Cold-water corals off Argentina and Uruguay (SW Atlantic): Present and past

• Applicant: Dr. Claudia Wienberg
• Subject Area: Oceanography
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564896815

Cold-water corals (CWCs) form coral mounds along continental margins and provide habitat for highly diverse deep-sea ecosystems. Knowledge of CWC ecosystems and their sensitivity to environmental change comes mainly from studies in the North Atlantic, while there are only few reports of their presence in the South Atlantic, such as off Uruguay and Argentina. There, CWCs and coral mounds occur north and south of the Brazil-Malvinas Confluence (BMC), which forms a major oceanographic frontal system in the region. These CWC sites are poorly studied, but it appears that the BMC forms a biogeographic boundary between two dominant species, Lophelia pertusa to the north and Bathelia candida to the south. The planned ARGURU expedition aims to (i) confirm the existence of such a strict biogeographic boundary, (ii) investigate the spatial distribution of CWCs along a depth transect off northern Argentina, and (iii) reconstruct the evolution of CWC reefs and mounds in response to climate-driven variations in the position of the BMC and the strength of the Antarctic Intermediate Water (AAIW). The accompanying project will focus on the initial evaluation of sediment cores collected during the planned expedition. Selected cores will be analysed to develop initial stratigraphic concepts for (a) (on-mound) cores taken from CWC mounds, which record past reef growth periods, and (b) (off-mound) cores taken from the surrounding seafloor, which represent palaeoceanographic archives of past environmental changes that have controlled reef/mound growth in the past.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 2520: Infrastructure area - Research Vessels
• Co-Investigator: Professor Dr. Dierk Hebbeln