scholarly journals Concentrations and fluxes of suspended particulate matters and associated contaminants in the Rhône River from Lake Geneva to the Mediterranean Sea

2021 ◽  
Author(s):  
Hugo Lepage ◽  
Alexandra Gruat ◽  
Fabien Thollet ◽  
Jérôme Le Coz ◽  
Marina Coquery ◽  
...  

Abstract. The Rhône River is amongst the main rivers of Western Europe and the biggest by freshwater discharge and sediment delivery to the Mediterranean Sea. Its catchment is characterized by distinct hydrological regimes that may produce annual sediment deliveries ranging from 1.4 to 18.0 Mt y−1. Furthermore, the course of the Rhône River meets numerous dams, hydro- and nuclear power plants, and agricultural, urban or industrial areas. Thus, suspended particulate matters (SPM) have been involved in the fate of hydrophobic contaminants such as polychlorobiphenyls (PCB), mercury (Hg) and other trace metal elements (TME), and radionuclides for decades. To investigate the concentrations and the fluxes of SPM and associated contaminants, as well as their sources, a monitoring network of 15 stations (three on the Rhône River and 12 on tributaries, from Lake Geneva to the Mediterranean Sea) has been set up in the past decade within the Rhône Sediment Observatory (OSR). A main purpose of this observatory is to assess the long term trend of the main contaminant concentrations and fluxes, and to understand their behavior during extreme events such as floods or dam flushing operations. The dataset presented in this paper contains the concentrations and fluxes of SPM as well as the concentrations and fluxes of several particle bound contaminants of concern (PCB, TME, radionuclides), the particle size distribution and the particulate organic carbon of SPM. Sediment traps or continuous flow centrifuges were used to collect sufficient amount of SPM in order to conduct the measurements. This observatory is on-going since 2011 and the database is regularly updated. All the data are made publicly available in French and English through the BDOH/OSR database at https://doi.org/10.15454/RJCQZ7 (Lepage et al., 2021).

2002 ◽  
Vol 37 (C1) ◽  
pp. C1-87-C1-92 ◽  
Author(s):  
F. Eyrolle ◽  
M. Arnaud ◽  
C. Duffa ◽  
P. Renaud

2000 ◽  
Vol 14 (2) ◽  
pp. 669-681 ◽  
Author(s):  
Richard Sempéré ◽  
Bruno Charrière ◽  
France Van Wambeke ◽  
Gustave Cauwet

2012 ◽  
Vol 9 (5) ◽  
pp. 1827-1844 ◽  
Author(s):  
C. Panagiotopoulos ◽  
R. Sempéré ◽  
J. Para ◽  
P. Raimbault ◽  
C. Rabouille ◽  
...  

Abstract. Carbohydrates are important components of the carbon cycle and may be used as indicators of the origin and the diagenetic status of marine and terrestrial organic matter. Nevertheless, comprehensive studies of both particulate (PCHO) and dissolved (DCHO) carbohydrates in rivers are scarce, and the seasonal and interannual variability of these compounds in relationship to the bulk particulate (POM) and dissolved organic matter (DOM) is largely unknown. For the period 2007–2009, we sampled once per month POM and DOM and measured the total suspended matter (TSM), POM, DOM, PCHO, and DCHO for the Rhône River, which flows into the Mediterranean Sea. Using these measurements, we estimated for the above parameters annual fluxes for the period 2007–2009. The estimated carbohydrate fluxes averaged 0.064 ± 0.026 × 1010 moles C yr−1 for PCHO and 0.042 ± 0.008 × 1010 moles C yr−1 DCHO, representing 6 % and 7 % of the annual flux of POC and DOC, respectively. During flood and low-water periods, POM variations were reflected into the PCHO pool, whereas this was not observed for DOC and DCHO, indicating a decoupling between particulate and dissolved organic matter. Our results also showed that flood and low-water periods may be differentiated using the ratios PCHO/DCHO and POC/DOC, which had a significant relationship. Based on the carbohydrate abundances in both the PCHO and DCHO pools, we conclude that this material mainly derives from allochthonous sources (vascular plants, bacteria and soils). Moreover, during flood events, an enrichment in mannose in POM was observed, probably reflecting an angiosperm source (leaves or grasses). By expanding our results to the northwestern Mediterranean Sea (Gulf of Lions), we found that the total organic carbon (TOC) fluxes of the Rhône River accounted for ~1 % of the standing stock of seawater TOC. Considering that glucose is the most abundant carbohydrate in both particulate and dissolved organic matter pools (~33 %), its annual flux in the northwestern Mediterranean Sea was estimated to 3.8 × 108 moles glucose.


2018 ◽  
Vol 163 ◽  
pp. 136-146 ◽  
Author(s):  
Richard Sempéré ◽  
Bruno Charrière ◽  
Javier Castro-Jiménez ◽  
Kimitaka Kawamura ◽  
Christos Panagiotopoulos

2011 ◽  
Vol 8 (6) ◽  
pp. 11165-11213 ◽  
Author(s):  
C. Panagiotopoulos ◽  
R. Sempéré ◽  
J. Para ◽  
P. Raimbault ◽  
C. Rabouille ◽  
...  

Abstract. Carbohydrates are important components of the carbon cycle and may be used as indicators of the origin and the diagenetic status of marine and terrestrial organic matter. Nevertheless, comprehensive studies of both particulate (PCHO) and dissolved (DCHO) carbohydrates in rivers are scarce, and the seasonal and interannual variability of these compounds in relationship to the bulk particulate (POM) and dissolved organic matter (DOM) is largely unknown. For the period 2007–2009, we sampled once per month POM and DOM and measured the total suspended matter (TSM), POM, DOM, PCHO, and DCHO for the Rhône River, which flows into the Mediterranean Sea. Using these measurements, we estimated for the above parameters annual fluxes for the period 2001–2010. The estimated carbohydrate fluxes averaged 0.061±0.043×1010 moles Cy−1 for PCHO and 0.041±0.0062×1010 moles Cy−1 DCHO, representing 8% and 7% of the annual flux of POC and DOC, respectively. During flood and low-water periods, POM variations were reflected into the PCHO pool, whereas this was not observed for DOC and DCHO, indicating a decoupling between particulate and dissolved organic matter. Our results also showed that flood and low-water periods may be differentiated using the ratios PCHO/DCHO and POC/DOC, which had a significant linear relationship. Based on the carbohydrate abundances in both the PCHO and DCHO pools, we conclude that this material mainly derives from allochthonous sources (vascular plants, bacteria and soils). Moreover, during flood events, an enrichment in mannose in POM was observed, probably reflecting an angiosperm source (leaves or grasses). By expanding our results to the northwestern Mediterranean Sea (Gulf of Lions), we found that the total organic carbon (TOC) fluxes of the Rhône River accounted for ~1% of the standing stock of seawater TOC. Considering that glucose is the most abundant carbohydrate in both particulate and dissolved organic matter pools (~33%), its annual flux in the northwestern Mediterranean Sea was estimated to 19.2×108 moles glucose-C.


Sign in / Sign up

Export Citation Format

Share Document