What is the Great Barrier Reef?

The Great Barrier Reef is the world’s largest coral reef system. It was formed some 500,000 years ago.

Made of 2,900 individual reefs and 900 islands, the Great Barrier Reef spans over approximately 344,400 square kilometers.

Before you dig deep into the Great Barrier Reef facts, here is a quick snapshot:

  • 1500+ fish species live there.
  • 30+ species of marine mammals live there.
  • 6 species of threatened marine turtles live there.
  • 134 species of rays and sharks live there.
  • It holds one-third of all soft corals found in the world.
  • There are 411 types of hard corals in the reef.

Okay, now that you have a quick idea of what the Great Barrier Reef is, it is time to dive right into the Great Barrier Reef facts.

Shall we start?

Fascinating Great Barrier Reef Facts: 1-5

1. The Great Barrier Reef is pretty old. It was formed some 500,000 years back. However, the formations that we see today are not as old as the reef itself. As a matter of fact, the current formations are actually only 6,000 to 8,000 years old.

2. The formations of the reef keep changing. This change occurs depending on the sea level. This explains why the current formations are way younger than the reef itself.

3. When we say formations, what exactly do we mean? They are basically large formations or structures which are made up of living organisms.

4. What living organisms actually? These living organisms in question are none other than coral polyps and zooxanthellae. Coral polyps are animals that come from jellyfish family. Zooxanthellae are a type of algae.

5. The coral polyps and the zooxanthellae live in a symbiotic relationship. The coral polyps provide a safe and cozy place for the algae. The algae in return provide the building blocks necessary for the polyps to survive. In addition to this, the algae also make limestone. This limestone is used for building the structures of the reef.

Fascinating Great Barrier Reef Facts: 6-10

6. The vast structures that are created out of the symbiotic relationship between the polyps and the algae are known for supporting a wide range of life forms. For instance, 30 different species of porpoises, dolphins and whales live in the Great Barrier Reef.

7. Don’t be surprised to see humpback whale, Indo-Pacific humpback dolphin and dwarf minke whale living in the reef area.

8. The reef is called home by 5,000 different mollusk species, 1,500 + fish species, and 17 sea snake species.

9. Among the fish species, the enchanting ones like clownfish, red-throat emperor and red brass are found here. The sea snakes that are found here are usually found in the southern section of the reef as opposed to the northern section. These snakes live in the warm waters and the maximum depth they reach is 160 feet.

10. Olive Ridley Turtle, Flatback Turtle, Loggerhead Sea Turtle, Hawksbill Turtle, Leatherback Sea Turtle and Green Sea Turtle are the six different turtle species that use the Great Barrier Reef as their breeding ground.

Fascinating Great Barrier Reef Facts: 11-15

11. Apart from that, there are large marine mammals (manatee relatives) called dugongs that live in large numbers in the reef. It is also not unusual to find a number of species of coral trout and snapper trouts in the reef.

12. Birds also call the Great Barrier Reef their home. There 215 bird species that roost or nest on the islands or simply visit the islands. Of these 215 species, 32 species are shore birds while 22 species are seabirds.

13. Roseate tern and sea eagle (white-bellied) are the commonly sighted birds in this reef.

14. Wondering about flora? The reef won’t disappoint you. Seagrass are pretty common in the reef and there are 15 different species available there. The commonest ones are Halodule and Halophila.

15. These seagrasses are actually food for the dugongs and the turtles. Apart from that, they are also the natural habitat for the fish living in the reef.

Fascinating Great Barrier Reef Facts: 16-20

16. The reef’s coastlines are covered with several salt marshes and mangroves. Any guess what you can find there? The ferocious and massive saltwater crocodiles!

17. The biodiversity of the Great Barrier Reef is extremely rich and it is also the home for various endangered species of marine animals. This is the reason why GBRMPA or Great Barrier Reef Marine Park Authority increased the count of highly protected zones in 2004 by nearly 30%.

18. Ever wondered how big is the Great Barrier Reef? If we calculate the length from the northernmost tip to its southernmost tip, it covers a whopping 1,600 miles or 2,575 kilometers.

