Influence of the Mediterranean Outflow Water (MOW) on the occurrence, distribution patterns and connectivity of deep benthic communities

The aim of the talk is to give an overview to the ATLAS partners of the PhD thesis that is being carried out by Cristina Gutiérrez and supervised by Cova Orejas and Andrea Gori. This PhD is focused on the characterisation and comparison of the deep benthic communities located inside and outside the depth range influenced by the Mediterranean Outflow Water (MOW), to understand the possible current and past relationship between Atlantic and Mediterranean deep benthic communities mediated by the oceanographic settings.

The study is based on the data acquired during the MEDWAVES cruise (September-October 2016), where selected study sites influenced by the MOW were analysed (the mud volcano Gazul, Formigas and Ormonde seamounts and Seco de los Olivos). ROV transects were conducted and High Definition videos recorded. Video transects are currently under quantitative analysis. After finishing the characterisation of the deep benthic communities, a comparative analysis among the study areas will be carried out based on the community composition, abundance and distribution pattern of the dominant species, as well as their population structure. To conduct this comparison, the relationship between the main environmental features (physicochemical characteristics of seawater and geomorphological characteristics of the sea floor) and the benthic community composition and biological features in the study areas will be analysed, including spatial explicit GIS-based analyses (e.g. species distribution models).

Finally, innovative next-generation indexes will be generated, specifically designed for the reliable assessment of the ecological state and degree of vulnerability of deep benthic ecosystems. This is of particular scientific interest nowadays in order to generate new procedures for the study of marine vulnerable ecosystems (VMEs) such as deep sponge grounds and CWC communities.

The results of this PhD project will lead to an evaluation of the conservation status of the studied benthic communities, helping to address the Good Environmental Status (GES) in the deep sea, and contributing to the Marine Spatial Planning (MSP). In addition, these results will contribute to establish conservation areas based on their species composition, vulnerability, and ecological role of the habitats.