摘要 : River deltas are particularly important in the ma-rine carbon cycle as they represent the transition between ter-restrial and marine carbon: linked to major burial zones, theyare reprocessing zones where large carbon fluxes can be... 展开 River deltas are particularly important in the ma-rine carbon cycle as they represent the transition between ter-restrial and marine carbon: linked to major burial zones, theyare reprocessing zones where large carbon fluxes can be min-eralized. In order to estimate this mineralization, sedimentoxygen uptake rates were measured in continental shelf sedi-ments and river prodelta over different seasons near the outletof the Rhone River in the Mediterranean Sea. On a selectedset of 10 stations in the river prodelta and nearby continentalshelf, in situ diffusive oxygen uptake (DOU) and laboratorytotal oxygen uptake (TOU) measurements were performedin early spring and summer 2007 and late spring and win-ter 2008. In and ex situ DOU did not show any significantdifferences except for shallowest organic rich stations. Sed-iment DOU rates show highest values concentrated close tothe river mouth (approx. 20 mmol 02 rr1-2 d-1) and decreaseoffshore to values around 4.5 mmol O_2 m~(-2)d~(1)with lowestgradients in a south west direction linked to the preferen-tial transport of the finest riverine material. Core incuba-tion TOU showed the same spatial pattern with an averagedTOU/DOU ratio of 1.2±0.4. Temporal variations of sedi-ment DOU over different sampling periods, spring summerand late fall, were limited and benthic mineralization ratespresented a stable spatial pattern. 收起