Historically, contemporary conservation approaches were less concerned with and informed about indigenous management and governance practices. In particular, the intangible cultural, spiritual and sacred values that are an integral part of indigenous ontologies were poorly www.iucn.org/parks www.iucn.org/parks ABSTRACT This article demonstrates the importance of indigenous ontologies in cross-cultural or 'both ways' coastal conservation management of the Dhimurru Indigenous Protected Area in north east Arnhem Land, Australia. In this action research, selected Yolŋu individuals identified concerns regarding recreational fishing and boating practices of non-Yolŋu. Yolŋu engaged in a discussion of the issues and the subsequent formulation of indigenous management responses. This led to the development of locally relevant guidelines for fishers and boaters with potentially broader applications in other Indigenous Protected Areas and beyond. We explore the 'both ways' approach adopted by the Dhimurru Aboriginal Corporation that guides collaboration between Yolŋu and non-Yolŋu. We illustrate how the approach facilitates indigenous ontologies to co-create conservation approaches together with contemporary conservation efforts informed by Western science. We further explore the disjunctures and synergies between the two and argue that these mix and can be compatible as part of the 'both ways' approach. In learning from this action research, we reflect on the process of cross-cultural learning and the role of researchers in the cross-cultural coproduction of knowledge and the formulation of guidelines for fishers and boaters.