After two years of collecting global data and developing models, scientists have a new, comprehensive way to measure the health of the world's oceans that recognizes humans as a part of an integrated marine ecosystem.
The scientists' report, published this week in the journal Nature, gave the oceans an overall score of 60 on a scale of 0 to 100. Among the world's 133 countries with ocean coastlines, scores ranged from 36 to 86; the United States scored slightly above average at 63.
The ocean health index measures 10 ways that people benefit from the oceans, including food, jobs, ability to sequester carbon from the atmosphere and pure aesthetic value. It also gives credit for clean waters and biodiversity, among other things.
The index score assigned to a particular ocean region reflects the degree of sustainability for each of these factors.