19. If we try to calculate the total area covered by the reef, it stands at an astonishing 344,400 square kilometers or 133,000 square miles. That’s slightly less than the total area covered by Japan (377,962 square kilometers).

20. Now that you have an idea of the area of the reef, you can very well guess that it is the largest system of coral reef in world and it is so big that it can actually be seen from space. Now that’s quite interesting, ain’t it?

Fascinating Great Barrier Reef Facts: 21-25

21. We usually learn about the seven wonders of world. However, we are not usually told about the Seven Natural Wonders of World. The Great Barrier Reef is one of them.

Just in case you were wondering about the list of Seven Natural Wonders of World, we will make your life simple. Here is the list:

22. The Great Barrier Reef sits on the slopes of Continental Shelf. Here the depth of water averages at 35 meters. However, the moment you drop off the Continental Shelf, you will encounter a depth of 2,000 meters.

23. The coral reef has a natural predator. Wondering who can eat the solid structure? This predator goes by the name Crown-of-Thorns Starfish. This guy is known for stripping living corals off the reef. Good thing however is that the corals are capable of regrowing after a predatory attack.

24. In the reef, what we see today is basically a thin layer of live corals that are no older than 6,000 to 8,000 years. However, underneath that layer lies a thick layer of dead algae and dead corals, which are 500,000 years old.

25. Of the total coral species that are found in this entire world, more than one-third (1/3rd) are found in the Great Barrier Reef alone.

Fascinating Great Barrier Reef Facts: 26-30

26. If you really think that the Great Barrier Reef is a single entity, you are grossly mistaken. It is actually a system composed of 2,900 different coral reefs along with cays and islands whose total count stands at 1,050.

27. Ever wondered how fast the corals grow? Their growth rate is 1.5 centimeters in a single year. These slow-growing corals are actually the reef’s backbone. They adapt continuously to the surrounding environment.

28. Now here is something really surprising. Did you know that the Great Barrier Reef has its very own Street View (of course underwater). It was the part of Google’s Underwater Earth project that was launched back in 2012.

29. Google didn’t send a car taped with a camera to capture the street view. It rather used Catlin Seaview Survey Project’s imagery. In case you are not aware of what this Catlin Seaview Survey Project is all about, here is a quick explanation: It was actually an expedition series that was launched in order to survey and explore and also to monitor coral reefs’ health across the world.

30. Visiting the reef will cost you some money in form of tax. The tax rate is USD 6 for a single day for a single visitor. However, the tax is applicable for any visitor who is above the age of 4 years.

The money thus collected is taken by Great Barrier Reef Marine Park Authority. The money is used for protecting and preserving the extraordinary and delicate ecosystem of the reef that is gradually being destroyed by human activities and global climate change.

Fascinating Great Barrier Reef Facts: 31-35

31. You may often hear people calling the Great Barrier Reef as the largest single organism on Earth. If so, it would easily beat the Blue Whale. Unfortunately, that is not true. Check out point #26. It is actually a system.

32. However, the reef is definitely the largest organic structure that exists on this planet. There is no other organic structure that is as big as this. This structure is considered as Australian Economy’s asset and is currently valued at USD 42.4 billion or AUD 56 billion (as per Deloitte Access Economics).

33. The reef is not completely covered by corals. The truth is that only 6% to 7% of Great Barrier Reef Marine Park is covered by corals.

34. In our last article on the Great Barrier Reef we mentioned that the whole area covered by the reef system is nearly as big as Japan, we didn’t mention that it is actually way bigger than many countries in this world.

To give you an accurate picture, the system (if considered as a country), will take the 63rd place in the list of countries organized in order of their size. This means, the reef system will sit between Germany and the Republic of Congo.

35. Even more surprise! The size of the reef (133,000 square miles) that we know today is actually 50% of what it used to be back in 1985 and earlier.

AIMS or Australian Institute of Marine Science says that because of the natural predator (Crown-of-Thorns Starfish), storms and coral bleaching, the reef system has been reduced to half its original size since 1985.

