scholarly journals Deep-Water Benthic Polychaetes (Vigtorniella Zaikai and Protodrilus sp.) in the Black Sea as Indicators of the Hydrogen Sulfide Zone Boundary

2012 ◽  
Vol 46 (4) ◽  
pp. e-19-e-27 ◽  
Author(s):  
V. Zaika ◽  
N. Sergeeva

Deep-Water Benthic Polychaetes (Vigtorniella ZaikaiandProtodrilussp.) in the Black Sea as Indicators of the Hydrogen Sulfide Zone BoundaryThe Black Sea hypoxic layer, situated near the boundary of the hydrogen sulfide zone, is inhabited by the polychaetesVigtorniella zaikai, Kisseleva, 1992 andProtodrilussp., which can serve as indicators of the interface between oxic and anoxic water. The maximum number of polychaetes in the northern part of the Black Sea occur at a depth of 150 m, while near Bosporus, where the flow of the Marmara Sea water enters the Black Sea, the peak depth varies from 150 to 250 m.

Author(s):  
O. Podymov ◽  
O. Podymov ◽  
N. Kuzevanova ◽  
N. Kuzevanova ◽  
A. Khvorosch ◽  
...  

The work demonstrates the results of the 6-years complex ship-borne monitoring of coastal zone in the north-eastern part of the Black Sea, carried out by the Southern Branch of P.P.Shirshov Institute of Oceanology, RAS, on a marine cross-section at the Blue Bay (Gelendzhik) beam 1-2 times per month. Climatic changes and eutrophication exert a significant impact on the sea water at the coastal area. In case of the Black Sea these factors pile up with a permanent hydrogen sulphide contamination of the sea water below 80-200 meters depth (depending on the season and distance from the shore). Strong pycno-halocline at the depths from 70 to 160 meters, formed due to the inflow of high salinity water from the Marmara Sea, inhibits the mixing between the water layers and, as a result, also limits the oxygen transport into the deeper layers. The winter cooling reduces the pycno-halocline and enriches the top active layer, down to the cold intermediate layer (CIL), with oxygen and nutrients, which subsequently lead to a vernal phytoplankton bloom. Formation of the thermocline and upper quasi-homogeneous layer (UQL), caused by the water warming in spring, at large extent determines a thickness of phytoplankton-rich layer during the spring and summer seasons. The work demonstrates seasonal and interannual dynamics of the UQL, thermocline, CIL and hydrogen sulphide boundary position in the coastal zone of the north-eastern part of the Black Sea.


2021 ◽  
Vol 28 (4) ◽  
Author(s):  
N. V. Markova ◽  
V. N. Belokopytov ◽  
O. A. Dymova ◽  
N. A. Miklashevskaya ◽  
◽  
...  

Purpose. The purpose of the study is to assess the coefficient of vertical turbulent exchange for different layers of the Black Sea basin based on the experimental data on microstructure of the physical fields obtained for the period 2004–2019 in the Black Sea and using the semi-empirical models. Methods and Results. New array of the temperature and salinity climatic fields was assessed by the results of numerical experiments. In the experiment, annual variation of the Black Sea hydrophysical parameters was reconstructed by the numerical model. Modeling included the scheme of assimilating the data of the climatic temperature and salinity array assessed. In contrast to the averaged data of the field observations, the modeled fields are compliant with equations of motion. Besides the temperature and salinity three-dimensional fields, the three-dimensional climatic fields of the Black Sea currents were also reconstructed for each day of a climatic year that is quite impossible using the observational data only. Spatial-temporal variability of the modeled three-dimensional fields was analyzed. The integral characteristics of the Black Sea water dynamics for the recent 30-year climatic period were studied and compared with the analogous ones for the previous century. Simulation was carried out by three-dimensional non-linear model of the Black Sea dynamics developed in Marine Hydrophysical Institute. The horizontal resolution of the model was 5 km, and the EMODNet bathymetry was used. The performed calculations showed that the increased spatial resolution of the temperature and salinity climatic array for the recent period made it possible to reconstruct the dynamics of the Black Sea in all layers in more detail. At the same time, significant small-scale variability of salinity fields was revealed. It was most pronounced at the deep-water horizons. Conclusions. Modeling using a new array of thermohaline fields revealed an increase in the integral temperature of the upper mixed layer in comparison with the experiment with assimilation of the previous version of the climatic array. At that, thinning and «break» of the cold intermediate layer found in the central part of the sea, indicates warming of the sea upper layer during the last 30 years. The highest noise detected at the deep-water horizons in the modeled salinity fields is related to quantity and quality of the salinity data resulted from the field observations. Taking into account insufficient calibration facilities for measuring seawater electrical conductivity, the next version of climatic TS-array requires a more strict procedure for verifying and processing the observation data obtained in the deep-sea layers.


