Freshwater ostracods from ice-wedge polygon ponds in Adventdalen, Svalbard

• Main Authors: Schneider, Andrea, Wetterich, Sebastian, Sannel, Britta, Schirrmeister, Lutz
• Format: Conference Object
• Language: unknown
• Published: Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research International Permafrost Association 2016
• Subjects: Adventdalen; Ice; Longyearbyen; permafrost; Svalbard; UNIS; wedge*
• Online Access: https://epic.awi.de/id/eprint/42027/; https://epic.awi.de/id/eprint/42027/1/poster_ICOP_AS.pdf; https://hdl.handle.net/10013/epic.48820; https://hdl.handle.net/10013/epic.48820.d001

Freshwater ostracods (Crustacea, Ostracoda) are of interest in modern biological studies, while fossil records of ostracod valves enable us to reconstruct past lacustrine environments. The about 1mm long crustaceans carry a calcite carapace that is biomineralized from dissolved components in the ambient water, and completely envelopes their body. Ostracods inhabit almost all aquatic environments, even shallow freshwater ponds in the vast circumartic permafrost areas. In high-latitude areas, ostracod species diversity, their modern ecological demands, and instrumental records of environmental parameters are only scarcely documented. Such reference information is the key to quantitatively reconstruct past environments from fossil ostracod assemblages. This gap in ostracod data limits their use as biological indicators in the Arctic, where the effects of future climate warming are expected to be strongest. The objective of the study presented here was to extend the data set on arctic freshwater ostracods and environmental records by characterizing presentday habitat conditions, abundance and diversity of ostracod assemblages in periglacial freshwaters on Svalbard. The aims of this project were 1. to conduct an inventory of the abundance, diversity and ecological ranges of the freshwater ostracods living in polygon ponds in Adventdalen near Longyearbyen (78°11’11”N, 15°55’20”E), 2. to determine the present-day hydrochemical and sedimentary characteristics of ostracod habitats, and 3. to witness temporal variability in a polygon pond during the Arctic summer season 2013. The study site was located near the University Centre on Svalbard (UNIS)-run monitoring site for thermal contraction cracking in ice-wedge polygons on a river terrace in outer Adventdalen (Christiansen 2005). Permafrost on Svalbard is estimated to be of late Holocene age with temperatures of -5.2 to -5.6 °C in boreholes in the Adventdalen area (Christiansen et al. 2010). Ice-wedge polygons form in cold-climate environments under permafrost conditions ...