This paper examines the social and economic characteristics of 21 coastal communities in Papua New Guinea and Indonesia, and explores the characteristics of the communities that employ exclusive marine tenure to answer the following questions: Which socioeconomic factors are related to the presence of CMT regimes? How might socioeconomic factors influence the ability of communities to employ or maintain CMT regimes? Distance to market, immigration, dependence on fishing, and conflicts were found to be related to the presence of highly exclusive marine tenure systems. Exploring these relationships will help conservation practitioners better understand how future social changes may influence the foundation of conservation and development projects.