The deep sea represents the largest ecosystem on earth. Due to its enormous dimensions and inaccessibility, the deep-sea realm is the worlds least known habitat. To understand ecological ties, the assessment of temporal variabilities is essential. Only long-term investigations at selected sites, describing seasonal and interannual variations, can help to identify changes in environmental settings determining the structure, the complexity, and the development of deep-sea communities. The opportunity to measure processes at sufficient time scales will also help to differentiate between natural variabilities and environmental changes due to anthropogenic impacts.High latitudes are amongst the most sensitive environments in respect to climate change, a fact urgently demanding the assessment of time-series in Polar Regions. The deep-sea long-term station Hausgarten of the Alfred Wegener Institute for Polar and Marine Research, Germany, was established in summer 1999 in the eastern Fram Strait off Spitsbergen. Beside a central experimental area at 2500 m water depth, we defined 9 stations along a depth transect between 1000-5500 m, and additional 6 stations along a latitudinal transect crossing the central Hausgarten station, which will be revisited yearly to analyse seasonal and interannual variations in biological, geochemical and sedimentological parameters.Moorings carrying current meters and sedimentation traps are used to assess hydrographic conditions in the area and to characterise and quantify organic matter fluxes to the seafloor. The exchange of solutes between the sediments and the overlaying waters are studied to investigate major processes at the sediment-water-interface. Vertical gradients of nutrients, organic carbon contents, C/N ratios, porosity and other geochemical parameters are determined to characterize the geochemical milieu of the upper sediment layers. Biogenic sediment compounds are analysed to estimate activities and total biomass of the smallest sediment-inhabiting organisms. The quantification of benthic organisms from bacteria to megafauna is a major goal in biological investigations.
AWI Organizations > Biosciences > Polar Biological Oceanography
AWI Organizations > Biosciences > Marine Animal Ecology
Helmholtz Research Programs > MARCOPOLI (2004-2008) > POL7-From permafrost to deep sea in the Arctic