Author(s):  
O. Podymov ◽  
O. Podymov ◽  
N. Kuzevanova ◽  
N. Kuzevanova ◽  
A. Khvorosch ◽  
...  

The work demonstrates the results of the 6-years complex ship-borne monitoring of coastal zone in the north-eastern part of the Black Sea, carried out by the Southern Branch of P.P.Shirshov Institute of Oceanology, RAS, on a marine cross-section at the Blue Bay (Gelendzhik) beam 1-2 times per month. Climatic changes and eutrophication exert a significant impact on the sea water at the coastal area. In case of the Black Sea these factors pile up with a permanent hydrogen sulphide contamination of the sea water below 80-200 meters depth (depending on the season and distance from the shore). Strong pycno-halocline at the depths from 70 to 160 meters, formed due to the inflow of high salinity water from the Marmara Sea, inhibits the mixing between the water layers and, as a result, also limits the oxygen transport into the deeper layers. The winter cooling reduces the pycno-halocline and enriches the top active layer, down to the cold intermediate layer (CIL), with oxygen and nutrients, which subsequently lead to a vernal phytoplankton bloom. Formation of the thermocline and upper quasi-homogeneous layer (UQL), caused by the water warming in spring, at large extent determines a thickness of phytoplankton-rich layer during the spring and summer seasons. The work demonstrates seasonal and interannual dynamics of the UQL, thermocline, CIL and hydrogen sulphide boundary position in the coastal zone of the north-eastern part of the Black Sea.


2001 ◽  
Vol 44 (2-3) ◽  
pp. 31-38 ◽  
Author(s):  
V. Eroglu ◽  
H. Z. Sarikaya ◽  
A. F. Aydin

Current and future wastewater treatment and disposal strategies of Istanbul city are presented. Istanbul is the largest city of Turkey and has a population of 10 million that may reach about 20 million in 2032. The city is divided into Asian and European sides by the Bosphorus Strait. The Sea of Marmara is an enclosed sea, connected to the Black Sea and Aegean Sea by the straits of Bosphorus and Dardanelles. Therefore, there is very strong and permanent stratification in the Sea of Marmara throughout the year, lower layers carrying Mediterranean and the upper layers carrying Black Sea water. This unique coastal structure of Istanbul necessitated a detailed study to determine the level of wastewater treatment and the location and depth of marine outfalls. A comprehensive three-dimensional water quality modelling study concluded that tertiary treatment including nitrogen and phosphorus removal is required for the effluent discharges into the Marmara Sea. However, enhanced primary or even primary treatment has been found satisfactory for discharges into the lower layers of the Bosphorus and into the Black Sea. Provisions for upgrading to secondary treatment were recommended. The status of existing and planned wastewater treatment plants and sea outfalls of Istanbul city are also presented. Although the amount of treated wastewater was only 63 percent in 1998, a target of 95 percent treatment level by the end of 2000 has been adopted in implementation plans. All treatment plants are located at or close to the coast except Pasakoy WWTP which is in the catchment area of Omerli Reservoir, the major source of drinking water for Istanbul city. The Pasakoy WWTP has been designed to treat wastewaters collected from the catchment area of Omerli Reservoir to tertiary level before ultimate disposal. The implementation programme together with the cost estimates are given. Total investment on water, wastewater and stormwater projects up to year 2032 is estimated at about 10 billion US Dollars. The share of the wastewater projects in this total is increasing with time. The financial analysis concluded that investments for a Higher Demand Scenario can be realised by raising the water tariffs to 1.0 $/m3 for Phase 1 and 0.9 $/m3 for Phase 2.


