We used to think of the ocean floor as a barren desert — devoid of life and unimportant to ocean health. But as scientists explore the depths, they are discovering that the deep ocean seafloor is home to many thriving and diverse ecosystems. Fields of tube worms sway around smoking hydrothermal vents, while fields of cold-water corals blanket the slopes of underwater ridges and mountains. These biodiversity “hot spots” provide shelter, protection, and breeding areas for many marine species. Unfortunately, these biodiverse places could soon be destroyed by deep-sea mining.