In situ measurement of time-series two dimensional O2 distributions at sediment-water interface using a planar O2 optode system connected with a submarine cable

The first long time monitoring of O₂ dynamics at sediment-water interface (SWI) was conducted using with a newly developed planar O₂ optode system for in situ measurement. The monitoring was carried out connecting the optode system with Hatsushima permanent station with a 100 meter-long extension cable under supporting by the operation of ROV Hyper-dolphin. The monitoring was successfully carried out for 113.3 hours. During the experiment, 3,141 two dimensional O₂ profiles and the corresponding pseudo-grayscale images across SWI were obtained, respectively. From the results, further understanding of new insights on dynamic interactions between fauna activities and environmental changes are expected.