Abstract
We propose to perform a comparative study on the biodiversity and ecosystem functioning of Lophelia pertusa and Madrepora oculata deep water coral reefs (DWCRs) in two systems, the Mediterranean Sea and the NE Atlantic. Large living DWCRs were recently detected in the Mediterranean Sea questioning that DWCRs are only remnants from the last cold period due to warming and losses of nutrients in Mediterranean Sea waters. Even for Atlantic DWCRs, the biology and ecology is poorly studied, although they are oceanic hot spots of biodiversity. We propose to study the species diversity of all major types of organisms from prokaryotes to corals. Besides estimating for the first time the prokaryotic diversity in DWCRs, we will also investigate their role (as well as that of zooplankton, protistan plankton, viruses and colloids) as food source in controlled aquarium studies, since it is still a mystery how DWCRs match their carbon and energy requirements. Moreover, a comprehensive stable isotope analysis of corals (and other suspension feeders) and potential food sources will show, whether this mystery can be explained by a strong benthic pelagic coupling or by a link to chemoautotrophic prokaryotes obtaining energy and carbon from cold seeps e.g. via methane. Benthic Landers will be put in for in situ studies of coral growth and calcification and for assessing ecosystem functions such as providing structural frameworks, community respiration and organic matter remineralization. The potential link between biodiversity and ecosystem functioning will be investigated for DWCRs and compared between DWCRs in the warm, nutrient-poor Mediterranean and the cold and less nutrient-poor NE Atlantic.
Netherlands