scholarly journals Features of the distribution of the suspended form of iron in the water column of the Caspian Sea

2021 ◽  
Author(s):  
В.В. Ковалев ◽  
К.Ю. Гамбург
Keyword(s):  
Surface Layer ◽  
Water Column ◽  
Caspian Sea ◽  
Chemical Elements ◽  
Suspended Particles ◽  
Solid Particles ◽  
Natural State ◽  
Caspian Basin ◽  
The Caspian Sea ◽  
Suspended Form

Статья посвящена изучению распределения железа в водной взвеси Среднего Каспия. Актуальность работыопределяется необходимостью оценки естественного состоя­ния морской среды и фиксации ее базового состояния (в том числе различных форм химических элементов) для дальнейшего использования с целью мониторинга экологической ситуации на шельфе Каспийского моря в условиях интенсификации геологоразве­дочных работ и разработки месторождений нефти. Цель работы. Установить характерные особенности поведения взвешенного железа в водах Среднего Каспия. Материалы и методы работы. Изучался материал, отобранный в 1989-1990 годах в ходе выполнения рейсов исследовательских судов. Принадлежащих Каспийскому НИИ рыбного хозяйства, до начала освоения нефтегазовых месторождений. Он представлен отфильтрованными частицами взвеси из 178 проб воды, взятых из различных слоев водной толщи на 63 станциях. Определение содержаний железа проводилось на спектрографе PGS-2 способом испарения. Результаты работы. Минимальные концентрации взвешенной формы железа в поверхностном слое водной толщи установлены на участке внутреннего шельфа и подводного склона котловины Среднего Каспия, что связано с выносом твердых частиц дрейфовыми течениями. Концентрации взвешенной формы железа в поверхностном слое возрастают к середине моря, что обусловлено стягиванием взвешенных частиц центростремительными силами циклонального течения. Придонный слой отличается повышенными концентрациями взвешенной формы железа. Возле дельт рек они связаны с оседанием выносимых с суши твердых частиц. Аномально высокие содержания взвешенной формы железа в придонном горизонте центральной части Среднекаспийской котловины, фиксируемые на отдельных станциях, обусловлены поступлением железа с эманациями донных грязевых вулканов и его коагуляцией в условиях щелочной среды. В целом, с увеличением глубины наблюдается последовательный рост концентраций взвешенной формы железа. Это связано с изменением солености и усилением вертикальной стратификации (уменьшением солености поверхностного горизонта и увеличением солености глубоких слоев). Это приводит к коагу­ляции и флокуляции органических и металлор­ганических коллоидов и переводу растворенного железа во взвесь The article is devoted to the study of the distribution of iron in the water suspension of the Middle Caspian Sea. The relevance of the work is determined by the need to assess the natural state of the marine environment and fix its basic state (including various forms of chemical elements) for further use in order to monitor the environmental situation on the shelf of the Caspian Sea in the conditions of intensification of exploration and development of oil fields. Aim. To establish the characteristic features of the behavior of suspended iron in the waters of the Middle Caspian. Materials and methods. The material selected in 1989-1990 during the voyages of research vessels was studied. owned by the Caspian Research Institute of Fisheries, before the development of oil and gas fields. It is represented by filtered suspended particles from 178 water samples taken from various layers of the water column at 63 stations. Determination of iron content was carried out on the PGS-2 spectrograph by evaporation. Results. The minimum concentrations of the suspended form of iron inthe surface layer of the water column were established on the section of the inner shelf and the underwater slope of the Middle Caspian basin, which is associated with the removal of solid particles by drift currents. The concentrations of the suspended form of iron in the surface layer increase towards the middle of the sea, which is caused by the contraction of suspended particles by the centripetal forces of the cyclonic current. The bottom layer is characterized by increased concentrations of the suspended form of iron. Near river deltas, they are associated with the subsidence of solid particles carried out from the land. Abnormally high concentrations of suspended iron in the bottom horizon of the central part of the Middle Caspian basin, recorded at individual stations, are due to the influx of iron with emanations of bottom mud volcanoes and its coagulation in an alkaline environment. In general, with increasing depth, there is a consistent increase in the concentrations of the suspended form of iron. This is due to a change in salinity and an increase in vertical stratification (a decrease in the salinity of the surface horizon and an increase in the salinity of the deep layers). This leads to coagulation and flocculation of organic and organometallic colloids and the transfer of dissolved iron into suspension.

