For researchers, a visit to the Northwestern Hawaiian Islands is like diving back in time. "It's radically different from the main Hawaiian islands and other islands where there's a lot of fishing that goes on. You've got a completely different cast of characters in the ecosystem," says John Rooney, coastal and marine geomorphologist for the Joint Institute for Marine and Atmospheric Research, a cooperative between NOAA and the University of Hawaii. As large predators, including sharks and uluas, and smaller types of fish are picked off, the ecosystem changes from coral dominated to algae dominated. Rooney, part of a team that is mapping the ocean floor, says the Caribbean and some areas around Florida are prime examples of this shift. But the remote location of the Northwestern Hawaiian Islands has protected the area from being overfished. "You get up here and see just how unspoiled it is," says Rooney. "To realize you're looking at, to a large extent, how reefs were before humans came on the scene - it's just exciting to see that and to know that you're witnessing nature the way Mother Nature intended."

Last summer, Rooney was one of 20 people who spent 28 days aboard the research ship Hi'ialakai to study the area, which will take decades to map. "When I'm towing a camera sled across the seafloor, I'm looking at a seafloor that probably nobody has ever looked at," he says.