The world’s largest structure made by living organisms, the Great Barrier Reef, is home to some of the most fascinating and photogenic creatures on earth. You can see it from outer space as a collection of tiny green islands and underwater walls running for long distances. Here are some fascinating facts about this reef off the coast of Queensland, Australia.
The reef was built through a collaboration between tiny jellyfish-like translucent animals called coral polyps, and a certain type of algae called zooxanthellae. The tiny soft polyps can live on their own, but they prefer to attach to hard surfaces via a hard limestone surface at their base. The algae provide the polyp with the material to create more limestone. The polyp attaches itself to a rock on the sea bed, then divides and clones itself slowly into thousands of individual polyps. The algae get a safe place to live in, in return.
The Great Barrier Reef may have started forming at a time when the earth was cooling towards many ice ages, apes were evolving, forests of kelp were growing in the sea, and seals and whales were spreading.
Multiplying coral polyps would have their hard bony calicles connect together into colonies. These colonies would have grown over hundreds and thousands of years, to become the Great Barrier Reef as it is today.
The average lifespan of a coral polyp in the wild is anywhere between two years to hundreds, while a colony can live for five years to several centuries. These colonies are home to a quarter of the ocean’s creatures, though the colonies themselves spread across less than 1 percent of the ocean floor.
Clearly, if coral colonies have a lifespan, the question arises, how long can the reef survive? Scientists have been saying that the Barrier Reef is in danger of dying out because of human activities. The reef is in danger from climate change (which corals are very sensitive to). Rising global temperatures is causing hot water to expel the algae that the corals need to sustain themselves. This is called bleaching, and a piece by Rowan Jacobson in Outside Magazine in October 2016 declared the Great Barrier Reef dead as of this year. The report may be exaggerated but the threat is real.
It’s not surprising that Queensland sees millions of visitors each year, who come to see the Great Barrier Reef. Tourism, recreational fishing and commercial fishing in the Reef bring in a whopping $5.8 billion to the Australian economy every year. The biggest contribution comes from the 2 million tourists a year, of course - $5.1 billion.
It’s not entirely an exaggeration to say so. For six years, Hong Kong gaming tycoon Tony Fung had been nursing dreams of building an $8 billion casino resort a little north of Cairns, the gateway to the Barrier Reefs. It was going to have an enormous artificial lake with three futuristic domes as Australia’s largest resort. He axed the plan in 2016, but in Queensland, you’ll always find pokies to gamble away your post-diving hours.
The reef is home to over 1500 species of fish, thirty species of dolphins, whales and porpoises, 5000 species of molluscs, 17 species of sea snake, six species of sea turtles, 215 species of birds, 15 species of seagrass along with dugongs and crocodiles. The reef has had its current form for only about 6000 to 8000 years, with dropping sea level letting in plenty of light for the reef to form.
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