Fascinating Great Barrier Reef Facts: 36-40

36. Believe it or not the Great Barrier Reef is actually privately owned by Torres Strait Islanders and Aboriginal Australians and the Government of Australia actually gives monetary compensation to those “Traditional Owners” for using the reef as a national marine property!

37. Will you believe if someone says you that four European explorers completely ignored the reef system during their voyages? It all started back in 1522 when Cristóvão de Mendonça – a Portuguese nobleman reached the reef but yet, decided to completely ignore it.

On 1605, Willem Janszoon – a Dutch navigator reached the reef and didn’t document it. A year later in 1606, Luís Vaz de Torres – a Galician seaman reached the reef and he too didn’t document it.

Then in 1768, Louis Antoine de Bougainville – an admiral from France, reached the reef. He did make an official record but did not explore the region simply because his crew members were short on life-supporting food supplies. So, he and his crew went to South Asian Coast.

38. Heard of Captain James Cook? He was a British adventurer. The British Government sent Cook on a mission to find a hidden continent near the country of New Zealand and take possession of the continent in name of the British Kingdom.

It was 1770 when Cook’s ship – the HM Bark Endeavour was passing through the region and accidentally hit the top of a reef. This caused immense damage to the ship and it had to be anchored and docked for carrying out repair work.

It was this accident that led Captain Cook to scout the region and appreciate the majestic beauty of the reef. Thus, the discovery of the Great Barrier Reef is attributed to Captain James Cook.

39. HM Bark Endeavour of Captain Cook was really lucky. However, another passenger ship called SS Yongala was not really that lucky. In 1911, SS Yongala was caught by a cyclone and blown off the eastern coast of Australia.

With the master stroke of the ultimate bad luck, the ship was drawn to the bottom of the ocean, drifting away 48 nautical miles farther out from Townsville’s Queensland City.

The ship was 350 feet long and today it rests within the Great Barrier Reef Marine Park’s perimeter. A wide rage of fish species have now made the sunken ship their home.

40. The Great Barrier Reef is world’s THE MOST DENSELY POPULATED ecosystem.

Fascinating Great Barrier Reef Facts: 41-45

41. A two-acre area of the Great Barrier Reef has way more fish species compared to the number of bird species that can be found in whole of North America. This should give you a fairly good idea of the rich biodiversity of the reef system.

42. Why are the coral reefs so important for ocean health? That’s because the coral reefs of not just the Great Barrier Reef but other coral reefs around the world are known for filtering the water by trapping the floating things. This makes the water crystal clear in the coral reef regions.

43. Coral reefs of the Great Barrier Reef has an amorous ambiance. While many species of animals come here for mating, the largest orgy on planet earth is that of the corals themselves.

Every year after the full moon of the springtime passes, the moon phase along with water temperature kicks off what is known as the “sex on the reef”.

It is the phase of mass spawning where the corals spend an entire week in reproduction. They release huge amounts of eggs and sperm, which go on to carry on the nearly still or motionless legacy of the corals.

44. The question is why does the mass spawning take place only once during a year? That’s because the corals have genes that are capable of detecting the moonlight. Once the correct conditions are detected by the genes, the “sex on the reef” starts. This happens every November.

45. The coral reefs of the Great Barrier Reef are facing a grave threat. They reef system is dying out gradually because of a number of factors like coral bleaching, increase in the population of Crown-of-Thorns Starfish, pollutions, oil spillage and more.

Fascinating Great Barrier Reef Facts: 46-50

46. Coral bleaching is the greatest danger. To be more specific, the rise the global temperature is causing the reef system to die out. It has been happening way faster than expected. A paper was published in the journal called Nature, which shows the grim fate of the Great Barrier Reef.

47. According to the paper, 2016 was period of vast coral bleaching that affected the large sections of reef to die out. To be more precise, there is a city in the eastern coast of Australia.

It is known as Cairns. To the north of Cairns is a large section of the reef system. A 500-mile section of this segment of the Great Barrier Reef system encountered coral bleaching.

