Figure 5. Examples of modeling of oxygen depletion curves in coastal seawater samples.

Oxygen depletion experiments from three incubation bottles (4, 6, 7) from St. 2 (Marselisborg Marina), September 2011. Air saturated water was injected in bottle “STOX 7” once O₂ was depleted (6 h). The dots show O₂ values recorded by the STOX sensor. Maximum rates (V_max) and half saturation constants (K_m) were determined by least squares fits (red solid line) using Eq. (2), derived from Michaelis-Menten kinetics. The method gave a relatively poor fit that might result in an underestimation of the K_m value for the “STOX 6”.