BIOGEOCHEMISTRY OF THE BLACK SEA ANOXIC ZONE WITH A REFERENCE TO SULPHUR CYCLE

2006 ◽  
pp. 67-104 ◽  
Author(s):  
Lev N. Neretin ◽  
Igor I. Volkov ◽  
Alexander G. Rozanov ◽  
Tatyana P. Demidova ◽  
Anastasiya S. Falina
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Anoxic Zone ◽  
Sulphur Cycle

Sulfur Isotopes in the Upper Part of the Black Sea Anoxic Zone

Oceanology ◽  
2017 ◽  
Vol 57 (6) ◽  
pp. 797-805
Author(s):  
A. V. Dubinin ◽  
E. O. Dubinina ◽  
T. P. Demidova ◽  
V. K. Chasovnikov
Keyword(s):  
Black Sea ◽  
Sulfur Isotopes ◽  
The Black Sea ◽  
Anoxic Zone

Ventilation of the Black Sea anoxic zone: Evidence from the sulfur isotope composition of sulfate

2017 ◽  
Vol 475 (2) ◽  
pp. 877-882
Author(s):  
A. V. Dubinin ◽  
E. O. Dubinina ◽  
S. A. Kossova ◽  
E. D. Berezhnaya
Keyword(s):  
Black Sea ◽  
Sulfur Isotope ◽  
Isotope Composition ◽  
The Black Sea ◽  
Anoxic Zone ◽  
Sulfur Isotope Composition

Determination of the reduced sulfur species in the anoxic zone of the Black Sea: A comparison of the spectrophotometry and iodometry techniques

Oceanology ◽  
2012 ◽  
Vol 52 (2) ◽  
pp. 181-190 ◽  
Author(s):  
A. V. Dubinin ◽  
T. P. Demidova ◽  
V. V. Kremenetskii ◽  
N. M. Kokryatskaya ◽  
M. N. Rimskaya-Korsakova ◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Anoxic Zone ◽  
Sulfur Species ◽  
Reduced Sulfur

A sulfur budget for the Black Sea anoxic zone

2001 ◽  
Vol 48 (12) ◽  
pp. 2569-2593 ◽  
Author(s):  
Lev N. Neretin ◽  
Igor I. Volkov ◽  
Michael E. Böttcher ◽  
Vladimir A. Grinenko
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Anoxic Zone

scholarly journals Oxygen, nitrogen and sulphide fluxes in the Black Sea

2000 ◽  
Vol 1 (2) ◽  
pp. 41 ◽  
Author(s):  
S.K. KONOVALOV ◽  
L.I. IVANOV ◽  
A.S. SAMODUROV
Keyword(s):  
Black Sea ◽  
Sea Water ◽  
Redox Balance ◽  
Vertical Flux ◽  
The Black Sea ◽  
Anoxic Zone ◽  
Stationary Model ◽  
Consumption Rates ◽  
Oxic Zone ◽  
Main Pycnocline

The fluxes and production/consumption rates of oxygen, nitrate, ammonium and sulphide are estimated in the paper utilising results of the 1.5-dimensional stationary model of vertical exchange in the Black Sea (Samodurov & Ivanov, 1998). The profiles of the vertical flux and rate of production/consumption of these substances have revealed a number of intriguing features in the biogeochemical nature of the Black Sea. An approximate redox balance of the counter-fluxes of nitrate and ammonium into the sub-oxic zone has been revealed confirming that intensive denitrification may be the primary loss of nitrogen in the Black Sea. A low ratio of the nitrate stock to the flux of nitrate from the oxycline confirms the possibility of prominent changes in the distribution of nitrate on the time scale of a year. The ratio of the nitrate to oxygen vertical flux has revealed a lack of nitrate in the oxycline above the nitrate maximum. The lateral (related to the "Bosporus plume") flux of oxygen in the layer of the main pycnocline appears to be very important for the existing biogeochemical structure of the Black sea water column being the reason of sulphide consumption inside the anoxic zone and changes in the ammonium-sulphide stoichiometry of the anoxic zone, the primary reason of the existence of the sub-oxic layer and the basic reason of relative stability of the sulphide onset.

Oceanographic Data Development for Anoxic Zone Boundary in the Black Sea

1997 ◽  
pp. 487-494 ◽  
Author(s):  
A. M. Suvorov ◽  
V. N. Eremeev ◽  
A. Kh. Khaliulin ◽  
E. A. Godin
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Zone Boundary ◽  
Anoxic Zone ◽  
Oceanographic Data

scholarly journals Isoprenoid Quinones Resolve the Stratification of Redox Processes in a Biogeochemical Continuum from the Photic Zone to Deep Anoxic Sediments of the Black Sea

2018 ◽  
Vol 84 (10) ◽  
Author(s):  
Kevin W. Becker ◽  
Felix J. Elling ◽  
Jan M. Schröder ◽  
Julius S. Lipp ◽  
Tobias Goldhammer ◽  
...  
Keyword(s):  
Black Sea ◽  
Ammonia Oxidation ◽  
Biogeochemical Cycles ◽  
Oxygenic Photosynthesis ◽  
The Black Sea ◽  
Redox Processes ◽  
Photic Zone ◽  
Anoxic Zone ◽  
Subsurface Sediments ◽  
Isoprenoid Quinones

ABSTRACTThe stratified water column of the Black Sea serves as a model ecosystem for studying the interactions of microorganisms with major biogeochemical cycles. Here, we provide detailed analysis of isoprenoid quinones to study microbial redox processes in the ocean. In a continuum from the photic zone through the chemocline into deep anoxic sediments of the southern Black Sea, diagnostic quinones and inorganic geochemical parameters indicate niche segregation between redox processes and corresponding shifts in microbial community composition. Quinones specific for oxygenic photosynthesis and aerobic respiration dominate oxic waters, while quinones associated with thaumarchaeal ammonia oxidation and bacterial methanotrophy, respectively, dominate a narrow interval in suboxic waters. Quinone distributions indicate highest metabolic diversity within the anoxic zone, with anoxygenic photosynthesis being a major process in its photic layer. In the dark anoxic layer, quinone profiles indicate the occurrence of bacterial sulfur and nitrogen cycling, archaeal methanogenesis, and archaeal methanotrophy. Multiple novel ubiquinone isomers, possibly originating from unidentified intra-aerobic anaerobes, occur in this zone. The respiration modes found in the anoxic zone continue into shallow subsurface sediments, but quinone abundances rapidly decrease within the upper 50 cm below the sea floor, reflecting the transition to lower energy availability. In the deep subseafloor sediments, quinone distributions and geochemical profiles indicate archaeal methanogenesis/methanotrophy and potentially bacterial fermentative metabolisms. We observed that sedimentary quinone distributions track lithology, which supports prior hypotheses that deep biosphere community composition and metabolisms are determined by environmental conditions during sediment deposition.IMPORTANCEMicroorganisms play crucial roles in global biogeochemical cycles, yet we have only a fragmentary understanding of the diversity of microorganisms and their metabolisms, as the majority remains uncultured. Thus, culture-independent approaches are critical for determining microbial diversity and active metabolic processes. In order to resolve the stratification of microbial communities in the Black Sea, we comprehensively analyzed redox process-specific isoprenoid quinone biomarkers in a unique continuous record from the photic zone through the chemocline into anoxic subsurface sediments. We describe an unprecedented quinone diversity that allowed us to detect distinct biogeochemical processes, including oxygenic photosynthesis, archaeal ammonia oxidation, aerobic methanotrophy, and anoxygenic photosynthesis in defined geochemical zones.

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