The activities differ considerably in their stage of development: some are relatively advanced while others are still in their infancy. To bring them on stream on a scale that would allow them to contribute in a meaningful way to global prosperity, human development, natural resource management and green growth will require considerable research and development (R&D) effort, investment and coherent policy support. The obvious - and in some cases less obvious -differences between land and sea have important implications as to how human activities are managed in the two very different environments. Nonetheless, although these differences affect the context and outcomes of marine operations, many of the concepts and techniques deployed in marine planning and management tend to be borrowed from practices on land.