Deep-sea corals, also called cold-water corals, aren't as inoculated against heat stress and bleaching as previously thought. Although ocean temperatures are colder at greater depths, new research shows that corals situated up to 35 meters (115 feet) below the surface are still prone to heat stress.

The ocean has absorbed 90% of the extra heat generated by human activity, and the pace of ocean warming has more than doubled since 1993. Warmer waters can cause corals to eject the symbiotic algae that give them their vibrant colors and vital nutrients, resulting in bleaching and sometimes death. Watch the video above to learn more about how cold-water corals are faring in a warmer ocean.