Tamborrino, Leonardo

Spatio-temporal distribution of cold-water corals and coral mounds in SE Atlantic

Cold-water corals (CWC) are the engineers of large deep-sea ecosystems and form unique biodiversity hotspots along most of the world's continental margins.However, only recently the significance of CWC (also on a global scale) has been revealed triggered by the progress in deep-sea technologies. CWC have the capability to construct significant large seabed
structures known as cold-water coral mounds*. Present knowledge about CWC and coral mounds regarding their formation and development through time, their spatial distribution, their ecology and their sensitivity to environmental change derived mainly from studies in the North Atlantic Ocean. For other regions in the Atlantic Ocean, in particular in the low latitudes, only few scattered reports of CWC exist. One example, for a low latitude CWC site is the upwelling area
off Angola and Namibia. The knowledge about the occurrence of CWC in this area was rather sparse. However, recent hydroacoustic campaigns revealed extended areas showing numerous seabed structures, which resemble coral mounds of the NE Atlantic. Although this region is characterised by an extensive oxygen minimum zone, the few reports about CWC demonstrate the great potential to find extensive and large CWC ecosystems along the Angolan and Namibian margins. The M122 expedition in early 2016 (RV METEOR M122 cruise) has conducted a survey and sampling programme to:
(a) validate if the hydroacoustically detected seabed structures are formed by CWC, and to
(b) investigate their spatial distribution, their vitality and the prevailing environmental setting, and to (c) reconstruct the development of these ecosystems across glacial-interglacial timescales.
Using material (acoustic data, ROV video footage, surface and core sediments) newly collected from the Namibian and Angolan continental margins during the M122 research cruise, the present project aims to reconstruct the spatial and temporal distribution of CWC and the formation and development of coral mounds with special emphasis on describing their geomorphological characteristics in this region in response to changing environmental conditions.