Impact of climatic change on the Great Barrier Reef
Climatic changes refer to lasting and significant changes in the weather patterns characterized by statistical distribution over a period spanning decades or hundred thousands of years. These changes may encompass extreme weather conditions and may happen due to variations in solar radiation reaching earth, biotic processes, volcanic eruptions, melting of the polar caps and plate tectonics. Certain activities undertaken by humans have also been recognized as contributing to negative climatic changes such as global warming. This climate change has threatened earth's ecosystems. The recent harsh change in the climate such as an increase in temperature takes a great toll on the world and results death of corals in the Great Barrier Reef and many other menaces which bear huge negativity and danger to the future of ecosystem. This paper will examine how the past and recent climatic changes have affected or will affect the Great Barrier Reef? It will also examine the potential courses of actions and adaptation to reduce the impact on the Great Barrier Reef by reviewing the case study of Queensland, Australia.
Synopsis on the Great Barrier Reef
Corals are marine living organisms that live in colonies and also have an external skeleton. They belong to the species of organisms known as Anthozoa. They form colonies as a ridge and exist in oceans. Corals use minerals and organic matters as food to survive present in their colonies and hence they are very beneficial to the environment.
The GBR is, in fact, a group of coral reef, and it is the largest and healthiest coral reef system in the world. The reef takes up spaces and comprises a network of up to 3000 different coral reef. According to Johnson & Marshall,( 2007), the reef used about 350,000 square kilometers (135,000 sq mi) which covers islands, inter-reef and lagoons. There are almost 900 islands, which are located in the Coral Sea at the coast of Queensland, Australia. Moreover, they reported that the Great Barrier Reef is a part of important ecosystem, and this accounted about AUD$6.9 billion economic activity and high social values which take place in the region (Bohensky et al., 2011).
Owing to its size, the Great Barrier Reef can be observed from the outer space as shown in Figure 1. Figure 1 is a snapshot of the Great Bear Reef present in Queensland, Australia. As a matter of fact, Great Bear reef are the living organisms that composed the world's largest single structure. Millions of tiny coral polyps can makeup the reef structure. The reef support wide diversity of life and it is immensely important in the world's ecosystem. However, climate changes have immense negative impact on the health of this colony of marine organisms (Great barrier reef, 2014).
Figure 1 A snapshot taken of divers on the Great Barrier Reef
Source adopted: (“Great barrier reef”)
Increase in temperature is one of the consequences or outcome of climate change. The temperature increase over the period of several days affects the Great Barrier Reef greatly. It results to coral bleaching that, therefore, leads to the death of corals in the reef. The global increase in temperature resulted into the warming up of the ocean temperature. Since coral reef is very sensitive to changes in temperature, and warmer temperature results to intensive stresses on the reef. Moreover, the corals in the Great Barrier Reef depend on zooxanthellae for some of their food; however, with sustained high temperature for many weeks, the zooxanthellae will leave their tissue that causes the corals to turn white. This is because the color of the corals is also dependent on the zooxanthellae. When this occurs, the coral could be said bleached and in this condition, they are not be able to withstand due to weakness and fight against diseases and consequently they may easily die (Brodie & Waterhouse, 2012).
According to Bohensky et al. (2009), coral bleaching was observed in 1998, and they pointed out that a little bleaching was common in the Pacific Islands during the summer, but there were cases in which the bleaching was worse in this island region. The bleaching events which took place in the National Park of American Samoa in 1994, 2002 and 2003 were simply beyond the normal range. Bleaching was predominantly a result of climatic changes and, therefore, would tend to become common if climatic changes continue or might be increased if the trend in climatic changes ramps up. This would greatly reduce the total health of the Great Barrier Reef (Bohensky,2009; Brodie &Waterhouse, 2012).
Since last 25 years, there have been recurrent and intensive bleaching events on the Great Barrier Reef and also on the global coral reef owing to recent harsh climatic changes. According to Fidelman et al., 2011, it has been observed over the past twenty years that bleaching and other instances were major causes of coral mortality that resulted to the loss of coral reef on the Great Barrier Reef (“How does climate change affect coral reef?”).
