Organic carbon budget at the sediment-water interface on the Gulf of Lions continental margin

International audienceOxygen uptake rates were measured at the sediment-water interface along a shelf-slope transect in the western Gulf of Lions (northwestern Mediterranean Sea). Values ranged from 0.6 to 48.0 mmol O2 m−2 d−1, and decreased from inshore to the continental slope. The overall mean was 36.8±11.2 mmol O2 m−2 d−1 for the coastal zone, 11.2±1.4 mmol O2 m−2 d−1 for the shelf and 2.4±1.8 mmol O2 m−2 d−1 for the slope. Slope stations exhibited significantly different values according to their location in the canyon axis (average 3.7±2.1 mmol O2 m−2 d−1) or open slope sites (average 1.5±0.9 mmol O2 m−2 d−1). Independent on the location, sediment oxygen uptake reached maximum rates in late spring, when fluxes were up to 4 times higher than in other seasons. Rates were significantly related (r=0.92, n=16, p