HR: 14:00h
AN: B23A-03    [Abstracts]
TI: The Influence of Seasonally Changing Groundwater/Surface Water Interaction on the Composition of Sediment Fauna
AU: * Schmidt, S I
EM: suse_semperula@yahoo.de
AF: SNSD Museum f. Tierkunde, Königsbrücker Landstr. 159, Dresden, 01099 Germany
AU: Hahn, H J
EM: hjhahn@uni-landau.de
AF: Universität Koblenz-Landau, AG Grundwasser Campus Landau Institut f. Biologie Im Fort 7, Landau, 76829 Germany
AU: Hatton, T J
EM: tom.hatton@csiro.au
AF: CSIRO Land & Water, CELS Floreat Private Bag No. 5, Wembley, WA 6014 Australia
AU: Woodbury, R J
EM: robert.woodbury@csiro.au
AF: CSIRO Land & Water, CELS Floreat Private Bag No. 5, Wembley, WA 6014 Australia
AU: Watson, G D
EM: gerald.watson@csiro.au
AF: CSIRO Land & Water, CELS Floreat Private Bag No. 5, Wembley, WA 6014 Australia
AB: Sediment fauna in both streams and groundwater are crucial to the functioning of sediment processes, and are known to be highly influenced by hydraulics. But how does the seasonal variation of groundwater/surface water interactions influence the faunal composition? This question was addressed in a small Western Australian catchment, where four stream sediment sites and 30 groundwater bores were sampled over the period of one year. Mixed fauna at those sites displaying groundwater/surface water interaction was expected. However, there were virtually no species common to groundwater bores and stream sediment tubes, although they were sampled using the same method. The missing species exchange was probably due to the small pore spaces. Since the hydrological and chemical variety within groundwater sites was surprising, going far beyond gradually changing interactions with surface water, we grouped the groundwater sites into four major hydrogeological classes and looked for patterns with which fauna reflected these groups. In two of these hydrogeological groups (Artesian and concentration zones) no fauna was found at all, while fauna was sampled regularly in discharging and recharging zones. Fauna in groundwater bores also reflected whether groundwater was recharged from precipitation alone or also at least seasonally from the stream.
DE: 0400 Biogeosciences
DE: 1829 Groundwater hydrology
DE: 1845 Limnology
DE: 1878 Water/energy interactions
DE: 9330 Australia
SC: Biogeosciences [B]
MN: 2005 Joint Assembly