There are lots of coldwater corals in NZ waters....usually very deep...the most beautiful are the black corals in the waters of Fiordland,which grow at quite shallow depths due to the freshwater invert layer on the surface,which is stained a peaty colour and creates an unusually dark environment (very heavy rainfall in the Fiords all year.)...fortunately they are protected as the area is a National Park.I once had the pleasure of studying the geology of a coral reef mound off of S. Ireland in a kilometer water depth. Check out the corals Lophelia pertusa and Madrepora oculata for some really amazing coral. Corals in 2 degree C water!