The research and management plan for the Ross Sea region MPA is currently under development. That plan will identify key research questions that aid in assessing the MPA’s efficacy in achieving its objectives. It may be helpful to have an agreed set of baseline data for key species which indicate the current status of marine ecosystems in the Ross Sea region. These data could then be used as benchmarks to evaluate MPA performance. This paper suggests candidate baseline data for seven key indicator species which were identified in the draft Research and Monitoring Plan presented to the Scientific Committee (Dunn et al. 2017). The candidate baseline data include estimates of the number of nesting pairs of Adélie and emperor penguins per MPA zone, region-wide estimates of the number of Weddell seals and Type C (Ross Sea) killer whales and estimates of the mean densities of Antarctic krill (Euphausia superba), crystal krill (E. crystallorophias) and Antarctic silverfish (Pleuragramma antarcticum) per MPA Zone. We invite Members to contribute any additional data they may have, particularly for species where the candidate baseline data presented here are spatially restricted.