"Just under a year ago, NASA released a map of marine dead zones. It helped us visualize the extent to which low-oxygen areas are harming ocean ecosystems. Now, there's an even better tool -- an interactive map from World Resources Institute.

The World Resources Institute has announced that new research from WRI and the Virginia Institute of Marine Science (VIMS) identifies over 530 dead zones and an additional 228 sites worldwide exhibiting signs of marine "eutrophication" -- or over-fertilized areas due to agricultural run-off.