Submarine cold vents are areas where specific geochemical species and gases are transported from the sub-seafloor into the water column and probably into the atmosphere. Cold vents are often associated with gas hydrates, which act as temporally variable sinks/sources for methane, the dominant geochemical species at cold vents. Upward-migrating fluids and gas hydrates have a strong impact on local, regional and global biogeochemical cycles. Particularly the expulsion of methane as dissolved or free gas has a n impact on the local carbon cycle, allows chemoautotrophic fauna to settle and causes massive carbonate precipitations. Gas hydrates directly influence the amount of released methane, which can be transported through the water column and may reach the atmosphere and influence our climate. Massive gas hydrate decomposition also endangers oil/gas platforms or pipelines and can trigger submarine landslides/tsunamis.
Although cold vents and gas hydrates certainly exist all over the world, our knowledge is restricted to some well investigated areas; but we know almost nothing about their ecological variability, lifespan or changes in fluid activity through time. New Zealand is an ideal place for integrative petrographic, geochemical and geophysical studies because at the Hikurangi Margin gas hydrates exists and fossil occurrences can be found on land. Offshore geochemical investigations will be carried out in this area for the first time. Its comparison to other vent areas and the direct relation to fossil occurrences close by will provide essential insight into the variability of cold venting through time. The integrative approach permits a unique data compilation and will strengthen the European knowledge and further consolidate the European leading position in this field of research. The upcoming research activities in the EU provide ideal conditions for future joint projects in Europe and abroad, for which the broadening of our knowledge is of essential need.
