Southern Caspian within the framework of international integrated isotope-geochemical studies during the maximum sea level rise in 1995–1996. Taking into account the available hydrometeorological data and the characteristics of water dating using transient tracers, it was concluded that after large-scale gravitational convection in the Middle Caspian caused by anomalous cooling of surface waters in the Northern Caspian at the end of the winter of 1976, a structure of water masses was formed that excluded deep water ventilation in the Middle and South Caspian Sea until the mid-90s.

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.

Sign in / Sign up

Export Citation Format

Share Document