48. Before the paper was submitted in Nature, an extensive survey was conducted where it was found that large sections of the reef were bleached out and is not likely to recover anytime soon or possibly, the corals will never recover and stay dead.

49. But here’s something you should know. The surveys were conducted by Professor Terry Hughes and his team, who were funded by the government.

They conducted aerial surveys and found that the corals ghosted out. But the problem with the survey was that it could not really determine whether the bleaching was caused by declining sea levels, low tides, increase in sea level, increase in global warming, storm damage or Crown-of-Thorns Starfish.

50. Hughes’ study lead to headlines like “25 million years old Great Barrier Reef is dead” and more. Fortunately enough, that’s not the case.

The Great Barrier Reef is far from being dead with the hardest hit areas ad per the Hughes report have only less than 5% damage as reported by divers who visited the areas given in Hughes reports. Source.

Fascinating Great Barrier Reef Facts: 51-55

51. What causes death of corals in the Great Barrier Reef? This is one question that must be answered first. One of the greatest threats is that of coral bleaching. What really is that?

Coral bleaching occurs when the temperature of the seawater rises above normal. Corals are very sensitive to temperatures. Rise in sea temperature triggers a phenomenon called coral bleaching.

52. Corals are known for having a symbiotic relationship with the algae. The corals polyps are known for capturing algae, which are single-celled plants. These algae get protection inside the corals and in turn, they take sunlight and convert it into food. This food is used by corals to survive.

53. This symbiotic relationship can exist only when the temperatures are normal. When the temperature increases, the algae start producing toxins. This is not acceptable to the coral polyps.

54. When the algae start producing toxins, they simply spew out the algae – a simple act of self-defense. When the algae are expelled, the corals take the ghostly white color. This is known as coral bleaching.

55. No algae means no food for corals. So, there are two things that can happen. The water temperature doesn’t return to normal and the coral polyps remain free of algae. Absence of algae means no food. So, the coral polyps gradually die either of diseases or starvation.

Fascinating Great Barrier Reef Facts: 56-60

56. The other thing that can happen is that the water temperature drops back to the normal. This is when the ghostly white coral polyps will capture algae again and spring back to life as the algae start producing food essential for the survival of the corals.

57. If the temperatures drop quickly enough, the corals can actually revive themselves within 10 to 15 years. So, coral bleaching may be temporary. In case of the Great Barrier Reef, it is difficult to say what will happen in near future.

It is true that the Global Temperature rose significantly in 2016 because of El Niño and coral bleaching did take place, it is too soon to claim that Great Barrier Reef is dead and will not be able to revive.

58. Wondering what dropping sea levels can do to Great Barrier Reef? Well, the corals need to live under water. This means that when sea levels decrease, coral reefs shrink to stay under water.

They can again grow back when the sea level increases. So, declining sea levels too do not mean that the Great Barrier Reef is dying. It is definitely dangerous but death is not definitive.

59. On the other hand, rise in sea levels is also a major threat. The maximum depth till which the coral reefs can survive is 150 feet. Any deeper than that means that the sunlight cannot penetrate. Sunlight is essential for survival of the corals. So, increase in sea levels is also a major threat!

60. Finally, the Crown-of-Thorns Starfish are a big threat to corals in Great Barrier Reef. The numbers of this natural predator of the corals are increasing in leaps and bounds.

Humans are responsible for that. Natural predators of the Crown-of-Thorn Starfish are increasingly captured by fishing activities and hence, the numbers of this starfish have increased in the Great Barrier Reef region. This is also a big threat to the survival of this natural wonder of world.

A Slice of the Great Barrier Reef is in Dubai

Great Barrier Reef is definitely in danger. Over the years, the situation can become even grimmer than what it is now. However, efforts have been made to save this largest organic structure on earth.

One of the solutions that people came up with was to move the whole reef to a hospitable place. The result was that a 5-ton slice was transported all the way to Dubai in year 2008. That’s fine.

But removing the whole country-sized system to a different location was not really a feasible option (at least logistically).


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