Extreme and severe weather events
The Great Barrier Reef experienced continuous, extreme and severe weather events during the period between September 2010 and November 2011. This began in the mid of 2010 with a strong La Nina and culminated to a prolonged and severe rainfall throughout eastern Queensland. The record river flows which increased beyond the average mark throughout the entire Great Barrier Reef, but, it was exceedingly high in the Southern half of the reef. Many rivers and dams overflowed over the spillways for a prolonged period. The Burdekin River, the Fitzroy River, the Burnett River and the Mary River are some of the main rivers that encountered this high rate of flow. The extreme and frequent rainfalls lead to the greater flooding that might occur and leads to the high rate of the resultant runoff. This simply results in to the deposition of more sediment in the oceans leading to risk on the coral health. Global warming result to increase in tropical storms and this has the capability of breaking coral in the Great Barrier Reef (Bohensky et al., 2011).
It should be important for the management and concerned agencies with the Great Barrier Reef having aim at controlling the extreme environmental events. The inability of the climatic management in this area simply results to poor health system of the Great Barrier Reef. However, there have been recent beacon of hopes in the reef plan management actions after 2013. This has been ensured by the powerful and effective management of the no-take zone of the Great Barrier Reef, high level top management of the estuarine and coastal regions of the reef and so forth ("Impacts of global," ).
Acidification of Ocean – The Alteration of Ocean Chemistry through Climatic Changes
Acidification of the ocean is a reduction in the PH value (Low PH) of the ocean owing to the continuous dissolution of carbon dioxide in it. According to Sutton et al., 2011 since the year 1800, the ocean has absorbed up to one-third of the carbon dioxide produced through human activities and half of the carbon dioxide produced by the burning of fossil fuels. The dissolution of carbon dioxide in the ocean results to an increase in its PH and hence it becomes more acidic. The acidity or low PH effect on color and nature of coral reef and could be observed in figure 2 ((Brodie &Waterhouse, 2012).
Figure 2: The color and nature of coral reef before the increase in the acidity of the oceans
Source adopted: ("Impacts of global," )
The danger of ocean acidification has made corals unable to absorb calcium carbonate. Coral reef use carbon calcium carbonate to maintain themselves and keep the skeleton healthy. When the corals become unable to absorb this important nutrient, their reef and skeletons may simply dissolve and hence resulting to coral mortality. Fidelman et al., 2013 pointed out that the PH of the ocean has been lowered by 0.11 units from 8.179 to 8.069 between 1751 and today. The available data showed that the ocean has become 30 percent more acidic than it natural environmental condition before 1751. Ocean acidification was one of the major causes of the death of corals and hence it is critical to reduce it in order to avoid the immense danger. This is equally true, that if the trend is left to continue without being addressed, and carbon dioxide emission is not checkmated, it is likely that ocean acidification will ramp up and consequently a greater number of corals in the Great Barrier Reef will die. Increase in the amount of carbon dioxide in the air generated by human activities and rapid industrialization greatly affecting the health of the coral reef. The ecosystem that may disturb reef over time in virtue of the excessive amount of carbon dioxide in the atmosphere is shown in figure 3 (GBRMPA, 2010).
Figure 3 Atmospheric changes on Reef over time due to excessive carbon di-oxide
Source adopted: GBRMPA, 2010.
The Great Coral Reef or the global coral reef is not the only marine organisms affected by ocean acidification. It also affects other organism as snails, clams, urchins and so forth. It also creates a difficult situation for them to absorb calcium carbonate to ensure their health and skeletons. If carbon dioxide production and emission continue at the current rate, the PH of the ocean will reduce to 7.8 by 2100. Brodie & Waterhouse, (2012) pointed out by conducting experimental studies that such low PH of 7.8 would result to the falling apart of the Great Barrier and the absolute dissolution of coral skeleton might occur (“How does climate change affect coral reef?”).
. Eutrophication and Algae Booms
Eutrophication is the depletion of oxygen in the water body. It occurs when water bodies become rich with dissolved nutrients from sewage or fertilizers. This encourages the decrease in growth of algae, and enhances the crown of thorn's starfish and so forth which deplete the oxygen level in the ocean body. Areas prone to eutrophication are known for their surge in crown of thorns starfish (Brodie & Waterhouse., 2012). It also results in a rapid increase in algae population and the dominance of macroalgae at the bottom of the water body that develop unfavorable environment for Great Bear Reef. These all factor becomes the major contributors to the mortality of the coral covers in the Great Barrier Reef as well as decline in sea grass. Brodie & Waterhouse, (2012) formulated a set of the criterion for description of the characteristics of eutrophic conditions in the Great Barrier Reef. They included part of the inshore Great Barrier Reef — South of Cooktown, small area of the mid-shelf, and the outer shelf of the reef in order to deem eutrophic at some points of the year (Bohensky et al., 2009).
