Microbial Processes in the Black Sea Water Column and Top Sediment: An Overview

Abstract. A steady state box model was developed to estimate the methane input into the Black Sea water column at various water depths. Our model results reveal a total input of methane of 4.7 Tg yr−1. The model predicts that the input of methane is largest at water depths between 600 and 700 m (7% of the total input), suggesting that the dissociation of methane gas hydrates at water depths equivalent to their upper stability limit may represent an important source of methane into the water column. In addition we discuss the effects of massive short-term methane inputs (e.g. through eruptions of deep-water mud volcanoes or submarine landslides at intermediate water depths) on the water column methane distribution and the resulting methane emission to the atmosphere. Our non-steady state simulations predict that these inputs will be effectively buffered by intense microbial methane consumption and that the upward flux of methane is strongly hampered by the pronounced density stratification of the Black Sea water column. For instance, an assumed input of methane of 179 Tg CH4 d−1 (equivalent to the amount of methane released by 1000 mud volcano eruptions) at a water depth of 700 m will only marginally influence the sea/air methane flux increasing it by only 3%.

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Response of the Black Sea methane budget to massive short-term submarine inputs of methane

Biogeosciences Discussions ◽

10.5194/bgd-7-9117-2010 ◽

2010 ◽

Vol 7 (6) ◽

pp. 9117-9136 ◽

Cited By ~ 2

Author(s):

O. Schmale ◽

M. Haeckel ◽

D. F. McGinnis

Keyword(s):

Steady State ◽

Water Column ◽

Black Sea ◽

Sea Water ◽

Stability Limit ◽

The Black Sea ◽

Intermediate Water ◽

Short Term ◽

Total Input ◽

Water Depths

Abstract. A steady state box model was developed to estimate the methane input into the Black Sea water column at various water depths. Our model results reveal a total input of methane of 4.7 Tg yr−1. The model predicts that the input of methane is largest at water depths between 600 and 700 m (7% of the total input), suggesting that the dissociation of methane gas hydrates at water depths equivalent to their upper stability limit may represent an important source of methane into the water column. In addition we discuss the effects of massive short-term methane inputs (e.g. through eruptions of deep-water mud volcanoes or submarine landslides at intermediate water depths) on the water column methane distribution and the resulting methane emission to the atmosphere. Our non-steady state simulations predict that these inputs will be effectively buffered by intense microbial methane consumption and that the upward flux of methane is strongly hampered by the pronounced density stratification of the Black Sea water column. For instance, an assumed input of methane of 179 Tg CH4 d−1 (equivalent to the amount of methane released by 1000 mud volcano eruptions) at a water depth of 700 m will only marginally influence the sea/air methane flux increasing it by only 3%.

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Microbial Processes in the Black Sea Water Column and Top Sediment: An Overview

Analytical pyrolysis of suspended particulate organic matter from the Black Sea water column

Aerobic and anaerobic methanotrophs in the Black Sea water column

Sulfur isotope geochemistry of the Black Sea water column

137Cs and 239,240Pu Concentrations in the Black Sea Water Column

The Stable Isotopic Composition of Sulphur Species in the Black Sea Water Column

Inorganic carbon fixation by sulfate-reducing bacteria in the Black Sea water column

Interplay between microbial community composition and chemodiversity of dissolved organic matter throughout the Black Sea water column redox gradient

Carbon and nitrogen isotopic ratios of suspended particulate organic matter (SPOM) in the Black Sea water column

Response of the Black Sea methane budget to massive short-term submarine inputs of methane

Response of the Black Sea methane budget to massive short-term submarine inputs of methane

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