scholarly journals Methanotrophic microbial communities associated with bubble plumes above gas seeps in the Black Sea

2006 ◽  
Vol 7 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Carsten J. Schubert ◽  
Edith Durisch-Kaiser ◽  
Christian P. Holzner ◽  
Lucia Klauser ◽  
Bernhard Wehrli ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Black Sea ◽  
The Black Sea ◽  
Bubble Plumes ◽  
Gas Seeps

scholarly journals Biogeochemical characteristics of shallow methane seeps of Crimean coastal areas in comparison with deep-sea seeps of the Black Sea

2020 ◽  
Vol 5 (4) ◽  
pp. 37-55
Author(s):  
T. V. Malakhova ◽  
V. N. Egorov ◽  
L. V. Malakhova ◽  
Yu. G. Artemov ◽  
N. V. Pimenov
Keyword(s):  
Black Sea ◽  
Deep Sea ◽  
Coastal Areas ◽  
The Black Sea ◽  
Gas Bubble ◽  
Gas Emission ◽  
Bacterial Mats ◽  
Seabed Sediments ◽  
Gas Seeps ◽  
Methane Carbon

Methane gas bubble emissions (seeps) are widespread phenomenon in the World Ocean, inter alia in Black Sea basin. The relevance of the research of methane seeps is due to their important role as a source of methane – greenhouse and environment-forming gas – for water column and atmosphere. The article presents a comparative analysis of the data from our biogeochemical 10-year studies of shallow gas seeps of the Crimean Peninsula and data on deep-sea gas seeps of the Black Sea. During 10-year period, apart from carrying out hydroacoustic research, the following parameters were determined: bubble gas component composition, methane carbon isotopic composition, microbial community structure of bacterial mats, covering gas bubble emission sites, and gas fluxes from separate seeps. During long-term monitoring, 14 separate gas bubble emission sites were detected and described in Crimean coastal areas; they were located from Cape Tarkhankut in the west of the peninsula to the Dvuyakornaya Bay in the southeast. Crimean coastal seeps were mostly of biogenic origin, with a seasonal type of gas bubble emission. Laspi Bay seeps were classified as emissions of deep gas of thermocatalytic genesis. A significant variation was recorded in values of isotopic composition of methane carbon δ13C-CH4 of bubble gas in coastal shallow areas (−94…−34 ‰), which indicates different conditions for bubble gas generation and maturation in seabed sediments. Similar to deep-sea seeps, coastal gas bubble emissions were accompanied by bacterial mats of diverse structure, with different dominating species. As shown, formation of stable bacterial biomass, usually consisting of sulfide- and sulfur-oxidizing bacteria, requires a fluid flux of reduced dissolved gases, while pointwise bubble gas discharge does not provide sufficient concentration gradients and can mechanically disrupt community structure. Various methods were used to estimate the size spectra of bubbles, as well as fluxes from separate seeps. Gas flux values varied from 1.8 L·day−1 (the Martynova Bay) to 40 L·day−1 (the Laspi Bay). The environment-forming effects, related to gas bubble emission in coastal areas, are discussed: effect of seeps on oxygen conditions in seabed sediments and in water column above gas emission sites, vertical water mixing due to gas lift effect, and fluid discharge at gas emission sites.

Natural oil and gas seeps on the Black Sea floor

2004 ◽  
Vol 24 (3) ◽  
Author(s):  
R.P. Kruglyakova ◽  
Y.A. Byakov ◽  
M.V. Kruglyakova ◽  
L.A. Chalenko ◽  
N.T. Shevtsova
Keyword(s):  
Black Sea ◽  
Oil And Gas ◽  
The Black Sea ◽  
Sea Floor ◽  
Natural Oil ◽  
Gas Seeps

Measuring methane from the seafloor to the atmosphere: an integrated experiment in the Black Sea

2020 ◽  
Author(s):  
Jean-Daniel Paris ◽  
Livio Ruffine ◽  
Hélène Leau ◽  
Thomas Giunta ◽  
Jean-Pierre Donval ◽  
...  
Keyword(s):  
Water Column ◽  
Black Sea ◽  
Methane Concentration ◽  
Critical Role ◽  
Energy Resource ◽  
The Black Sea ◽  
Pilot Experiment ◽  
Bubble Plumes ◽  
Joint Monitoring

