Hydrochemical Studies of Deep-Water Basins of the Caspian Sea in August–September 2013 Onboard the R/V “Nikifor Shurekov”

2015 ◽  
Vol 55 (1) ◽  
pp. 162-164
Author(s):  
L. A. Dukhova ◽  
E. A. Serebrennikova ◽  
A. K. Ambrosimov ◽  
A. A. Klyuvitkin
Keyword(s):  
Deep Water ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Hydrochemical Studies

Hydrochemical studies of deep-water basins of the Caspian Sea in August–September 2013 aboard the R/V Nikifor Shurekov

Oceanology ◽  
2015 ◽  
Vol 55 (1) ◽  
pp. 145-147 ◽  
Author(s):  
L. A. Dukhova ◽  
E. A. Serebrennikova ◽  
A. K. Ambrosimov ◽  
A. A. Klyuvitkin
Keyword(s):  
Deep Water ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Hydrochemical Studies

scholarly journals Analysis of deep-water exchange in the Caspian Sea based on environmental tracers

2000 ◽  
Vol 47 (4) ◽  
pp. 621-654 ◽  
Author(s):  
F. Peeters ◽  
R. Kipfer ◽  
D. Achermann ◽  
M. Hofer ◽  
W. Aeschbach-Hertig ◽  
...  
Keyword(s):  
Deep Water ◽  
Caspian Sea ◽  
Water Exchange ◽  
Environmental Tracers ◽  
The Caspian Sea

Hydrochemistry and nutrient distribution in southern deep-water basin of the Caspian Sea

2018 ◽  
Vol 127 ◽  
pp. 406-411 ◽  
Author(s):  
Abolfazl Saleh ◽  
Ali Hamzehpour ◽  
Ali Mehdinia ◽  
Kazem Darvish Bastami ◽  
Said Mazaheri
Keyword(s):  
Deep Water ◽  
Caspian Sea ◽  
Nutrient Distribution ◽  
The Caspian Sea ◽  
Water Basin ◽  
Deep Water Basin

scholarly journals Assessment of Changes in the Structure of Zooplankton Communities to Infer Water Quality of the Caspian Sea

Diversity ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 122 ◽  
Author(s):  
Elena Krupa
Keyword(s):  
Water Quality ◽  
Deep Water ◽  
Caspian Sea ◽  
Size Structure ◽  
The Caspian Sea ◽  
Structural Variables ◽  
Zooplankton Communities ◽  
Average Individual ◽  
Individual Mass

The work aimed to study the structural variables of zooplankton to assess the water quality of the Caspian Sea. Studies of zooplankton were conducted in the spring and summer of 2008 and 2010. Abundance, biomass, an average individual mass of a specimen, Shannon Bi, Shannon Ab, Δ-Shannon indices, and Clarke’s W-statistic were calculated for zooplankton. Quantitative variables of zooplankton were the highest in the Northeastern and Northern Caspian, decreasing towards the Middle Caspian. In the Northeastern and Northern Caspian from spring to summer, the number of zooplankton, and the values of Shannon Bi and Shannon Ab indices decreased; the values of Δ-Shannon and Clarke’s W-statistic increased. In the Middle Caspian, the biomass of the community increased; the values of Δ-Shannon and Clarke’s W-statistic decreased. From spring to summer, the value of an average individual mass of a specimen decreased over the entire surveyed area. The jellyfish Blackfordia virginica and Moerisia pallasi significantly influenced the size structure of the holoplankton. Seasonal dynamics of structural variables of zooplankton as well as changes in water transparency showed that water quality improved from spring to summer in the shallow northern and northeastern areas of the sea, and decreased in the deep-water Middle Caspian.

Special features of the hydrochemical conditions variability in the deep water basins of the Caspian Sea

Oceanology ◽  
2015 ◽  
Vol 55 (2) ◽  
pp. 194-199 ◽  
Author(s):  
E. A. Serebrennikova ◽  
V. V. Sapozhnikov ◽  
L. A. Dukhova
Keyword(s):  
Deep Water ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Hydrochemical Conditions

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.

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