scholarly journals THE DISTRIBUTION OF DISSOLVED FORMS COPPER IN THE WATER COLUMN OF THE CASPIAN SEA

2018 ◽  
Author(s):  
В.В. Ковалев ◽  
С.Г. Парада
Keyword(s):  
Surface Layer ◽  
Spatial Distribution ◽  
Water Column ◽  
Caspian Sea ◽  
Sea Water ◽  
Average Content ◽  
Vital Activity ◽  
The Caspian Sea ◽  
Organic Complexes ◽  
High Concentrations

По результатам химических анализов проб воды Северного, Среднего Каспия и, частично, Южного Каспия, отобранных по профилям из различных горизонтов водной толщи, определены содержания растворенных форм меди. Построены карты пространственного распределения этого элемента в поверхностном и наддонном водных горизонтах, а также по вертикальным разрезам водной толщи, выявлены закономерности их распространения в объеме морской воды. Установлены средние содержания растворенных форм меди в поверхностном (8,6 мкг/л) и в наддонном (9,6 мкг/л) горизонтах  Каспийского моря. Выделены участки с аномально высокими (более 20 мкг/л) и аномально низкими (менее 5 мкг/л) концентрациями растворенных форм меди в них. Особенности распределения растворенных форм меди по вертикали водной толщи определяются жизнедеятельностью планктонных организмов и их отмиранием. В поверхностном слое аномально высокие концентрации меди связаны с прижизненным накоплением металла планктоном. На глубинах свыше 100 м аномально высокие ее концентрации связаны с распадом отмерших организмов и выделением меди и других металлов в виде органических комплексов According to the results of chemical analyzes of water samples from the Northern, Middle Caspian and, partially, the Southern Caspian, taken from profiles from different horizons of the water column, the contents of dissolved forms of copper were determined. Maps of the spatial distribution of this element in the surface and supra-aquatic horizons, as well as along vertical sections of the water column, have been constructed, and patterns of their distribution in the volume of sea water have been revealed. The average content of dissolved forms of copper in the surface (8.6 μg/l) and in the above bottom (9.6 μg/l) horizons of the Caspian Sea has been established. Selected areas with abnormally high (more than 20 μg/l) and abnormally low (less than 5 μg/l) concentrations of dissolved forms of copper in them. The specific features of the distribution of dissolved forms of copper along the vertical of the water column are determined by the vital activity of planktonic organisms and their death. In the surface layer, abnormally high concentrations of copper are associated with the lifetime accumulation of metal by plankton. At depths above 100 m, its abnormally high concentrations are associated with the decay of dead organisms and the release of copper and other metals in the form of organic complexes

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.

The content of mercury and lead in the feed base of valuable fish species of the Caspian Sea

Fisheries ◽  
2021 ◽  
Vol 2021 (4) ◽  
pp. 10-14
Author(s):  
Tatiana Ershova ◽  
Vladimir Chaplygin ◽  
Vyacheslav Zaitsev ◽  
Alisher Khursanov ◽  
Natalia Shaboyants
Keyword(s):  
Caspian Sea ◽  
Chemical Elements ◽  
Essential Elements ◽  
The Body ◽  
The Caspian Sea ◽  
Rhithropanopeus Harrisii ◽  
The North ◽  
Living Organisms ◽  
Taxonomic Groups ◽  
High Level

Mercury and lead are not essential elements and have a high degree of toxicity to all groups of living organisms, including hydrobionts. In turn, the accumulation of dangerous chemical elements in the primary trophic units of marine ecosystems is also reflected in the high level of accumulation and toxication of fish-valuable objects of fishing. As part of the study of the ecological state of the biota of the Volga-Caspian basin, there is a need to study the concentrations of heavy metals such as mercury and lead. The aim of the work is to study the content of mercury and lead in some invertebrate species of the Caspian Sea. The main source of mercury and lead in the body of the studied species is the water of the north-western part of the Caspian Sea. Among the studied taxonomic groups of organisms, mercury accumulators were all species of mollusks, as well as Balanus improvises and Rhithropanopeus harrisii. The lead concentrating organisms were Cerastoderma lamarcki and Mytilaster lineatus, Rhithropanopeus harrisii, and Balanus improvises.

