Greenpeace is researching the world's largest underwater canyons at the bottom of the Bering Sea using a Waitt Institute submarine. The Pribiloff and Zhemchug canyons are known as the "Grand Canyons of the Sea," yet little is known about the diversity and distribution of life on the sea floor. Today, overfishing and destructive fishing methods like trawling are damaging these canyons and threatening the food supply for marine mammals, birds and Native communities who depend on the marine ecosystem.