"Anthropogenic pollutants affect ecosystem services of freshwater sediments: the need for a "triad plus x" approach"Freshwater sediments and their attached microbial communities (biofilms) are a essential features of of rivers and lakes providing valuable ecosystem services such as nutrient recycling or self-purification which extend beyond the aquatic environment. Anthropogenic pollutants, whether from the industrial era or as a result of our contemporary lifestyles can negatively affect these functions with hitherto unknown consequences on ecology, the economy and human health. Thus far, the singular view of the involved disciplines such as ecotoxicology, environmental microbiology, hydrology and geomorphology prevented a deeper understanding of this emerging issue.
Main features: This paper discusses briefly the progressions and the state-of-the-art methods within the disciplines of concern related to contaminated sediments; ranging from ecotoxicological test systems, microbiological / molecular approaches to unravel changes of microbial ecosystems up to the modeling of sediment transport and sorption/desorption of associated pollutants. First bilateral research efforts on contaminated sediments include efforts to assess ecotoxicological sediment risk including sediment mobility (ecotoxicology & engineering), enhance bioremediation potential (microbiology & ecotoxicology) or to understand biostabilisation processes of sediments by microbial assemblages (microbiology & engineering).
Conclusions and perspectives: In freshwater habitats, acute, chronic and mechanism-specific toxic effects on organisms, shifts in composition, structure and functionality of benthic microbial communities as well as the obstruction of important ecosystem services by continuously discharged and long-deposited pollutants should be related to the in situ sediment dynamics. To achieve an improved understanding of the ecology of freshwater sediments and the impairment of their important ecosystem functions by human derived pollutants, we suggest a "triad plus x" approach combining advanced methods of ecotoxicology, environmental microbiology and engineering science.