A joint mesocosm experiment will take place in February/March 2013 in the bay of Villefranche, near the Laboratoire d’Océanographie de Villefranche (LOV; http://www.obs-vlfr.fr/LOV/). Nine mesocosms (52 m³) will be deployed over a 30 days period and 6 different levels of pCO₂ and 3 control mesocosms (~ 400 μatm), will be used, in order to cover the range of pCO₂ anticipated for the end of the present century. During this experiment, the potential effects of these perturbations on chemistry, planktonic community composition and dynamics including: eucaryotic and prokaryotic species composition, primary production, nutrient and carbon utilization, calcification, diazotrophic nitrogen fixation, organic matter exudation and composition, micro-layer composition and biogas production will be studied by a group of 20-25 scientists from 8 institutes and 6 countries.

This is the second mesocosm experiment that will be conducted in the Mediterranean Sea in the framework of the MedSeA project. While the first experiment, conducted in June/July 2012 in Corsica, was dedicated to the assessment of ocean acidification effects during the summer oligotrophic period, this second experiment will take place during the winter-spring phytoplanktonic bloom. A blog dedicated to this experiment can be viewed at: http://medseavillefranche2013.wordpress.com