Sub-seabed CO2 Storage: Impact on Marine Ecosystems
Carbon dioxide capture and storage (CCS) is considered as a key technology for the reduction of CO2 emissions from industrial facilities. Consequently, the European Commission promotes the implementation of CCS in Europe at industrial scale by supporting selected demonstration projects, several of which aim to store CO2 below the seabed. Currently, little is known about the short- and long-term impacts of sub-seabed CO2 storage on marine ecosystems, consequently, ECO2 aims to establish a framework of best environmental practices for sub-seabed CO2 injection and storage.
ECO2 investigated the sedimentary cover at active and potential CO2 storage sites (Sleipner, Snøhvit, B3 field) using novel geophysical baseline studies, monitoring and modelling techniques to better understand the mechanisms of CO2 migration. It assessed the effects of leakage of CO2 through the sediment at storage sites and natural analogues and quantified the fluxes across the seabed and into the water column by means of sophisticated monitoring techniques and investigated the impact on benthic organisms, through experiments. All fieldwork data is stored in the project database. The main targets
of 2011 to 2013 research expeditions were the Utsira CO2 storage formation (Sleipner) in the Norwegian North Sea where Statoil stores CO2 since 1996 and the natural CO2 seepage site Panarea in the Mediterranean Sea. At Sleipner an intensive shallow-focused monitoring programme has been conducted to assess the sedimentary cover and the chemical composition, its fluxes and the techniques to trace any irregularity. Whereas at Panarea the CO2 migration and the behaviour of gas bubbles within the water as well as the effect on the benthic ecosystem was studied for different spatial and temporal
flux rates. The environmental risks associated with CCS and how these risks may impact on the financial, legal, and political considerations surrounding the future geological storage were elaborated. The public perception group investigated trust and context as two influencing factors. ECO2 presents itself and its public results (e.g. cruise reports, a CCS glossary etc.) on a webpage (eco2-project.eu) and further informs stakeholders and interested individuals about new findings and the project progress via press releases, articles and e.g. lunch briefings at the European Parliament. The results and final product of ECO2 will be of scientific and political value to all stakeholders within the European Member States and beyond regarding CCS, ocean acidification, climate change and other related issues.
ECO2 evaluates the likelihood of leakage from sub-seabed CO2 storage sites, the possible impacts on marine ecosystems and the associated economic and legal issues. Project partners are using cutting-edge monitoring technology and novel approaches, including autonomous underwater vehicles (AUV) with synthetic aperture sonar to detect shallow-focussed irregularities in the integrity of the sedimentary cover of storage sites, and membrane inlet mass spectrometry (MIMS) to trace potential leakage. Sophisticated computer models interlink the natural scientific and economic results and interpretations. The majority of research expeditions, gathering the essential core data of the project, are funded by national sponsorship. The project follows a multi-disciplinary and comparative approach investigating active and potential storage sites as well as natural CO2 seep sites.