Climate-smart, 3-D protected areas in the high seas

Marine species are moving rapidly in response to warming, often in different directions and with variations by location and depth. This poses challenges to conventional reserve design. We develop a three-dimensional planning approach for the high seas that conserves biodiversity, minimises exposure to climate change, retains species within reserve boundaries, and reduces fishing conflict. Resultant climate-smart networks cover 11% of the high seas (5% of the ocean) and represent low-regret conservation options that are the first places to designate as new high-seas marine reserves. With the current push to increase the area of ocean under protection to 30%, we must confront the challenges of climate-smart three-dimensional conservation in the 41% of the ocean that is beyond countries’ jurisdictions.