<p>Methane is an important greenhouse gas and an energy resource. Methane in sea water can originate from microbially-mediated organic matter (OM) degradation processes at shallow depth  within the sediments, or from thermal cracking of refractory OM at deeper depth. On continental margins, this methane is stored in specific sedimentological bodies or as gas hydrates, or is released at the seafloor as submarine geological seeps followed by its oxidation in the water mass. However, methane released at the seafloor may not entirely be oxidized in the water column and a fraction of it may ultimately reach the atmosphere. The factors that govern the magnitude of methane transfer through the water column to the atmosphere remain poorly known. It has been identified that the amount of methane transferred to the atmosphere is strongly dependent on sites, and the thickness of the water column plays a critical role.</p><p>The Black Sea shelf and margin are known to host a large number of strong methane seepages. It has therefore been identified as a perfect candidate to investigate the fate of methane released from the seafloor to the atmosphere. This area can also act as a proxy for investigating the fate of methane in potential scenarios of hydrate destabilization in a changing climate, which can become a societal problem in the future. In the frame of ENVRIplus H2020 project (www.envriplus.eu) we developed a joint pilot experiment to measure methane transfer from the seafloor to the atmosphere, in a pilot study involving European research infrastructures ICOS, Eurofleets, EMSO and ACTRIS. We investigated the influence of depth by mapping CH4 concentration and bubble distribution at two different sites, at 60m and 100m water depth, respectively. The pilot experiment developed joint monitoring strategy for methane detection at various levels starting from the seafloor and moving across the water column, the water/air interface and the atmosphere. An EK80 echosounder was used to identify emission areas through massive bubble plumes. The methodology applied integrates (1) sampling from the geosphere, hydrosphere and atmosphere for laboratory measurements of methane concentration by well-proven standard methods together with δ13CH4 analysis, (2) in situ measurements of methane concentration into the water column and the atmosphere, and (3) the deployment of a seafloor observatory for a short monitoring period (4-5 days) to evaluate the temporal variability of gas fluxes.</p><p>During the cruise we found several occurrences of bubble plumes extending near the surface. Our measurements indicate that dissolved methane concentration drastically decreases from the seafloor to the water surface, highlighting its degradation and dispersion along the pathway to the atmosphere. The atmospheric data suggests a consistent input of marine methane to the atmosphere at the shallower site,. Our study highlights the observational challenges both for the measurement of methane from in situ and laboratory methods, and for the estimation of sea surface fluxes.</p>

Noble gas anomalies related to high-intensity methane gas seeps in the Black Sea

2008 ◽  
Vol 265 (3-4) ◽  
pp. 396-409 ◽  
Author(s):  
C.P. Holzner ◽  
D.F. McGinnis ◽  
C.J. Schubert ◽  
R. Kipfer ◽  
D.M. Imboden
Keyword(s):  
Black Sea ◽  
High Intensity ◽  
Noble Gas ◽  
The Black Sea ◽  
Methane Gas ◽  
Gas Seeps

Ecological evaluation of aquatic microorganisms role in xenobiotics transformation with the reference to the Black sea

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
M. Pavlovska ◽  
◽  
I. Solomenko ◽  
I.E. Prekrasna ◽  
◽  
...  
Keyword(s):  
Microbial Communities ◽  
Black Sea ◽  
Sea Water ◽  
The Black Sea ◽  
Ecological Evaluation ◽  
Current Perspective ◽  
Polycyclic Aromatic ◽  
Analytical Review ◽  
Closed Water ◽  
Functional Shift

The present analytical review is dedicated to the current perspective of the issue of the Black sea xenobiotics pollution. The Black sea is extremely vulnerable to pollution impact, as it is a semi-closed water-body under the influence of significant inflow from the Danube, Dnipro and Dnister rivers. According to the recent data from the UNDP EMBLAS project 80 types of organic pollutants were identified in the Black Sea water samples. Those included 17 pesticides with the concentration above the safety thresholds both in the offshore and in the coastal waters. It has been previously shown that xenobiotics’ inflow results in taxonomic and functional shift of microbial communities inhabiting aquatic environment. Microbial-mediated degradation and biological pump control the polycyclic aromatic hydrocarbons’ flux in marine ecosystems, which prevents their accumulation in the food web. The data on xenobiotics pollution in both water column and sediments is summarized in the present review. The recent studies targeting the microbial communities’ role in biotransformation and translocation of substances with xenobiotic behavior are analyzed. The significance and topicality of the case-studies focusing on aquatic microbial communities functional response towards xenobiotics’ pollution is highlighted and the Black Sea ecosystem is suggested as the plausible example for addressing the above mentioned issues

Unexpected occurrence of hopanoids at gas seeps in the Black Sea

2003 ◽  
Vol 34 (1) ◽  
pp. 81-87 ◽  
Author(s):  
Volker Thiel ◽  
Martin Blumenberg ◽  
Thomas Pape ◽  
Richard Seifert ◽  
Walter Michaelis
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Gas Seeps
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