6 Did Quaternary Climate Fluctuations Affect Mediterranean Deep-Sea Coral Communities?

Abstract

Despite our limited current knowledge on fossil Mediterranean deep-sea corals, data collected so far hint at a strong influence of climate modifications on the distribution and diversity of these organisms through the Quaternary. Several species still living in the North Atlantic became extinct in the Mediterranean Sea at the Pleistocene-Holocene boundary, and the highest cold-water coral mound accretion rates known so far occurred during the last deglacial phase. Thermal variations of deep-sea waters have certainly affected distribution and survival of the most stenothermic coral species. However, changes in other environmental variables (such as current intensity, food supply and sediment rate, oxygenation), influenced by climate forcing, seem to have highly contributed to the decreased diversity of deep-sea corals and reduced accretion rate of coral mounds through the Quaternary. In order to precisely correlate the observed modifications of paleoassemblages with climate fluctuations, additional research effort needs to be conducted on both emerged and submerged coral deposits.