The geological history of Australia is long and complex. What we know as the Great Barrier Reef today was once little more than a few coral polyps, and these didn’t last too long. But over time the Great Barrier Reef has grown to the stunning ocean wonder known the world over. About 2 million visitors come to the reef each year, and the reef is estimated to bring in as much as $5 billion to the country annually.
And it’s no surprise why, either. Besides the stunning opportunities for diving, boating, and swimming around the reef, there are also plenty of great islands that have a wonderful variety of activities for people of all ages. And the Great Barrier Reef is a great staging ground for adventures further inland around Cairns and the greater Queensland area.
Coral needs sunlight to grow, and can only do that at depths of 150m (490 ft). They also need seawater constantly, so cannot grow above sea level either. 25 million years ago the first coral began to form when Australia drifted far enough north to be in tropical waters, but the sea levels fluctuated to such an extent that all coral growth that did occur quickly died off. Sediments washing down from the Great Dividing Range also made growth unfavorable.
That all began to change 10 million years ago when sea levels lowered. The sediment in place from millennia earlier proved ideal, and a warming period 400,000 years ago also allowed seawaters to increase in temperature by as much as 4 °C (7 °F). The Great Barrier Reef Marine Park Authority (GBRMPA) thinks that the earliest examples of complete coral formations can be traced back 600,000 years, and the Reef Research Center’s discover of coral deposits that have been dated back 500,000 years seems to back up this claim.
What we know as the Great Barrier Reef today began when the current Earth’s ice sheets were at their maximum extent around 20,000 years ago. This was called the Last Glacial Maximum, and it created sea levels 120m (390 ft) lower than we know them as today. When the Late Glacial Maximum started 13,000 years ago, these lower sea levels began to rise, and coral grew up with them. The large sedimentary hills that had been formed from runoff from the Great Dividing Range slowly became islands, and coral deposits began to grow onto them. When those islands were submerged by the continued rise in sea levels, the coral continued to grow, creating the large reef islands and cays we associate with the Great Barrier Reef today. By 6,000 years ago the seas stopped rising and the Great Barrier Reef as we know it was in place, and still growing.
The Reef Today
Today the Great Barrier Reef stretches for over 2,600 km (1,600 mi) over roughly 344,400 square kilometers (133,000 sq mi), and is comprised of 2,900 different reefs and 900 unique islands. Billions of coral polyps make it what it is, and the amount of life supported by this natural wonder of the world is simply astounding.
More than 1,500 different fish species inhabit the reef, including clownfish, red bass, and coral trout. Dugongs call the reef home, and dolphins, humpback whales, and dwarf minke whales often visit. There are seventeen different species of sea snakes currently residing there, and fifteen different species of seagrass thrive in the area.
It is that delectable seagrass treat which attracts so many sea turtles, six different species, in fact. They include the loggerhead, flatback, leatherback, hawksbill, olive ridley, and green sea turtle. Sharks, stingrays, and chimaera are also common, and 125 species make this place their regular abode. There are also nine different kinds of seahorses, and seven species of frogs. And birds love the reef too, with anywhere from 1.4 to 1.7 million nesting and breeding their each year.
In 1981 the reef was chosen as a World Heritage Site, and a large part of it today is protected by the Great Barrier Reef Marine Park, which was created in 1975. The GBRMPA is tasked with monitoring the park, which is comprised of 17 different islands.
One of the best places for visitors to the Great Barrier Reef is Whitsunday Island. The island is part of the larger Whitsunday Islands, which is comprised of 74 different islands of various sizes, all located south of Bowen and north of Mackay, or about 900 km north of Brisbane.
The islands should really be called the ‘Whit-Monday Islands,’ as the day of discovery by Captain James Cook in 1770 was off by one. And Cook didn’t have the best of luck in the area anyways. His ship the Endeavour was forced to limp into a river near modern Cooktown after running aground on a rather nasty shoal. His journey was delayed for seven weeks, and the river he used for repairs has been called the Endeavor River ever since.
While Cook passed Whitsunday Island by, all manner of visitors since then have been rushing to it in droves. 700,000 people visited the islands in one year from 2008 to 2009, and the trend doesn’t look to be slowing any.
Whitsunday Island is the largest in the group of 74 islands that bear its name, and it was voted as the top Eco Friendly Beach in the world in 2010 by CNN. And it’s an easy island to get to, as well. Boats depart constantly from Airlie Beach and Shute Harbour. There are six campgrounds on the island, making it an ideal spot to plan a real evening out. And the beautiful white sands of the 7 km long Whitehaven Beach are a real treat.
The sands on the beach are leftover from millions of years ago when the Great Barrier Reef itself was little more than sedimentary runoff from the Great Dividing Range and other areas reached by strong ocean currents. It’s made up of 98% silica, which is where the bright white color comes from. And walking on the beach on even the hottest of days won’t pose a problem. The silica-rich sand doesn’t retain heat like other beaches do, so you won’t have to hop about or constantly wear sandals.
While Whitsunday is the largest island in the Whitsunday Island group, Hamilton Island is the largest in regard to people, with 1,347 residents in 2006. It’s also one of the best islands in all of Australia for yachting, and holds the annual Hamilton Island Race Week yachting festival, which attracts more than 150 yachts for a weeklong racing spree around the islands. The end of the festival sees all of the yachts gather together at Whitehaven Beach for ‘Whitehaven Day,’ and all-day beach party that any visitor coming in late August won’t want to miss.
The Hamilton Island Airport also makes it easy to come directly to the island for a great Queensland holiday vacation. And there are plenty of ferries heading to the mainland at all hours of the day, as well as several shuttle buses that continually transport visitors from one island locale to the next. And visitors coming from July to September will have a good chance of seeing migrating whales moving through the warm waters.
The Hamilton Island Cup is another great sporting even that has occurred each year since 1984. Now called the Gatorade Clash of the Paddles, the competition is a 4-day outrigger canoeing event that draws water enthusiasts from around the world each June. Anyone with a crew can register, and even if you don’t want to paddle your way to glory, you can have quite the fun time watching the races.