Environmental conditions determine the spatial distribution of macrobenthic species and communities. Insight into the underlying dependencies is an essential prerequisite for understanding of ecosystem functioning and processes in marine environment. The technique for predictive modelling of species occurrence in response to driving abiotic factors (salinity, water depth and seabed sediment characteristics) was developed based on single-factor logistic regression models. It was successfully applied in case studies on both a regional (Mecklenburg Bight, Pomeranian Bight) and large scale (Baltic Sea) to develop the habitat suitability maps for selected species from different functional groups (i.e. grazers, deposit and suspension feeders, and predators). (1) We will test the controversial hypothesis that a loss of biodiversity threatens ecosystem’s functioning. (2) The main aim of this subtask therefore is to combine the mapping of sedimentary properties with existing habitat maps and compare the distribution patterns with detailed maps of benthic macrofauna. (3) We will acquire a comprehensive spatial approach that leads to a suitable area-wide habitat modelling. Additional complementary datasets and accounting activities of key macrofauna species are prerequisite for better understand the role of biodiversity and of their ecological services in sediments. (4) Therefore different functional properties of benthic macrofauna assemblages in the south-western Baltic Sea will be studied in the model area Mecklenburg Bight in close cooperation with WP2.