Intergovernmental Oceanographic Commission
Division of Earth Sciences, UNESCO


Abstract deadline: July 15th 2003!


Session 2 - Ocean Margin Ecosystems:
Deeper-water Ocean Margin Ecosystems thrive along a steep bathymetric gradient thereby inhabiting a broad range of seabed settings such as slopes, canyon systems and slide areas and are being exposed to contrasting regimes of oceanic circulation patterns. The recent discoveries of deep water coral reefs, carbonate mounds, cold seeps, and subsurface bacteria along Europe's deep-water frontier challenge our understanding of geosphere-biosphere interactions at ocean margins. The deep-water reefs and mounds (1) occur in a large variety of dimensions, structures and geometries, thus shaping margin morphology, (2) provide the frame for an extremely rich biodiversity and biomass and thus form an important biological resource that already is commercially exploited for fish and marine natural products, (3) represent a hitherto unexplored paleoenvironmental archive within the reef framework, which can document past and present global changes, (4) are supposed to be linked to fluid flow such as hydrocarbon emanation from the geosphere beneath, (5) are challenging targets for the future development of state-of-the-art marine technology such as ROVs, AUVs, and especially long-term monitoring observatories.

The significance of geosphere-biosphere coupling in margin sediments is becoming increasingly important for the assessment of ocean margin life and ecosystems. In marine sediments the subsurface biomass has been estimated to be equivalent to approximately 10% of all surface life, possibly even higher. Thus a major component of life on Earth exists far away from sunlight and from plants that trap this energy, and it is difficult to understand what energy sources are available in such deep and ancient deposits (millions of years). In addition, as some bacteria and archaea can live at very high temperatures (up to ~110°C and possibly higher) and pressures (>1,000 atm), conditions that are reached only several kilometres below seafloor. This may bring bacteria into the temperature window of fossil fuel formation (100-150°C) where high temperature activates ancient organic material and induces thermocatalytic conversion to hydrocarbons and other compounds. These are compounds that some bacteria can use as energy sources, and hence this heating during burial may provide a mechanism for maintaining a deep biosphere. At some locations, such as seeps and mud volcanoes, these thermogenic compounds are brought to the surface where they greatly stimulate benthic productivity and may provide windows into the deep biosphere.

To co-ordinate research on these new habitats, make the technological developments for their study, start to integrate this knowledge into our understanding of ocean margin ecosystems and function, and to disseminate this information for sustainable use of ocean margin ecosystems a conference on this topic is necessary and timely. This conference will offer a platform for a dialogue between academia, industry, environmental stakeholders and the public.


Conference secretary:
Kai Rune Mortensen
Phone: +47 776 44428
Fax: +47 776 45600

Organizing committee:  
Prof. Jürgen Mienert (Chairman)
Dr. Serge Berne
Prof. Miquel Canals
Prof. Christian Dullo
Dr. Dan Evans
Prof. André Freiwald

Prof. Jean Pierre Henriet
Dr. Bo B. Joergensen
Dr. Jean Klerkx
Dr. Gilles Lericolais
Dr. Gilles Ollier
Prof. John Parkes
Dr. Constantine Perissoratis

Prof. Monti Priede
Dr. Alexei Suzyumov
Dr. Fabio Trincardi
Dr. Tjeerd van Weering
Prof. Phil Weaver
Prof. Graham Westbrook

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