Growing international and national focus on quantitatively measuring and improving ocean health has increased the need for comprehensive, scientific, and repeated indicators to track progress towards achieving policy and societal goals. The Ocean Health Index (OHI) is one of the few indicators available for this purpose.

This study develops a wide-ranging index to assess the many factors that contribute to the health and benefits of the oceans, and the scores for all costal nations are assessed.

The rapid increase in the science and implementation of marine protected areas (MPAs) around the world in the past 15 years is now being followed by similar increases in the science and application of marine ecosystem-based management (EBM).

The management and conservation of the world's oceans require synthesis of spatial data on the distribution and intensity of human activities and the overlap of their impacts on marine ecosystems.