Island Conservation (IC) and Scripps Institution of Oceanography (SIO), UC San Diego, co-convened a meeting of practitioners and researchers to assess the Global Links for Island Marine Restoration(GLIMR). These global experts in the diverse fields of island restoration, invasive species management, and wildlife conservation, were assembled and worked for eight months to evaluate the state of the knowledge of land-sea linkages in the context of invasive species management and island restoration. The result is this white paper synthesis of the science and research recommendations and a manuscript that will be submitted to a peer-reviewed journal. The intended audiences for this endeavor include island communities, governments, conservation and sustainable development non-governmental organizations, scientists, and funders. Throughout the report, readers will find that the key takeaways, identified by the authors, are represented in blue italics. This study was made possible by the generous support from the IC Board of Directors, the Center for Marine Biodiversity and Conservation at SIO, the Nature Conservancy California Chapter, the Leo Model Foundation, and the Archie Arnold Trust.

Islands support unique plants, animals, and human societies found nowhere else on the Earth. Local and global stressors threaten the persistence of island ecosystems, with invasive species being among the most damaging, yet solvable, stressors. While the threat of invasive terrestrial mammals on island flora and fauna is well recognized, recent studies have begun to illustrate their extended and destructive impacts on adjacent marine environments. Eradication of invasive mammals and restoration of native biota are promising tools to address both island and ocean management goals. The magnitude of the marine benefits of island restoration, however, is unlikely to be consistent across the globe. We propose a list of six environmental characteristics most likely to affect the strength of land-sea linkages: precipitation, elevation, vegetation cover, soil hydrology, oceanographic productivity, and wave energy. Global databases allow for the calculation of comparable metrics describing each environmental character across islands. Such metrics can be used today to evaluate relative potential for coupled land-sea conservation efforts and, with sustained investment in monitoring on land and sea, can be used in the future to refine science-based planning tools for integrated land-sea management. As conservation practitioners work to address the effects of climate change, ocean stressors, and biodiversity crises, it is essential that we maximize returns from our management investments. Linking efforts on land, including eradication of island invasive mammals, with marine restoration and protection should offer multiplied benefits to achieve concurrent global conservation goals.