Environmental impacts of physical and dynamical characteristics of the southern coastal waters of the Caspian Sea

2021 ◽  
pp. 1-14
Author(s):  
Siamak JAMSHIDI ◽  
Mahdieh JAFARI
Keyword(s):  
Water Column ◽  
Caspian Sea ◽  
General Circulation ◽  
Middle Part ◽  
Marine Debris ◽  
The Caspian Sea ◽  
Seasonal Thermocline ◽  
Field Samples ◽  
Current Characteristics ◽  
Coastal Flow

ABSTRACT This research evaluated the variability of current characteristics and seawater properties in the middle part of the southern shelf of the Caspian Sea. The effect of the coastal flow on marine debris dispreading was assessed in the southern Caspian Sea for the first time. The findings showed the existence of thermal stratification containing seasonal thermocline with thickness of about 40 m in the water column. Maximum monthly along-shore current velocities around 1.3 m s−1 were observed in November and December. Monthly variations were clearly found in both flow velocity and local wind components. However, no significant levels of correlation between wind and current speeds were observed during the study in the region. In some cases, the mean monthly cross-shore component velocities were measured at about 29 cm s−1 in November. The findings indicated that there was no upwelling phenomenon associated to the regional wind in the study area. In situ current measurements indicated dominant east and north-northeast directions, presumably related to the effect of general circulation in the southern basin. Current profiles in the water column displayed similarity in directions at 10, 15 and 20 m depths over the continental shelf. The field samples and analysis revealed that the soft and smaller-scale seawater litters can be carried long distances by the current along the coast. Most coastal based and marine litters originated from the tourist activities (in the middle and western parts of the shores) and waste emanated from the river (Tonekabon-Nowshahr).

scholarly journals SPECIFIC FEATURES OF DISTRIBUTION OF MINERALS IN ORGANS AND TISSUES OF HERRING SPECIES (CLUPEIDAE) IN CASPIAN SEA

2021 ◽  
Vol 2021 (1) ◽  
pp. 100-106
Author(s):  
Tatiana Ershova ◽  
Vyacheslav Fedorovich Zaitsev ◽  
Vladimir Chaplygin ◽  
Asylbek Shakhmuratovich Kanbetov
Keyword(s):  
Heavy Metals ◽  
Caspian Sea ◽  
Chemical Elements ◽  
Electrothermal Atomization ◽  
The Caspian Sea ◽  
Lead And Cadmium ◽  
Zinc Cadmium ◽  
Definition Of ◽  
Cadmium And Lead ◽  
Standard Techniques

Research objective was to identify the specific features of distribution of microelements (zink, manganese, lead, cadmium) in organs and tissues of black-backed shad Alosa kessleri kessleri (Grimm, 1887) and Dolginsky herring Alosa braschnikowii braschnikowii (Borodin, 1904) caught in the Caspian Sea. Accumulated in the tissues and organs of fish in concentrations exceeding the maximum permissible limits, heavy metals pose a danger to human health. Sampling was carried out by the standard techniques, definition of minerals was made by method of atomic and absorbing spectroscopy using an atomic and absorbing spectrometer with electrothermal atomization of MGA-915 MD. The analysis of the obtained data showed that distribution of minerals in the organs and tissues of the studied herring species had a similar pattern: the highest concentrations of minerals were registered in the gills and liver, the smallest - in muscle tissue. In comparison with black-backed shad the organs and tissues of Dolginsky herring had higher concentrations of chemical elements. Zinc has been found to accumulate mainly in the liver; manganese, lead and cadmium - in the gills. Accumulation of zinc, cadmium and lead in the studied bodies and tissues of fishes exceeded acceptable level.

Biogeochemical processes in the water column of the Caspian Sea in November 2008

2010 ◽  
Vol 434 (2) ◽  
pp. 1381-1385 ◽  
Author(s):  
A. Yu. Lein ◽  
I. I. Rusanov ◽  
A. A. Klyuvitkin ◽  
M. D. Kravchishina ◽  
E. E. Zakharova ◽  
...  
Keyword(s):  
Water Column ◽  
Caspian Sea ◽  
Biogeochemical Processes ◽  
The Caspian Sea

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
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