What do corals represent in the marine ecosystem?
“Reefs play a role of planetary importance, comparable to that of primeval forests on land, of which they are the marine equivalent. Like the primeval forests they produce oxygen and contain a biological patrimony of exceptional diversity. But the comparison ends there. Although their cells are crammed full of symbiotic algae, corals are animals and not plants. Also, by building their skeletons, the accumulation of which forms the structure of the reefs, they absorb and precipitate enormous quantities of calcareous substances.” What are the different sorts of corals and which are the most threatened? “Calcareous substances (calcium carbonate) are the main component of the skeleton of most corals. However there are hard corals and soft corals. Hard corals, which are home to symbiotic algae and form reefs, have an external skeleton, which is often very thick. Red coral and similar species which live hidden from light, have an internal skeleton. The skeleton of soft corals is made up of t