Over the last 50 years, it has been observed that there is the greatest external source of death of the Great Barrier Reef that is due to increase in the crown of thorns starfish population. Crown of thorn's starfish was responsible for 36.7 percent mortality and damage of the coral reef. This was the greatest source of damage to the reef as it caused 5.6 percent damage; developed disease 6.5 percent; storms were responsible for 33.8 percent damage, and some unknown caused 17.4 percent damage (Varum, & Melo, 2010).
Adaptation Strategies to Reduce Damages on the Great Barrier Reef
In developed nations, there has been noticeable measure in the context of increase in climatic change adaptation strategies in order to track the climatic changes. Different level of governance are leveraging various adaptation measures for efficient climatic change adaptation (Westerhoff, Keskitalo, & Juhola, 2011). One of the main viewpoints of the Australian National government's climatic change strategy is adaptation to unavoidable climatic change. The adaptation and the impact of climate change is a greatly upheld at all various levels of governance in Australia. Changes in the climate are multidimensional. This result to a multiple scale effects and causes and, therefore, requires considerate consideration (Great Barrier Reef, Marine Park Authority, n.d.; Measham et al., 2011).
The Great Barrier Reef Marine Park Authority, abbreviated as (GBRMPA) is playing an immense role in ensuring mitigation strategies to minimize climatic impact on the Great Barrier Reef. They have the task with the responsibility of enlightening the public on the consequences of climatic activities on the reef and also engaging people on actively participating in the reduction of these climatic activities (GBRMPA, (2010). The activities of the Great Barrier Reef Marine Park Authority are on the increase nowadays to compensate for the upsurge in climatic change threat on the reef. The efforts of GBRMPA and many non-governmental organizations have resulted to increase public enlightenment and education, as well as the ramping up of the mitigation efforts. Result obtained from a survey showed an increased level of awareness and concern about climatic change in the Australian community. Obviously, there was a huge success in cognitive and affective engagement; however, it appeared that there was a great limitation in behavioral engagement, in the reduction and mitigation of climatic changes (De’ath, Lough & Fabricius, 2009; Sutton. & Tobin, 2011).
Great Barrier Reef Climate Change Action Plan
A well-organized response to climatic change threat on the Great Barrier Reef has been outlined in the GBR Climatic Change Action Plan. This plan focused on strategies and techniques in order to develop a partnership, and direct actions to make the GBR resilient to climatic change. The aim was to ensure that the impact made on the GBR industry including recreational fishing, tourism and commercial fishing which accounts for a significant reduction in amount of national's economy. Over the first three years of the GBR Climatic Change Response Program, knowledge, adaptation measures and partnerships have been established for the Great Barrier Reef, and this is supporting the structure of the action plan. Other relevant scientific action and adaptation initiatives such as research program have been carried out by the National Climate Change Adaptation Framework to make it be harmonized with the action plan. There are four major objectives underpinning the action plan. These include targeted science, reduced climate footprints, adaptation of industries and regional communities and a resilient Great Barrier Reef system ( Brodie & Waterhouse., 2012).
Conclusion
The Great Barrier Reef is facing intense threats posed on it by the various climatic changes including global warming, bleaching and so forth. In facts, there are noticeable signs of vulnerability in the reef. The mass coral bleaching event which has taken place during the period 1998-2002 is a good example to take into consideration. Corals have greatly survived from bleaching, and only few percent died due to bleaching. ("Great barrier reef,")
The immense climatic impacts on the Reef can be greatly reduced with the help of climatic strategic plans and actions. The role played by Climatic Change Response Program and Great Barrier Reef Marine Park Authority is significant to protect Great Bear Reef, and other islands could adopt it. Many Australian and global industries depend on the Great Barrier Reef for their survival. The GBR tourism industry contributes $6 billion to the nation’s economy. This makes it highly imperative to reduce the immense climatic impacts on it and ensure sustainability and resilience in the reef. There is a need to increase the involvements and knowledge of stakeholders to ensure reduced climate footprints all over the world to protect Great Bear Reef.
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