Benthic foraminiferal assemblages in the Cap de Creus canyon and adjacent open slope: Potential influence of dense shelf water cascading and open- ocean convection

摘要

The NW Mediterranean Sea is subjected to episodically intense events of dense shelf water cascading (DSWC) and open-ocean convection (OOC) that ventilate the seafloor and also have important consequences on organic matter inputs to the seabed and sediment dynamics. The influence of the massive physico-chemical disturbance driven by these events on deep-sea ecosystems is poorly known, and, to date, no information is available on the response of benthic foraminiferal assemblages. To provide insights on these gaps of knowledge, in April 2009 we investigated the foraminiferal faunas along the major axis of the Cap de Creus canyon (at 1000, 1900 and 2400 m depth) and at two additional stations located on the adjacent open slope (at 1000 and 1900 m). The area under scrutiny was hit by intense DSWC and OOC events in winters 2005 and 2006, and during winter 2009 an intense OOC event occurred, with detectable consequences observed at 1500 m depth.