The world’s biggest living structure is The Great Barrier Reef. The only living thing visible from Earth’s orbit. The Great Barrier Reef runs parallel to the Queensland coast and spans from North of Cape York to near Bundaberg in the South – a total distance of 2600 kilometres and covering an area of approximately 344,400 square kilometres.
Built by billions of coral polyps (tiny organisms) and playing host to a diverse range of species including more than 1500 species of fish and over 400 species of corals the Great Barrier Reef is a World Heritage area and one of the Seven Natural Wonders of the World. Comprised of over 3000 individual reef systems and hundreds of tropical islands many vulnerable and endangered species are inhabitants of The Great Barrier Reef.
Coral is ‘alive’ due to its thin coating of coral polyps which develops a chalky limestone skeleton. Coral grows from the division of these polyps. This multiplication of polyps is called budding. Reproduction of the corals of the reef occurs through coral spawning. Over one third of coral on The Great Barrier Reef reproduces this way. This event can be witnessed on the inner reefs during the week after the full moon in October and on the outer reefs in November/December. This mass spawning sees corals releasing gametes leading to slicks of spawn on the surface of the sea. Spawning always occurs at night and the slicks won’t last longer than two days. Corals are inventive reproducers and it is likely that many of the mechanisms used are still undiscovered.
For most people coral wouldn’t be considered aggressive, yet they can grow over the top of neighbours and at night some corals can attack each other in a battle for space. Some can extrude mesenteric filaments to digest the tissues of their neighbours or, in the case of some species, tentacles up to 7cm long to sting their competition.
The Great Barrier Reef is also a breeding ground for Humpback Whales, migrating from Antarctica to use the warm waters of the Coral Sea between May and September. The whales come to calve and build up strength before returning to the Antarctic in Summer. Minke whales can also be seen, mainly around the ribbon reef area.
The coral reefs exist offshore from the coast of Queensland. Coral thrives better in clean water free of nutrient and freshwater. The best corals are generally found in the clean waters of the outer reef. Thala is located in close proximity to the Great Barrier Reef. With a short boat ride you can visit the crystal clear waters and stunning colour of the reef. Popular points to access The Great Barrier Reef in North Queensland are from Port Douglas and Cairns.