these colonies are home to starfish sea urchins lots of different fish and countless other kinds of animal. as windy and our cold water corals are called the bioengineers of the deep many species of fish including ones that are commercially fish use these coral reefs as spawning grounds as a place to feed and also a shelter so they play an important role in shaping the deep sea ecosystem in netty sea researchers have identified four thousand six hundred species that live in cold water coral reef ecosystems and each expedition uncovers more but how cold water corals reproduce is still something of a mystery. the world down there in the depths is astoundingly diverse and puzzling it would be terrible if it were lost before we managed to understand it.