Results from the European Deep Ocean Margins Research Training Network
Ocean margins mark the transition zones between continents and oceans, where the bulk of sediments are deposited and 50% of marine productivity takes place. The coastal ocean has always been vital for humankind in terms of exploitation of resources, as well as commerce and communication. It has been mainly during the last decade when economic and political interest (e.g., for hydrocarbon search, fisheries and seafloor usage) has spread into deeper waters beyond the shelf break to the continental slope and rise—a zone we herein refer to as the ‘‘Deep Ocean Margin’’ (DOM). Ocean margins are also of great scientific value: scientists study them to understand global climate, sea-level changes, biogeochemical cycles and the flux of fluids from the lithosphere to the ocean and, eventually, to the atmosphere. The recognition of the widespread occurrence of submarine landslides and the discovery of cold-water corals and associated communities are just two examples that illustrate the dynamic nature of the DOM and the scientific and technical challenges they pose. Understanding the mechanisms, architecture, and consequences of submarine landslides is of great importance due to the increasing interest for natural resources in DOM areas, to the geological contribution that landslides make in shaping ocean margins, and to the potential of landslides to trigger large tsunamis that would impact coastal areas (Locat and Mienert 2003; Canals et al. 2004; Lykousis et al. 2007). Cold-water corals illustrate the variability and diversity of Earth’s ecosystems and also the limitations of our knowledge on DOMs. Cold-water corals are not only a unique ecosystem that has been seriously damaged in many areas because of trawling activities, but also a refuge and breeding place for many marine species, including some of commercial interest, and a potential source for biosubstances of pharmaceutical interest. While their distribution along the European margins is now rather well known, a sound comprehension of their occurrence is essential in order to understand biological activity and related geological processes, and to permit sustainable resource exploitation and effective preservation of these deep-water habitats (Roberts et al. 2006; Freiwald and Roberts 2005; UNEP 2007).