This article employs political ecology and common property theory to examine sea turtle conservation, how it is articulated and executed at different sociopolitical and geographic scales, and the consequences for local rights of access to resources. It draws on ten years of research at various field sites in Costa Rica, and on sea turtle conservation policy in general, to show that although most sea turtle conservation policy is legitimized in the language of ecology, beliefs about rights to sea turtles as a resource underlie ecological arguments. This becomes clear through analysis of the local, national, and international scales, where ecological arguments are employed differently in order to discount or promote certain types of property rights and to promote particular types of conservation interventions; thus, promoting conservation action at a particular scale is not simply a matter of ecological necessity. The article's main purpose is to outline a political ecology of sea turtle conservation; it also contributes to political ecology and common property theory, and illustrates the productive combination of these for analyzing conservation. Furthermore, it addresses questions about the appropriate scale at which conservation should take place and the rights of local people to use and manage resources, both of which are topics of considerable debate in the wider conservation community.