The Arctic Ocean is one of the most unexplored places on Earth. It's also changing rapidly -- in the summer, sea ice is melting more quickly than usual, due to rising air temperatures. . . .
The Healy, a 420-foot U.S. Coast Guard icebreaker, recently ferried a team of more than two dozen biologists to the most remote parts of the Arctic Ocean. The expedition, funded by the National Oceanic and Atmospheric Administration (NOAA) was dubbed the "Hidden Ocean" cruise.
A region where it's rare to glimpse a living creature anywhere on the horizon seems an unlikely spot for biologists. But in reality, the environment is teeming with life, and the biologists know just where to look for it -- all the way from above the ice to two miles below the surface, on the ocean's floor.
That sea floor is larger in size than the United States, and scientists are studying it with unmanned submersibles, cameras and nets, looking to chart its biodiversity.