GEO-REFERENCED VIDEO-MOSAICKING AS AMEANS TO GIS-SUPPORTED SEA FLOORCOMMUNITY MAPPING AT HÅKON MOSBY MUDVOLCANOK. Jerosch (1), M. Schlüter (1), J.-P. Foucher (2)(1) Alfred-Wegener-Institute for Polar and Marine Research (AWI), Germany, (2) InstituteFrançais de Recherche pour l Exploitation de la Mer (IFREMER), FranceDuring RV Polarstern cruise ARK XIX3b (2003), we conducted geo-referenced videomosaickingto enhance our knowledge of the distribution of different community typesat the Håkon Mosby Mud Volcano (HMMV). This distribution is most likely linked tocertain biological and sedimentological characteristics which select for these communities.Special emphasis was put on the distribution and density of conspicuous whitemats that consisted of sulphur-oxidizing bacteria(dominant species: Beggiatoa)and ofpogonophoran worms, who rely on endosymbiotic bacteria.A vertical camera that was mounted onto the remotely operated vehicle Victor 6000generated a video flow which was processed by means of the IFREMER software MATISSE.This software facilitated the process of digital merging of images to mosaics.Navigational data including dead-reckoning and acoustic USBL positioning providedthe basis for geo-referencing of the images.As all data were geo-referenced we were able to carry out spatial analyses (GIS).This analysis allowed us to estimate the percentage coverage of different habitat typeswhich can subsequently be overlaid with other parameters defining habitat structure,e.g. bottom temperature and salinity, to accomplish a multi-disciplinary view of theHMMV and improve our understanding of this ecosystem.The mosaics obtained encompass 9% of the total edifice of the volcano increasing boththe accuracy and resolution of previous community and habitat maps. The footageshowed that bacterial mats and pogonophoran worms colonized extensive areas ofHMMV. Areas with a rough topography and small patches of sulfide oxidizing communitieswere interpreted to indicate large methane release. A provided methane releaserate can be estimated for each habitat type. The spatial analysis of the habitatdistribution that we conducted is a major step toward yielding the total discharge ofmethane through the surface of HMMV.