The challenge to manage coastal resources within Asia-Pacific's Coral Triangle has gained global attention. Co-management is promoted as a key strategy to address this challenge. Contemporary community-based co-management often leads to ‘hybridization’ between local (customary) practices, and science-based management and conservation. However, the form of this hybrid has rarely been critically analysed. This paper presents examples of co-management practices in eastern Indonesia and Solomon Islands, focusing in particular on area closures. In contrast to the temporary closures used before the influx of sustainability discourses, contemporary closures are periodically-harvested but predominantly closed, reflecting attempts to reduce fishing effort and enhance ecological sustainability. When areas are opened, harvests are relatively short and largely triggered by the social and economic needs of particular individuals or whole communities. In all cases, engagement with environmental management interventions has led to more formalized access and use arrangements. The harvesting and management practices observed are influenced by these relatively recent interventions designed to promote sustainability, but also by religious institutions, increasing resource demand, and modernization. This study unpacks some of the contemporary influences, particularly environmental sustainability initiatives, on local management practices, and provides insights for co-management in practice.