Carbon inputs of the Rhône River to the Mediterranean Sea: Biogeochemical implications
Article first published online: 21 SEP 2012
Copyright 2000 by the American Geophysical Union.
Global Biogeochemical Cycles
Volume 14, Issue 2, pages 669–681, June 2000
How to Cite
2000), Carbon inputs of the Rhône River to the Mediterranean Sea: Biogeochemical implications, Global Biogeochem. Cycles, 14(2), 669–681, doi:10.1029/1999GB900069., , , and (
- Issue published online: 21 SEP 2012
- Article first published online: 21 SEP 2012
- Manuscript Accepted: 24 AUG 1999
- Manuscript Received: 19 JAN 1999
Since the damming of the Nile, the Rhône River is the main freshwater and sediment supplier to the Mediterranean Sea. We estimated for the period 1987–1996, the dissolved and particulate organic carbon (DOC and POC), dissolved inorganic carbon (DIC), and total suspended matter (TSM) fluxes of the Rhône River to the Mediterranean Sea to be 1.1 ± 0.2, 1.6 ± 0.5, 16.2 ± 0.3 × 1010 moles C yr−1, and 9.9 ± 6.4 × 106 t yr−1, respectively. PIC flux was estimated to be 8.2 ± 5.4 × 109 moles C yr−1. On the basis of literature data, we estimated that nearshore bacterial respiration of Rhône derived labile-POC and -DOC (LPOC and LDOC) might produce in a few days ∼0.21 and 0.12 × 1010 moles CO2 yr−1, respectively. Extended to the whole Mediterranean, this study suggests that bacterial respiration of labile organic carbon derived from Mediterranean rivers might rapidly (days) produce 2.6-11 × 1010 moles CO2 yr−1. On the continental shelf, up to 4.7 × 1010 moles of organic carbon introduced by primary production and Rhône export would escape each year to sedimentation and bacterial mineralization and would be exported off the shelf. Moreover, as total carbon fixed by phytoplankton exceeds (+ 5.2 × 1010 moles C yr−1) the CO2 produced by bacterial respiration (on average), the biological system on the shelf, could be considered as an autotrophic system and then a sink for atmospheric CO2. However, these numbers need further examination because of the large uncertainties associated currently to the bacterial growth efficiency values (±100%).