Author(s):  
S. Z. Baykara ◽  
E. H. Figen ◽  
A. Kale ◽  
T. N. Veziroglu

Hydrogen sulphide, an acid gas, is generally considered an environmental pollutant. As an industrial byproduct, it is produced mostly during fuel processing. Hydrogen sulphide occurs naturally in many gas wells and also in gas hydrates and gas-saturated sediments especially at the bottom of the Black Sea where 90% of the sea water is anaerobic.The anoxic conditions exist in the deepest parts of the basin since nearly 7300 years, caused by the density stratification following the significant influx of the Mediterranean water through the Bosphorous nearly 9000 years ago. Here, H2S is believed to be produced by sulphur reducing bacteria at an approximate rate of 10 000 tons per day, and it poses a serious threat since it keeps reducing the life in the Black Sea. An oxygen–hydrogen sulphide interface is established at 150–200 m below the surface after which H2S concentration starts increasing regularly until 1000 m, and finally reaches a nearly constant value of 9.5 mg/l around 1500 m depth.Hydrogen sulphide potentially has economic value if both sulphur and hydrogen can be recovered. Several methods are studied for H2S decomposition, including thermal, thermochemical, electrochemical, photochemical and plasmochemical methods.In the present work, H2S potential in the Black Sea is investigated as a source of hydrogen, an evaluation of the developing prominent techniques for hydrogen production from H2S is made, and an engineering assessment is carried out regarding hydrogen production from H2S in the Black Sea using a process design based on the catalytic solar thermolysis approach. Possibility of a modular plant is considered for production at larger scale.


Author(s):  
Elena Kovaleva ◽  
Elena Kovaleva ◽  
Alexander Izhitskiy ◽  
Alexander Izhitskiy ◽  
Alexander Egorov ◽  
...  

Studying of methane formation and distribution in natural waters is important for understanding of biogeochemical processes of carbon cycle, searching for oil and gas sections and evaluation of CH4 emissions for investigations of greenhouse effect. The Black Sea is the largest methane water body on our planet. However, relatively low values of methane concentration (closed to equilibrium with the atmospheric air) are typical of the upper aerobic layer. At the same time, the distribution pattern of CH4 in surface waters of coastal areas is complicated by the influence of coastal biological productivity, continental runoff, bottom sources, hydrodynamic processes and anthropogenic effect. The investigation is focused on the spatial variability of dissolved methane in the surface layer of the sea in coastal regions affected by the continental runoff and anthropogenic pressure. Unique in situ data on methane concentrations were collected along the ship track on 2 sections between Sochi and Gelendzhik (2013, 2014) and 2 sections between Gelendzhik and Feodosia (2015). Overall 170 samples were obtained. Gas-chromatographic analysis of the samples revealed increase of CH4 saturation in the southeastern part of the Crimean shelf and the Kerch Strait area. Such a pattern was apparently caused by the influence of the Azov Sea water spread westward along the Crimean shore from the strait. This work was supported by the Russian Science Foundation, Project 14-50-00095 and the Russian Foundation for Basic Research, Project 16-35-00156 mol_a.


Author(s):  
Olga Mashukova ◽  
Olga Mashukova ◽  
Yuriy Tokarev ◽  
Yuriy Tokarev ◽  
Nadejda Kopytina ◽  
...  

