Marine biodiversity, the variety of life in the ocean and seas, is a critical aspect of all three pillars of sustainable development—economic, social and environmental—supporting the healthy functioning of the planet and providing services that underpin the health, wellbeing and prosperity of humanity. Marine ecosystems provide innumerable services for coastal communities around the world. For example, mangrove ecosystems are an important source of food for more than 210 million people,'1 but they also deliver a range of other services, such as livelihoods, clean water, forest products, and protection against erosion and extreme weather events.