With 80% of the earth’s surface being water, it isn’t surprising that there are more than 1,000 coral species that make up the underwater cities we know as coral reefs. Coral reefs are underwater structures composed of skeletons of marine invertebrate animals known as hermatypic corals which survive by creating hard exoskeletons that protect their soft bodies.
Each individual coral is called a “polyp.” Coral is able to grow to such magnificent size because new coral polyps will grow on the exoskeletons of existing polyps, over time creating a reef. Polyps are given their stunning color from algae that live just inside each polyp’s cell wall producing the results of photosynthesis, which the polyp then turns into protein, fat and carbohydrates necessary for the survival of the reef. The algae and the polyp form a symbiotic relationship because the polyp, in turn, shelters the algae and provides the carbon, nitrates and phosphates the algae needs for photosynthesis.
These reefs are complex and require a recipe of necessities to exist and grow. Reef-building corals require waters that are clear, warm and salty. If any of these requirements are not met, the algae become “stressed” and eject from the polyp. Without the Algae, the polyp loses its color and dies if not reabsorbed soon after.
Explore the amazing underwater world of coral reefs in our new film “The Last Reef 3D.” With stunning visuals and the giant IMAX® screen, there is no better way to become immersed in these vibrant underwater cities and to learn about their complicated and beautiful ecosystems.