Abstract (eng)
Groundwater fauna plays a major role as a bioindicator and for water purification, but is mostly neglected in the assessment of groundwater systems. For an inclusive approach, it is important to identify connections between the distribution patterns of groundwater fauna, abiotic key factors and community structures. In large parts of Austria, groundwater fauna is not yet investigated and previous research studied exclusively natural regions. Therefore, this is a baseline survey that evaluates the distribution of stygofauna in differently influenced regions. In the glacio/fluvial aquifers of the River Mur Valley, Styria/Salzburg (Austria) 45 groundwater wells were sampled in June 2020 and the collected groundwater animals were divided into 11 taxonomic groups. The majority of the sampled organisms belonged to the subphylum Crustacea. Especially the distribution of Oligochaeta and Copepoda suggested, that these two groups could act as indicators for high faunal richness. By comparing a selected set of environmental/influencing parameters, it was shown that the fauna richness and the rate of inhabited groundwater wells were higher in natural regions, than in urban or agricultural areas. Few wells were not inhabited (18 %) and hydrochemical factors indicated no impact on the fauna distribution. Between the lower and upper regions of the Mur Valley, differences in community structures and fauna distribution were observed, which result from variations in altitude, groundwater temperature, aquifer structure, depth of the groundwater table and historical influence (e.g. glacial periods). Further taxonomic identification of the sampled fauna as well as seasonal changes should be considered in prospective investigations.