Effects of CO2 Induced pH Decrease on Shallow Benthic Microbial Communities

Two mesocosm experiments (18 and 10°C) have been carried out in order to investigate the effects of pH reduction due to pCO2 increase on benthic microbial communities collected from the Gulf of Trieste (Northern Adriatic Sea). During each experiment 3 mesocosms with different pH values were set up (6.5, 7 and an aerated control ~ 8). The analyses focussed on prokaryotic abundance, degradation processes and prokaryotic carbon production. Preliminary results highlight differences in metabolic response to CO2 in terms of organic matter degradation patterns whereas prokaryotic numbers and C production seemed to be less affected by pH decrease.