Description: Glass sponges (Porifera, Hexactinellida) are important structuring components of the benthos in Antarctic shelf regions. These sessile filter feeders can grow up to 2 m in height and form extensive sponge beds in some areas, dominating the benthic biomass and providing habitat for a variety of other animals. However, much of their ecology is still unknown to date, including the factors determining their distribution and abundance. In the current study, we investigate glass sponge distribution and abundance in the south-eastern Weddell Sea in relation to environmental factors (water mass characteristics, currents, ice cover), as well as food availability and abundance of predators. During two recent expeditions with RV Polarstern, we collected photos and videos of the ocean floor by using different gear equipped with HD cameras: a multi grab (MG), an Ocean Floor Observation System (OFOS) and a Remotely Operated Vehicle (ROV). For each of 28 stations, 30 images are selected and analyzed for abundance and species composition of glass sponges and their predators, as well as substrate characteristics. In addition to that, we measured temperature, salinity, dissolved silicate, particulate silicate and bacterial cell numbers. Furthermore, model and/or satellite data on current strength and mean annual ice cover will be included in the study. Glass sponge abundance will be analyzed in relation to the environmental data and predator abundance in order to identify the factors determining the abundance and distribution of glass sponges in the south-eastern Weddell Sea. Our findings will provide an important baseline to assess how glass sponge communities might change in a changing Antarctic environment.