Fig. s2.
Comparison of the pore water profiles of SO42-, CH4 and alkalinity of two cores from one each of the two deep-sea trenches investigated and from a core recovered from the upper slope depot center of the high production area off Namibia (Riedinger et al., 2006). Although the total organic carbon content in the sediments from the both trenches investigated in this study is on average 6 times lower, comparable turnover rates are observed. The relatively low CH4 concentrations may be caused by outgassing during core retrieval.