As the first large-scale MPA in an area beyond national jurisdiction, the Ross Sea region MPA sets a precedent for design, adoption and implementation of other MPAs on the high seas and in the Southern Ocean. This ASOC Background paper includes an article in press in Marine Policy: “The Ross Sea, Antarctica: A highly protected MPA in international waters,” which presents a detailed explanation of the governance of the Ross Sea region MPA, including the active and ongoing management, research and monitoring. The paper further described how and why the majority of the MPA qualifies under the new MPA Guide as a highly protected MPA. As CCAMLR moves towards establishing a network of Southern Ocean MPAs, the Ross Sea region MPA can provide valuable guidance. Currently, three additional Southern Ocean MPAs remain under negotiation – in East Antarctica, the Weddell Sea, and around the Antarctic Peninsula. The prohibitions and restrictions coordinated through CCAMLR’s Conservation Measures, and the active management, research, monitoring and enforcement of the Ross Sea region MPA illustrate that CCAMLR and its Member States can and will actively manage and enforce MPAs. The paper concludes that the Ross Sea region MPA is currently, and for the foreseeable future, highly protected from potentially destructive human activities, and is thus exemplary of a large-scale highly protected MPA.