Covering more than two-thirds of the planet, the ocean is fundamental to human well-being. Marine plants that thrive in our coasts and seas, such mangrove and kelp forests, tidal marshes and seagrass meadows, provide a plethora of goods and benefits both to the environment and people. Estimates of the ocean’s contribution to the world economy range from US$1.5 trillion to US$3 trillion a year, about 5 % of all economic activity in the world. Driven by a growing global population and the need for new sources of growth, the ocean is becoming more and more an economic frontier and a dynamic three-dimensional environment where resources are rich and varied. This has given rise to a new concept or framework for action to reduce the risks: the transition of the current ocean economy to a “blue economy” with “blue growth.”