This project focused on microseismic monitoring protocols within a marine context in the Gippsland Basin. It used natural seismic sources to constrain geomechanics of CO2-storage reservoirs. The project successfully improved seismograph coverage of the Gippsland Basin area and reduced uncertainties with epicentre location of events in the region. Techniques were developed to allow microearthquake studies in other regions with relatively soft surface sediments, site amplification and surface noise, especially ocean noise. Development of velocity models was limited by a sparsity of recorded offshore events in the region of proposed CCS activities. However, it is expected the developed methods will be applicable to the growing database of events that the deployed network is expected to record in the following years.