Influence of the Mediterranean Outflow Water on benthic ecosystems: answers and questions after a decade of observations

Abstract

Deep-water Circulation: Processes & Products. International Congress 16-18 june 2010, Baiona, Pontevedra, Spain.-- 2 pagesCold-water coral (CWC) ecosystems are closely tied to oceanography; they necessitate a careful balance of bottom current strength in order to survive. The discovery of the large CWC mounds in the Porcupine Seabight gave insight to the strong association with the dynamics of a very distal Mediterranean Outflow Water (MOW), both in the present-day as in the geological past. Although the MOW is thoroughly mixed north of Iberia, its physical characteristics enable local enhancing through internal tides. Observations of CWC reefs along the Bay of Biscay and the Cantabrian margins confirm this water mass is a real driver of benthic habitats (corals and oysters), controlling both physical (morphological) as oceanographic factors. They also give hints regarding the possiblenucleation and growth patterns of the large CWC mounds as well as their (palaeo)environmental constraints. However, the discovery of «dead» CWC reefs on mounds along the Moroccan margin has left many questions on the influence of intermediate water masses on these ecosystems and calls for a thorough investigation of the local palaeoceanography; are these glacially thriving reefs influenced by MOW or meddies