DEEP REST will investigate two remarkable deep-sea ecosystems namely polymetallic nodule fields and hydrothermal vents, including their extended peripheries. Four major areas will be investigated: the Clarion-Clipperton Zone (CCZ) and the DISCOL Experimental Area (DEA) in the Pacific Ocean for nodule fields and the northern Mid-Atlantic Ridge (nMAR), and the Arctic Mid-Ocean Ridge (AMOR) for active and inactive hydrothermal vents. These remote ecosystems are at risk of exploitation of their associated strategic metal resources, i.e. polymetallic nodules (PMN) and seafloor massive sulfides (SMS). Information on how to mitigate the impacts of future mining activities are of utmost importance. The International Seabed Authority (ISA) is currently drafting the mining code that will regulate mining operations in the Area and is working on the development of Regional Environmental Management Plans (REMPs). Moreover, at national level, the Norwegian Government recently passed the Seabed Minerals Act, and has initiated a process that may lead to commercial mining activities under Norwegian jurisdiction. The elaboration of strategies to use the oceans in a sustainable manner is fundamental as proclaimed in the “Decade of Ocean Science for Sustainable development (2021-2030)” and the “Decade on Ecosystem Restoration” launched by the UN as well as in Mission Starfish 2030 of the EU. However, questions about the impacts of mining and resilience of deepsea communities to anthropogenic activities are still pending. DEEP REST will enhance fundamental knowledge on species and functional diversity and their interconnections to develop effective environmental management plans and regulations to protect unique and vulnerable marine habitats. We will evaluate the effectiveness of passive and innovative active restoration approaches on the recovery of ecosystem biodiversity and assess how these actions could contribute to maintaining ecosystem functions and services. A crucial and yet missing multi-dimensional analysis of alternative conservation strategies will be conducted, including an evaluation of ecosystem services under different institutional regimes. A major objective of this project is to contribute to European and international environmental policies. Therefore, we propose to integrate data from past and present studies so that scientific findings can be used to recommend concrete conservation and/or restoration actions that will also be applicable to other areas. An original outreach and awareness strategy will be developed about the governance and issues surrounding deep-sea resources including policy briefs and a theater play