The MoMARDREAM-Naut Leg 1 cruise (8 - 19 July 2007) was the first part of the multidisciplinary project MOMARDREAM lead jointly by Jérôme Dyment (IPGP-Paris), Françoise Gaill (CNRS-Université Paris 6) and Yves Fouquet (IFREMER). The first 9 Nautile dives were dedicated to the biology and geology of the Rainbow site at the Mid-Atlantic Ridge (MAR). Françoise Gaill was the chief scientist and Jérome Dyment the project leader.

At 2300-m depth, Rainbow is among the few discovered MAR sites hosted on ultramafic rocks. The chemical composition of fluids is unique to date on many aspects including the exceptional enrichment of fluids in iron. This element therefore plays a major role in geological, hydrothermal and biological processes. MOMARDREAM objectives are related to these processes. One of the central issues is to understand the role of this element in the symbiotic relationship between Rimicaris exoculata shrimps and their associated bacteria. These interactions were studied in situ and in vivo, in pressurized aquaria (IPOCAMP) sampled with PERISCOP.

In addition, geological surveys and sampling were performed to anticipate an IODP drilling project lead by Yves Fouquet (IFREMER). A second series of the MoMARDREAM cruises will be performed later with the VICTOR ROV for microbathymetry and magnetic surveys.

For more information and daily dispatches:,debut-de-la-campagne-momardream.html