Abstract
A potential CO2 seepage from sub-seabed storage may cause cascade effects in marine ecosystems if it influences a process that has a key-function in the complex ecosystem. Therefore not only the primary effects (CO2 increase and pH decreases) but also secondary effects (change in the mobility, and bioavailability of trace and heavy metals and organic toxins) should be studied. These impacts are still poorly understood. Here we present the preliminary results of an experimental study in a titanium pressure tank on the impact of CO2 seepage on trace elements mobility and bacterial composition at the sediment-water interface and some perspectives for future research.