The ocean as frontier

Abstract This editorial explores how the concept of the frontier calls attention to the ocean as a space of both opening and closure. Whilst the new opportunities suggested by a frontier imply an opening, the realisation of these opportunities typically requires a degree of (en)closure. At the same time, however, because spaces like the ocean cannot easily be enclosed by existing political institutions, the frontier opens new spaces for regulatory and, ultimately, ethical innovations. In short, while there is much to be concerned about in the opening of the ocean as a “frontier”, this opening also presents political opportunities.