Use of the Panarea Natural Test Laboratory for Offshore CO2 Leakage Monitoring and Impact Studies

The natural CO2 leaking site near Panarea Island, Italy, has been used as a field laboratory to study potential impacts of CO2 on surface water chemistry and biology and to test innovative monitoring tools. Work involved 4 campaigns, one for each season, in which a 700 m long transect was sampled, benthic chamber measurements were made, and ADCP current measurements were conducted. In addition, an in house developed pCO2 continuous monitoring station was deployed for a 6 month period, during which it measured temperature and pCO2 values once every two hours and transmitted the values in real time to a web-based server. Results show the complexity of working at a real world site, as the dynamic marine system results in plume smearing and rapid dilution of the leakage signal. While making monitoring more difficult, this dilution means that impact will be limited (at least at leakage rates comparable to the Panarea site). In addition, the results also imply that future biological impact studies must take into account temporal variability, and not address only static pCO2 conditions.