Description
Carbon Capture and Storage (CCS) under the seabed is regarded as a key technology for the reduction of CO2 emission to the atmosphere. The CO2MARINE sets out to assess the impact of increased CO2 level due to potential leakage from the sub-seabed reservoir on geochemical processes and benthic biota at the hydrostatic pressure relevant to the potential CO2 storage site in the Baltic Sea. The project will define environmental risk related to CO2-induced modifications to chemical gradients and mobilization processes and their combined effects on marine organisms. The ultimate outcome will be a list of chemical indicators and biological markers which will be proposed for use in detection and monitoring of CO2 leakages from marine sub-seabed storage sites. The project will identify methods to monitor the marine environment above a CO2 storage site, thereby providing support to environmental management of CCS under the seabed in the Baltic Sea. Norwegian institutions (SINTERF, NTNU, NIV) will provide experimental facility and complementary expertise.
Summary of project results
Sub-seabed Carbon Capture and Storage (CCS) is regarded a mitigation technology for the reduction of CO2 emissions. Recently, a potential CO2 storage site has been proposed in an abandoned oil reservoir (B3 field) in the Polish sector of the Baltic Sea but storing large volumes of liquid CO2 raises concerns about the environmental consequences of potential leakage. The CO2MARINE project set out to assess the impact of CO2-induced water acidification on geochemical processes in sediments and seawater, and on benthic biota. In a series of laboratory experiments in the TiTank, sediments and two macrobenthic species (bivalve Limecola balthica and polychaete Hediste diversicolor) were exposed at relevant hydrostatic pressure (9 bar) to three CO2 levels (pH 7.7-6.3), which simulates different leakage scenarios. Injection of CO2 brought about mobilization from sediments to seawater of trace elements (Pb, Hg, Co, Zn, As, U and some REE), particularly their adsorbed forms. Enhanced formation of freshly oxidized Fe(II) to Fe(III) (oxyhydr)oxide phases at the sediment surface increased Fe bounded P (non-apatite P). Under acidic conditions, dissolved organic carbon (DOC) transformed from labile (easily degradable) to more refractory forms that may have serious consequences on marine benthic ecosystem. A 1-D benthic-pelagic coupled transport biogeochemical model BROM has been applied to the B3 area. Numerical experiments of gas leakage under different leakage scenarios allowed to predict changes in the concentration of biogeochemical parameters and fluxes, and to estimate the maximum probable restoration time. The multibiomarker analyses demonstrated biological responses to seawater acidification. In the acidic environment, the bivalves showed shell corrosion, retarded growth rate and discrete histological changes in the digestive gland. No significant pH-related variations in activity of enzymes involved in oxygen metabolism, antioxidative defence, acid-based balance, detoxification and neurotransmission were found suggesting no elevated toxicity due to decreased pH. Given specific conditions on the seafloor in the area of the potential CO2 sub-seabed storage and the geochemical and biological impacts revealed in this project, the environmental effects of the potential CO2 leakage can be considered limited. By producing new experimental knowledge, the CO2MARINE project provided important support for CSS environmental risk assessments in the Baltic Sea.
Summary of bilateral results
The CO2MARINE project consisted of five partners from Poland and Norway which created efficient cross-organization partnership and combined efforts toward project shared goals. The partnership was built on give-and-take bilateral collaborative relationship which strengthened the existing personal research collaboration and capacity for long-term cooperation among partner organizations. Bilateral funds initiated also ad hoc collaboration among students and scientists of both countries in a form of supplementary informal topic-oriented projects and among entities through formal agreements (e.g. within EU Programme ERASMUS+). Involvement of all partners into project tasks and labour allowed exchange of know-how, experience transition and access of scientists from both countries to unique research facilities. Implementation of the project provided important insights into better understanding of environmental issues related to CCS and contributed significantly to environmental risk assessment associated with potential CO2 leakage from sub-seabed storage reservoir. An important aspect of bilateral research cooperation within the CO2MARINE were shared results through sharing of experience, research expertise and technology between partners in Poland and Norway. In addition, the CO2MARINE project supported an internal process of internationalisation within partner institutions of which several were able to recruit full time staff working with international bilateral programme. Bilateral partnership resulted also in several joint activities, including project workshops and general assemblies, conferences, study visits and trainings. Presentation of the project results and achievements at international and national open-public events improved visibility of each partner institution and the bilateral programme.