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and Ampullospira) and three subgenera (Globularia, Deshayesia, and Cernina within the genus Globularia). Forty−six Cainozoic species revealed residual colour patterns and 29 of them, belonging to six genera (Ampullina, Globularia, Crommium, Amaurellina, Pachycrommium, Amauropsina)

The spatial and temporal composition of organic matter (OM) was investigated in the Moselle watershed (Lorraine, France). The spatial composition was studied using different stations along the river and four tributaries. In addition, one anchor station was used in order to better understand the temporal OM composition during different hydrologic regimes and seasons. The first part of the organic characterization consisted of the extraction of the lipidic OM with an automatic extractor. The extracts were analyzed for their lipidic fatty acids (Lip-FAs), polycyclic aromatic hydrocarbons (PAHs) and sterols using gas chromatography-mass spectrometry (GC-MS). The insoluble fraction was also analyzed with thermochemolysis-GC-MS (TMH-GC-MS) using tetramethylammonium hydroxide (TMAH) and lignin phenols, permethylated deoxy aldonic acids and refractory fatty acids (Ref-FAs) were analyzed. The results showed that one station, (Florange station) on the small Fensch stream tributary displayed variations in the composition of the molecular OM with higher microbial markers (C 16:1 , C 18:1w7 , C 18:1w9 , coprostanol) inputted to the highly industrialized and urbanized areas in this small sub-catchment. The other stations showed rather similar organic composition (Lip-FAs, Ref-FAs, sterols, lignin compounds, PAHs) due to the size of the catchment (10,000 Km 2) or the integrative state of the suspended particulate matter (SPM). The regime flow involved a decrease in SPM OM content as well as a decrease of the palmitoleic acid/palmitic acid (C 16:1 /C 16:0) ratio and an increase of (stigmastanol+sitostanol+stigmasterol+sitosterol)/(cholesterol+cholestenol) (C 29 /C 27(ST)) ratio revealing the presence of more allochthonous OM. The increase in regime flow was also correlated with a growing contribution of more degraded OM in the SPM that could be related to the leaching of subsurface soils from the watershed or to the remobilization of surface sediments. Seasonal variations were also observed, with a stronger contribution of autochthonous production during low flow level in summer. This work shows the importance of OM characterization in SPM in order to better assess to the spatial and temporal OM variations in the water column.

International audiencePurposeSuspended particulate matter (SPM) plays an important role in the transport and fate of contaminants in the environment. To better understand the relationships between contaminants and SPM, SPM properties, and their variations with flow regime, river size, land use, and season should be considered.Materials and methodsThe grain size distribution, elemental composition, and mineralogy of SPM from different stations along the Moselle River (Lorraine, France) were investigated at the particle scale during different flow regimes. The resulting data were compared with the elemental composition of the dissolved compartment to understand the role of particles in element transport.Results and discussionThe grain size distribution, elemental composition, and mineralogy of SPM along the Moselle River and during different flow regimes showed only slight variations, except for the Fensch and Orne tributaries, two rivers that were impacted by inherited steel-making industrialization and different land use. In the Moselle River, SPM mainly consisted of clay minerals, while in Fensch and Orne Rivers, SPM mainly consisted of multiple types of anthropogenic particles. The diffuse urbanization gradient was hardly recognized based on the Trace Metal Element (TMEs) content in the river SPM, while the rivers impacted by the steel industries had greater TME contents. Finally, the TME content in the Moselle SPM was more strongly influenced by water flow than by the position of sampling on the linear reach of the Moselle River. The partitioning of TMEs in the particles and water at the main Moselle station (Frouard) revealed that SPM predominantly contributed to TMEs transport.ConclusionsThis study confirmed that catchment geology greatly contributed to the SPM composition in the mean-sized rivers. In addition, the high anthropogenic pressure could be deciphered for small tributaries. Furthermore, this study allowed us to observe the high contribution of particles to TMEs and Rare Earth Element (REEs) transportation. Characterization of suspended particulate matter in the Moselle River (Lorraine, France): evolution along the course of the river and in different hydrologic regimes. Available from: https://www.researchgate.net/publication/287807742_Characterization_of_suspended_particulate_matter_in_the_Moselle_River_Lorraine_France_evolution_along_the_course_of_the_river_and_in_different_hydrologic_regimes [accessed Jan 15, 2016]