We studied for the first time luminescence characteristics of the some micromycetes, isolated from the bottom sediments of the Black sea from the 27 m depth. Luminescence parameters were registered at laboratory complex “Svet” using mechanical and chemical stimulations. Fungi cultures of genera Acremonium, Aspergillus, Penicillium were isolated on ChDA medium which served as control. Culture of Penicillium commune gave no light emission with any kind of stimulation. Culture of Acremonium sp. has shown luminescence in the blue – green field of spectrum. Using chemical stimulation by fresh water we registered signals with luminescence energy (to 3.24 ± 0.11)•108 quantum•cm2 and duration up to 4.42 s, which 3 times exceeded analogous magnitudes in a group, stimulated by sea water (p < 0.05). Under chemical stimulation by ethyl alcohol fungi culture luminescence was not observed. Culture of Aspergillus fumigatus possessed the most expressed properties of luminescence. Stimulation by fresh water culture emission with energy of (3.35 ± 0.11)•108 quantum•cm2 and duration up to 4.96 s. Action of ethyl alcohol to culture also stimulated signals, but intensity of light emission was 3–4 times lower than under mechanical stimulation. For sure the given studies will permit not only to evaluate contribution of marine fungi into general bioluminescence of the sea, but as well to determine places of accumulation of opportunistic species in the sea.


Author(s):  
Natalia Andrulionis ◽  
Natalia Andrulionis ◽  
Ivan Zavialov ◽  
Ivan Zavialov ◽  
Elena Kovaleva ◽  
...  

This article presents a new method of laboratory density determination and construction equations of state for marine waters with various ionic compositions and salinities was developed. The validation of the method was performed using the Ocean Standard Seawater and the UNESCO thermodynamic equation of state (EOS-80). Density measurements of water samples from the Aral Sea, the Black Sea and the Issyk-Kul Lake were performed using a high-precision laboratory density meter. The obtained results were compared with the density values calculated for the considered water samples by the EOS-80 equation. It was shown that difference in ionic composition between Standard Seawater and the considered water bodies results in significant inaccuracies in determination of water density using the EOS-80 equation. Basing on the laboratory measurements of density under various salinity and temperature values we constructed a new equation of state for the Aral Sea and the Black Sea water samples and estimated errors for their coefficients.


Author(s):  
Svetlana Rubtsova ◽  
Svetlana Rubtsova ◽  
Natalya Lyamina ◽  
Natalya Lyamina ◽  
Aleksey Lyamin ◽  
...  

The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.


Author(s):  
Elena Kovaleva ◽  
Elena Kovaleva ◽  
Alexander Izhitskiy ◽  
Alexander Izhitskiy ◽  
Alexander Egorov ◽  
...  

Studying of methane formation and distribution in natural waters is important for understanding of biogeochemical processes of carbon cycle, searching for oil and gas sections and evaluation of CH4 emissions for investigations of greenhouse effect. The Black Sea is the largest methane water body on our planet. However, relatively low values of methane concentration (closed to equilibrium with the atmospheric air) are typical of the upper aerobic layer. At the same time, the distribution pattern of CH4 in surface waters of coastal areas is complicated by the influence of coastal biological productivity, continental runoff, bottom sources, hydrodynamic processes and anthropogenic effect. The investigation is focused on the spatial variability of dissolved methane in the surface layer of the sea in coastal regions affected by the continental runoff and anthropogenic pressure. Unique in situ data on methane concentrations were collected along the ship track on 2 sections between Sochi and Gelendzhik (2013, 2014) and 2 sections between Gelendzhik and Feodosia (2015). Overall 170 samples were obtained. Gas-chromatographic analysis of the samples revealed increase of CH4 saturation in the southeastern part of the Crimean shelf and the Kerch Strait area. Such a pattern was apparently caused by the influence of the Azov Sea water spread westward along the Crimean shore from the strait. This work was supported by the Russian Science Foundation, Project 14-50-00095 and the Russian Foundation for Basic Research, Project 16-35-00156 mol_a.


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