After two years of effort, an international team of 65 scientists, policymakers and environmentalists has completed the first phase of what might appear to be an impossible task: assessing the health of the ocean and assigning it a 'score'.

Their conclusion? Out of a possible score of 100, the ocean's health rates a 60. The lowest score - 36 - went to the waters off Sierra Leone, while the waters surrounding uninhabited Jarvis Island, near Hawaii, merited an 86. United States waters averaged a score of 63.