449
12.5
Applications
Fig. 12.18
Relation between the benthic oxygen respiration, TOC and the oxygen concentration in bottom waters
(after Seiter et al. 2005). a) A significant influence of oxygen-depleted bottom water on the benthic respiration rates
and the TOC contents for water depths below 1000 m could be observed for the northeast Pacific region when O 2
drops below 50–70 mmol m
3 . As to be expected, the highest TOC contents correspond to lowest concentration
values of bottom-water oxygen. Above 125 mmol m
3 , the organic carbon content decreases with increasing bottom
water oxygen concentration. b) If oxygen concentrations at the sediment-water interface are maintained by bottom
water mixing, there is no effect of this parameter on the overall benthic fluxes. Nevertheless, scattering of data
might result from the seasonal and interannual variations in bottom water oxygen content and the local variations
of the sedimentation rates of inorganic components, which are likely to dilute the input of organic carbon.
Fig. 12.19 Global distribution pattern of the diffusive oxygen uptake (DOU) at the sea floor (1º x 1º; >1000m water
depth; after Seiter et al. 2005).