The Commission has asked the Scientific Committee to review the science supporting a joint New Zealand-United States proposal to establish a marine protected area (MPA) in the Ross Sea Region (RSR). A substantial amount of material has already been presented to the Scientific Committee and its working groups, and here we provide an abridged and annotated summary of that material. We organize our summary by linking spatial data to the specific protection and scientific objectives of the jointly proposed MPA, and we summarize science pertaining to coastal areas and the continental shelf, the continental slope, the Balleny Islands and vicinity, and the northern RSR. A set of maps (provided in an Appendix) illustrates the distributions of animals and ecosystem process areas in relation to the boundaries of the jointly proposed MPA. When all relevant distributions are simultaneously overlaid on a single map it is clear that the MPA can achieve significant protection and science outcomes, the latter of which may help the Scientific Committee to understand the ecosystem effects of fishing distinct from those of climate change and thus improve the management of toothfish fisheries generally. To achieve the protection and science objectives of the jointly proposed MPA, the Commission will need to redistribute catches taken by the longline fishery for Antarctic toothfish. About 20% of the historical catch taken by the fishery was removed from within the boundaries of the proposed MPA. Although it is not possible to estimate a specific period of time for which the proposed MPA would need to remain in force, several decades are needed to deliver the science outcomes related to understanding the distinct effects of climate change and fishing.