Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Maria S. Merian	MSM20-4	14.03.2012 - 07.04.2012		NW Atlantic (Limit 40?W) Gulf of Mexico

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Hebbeln Dierk	Universitat Bremen, Zentrum fur Marine Umweltwissenschaften	Bridgetown	Freeport

Ziel der Reise / Objectives of Cruise:

The leg MSM 20-4 started on the 14.03.12 in Bridgetown (Barbados) and ended on the 07.04.12 in Freeport, Bahamas. It carried out multidisciplinary research on the diversity and long-term development of cold-water coral ecosystems in selected areas along the Mexican margin (off Yucatan), along the West Florida margin, and along the western margin of the Great Bahama Bank. These studies contribute to TRACES - the Trans-Atlantic Cold-Water Coral Ecosystem Study, an international initiative to establish a basin-wide analysis of the cold-water coral ecosystems in the North Atlantic. Thus, for this expedition the following three core questions have been in the focus: (1) How divers are the cold-water corals and the structure and composition of the entire cold-water coral ecosystems in the western Atlantic? (2) How did the cold-water coral ecosystems in the western Atlantic developed under varying climate forcing, as e.g. over the last glacial/interglacial cycle? (3) Which similarities and/or differences exist between the cold-water coral ecosystems in the western and in the eastern North Atlantic today and through their long-term development? To answer these questions various target areas in the western Atlantic have been investigated during Leg MSM 20-4. These comprised "potential" CWC mounds along the Campeche Bank (Yucatan Peninsula) and the West Florida Slope within the Gulf of Mexico, and reported CWC occurrences in the Florida Straits. For all working sites station work started with a detailed hydro-acoustic mapping (multibeam echosounder, Parasound) which formed the base for planning optimised dives with an remotely operated vehicle (ROV). Extended video surveys with the ROV Cherokee were used to characterise the facies and fauna and to identify most suited coring sites. Based on this information, positions have been defined to conduct a dedicated sampling (gravity cores, box cores, grabs, water samples) and monitoring (CTD) programme within or in the direct vicinity of the observed cold-water coral ecosystems. During previous expeditions this strategy has already been proven to be very successful in sampling CWC material and data of their surrounding environment.

Messungen / Measurements