Do you like to dive and swim where there is a lot to discover? Or are you simply fascinated by the secrets that the big, wide sea holds? Then one day you should visit the coral reef in Australia, the Great Barrier Reef, and explore the colorful underwater world with its numerous creatures. But do you know what a coral reef actually is?
as reefs refers to elevations in the sea caused by the deposition of rocks or other natural rocks. The elevations in coral reefs are favored among other things by deceased corals, since their skeletons consist of limestone, which settles over time. These rock and coral reefs are also home to a wide variety of marine animals that live together in colonies under water.
Corals are immobile sea creatures that remain in one place throughout their lives. Did you know that tiny algae live on the corals? The coral needs the algae because they produce certain vital nutrients for the marine animal: The coral gives off CO2, which the algae in turn converts into glucose and oxygen, for example, with the help of sunlight. The algae are also largely responsible for the rich colors of the coral.
This coexistence of the coral and algae, where both parties benefit from each other, will also symbiosis called.
Great Barrier Reef Australia – Map and fact sheet
Here you can find out everything you need to know about the Great Barrier Reef at a glance:
- The Great Barrier Reef is located on the east coast of Australia next to the Australian state of Queensland, i.e. in the South Pacific.
- The reef consists of about 2900 individual coral reefs, several sandbanks and about 900 islands. The Whitsunday Islands are one of the most famous islands.
- Largest coral reef in the world.
- Also recognizable from space.
- Area: approx. 347,000 km2
- Length: about 2300 km
- was divided into several sections from north to south: Far Northern Section, Northern Section, Cairns Section, Central Section and the Southern Section.
- UNESCO World Heritage Site since 1981
Most of the time, natural sites that are very special and therefore valuable are declared World Natural Heritage Sites. As natural world heritage sites, the member states of the United Nations (UN) place them under special protection and great efforts are made to preserve them.
In Figure 1 you can see the Great Barrier Reef drawn in green. The reef is located in northeastern Australia.
Figure 1: Great Barrier Reef Map
Great Barrier Reef – Formation
When do you think coral reefs formed? Scientists estimate that the formation of the northern Great Barrier Reef is already happening 15 million years started. The age of the middle and southern Great Barrier Reef is estimated at ca. two million years estimated. Basically, however, you can remember that the visible part of the Great Barrier Reef is only around 10,000 years has arisen.
The Australian coral reef got its name from the British explorer Matthew Flinders. At the beginning of the 19th century, he recorded the waters off the Australian state of Queensland on a map. At the same time, Flinders tried to find a shipping route through the coral reef, but failed. For him, the reef was an insurmountable barrier, so to speak, which is why he called it the Great Barrier Reef.
Of the origin of the Great Barrier Reef lies in the continental plate shift. Around 15 million years ago, the island of Australia migrated to another region where the climate was much higher due to the shifting of the continental plates more tropical and warmer was. Due to the new location, the water temperature around Australia rose, for example, so that the reef-forming corals could multiply under optimal conditions. They began to spread on the ground near the coast.
The earth is made up of seven major tectonic plates (Pacific Plate, Antarctic Plate, North American Plate, South American Plate, African Plate, Eurasian Plate, Australian Plate) that are moving steadily but very slowly. This constant movement of the plates z. B. Mountains like the Alps. For example, when two continental plates move against each other, a mountain usually forms at the point where they meet.
As you have already learned, the Great Barrier Reef actually consists of many different individual reefs that have their own history of formation. For example, some areas of the Great Barrier Reef belonged to B. earlier to Mainland and are due to rising water levels sunken. Some of the islands that lie between the coral reef and what is now the mainland are actually the tops of sunken mountains. On the slopes of these mountains, corals then gradually settled and multiplied there.
If you would like to learn more about the continent of Australia, then please read the summary «Cultural Studies Australia and New Zealand».
However, the Great Barrier Reef is not a coral reef that will stay in shape forever: the Great Barrier Reef will continue to change in size and appearance for centuries to come change. So the development process of the coral reef will never really be finished. Many corals will die off, but new ones will appear as long as efforts are made to preserve the reef.
