Benthic studies at the LTER (Long-Term Ecological Research) observatory HAUSGARTEN focus on small- and large-scale distribution and diversity patterns of sediment-inhabiting organisms from the meiofauna (size range 32 - 1000 µm) to the epi-/megabenthos (size range > 2 cm). Sampling at HAUSGARTEN is conducted on an annual base since 1999 to detect and track the impact of environmental changes on the deep-sea benthos. Furthermore, we carry out a number of biological short- and long-term experiments to determine the factors controlling deep-sea benthic biodiversity.
To study the impact of abiotic and biotic changes in environmental variables on the small biota, virtually undisturbed sediments are taken with a video-guided multiple corer (MUC). We analyse distribution and activity patterns and community shifts by means of biochemical methods. Spatial and temporal distribution patterns of meiofauna organisms are analysed with special focus on nematodes (“roundworms”), which are identified up to species level and classified in functional groups.
Surface sediments, sampled with a giant box corer (GBC), are analysed for patterns of standing stock, composition, and diversity of macrofauna organisms (size range 0.1 - 2 cm). Organisms were identified to the lowest possible taxonomic level and become weighed for biomass estimations. Macrofauna studies are carried out in close cooperation with Polish and Russian colleagues.
Large-scale distribution patterns of megafaunal assemblages at HAUSGARTEN are assessed by means of towed and remotely-controlled photo/video systems. To rapidly analyse large quantities of images, we developed computer algorithms that can be trained to automatically detect organisms on seafloor images. Sporadic sampling of megafauna for taxonomic identification and for ground-truthing of the photo and video footage is carried out using epibenthic sleds, Agassiz trawls, and occasionally the suction system ('slurp gun') of a Remotely Operated Vehicle (ROV).
Contact: T. Soltwedel, C. Hasemann, I. Schewe, J. Dannheim, M. Bergmann, A. Purser
Literature:
Soltwedel, T., Grzelak, K., Hasemann, C. (2020). Spatial and temporal variation in deep-sea meiofauna at the LTER Observatory HAUSGARTEN in Fram Strait (Arctic Ocean). MDPI - Diversity 12 (7). doi: 10.3390/d12070279
Käß, M., Vedenin, A., Hasemann, C., Brandt, A., Soltwedel, T. (2019). Community structure of macrofauna in the deep Fram Strait: A comparison between two bathymetric gradients in ice-covered and ice-free areas. Deep-Sea Research I 152 (103102). doi: 10.1016/j.dsr.2019.103102
Taylor, J., Staufenbiel, B., Soltwedel, T., Bergmann, M. (2018). Temporal trends in the biomass of three epibenthic invertebrates from the deep-sea observatory HAUSGARTEN (Fram Strait, Arctic Ocean). Marine Ecology-Progress Series 602: 15-29.
Grzelak, K., Kotwicki, L., Hasemann, C., Soltwedel, T. (2017): Bathymetric patterns in standing stock and diversity of deep-sea nematodes at the long-term ecological research observatory HAUSGARTEN (Fram Strait). Journal of Marine Systems 172: 160-177.
Taylor, J., Krumpen, T., Soltwedel, T., Gutt, J., Bergmann, M. (2017): Dynamic benthic communities: assessing temporal variations in benthic community structure, megafaunal composition and diversity at the Arctic deep-sea observatory HAUSGARTEN between 2004 and 2015. Deep-Sea Research I 122: 81-94.
Vedenin, A., Budaeva, N., Mokievsky, V., Pantke, C., Soltwedel, T., Gebruk, A. (2016): Spatial distribution patterns in macrobenthos along a latitudinal transect at the deep-sea observatory HAUSGARTEN. Deep-Sea Research I 114: 90-98.
Meyer, K., Bergmann, M., Soltwedel, T. (2013): Interannual variation in the epibenthic megafauna at the shallowest station of the HAUSGARTEN observatory (79°N, 6°E). Biogeosciences 10: 3479‑3492.
Hasemann, C., Soltwedel, T. (2011): Small‑scale heterogeneity in deep‑sea nematode communities around biogenic structures. PLOS One 6(12): 1‑13.
Bergmann, M., Soltwedel, T., Klages, M. (2011): The interannual variability of megafaunal assemblages in the Arctic deep sea: preliminary results from the HAUSGARTEN observatory (79°N). Deep-Sea Research I 58: 711‑723.
