Trivia: The Great Barrier Reef

Here are some lesser-known facts about the largely visited Great Barrier Reef. - The Great Barrier Reef, the Earth's biggest coral reef ecosystem is located in the Coral Sea, off the north-eastern coast of Australia, straddling over 2,300km of coastline from the Torres Strait to Bundaberg, in the state of Queensland. - The single largest structure in the world, it's made of coral colonies built by billions of tiny living organisms, known as coral polyps. It's essentially a mass of limestone, made from the skeletons of millions of marine animals and plants. - There are hard corals and soft corals, which are built by invertebrate polyps. Coral polyps extract limestone from the sea water, using it to build the outer, protective exoskeleton. Most corals get their energy through algae that live within their tissue, and need sunlight, thus growing in shallow clear waters. - Since their scientific names are so long and boring, and really who can remember all that anyway, corals are mostly referred to by the way they look - like plate, boulder, vase, brain or stag horn. - The most common types of reefs found here are the Ribbon, Platform and Fringing reefs. - The reef is composed of a staggering 2,900 individual coral reefs and 900 islands. That's bigger than Italy. - The largest protected marine area in the world, the reef is home to unimaginable numbers of marine wildlife and supports 400 types of coral, more than 1,500 species of fish, 3,000 species of molluscs, 30 species of whales, porpoises and dolphins, 500 species of seaweed, 14 species of sea snakes, 6 species of sea turtles, 215 species of birds and large populations of dugongs. - It's also a safe haven to the endangered loggerhead and green sea turtles, and a breeding ground for humpback whales. - The Great Barrier Reef is bigger than the Great Wall of China. - It can be seen from outer space. - The Great Barrier Reef is also home to your favourite clown fish, Nemo and Marlin and Dory, the endearing Regal Tang. - The most common sharks found on the reef are the white tip reef and black tip reef sharks. They're quite timid, and don't hang around divers too long. - Not everyone on the reef's your friend though. Look out for the notorious box jellyfish, also called marine stingers, are found close to the mainland of Northern Queensland and are very common between October and March. They're extremely venomous, with a nasty sting that's sometimes fatal to humans. - The Giant Clam, the largest bivalve mollusc to ever live on this planet, is found here. It can grow to a meter long, and live up to a whopping 70 years. Since they don't get around much, most of them are also hermaphrodites. - Human activities, coral bleaching and very hungry crown of thorn starfish pose the biggest threat to coral reefs. - Green sea turtles love eating sea grass, and often hide in the reef to take power naps, coming up to the surface to pose for pictures every twenty minutes or so. - Sea cucumbers, found along the ocean floor, are like the reef's personal housekeeping staff, cleaning it up as they move along, some moving at a mind boggling 30cm a day. - Clown fish live in anemones, and most baby anemone fish can swim quite fast, up to 9 body lengths per second, and could give Ian Thorpe a swim for his money (he moves at about two body lengths a second, the slow poke). - Coral trout, start out as females, and as they grow larger, change sex to male. - Over a million people visit the Great Barrier Reef each year, which generates about 63,000 jobs in tourism, contributing a strong AUD 5 billion to the economy. In case we have missed out on a trivia, you're free to add to the list.