This dataset contains temperature (°C) and dissolved oxygen concentrations (µmol/l) acquired between August 2013 and July 2014 using an Aanderaa optode (model 3830, sensor head # 1180-520, salinity setting 3.5%, uncorrected for pressure) The sensor. The sensor was positioned on a mussel bed at the base of the Tour Eiffel edifice (1695m depth). Data was acquired every 15 minutes. A two-point calibration at 0% and 100% saturation levels is performed at each maintenance cruise. The optode connected to the TEMPO ecological module is part of the SeaMoN East monitoring node.