Description: Das Projekt "Microbial methane consumption in contrasting ocean environments: effects of elevated seepage and geochemical boundary conditions" wird/wurde gefördert durch: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung. Es wird/wurde ausgeführt durch: Universität Basel, Umweltgeowissenschaften.Large quantities of the green house gas methane (CH4) are stored in sediments of continental margins, most importantly in the form of clathrate hydrate, which forms naturally when CH4 and water are subjected to low temperature (T) and high pressure (p). Typically, these conditions are met below 300 to 600 m water depth. An increase in bottom water T thus shifts the upper P/T boundary at which CH4 hydrates are stable towards greater water depth. Consequently, hydrate layers could then be exposed to P/T conditions where they become unstable. This leads to a liberation of CH4 into surface sediments, the overlying water column and, potentially, into the atmosphere where it further contributes to global warming. However, microbial CH4 oxidation may counteract this development. At present, most methane is retained in anoxic ocean sediments because it is oxidised by specialised archaea in consortium with sulphate reducing bacteria. In addition, aerobic bacteria in the water column consume CH4 that has by passed the benthic, microbial filter. Nevertheless, at so-called cold seeps where large quantities of CH4 are transported into surface sediments, significant amounts of CH4 may escape both, the sedimentary as well as the water column part of the microbial filter and are then released into the atmosphere. Yet, the efficiency of the microbial filter is not well constrained as are environmental factors controlling abundance and activity of methanotrophs, or selecting for specific phylogenetic groups. To close this knowledge gap, we will investigate microbial activity, abundance and identity at different types of cold seeps. We plan to determine limits of anaerobic and aerobic methanotrophy and to identify key environmental factors controlling activity, abundance and identity of the methanotrophic community. The study sites will be sampled within the frame work of international, seagoing expeditions.
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Tierhaltungsanlage ? Filterbrunnen ? Gashydrat ? Wassertemperatur ? Bodenwasser ? Filter ? Meeresboden ? Methan ? Bakterien ? Globale Erwärmung ? Gewässergrund ? Konsum ? Niedrigwasser ? Oxidation ? Standortwahl ? Studie ? Mikroorganismen ? Sediment ? Meeresgewässer ? Biologische Aktivität ? Atmosphäre ? Ökologischer Faktor ? Speicherung ? Wasseraufbereitung ? Wasserstand ? Treibhausgas ? Gas Seeps ?
License: cc-by-nc-nd/4.0
Language: Englisch/English
Time ranges: 2012-04-01 - 2015-03-31
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