Ocean health is critical to all life on this planet. Phytoplankton, the microscopic plants found in the sunlit area of almost all oceans, generate about half of the Earth’s oxygen, and the complex interaction between the ocean and the atmosphere sustains our climate. Yet the oceans are in decline, largely because of human activities that are driving the collapse of fisheries, the loss of biodiversity, and the acidification of seawater. The evidence suggests that to halt this downward slide, more of the world’s ocean must be protected. In 2016, members of the International Union for Conservation of Nature, a global authority on the status of the natural world, adopted a motion recommending that nations protect 30 percent of their waters from all extractive activities by 2030. Safeguarding ocean space in marine protected areas (MPAs) has been proved to help conserve marine life and associated habitats. Creation of MPAs can improve ocean health and provide multiple benefits to the people whose lives and traditions are linked to these waters.