Sustainably managing the vast ocean realm of the United States, the largest of any nation (11 million square kilometers in the Pacific, Arctic, and Atlantic oceans), has proven elusive. Present jurisdictional borders reflect the world views of the 18th or 19th centuries, antedating modern marine sciences. Different agencies manage different activities in the same places. Natural and social scientists report increasing loss of marine biodiversity and growing conflicts among human uses, signs that the old paradigm has not served the national interest. Biodiversity patterns and human uses (e.g., shipping, oil and gas production, commercial and recreational fishing, aquaculture, whale-watching, scuba diving, and surfing) are all spatially heterogeneous. Planning for managing oceans to reflect these spatial patterns and coordination among federal, state, tribal, and local governments can lead to more successful outcomes. In 2009, President Obama announced that the United States will adopt comprehensive ecosystem-based spatial planning for our oceans, coasts, and Great Lakes. Moreover, he declared that science will be the basis of marine spatial planning in the nine large marine ecosystems comprising U.S. waters. The resulting interagency coordination and realignment of pernicious borders will affect governance of an area larger than the entire U.S. landscape. This symposium will address key science and technology issues affecting the new domestic spatial management paradigm.