According to the preliminary scientific forecast Great Barrier Reef may totally disappear by 2030. Human activity causes a great damage to marine ecosystem of Western Australia’s coast. The importance of Great Barrier Reef is very high, because it’s the largest coral reef ecosystem on our planet, home to an amazing diversity of plants, animals and habitats.
The subject of our research work is the ecosystem of Great Barrier Reef.
The aims of our research work are:
to review scientific material on this issue;
to estimate environmental degradation along Western Australia’s Coral Coast;
to find out the reasons of catastrophic damage of corals;
to identify the measures of environmental protection of Great Barrier Reef.
We used empirical method of research (analysis of materials received from scientific journals and theoretical methods of research (interpretation, comparison and compilation of information).
The relevance of the research work is obvious, because the coral bleaching is caused by record-breaking temperatures, driven by global warming. Consequently, search for efficient ways of solving the problem of coral bleaching is an urgent one.
1 The Great Barrier Reef of Australia is the largest coral reef ecosystem on Earth
The Great Barrier Reef is one of Australia’s most remarkable natural gifts. It is blessed with the breathtaking beauty of the world’s largest coral reef. The Great Barrier Reef consists of 3,000 reefs and 900 offshore Islands, and is considered the largest natural feature created by living beings.Corals are made up of thousands of tiny micro - organisms called polyps. The length of the polyps is only a few millimeters.They absorb calcium dissolved in seawater, forming a calcareous skeleton of the colony. Its area considerably exceeds the area of England, the Park's reefs with a total area of almost 344,5 thousand sq km stretch along the Australian northeast coast for 2.5 thousand km of reef-building corals are widely distributed in the tropical zone of the World ocean and are its characteristic features. This is why the tropical zone of the World's oceans is often considered a special natural zone of coral reefs.
It should be pointed out, that the most of the Coral Reef is located under water and, according to many researches, 90% has not been studied yet. Coral reefs are located in coastal zones near sea level or at a shallow depth of no more than 50 meters.Some reefs can exist at a depth of about 120 meters, but this happens quite rarely.The main condition for the successful development of coral reefs is the optimal combination of temperature, depth and salinity of water. Corals like warm water and are able to grow at sea water temperatures from 18 to 30 C. Mostly coral reefs are located in tropical latitudes and in places where shallow and warm currents pass.
Finally, the Great Barrier Reef is an ecosystem that supports thousands of representatives of underwater flora and fauna, and has been protected by UNESCO since 1981. It is considered one of seven wonders of world created by nature.
2 Environmental degradation along Western Australia’s Coral Coast
The Great Barrier Reef is a huge natural breakwater that protects the coast from the destructive effects of waves and surf, and flood-proof. In the coastal sands of coral Islands, there are placers of heavy metals. On some Islands, deposits of phosphoresces, constructionmaterials, mother-of-pearl and pearls are being worked. The deposits of the limestone of the Great Barrier Reef contain oil and gas.
Not forget that coral reefs are best developed where the mean annual surface water temperatures approximately 23-25 °C . No significant reefs occur where such temperatures fall below about 18 °C. Therefore, global warming of the Oceans can damage the Great Barrier Reef significantly. Besides the increase of sea temperature in the area of the Great Barrier Reef there has been another phenomenon observed by tourists recently [1,с.57]. This phenomenon is known as bleaching and it has caused the devastation among coral reefs since the early 1980s. Many experts believe that the most likely factor of coral bleaching is unusually high seawater temperature approximately 30 °C. Some researchers state another factors linked to coral bleaching. It may be a rising acidity, ultraviolet radiation, water pollution and even disease.
3 Severe bleaching of Great Barrier Reef causes catastrophic damage
According to the latest data, some part of the Great Barrier Reef is under threat of extinction. In 2016 the most unprecedented bleaching was observed. Last time this process affected 90% of the entire Barrier Reef. According to various estimates, from 29% to 50% of the total amount of corals was completely damaged (see Appendix). In 2017 the process of bleaching continued and took over new areas. In the most damaged Northern part of the Reef, stretching for 700 km scientists of James Cook University recorded the death of 67% of shallow-water corals during 8-9 months.
The cause of coral bleaching and death was an increase in water temperature by almost 1 degree compared to 2016. Scientists believe that these events are directly related to global warming and human impact.Coral bleaching occurs as a result of the ousting of symbiotic algae which give the corals a bright color. Without algae corals can be easily destroyed by external influence. The increase in the temperature of the water is the most common but not the only cause of coral bleaching. To sum up, the main causes of coral bleaching are ultraviolet radiation, water pollution, rising sea levels and changes in water acidity and the ousting of symbiotic algae.
4 The required steps to protect the ecosystem of Great Barrier Reef
The extinction of this unique coral ecosystem will lead to the severe reduction of the ocean biodiversity. Most of the animals living near corals can’t live anywhere else, they have a very special food “chain” and as a result these chains will be totally restructured.
Most of the atmospheric oxygen on Earth isn’t produced only by forests, but also by oceanic phytoplankton that feeds on green algae and sea habitants which become valuable fertilizers [2, с.12]. Thus, the amount of oxygen depends directly on the amount of phytoplankton.
The extinction of corals will change the chemical composition of deep-ocean seawater. Besides the corals remove the calcium compounds from deep-ocean seawater and thereby help purify the water from acid. It’s very clear from these observations that the process of acidification of oceans may cause the global extinction of living organisms.
Moreover, the extinction of corals will lead to the global change of the structure of ocean currents and may cause the change air masses’ movement that depends on these currents. There is prevailing agreement that the Great Barrier Reef is a kind of protective level that the first get destructive waves. Otherwise, Australian coast may be at risk of washing-out process.
Not forget that The Great Barrier Reef attracts million of tourists and divers every year. And tourism industry provides for national economy and airlines.
Many research works are devoted to the issue of saving and protecting the Great Barrier Reef. The author of the book «The Great Barrier Reef» James Woodford represents 10 steps to save the Great Barrier Reef. Some experts believe that these steps may have positive effects. Here are some critical actions that must be taken:
restore and increase marine science research budgets as a matter of high priority;
boost research into possible actions to assist environments threatened by climate change;
introduce strong controls to agriculture for all catchments that flow into the Great Barrier Reef;
prevent dumping of spoils on or near the Great Barrier Reef.
To sum up, the Australian government has been making attempts to save The Great Barrier Reef. Nowadays scientists, ecologists, political and public figures are searching for ways of ecosystem restoration. Although, the problem of extinction of Great Barrier Reef has already become a global problem, it hasn’t been solved yet.
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Богданов Б. П. Спасти от гибели Большой Барьерный риф Австралии – спасти человечество //Norwegian Journal of development of the International Science №28-2019.
Encyclopedia Brinannica /Coral reef/Geology https://www.britannica.com/science/coral-reef
Picture 1. The Great Barrier Reef