Regional warming observed at the Antarctic Peninsula since the 1950ies caused a collapse of the Larsen AB ice-shelves in 1995, respectively 2002. The ecological impact of these events is studied by multidisciplinary scientific teams on several Antarctic expeditions (2007, 2011 and 2013) to track and monitor the ongoing oceanographic and ecological dynamic changes. Sponges play a key role in the bentho-pelagic coupling and as hosts for other organisms. The here proposed research project is designed to analyze the impact of climate change on the diversity of Porifera within the Antarctic shelf communities and their response to the disintegration of permanent ice-shelves. Detailed faunistic comparisons will be done between the sponge faunas from the repeated stations of the tree expeditions and between the Larsen ACB area and reference stations. Assumed speciation processes and colonization of the Larsen shelves by pioneer and deep-sea sponge taxa will be tested by comparative morphological and molecular methods as well as parallel investigations of the sponge infauna. Ecological successions are detected by systematic and quantitative evaluation of ROV transsects, and we further target the reconstruction of sponge biomasses and silica content in the Antarctic 'sponge gardens'. This project will bring important hints to future ecological developments due to ongoing disintegration of the Antarctic ice-shelves.
Makrozoobenthos of soft-bottom benthic communiy was collected by van-Veen grabs and beam trawls to sample the infauna and epifauna. Samples were collected between 2003 and 2004 in spring, summer and autumn each year. Benthic data were collected in the North Sea, German Bight off the East Frisian Coast. Benthic community was evaluated for potential changes after cessation of bottom trawling. In July 2003, the research platform FINO 1 was built as a pilot project for future offshore wind farms. The platform is located at 28 m water depth in the German Bight, 45 km off the Island Borkum. The surroundings of the platform (500 m radius) are closed for all shipping activities (except scientific activities) and are thus protected from trawling activities. Two zones beyond the 500 m radius, 9 km apart from the protected area in north-western and eastern direction were chosen as reference sites. Sampling follwed a BACI-design (before-after-control-impact), i.e. comparing the protected area to the further trawled areas. In both areas, protected and trawled area, sampling of the benthic community was carried out with “RV Heincke” during 2 periods. The first sampling period, defined as “pre-closure”, includes two sampling campaigns: one campaign 3 months before and one campaign 2 weeks after fishery closure of protected area (March/April and July/August 2003). “Post-closure” sampling was also carried out in two campaigns: one campaign in July/August and one campaign in September/October 2004, i.e. 12-14 months after fishery closure of protected area. Data for each campaign comprise different stations in the area, sampled by grab samples (infauna) and beam trawl samples (epifauna). Biodiversity data of species include abundance (count data) and biomass (wet mass, g) per sample, as well as sediment grain sizes, organic carbon, total carbon, nitrogen and sulfur content as accompanying environmental data.