Related Experiment Video
Updated: Mar 26, 2026

A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life
Published on: January 9, 2017
Influence of dams on sediment continuity: A study case of a natural metallic contamination
Franck Frémion1, François Bordas1, Brice Mourier1
1Groupement de Recherche Eau Sol Environnement, Université de Limoges, 123 avenue Albert Thomas, 87060 Limoges Cedex, France.
Abstract:
Sediments play an important role on the quality of aquatic ecosystems, notably in the reservoir areas where they can either be a sink or a source of contaminants, depending on the management and hydrological conditions. The physicochemical properties of 25 surface sediments samples of a reservoir catchment (Vaussaire, Cantal, France) were studied. Results show a strong influence of dam presence, notably on the grain size and organic matter (OM) contents. The concentrations of trace metals and metalloids (As, Cd, Cr, Cu, Ni, Pb and Zn) were also measured and compared with worldwide reservoir concentrations and international sediment quality guideline levels in order to assess the intensity of the metallic contamination. Cr and Ni are the trace elements presenting the significantly highest values at the catchment scale. Enrichment Factors (EF), calculated using both local and national backgrounds, show that metals have mainly a natural origin, explaining especially the Cr and Ni values, linked with the composition of parental rocks. Unexpectedly, all the observed metal concentrations are lower in the reservoir than upstream and downstream, which might be related to the high fresh OM inputs in the reservoir, diluting the global metallic contamination. Multivariate statistical analyses, carried out in order to identify the relationship between the studied metals and sediment characteristics, tend to support this hypothesis, confirming the unusually low influence of such poorly-degraded OM on trace element accumulation in the reservoir.
Related Concept Videos
Acid Mine Drainage
Design Example: Analyzing Capacity Contours for Flood Risk Assessment
Freshwater Microbial Ecology
Microbial Bioremediation of Uranium
Coagulation
Microbes and Other Elemental Cycles

