Interactive comment on “Experimental assessment of the sensitivity of an estuarine phytoplankton fall bloom to acidification and warming” by Robin Bénard et al

The manuscript of Bénard and collaborators reports on an experiment that has been conducted using indoor mesocosms (2.6 m3) to test for the effect of ocean acidification and warming on the development of a fall phytoplankton bloom in the Lower St. Lawrence Estuary. The experiment setup comprised 2 sets of 6 mesocosms installed in two temperature-controlled containers, that were filled with seawater sieved onto 250 microns. In one container, the water temperature was raised by 5◦C compared to the mesocosms installed in the other container (10 vs. 15◦C). A gradient approach (no replicates) has been considered for pCO2/pH covering a range of pH from 7.2 to 8.6. The experiment lasted 13 days and covered the development of a bloom and its decline. Major conclusions of this study are that pCO2 has no effect on all measured param-