Physical oceanography from CTD during Maria S. Merian cruise MSM20/4 in spring 2012

With an extension of > 40 km**2 the recently discovered Campeche cold-water coral province located at the northeastern rim of the Campeche Bank in the southern Gulf of Mexico belongs to the largest coherent cold-water coral areas discovered so far. The Campeche province consists of numerous 20-40 m-high elongated coral mounds that are developed in intermediate water depths of 500 to 600 m. The mounds are colonized by a vivid cold-water coral ecosystem that covers the upper flanks and summits. The rich coral community is dominated by the framework-building Scleractinia Enallopsammia profunda and Lophelia pertusa, while the associated benthic megafauna shows a rather scarce occurrence. The recent environmental setting is characterized by a high surface water production caused by a local upwelling center and a dynamic bottom-water regime comprising vigorous bottom currents, obvious temporal variability, and strong density contrasts, which all together provide optimal conditions for the growth of cold-water corals. This setting - potentially supported by the diel vertical migration of zooplankton in the Campeche area - controls the delivering of food particles to the corals. The Campeche cold-water coral province is, thus, an excellent example highlighting the importance of the oceanographic setting in securing the food supply for the development of large and vivid cold-water coral ecosystems.