Global biodiversity in cold-water coral reef ecosystems

Over half of all scleractinian coral species inhabit ocean depths greater than 50 m, some of which are capable of constructing reefs tens of kilometers long and hundreds of meters high. The biodiversity of life found on these cold-water coral reefs is astounding yet remarkable since, in contrast to the photic and mesophotic zones, so few coral species actually create a framework matrix at these depths. In light of rapid climate change and unprecedented rates of anthropogenic disturbance, it is urgent we understand how biodiversity in the depths of our oceans is coupled to the persistence of these habitats. We provide a synthetic overview of animal biodiversity associated with major reef framework-forming species, discussing this with respect to global trends in species diversity, composition, and regional species pools, large knowledge gaps, and also the frontiers in technology that cold-water coral science is adopting to help address these gaps.