Inhalt: | Continental margin, cold seep, methane, anaerobic oxidation of methane, AOM, sulphate reduction, biogeochemistry, green hous gas, biomarker, archaea, ANME, mud volcano, Haakon Mosby Mud Volcano, Tommeliten, Gulf of Cadiz, pockmark. - In this thesis, a variety of different cold seep systems (mud volcanoes and a gas seep) were investigated using a multidisciplinary approach to gain a more systematic understanding of these, methane-driven biogeosystems. The main goals were the detection and quantification of hot spots of methane oxidation as well as an assessment of environmental factors determining the activity and the distribution of methanotrophic communities. Furthermore, key microbial players were identified and the impact of Anaerobic Oxidation Of Methane (AOM) and Aerobic Oxidation Of Methane (MOx) on the surrounding, marine environment was studied. The investigations revealed the following: 1. Submarine mud volcanoes are colonized by specialized microbial communities utilizing the fluxes of reduced substrates such as methane and sulphide as energy source. At the actively methane-seeping Haakon Mosby mud volcano (HMMV, Barents Sea), a distinct spatial zonation of several novel clades of free-living and symbiotic aerobic and anaerobic methanotrophs was found. The main selection mechanism determining vertical and horizontal distribution and dominance of the methanotrophic communities were fluid flow rates controlling access to electron acceptors for methane oxidation. 2. The analysis of archaeal and bacterial specific lipid ... |
