The ocean is enormous, indeed so large that for centuries we assumed that there was nothing we could do to substantially harm it. Unfortunately, we now know that this is not true. We are having success on some fronts, such as saving species from extinction, protecting ocean waters, fishing more sustainably, and restoring damaged ecosystems by replanting critical species and reducing pollution. Even actions on land, such as removing dams from rivers and rats from islands, can make an important difference to marine life. Of course, we still need to do much more, and do it faster. In the future, we can turn to new tools drawn from the natural and social sciences. Big data and genetic interventions have a role to play, as do ocean-based renewable energy sources and new financing schemes. Perhaps most important is the growing recognition that success depends on empowering local communities in efforts to create a healthier ocean. (#37775)