This report identifies the numerous pathways through which land-based activities generate impacts on coastal resources, acknowledging that they can differ, depending on the location, type, condition and resilience of the local ecosystems. It also identifies implications for the sustainable blue economy of changes to the coastal resource base caused by land-based activities. This is further explored in detailed assessments of shrimp aquaculture and coastal mining. Based on its scientific findings, the report calls for vastly improved governance approaches to reduce the negative impacts of land-based activities on coastal resources as well as supporting the transition to a sustainable blue economy. The key messages of the report are as follows: 1) Living coastal resources are most threatened by land-based activities. 2) All parts of the blue economy are vulnerable to changes in coastal resources, particularly fishing, aquaculture and tourism. 3) Existing land-sea governance approaches cannot cope with the impacts on coastal resources created by land-based activities. 4) Land-sea governance urgently needs to be strengthened to protect coastal resources from the impacts of land-based activities and to support the transition to a sustainable blue economy. 5) Tackling the impacts of land-based activities on coastal resources is a global priority.