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2K - Sediment Assays (TU18/11) Ecotoxicological sediment survey of large German rivers. Tillmann, Michaela1, Duft, Martina1, Schulte-Oehlmann, Ulrike2, Oehlmann, Jörg2, 1 International Graduate School (IHI), Zittau, Germany2 J.W. Goethe University, Frankfurt/Main, Germany ABSTRACT- In this project a nation-wide, ecotoxicologically-based sediment survey was carried out. For this purpose, more than 200 sediment samples from 12 selected large German rivers (Danube, Elbe, Ems, Main, Mosel, Neckar, Neisse, Odra, Rhine, Ruhr, Saar and Weser) were analysed with regard to abiotic parameters (heavy metals, PAH, organic carbon content, particle size) and also by means of two biological test systems with benthic invertebrates (the nematode test with Caenorhabditis elegans and the chironomid test with Chironomus riparius ). Subsequently, this comprehensive data set was analysed statistically. By means of an iterative method, a five-stage, statistically-derived assessment concept was developed founded on the results of the biological tests, following the EU water framework directive. In general, the classification with the nematode test turned out to be the more sensitive method. Principal component analyses and correlations showed that the parameters of both biotests provided different information, which suggests that a combined use of both tests is needed to asses the toxicity of sediments. Correlations also indicate a connection of biotest results and abiotic parameters (organic carbon content, particle size and heavy metal contamination). Key words: German rivers, sediment bioassay, Caenorhabditis elegans , Chironomus riparius |