The first Europeans to come very close to the Great Barrier Reef were British navigator James Cook and his crew. In 1770 they were sailing along the east coast of Australia and ran aground near Cape Tribulation on June 11, 1770 and had to stay there for a month for repairs. There they saw the Great Barrier Reef for the first time.
Great Barrier Reef – Animals
The Great Barrier Reef is unique because of its size and biodiversity the most biodiverse area in the world. It is also the largest structure in the world created entirely naturally by only living things. The coral reef is the habitat of numerous creatures, which you can see in Figure 2. Some of the different sea creatures include:
- 1500 species of fish
- about 400 different types of coral
- 20 species of reptiles
- 200 species of birds
- 5000 species of molluscs, such as B. sea snails or mussels
- Six out of seven sea turtle species in the world
- Rays, sharks, tuna, dolphins, humpback whales and many more animals
Figure 2: Corals and fish in the Great Barrier ReefSource: skr.de
Coral reefs are also an important part of animal reproduction: the islands of the Great Barrier Reef are important breeding grounds for a wide variety of birds. Humpback whales, which otherwise live near Antarctica, also come to the Great Barrier Reef to give birth because of the high temperatures there. Sea turtles or fish can lay their eggs between the corals, so that the branches of the coral cover the eggs as much as possible and protect them from predators.
Great Barrier Reef Tourism
The Great Barrier Reef is a special attraction for tourists. Every year more than 1.6 million people come to discover the breathtaking water world of the Great Barrier Reef. Australia’s annual income from tourism on the Great Barrier Reef is around four billion Australian dollars. Overall, the Great Barrier Reef is one of them most popular tourist attractions of the world.
Australia is not only a popular holiday destination, but also for work & travel. The «Work & Travel» article provides you with all the information you need on the subject!
For tourists, the coral reef is suitable for sailing, swimming and relaxing. The Great Barrier Reef is also an attractive destination for divers and snorkelers, as there are many animals and colorful corals to admire in the underwater world.
In addition, there are around 820 providers of trips to the Great Barrier Reef around the Great Barrier Reef. Tourists can decide whether they prefer to get there by boat or in a small helicopter.
Would you like to learn more about tourism in Australia? Then take a look at the article on «Tourism in Australia».
Threats to the Great Barrier Reef
Owing to water pollutionthe global warmingto the climate change and oil slicks in the sea by ships, the Great Barrier Reef has already had to cope with some damage. In addition, the ongoing tourism is another stress factor for the corals and animals.
consequences of climate change
If the temperature of the water rises just a little due to global warming and is therefore more than the 20 to 30 degrees Celsius actually required, the process of coral bleaching begins. During coral bleaching, the corals begin to shed the algae living on them, causing them to lose their color. If the corals remain pale and without algae for several weeks, they can no longer recover and slowly die off, since the algae are actually essential for their life cycle.
coral bleaching have occurred several times in the last ten years, but the reefs have partially recovered. Despite everything, researchers have found that coral numbers have been reduced by more than half since 1996.
Figure 3: Great Barrier Reef from above Source: tagesschau.de
damage by humans
Humans are also a major contributor to coral death. Although tourism is financially very good for the Australian economy, on the other hand, the corals are also stressed by many tourists, as the following example should show you.
Many divers and tourists disobey the instruction not to touch the corals. Corals are very sensitive creatures, which is why touching them should actually be avoided. Some tourists break off a coral to have a small souvenir. Because many people do it, the number of corals is quickly reduced.
In addition, environmental pollution is another reason for the extinction of corals: the waste water from hotels or companies is often discharged into the sea, which leads to acidification of the water. The algae and corals also die off as a result of the acidification. The numerous bathing tourists should use as little sunscreen as possible, since the coral also does not tolerate the substances in the cream well. Agriculture near the coast also contributes to acidification of the seas through the use of pesticides and fertilizers.
As global warming progresses, scientists suspect that the current generation in 2022 could be the last generation to fully experience the Great Barrier Reef. Researchers assume that according to the current level of global warming, the Great Barrier Reef and its corals will be extinct by the year 2100. You can see what faded or dead coral looks like in Figure 4.
Figure 4: Dead/faded…