Measurements were conducted in a growth chamber held at a constant temperature of 20°C with variable light conditions; 0. 25, 150, 350 PAR (0 µmol photons m-2 s-1), respectively.Instrumentation : Optode microprofiling device from PreSens GmbH (Germany, www.presens.de) with an Automated Micromanipulator (AM), needle-type optodes for measurements of oxygen (PM-PSt7) and pH (PM-HP5).Time: July 2017.Depth "0" is defined as the top of the microphytobenthos layer at the sediment-water interface.Salinity: 35‰.Temperature: 20°.