Figure 4.

Methane oxidation measured as ¹³C-DIC accumulation, (a) over a 13-day time series with water from 200 to 226 m, on the upper margin of the OMZ, where oxygen is close to LOD (~1.4 μmol l⁻¹) and methane is rising above background concentrations, and (b) over 5 months with varying initial concentrations of methane.