Long regarded as an empty and inhospitable environment, the deep ocean is rapidly emerging as an ecological hot spot with a remarkable diversity of biological life. Yet, the world's oceans are currently on a dangerous trajectory of decline, threatened by acidification, oil and gas drilling, overfishing, and, in the long term, deep-sea mining, bioprospecting, and geo-engineering. In The Geopolitics of Deep Oceans, noted environmental sociologist John Hannigan examines the past, present and future of our planet's `final frontier'. The author argues that our understanding of the deep - its definition, boundaries, value, ownership, health and future state - depends on whether we see it first and foremost as a resource cornucopia, a political chessboard, a shared commons, or a unique and threatened ecology. He concludes by locating a new storyline that imagines the oceans as a canary-in-the-mineshaft for gauging the impact of global climate change. The Geopolitics of Deep Oceans is a unique introduction to the geography, law, politics and sociology of the sub-surface ocean. It will appeal to anyone seriously concerned about the present state and future fate of the largest single habitat for life on our planet.