The influence of microhabitat features on benthic foraminiferal distributions and biofacies along a bathymetric transect on the central-southern Mediterranean Sea (Sicily, Italy)

The Mediterranean Sea is a mid-latitude semi-enclosed basin connected to the Atlantic Ocean and surrounded by the Mediterranean region. The investigation of the central part of the Mediterranean Sea is of particular importance as it divides the Tyrrhenian Sea and the western Mediterranean Sea from the eastern Mediterranean, where different water masses are encountered. A total of twelve stations were sampled along a ca. 150 m depth transect between the southern tip of Sicily and archipelago of Malta in July, 2013. Physico-chemical parameters of water and sediments were measured in vertical profile and three-replicated sediment samples were collected by box-corer. Total benthic foraminiferal assemblages were studied in order to identify the distribution and biofacies of the most abundant taxa and to relate them to the different water masses. Additionally, the microhabitats of live benthic foraminifera were documented by slicing the core at 0.5 cm intervals from 0 to 1 cm depth, and 1 cm intervals from 1 to 2 cm depth. The transect allowed to better understand the TROX model for calcareous and agglutinated foraminifera from both the >150 ?m and 63-150 ?m fractions. On the basis of the living benthic foraminiferal assemblages coupled with the analysis of the sedimentary organic matter content, it was possible to identify an assemblages succession that probably reflects the increasing scarcity of trophic resources, typical of this environment, along the inshore/offshore gradient and the importance of the role played by the proximity to the coast for the food recovery.