Feseker, Tomas

Hensen, Christian

Reischke, S.

Treude, Tina

English

OceanRep

Geophysical Research Abstracts,Vol. 11, EGU2009-11025, 2009EGU General Assembly 2009© Author(s) 2009Microbial methane oxidation and chemoauthotrophic communities at theNorth Alex mud volcano, Eastern MediterraneanT. Treude, S. Reischke, T. Feseker, and C. HensenLeibniz Institute for Marine Sciences, IFM-GEOMAR, Kiel, Germany (ttreude@ifm-geomar.de)North Alex mud volcano, located on the upper slope of the western Nile deep-sea fan, is characterized by an activeseepage center transporting pore fluids and gases from deep subsurface sources to the sediment-water interface. Wesampled different locations between the center and rim of the mud volcano with ROV and multicorer to study theactivity of benthic microorganisms involved in aerobic and anaerobic oxidation of methane as well as associatedchemoautotrophic communities. Highest methanotrophic activity was found in the mud volcano center, wheresediments exhibited high methane and sulfide concentrations. Chemoauthotrophic organisms included filamentoussulfur bacteria (Beggiatoa spp.) and symbiont bivalves (Calyptogena spp., Acharax spp.). In the vicinity of thesouthern mud volcano rim a large tubeworm field (Lamellibrachia spp.) was discovered. The field was associatedwith authigenic carbonate precipitates and chemoautotrophic bivalves of the family Lucinidae. Abundant ray eggsplaced within the tubeworm field as well as the presence of small fish, shrimp and squid indicated that this habitatwas utilized as a nursery ground by marine organisms that are not typically related to seepage activity. Preliminarydata on benthic microbial methane turnover, geochemical gradients as well as temperature profiles across thesediment-water interface will be presented.

Microbial methane oxidationand chemoauthotrophic communities at the North Alex mud volcano, eastern Mediterranean

Abstract

Similar works

Full text

Available Versions

OceanRep