Oceans cover almost three-quarters of the planet, yet we are just beginning to discover the extent of the resources beneath their surfaces. We are also just beginning to understand the complexity of the interactions that tie oceans to the rest of Earth’s systems. And then there is the coastal biome, where vital ecosystem services are most vulnerable. The coastal biome’s links with both land and ocean extend its reach and vulnerability both far inland and well out to sea. This paper is based on contributions from an international group of experts. It is not intended to be comprehensive. Instead, it highlights areas of ocean and coastal management for which a better understanding of the economic value of marine ecosystem services could: • substantially improve the management of critical marine resources; • improve governance, regulation, and emerging ocean policy; and, • provide a better understanding of the potential economic challenges that arise from a rapidly changing environment.