The chapter aims to demonstrate the necessity of using an integrated approach when dealing with the oceans, seas, marine resources and human well-being nexus at the sub-national, national, regional and global level. It identifies important inter-linkages between nexus areas and elaborates on important classes of threats affecting it. The chapter examines the scientific coverage of interlinkages and threats, lists illustrative scientific reports and indicates areas for further research as suggested by contributing experts. The chapter documents selected case studies that illustrate the inter-linkages between nexus areas and the need to use an integrated approach when implementing measures at the sub-national and regional levels with the aim of creating positive impacts for both humans and the environment.