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(W/EH070) The development and application of a TIE approach for marine sediments. Vangheluwe, M.1, Van Sprang, P.1, Speleers, L.2, Dumon, G.3, Janssen, C.4, 1 2 3 4 ABSTRACT- The use of numerical sediment quality criteria is hampered through the absence of clear relationships between sediment contaminant concentrations and their impact on aquatic life. To improve the decision making in sediment management strategies a better understanding is needed of which of the contaminants present cause the toxic effects. The aim of the current study was the development of a Toxicity-Identification-Evaluation methodology (TIE) with the marine amphipod Corophium volutator. During TIE procedure development both primary and secondary exposure routes were taken into account. The procedures with the sediment pore waters consisted of the specific fractionations and manipulations as described by the US EPA. The developed TIE methods with the whole sediment were aimed at removing and/or decreasing contaminant bioavailability. The second set of tools applied in this study consisted of extraction techniques such as methanol/water extraction and the use of Low Density Polyethylene (LDPE) detoxicification spiders to scavenge organic contaminants. Finally the developed TIE procedures were validated in two case studies. The pore water TIE was successfully applied for the identification of sediments which ammonium toxicity. The second case study involved a marine sediment spiked with TBT. The pore water TIE only partly revealed TBT-related toxicity. The whole sediment TIE was not successful in pin-pointing TBT as the toxic compound. Only the use of LDPE detoxification spiders seems to be a promising tool for the removal of organic contaminants in sediments. Future work should be focussed on increasing the removal rates and on prolonging the ageing period of the treated sediments before conducting whole sediment toxicity tests. Key words: Sediments, TIE, Tributyltin |
