Introduction Climate change impacts coral reefs in a variety of ways. Coral bleaching is an increasing global phenomena that must not be undermined. The importance of coral reefs and the recognition of coral bleaching will be examined, along with the effects and impacts of climate change on coral bleaching.
What are Coral Reefs? reword entire paragraph. Coral reefs are distributed in the shallow, sun lit waters of the tropics and subtropics. They capture the abundant sunlight, converting it into organic energy, which either flows directly through the ecosystem or is used to power important processes such as calcification (In Transition- Ove). Corals are composed of hundreds to hundreds of thousands of individual animals known as polyps
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These changes have occurred quickly, and the ecosystems are faced with a great challenge of adaptation (Ove). Coral bleaching has always occurred from environmental stresses such as temperature variation, salinity variation, pollution, overfishing, and so on (Chap 1). This means climate change is not the only contributing factor to coral bleaching, but it is gaining high recognition as the leading global scale contributing factor (chap 1). The main difference between the bleaching events in the past compared to now are localized events versus globalized events. The enhanced greenhouse effect has created an increase in the frequency and the size of coral bleaching occurrences caused from thermal increase (chap 1). These are known as mass bleaching events, this is where entire coral reefs are affected by coral bleaching and they are no longer only localized (chap 1). Mass bleaching events occur because the coral reef is exposed to higher temperatures over a longer period of time, rather than a short period of time, where corals can then recover (Ove). The length of time that a coral reef is exposed to a particular anomaly can be analyzed with “degree heating weeks, also known as DHW (Ove, 395). If the coral reefs are exposed with a value of less than 4 DHW’s then it is likely the coral will recover quickly, if the DHW value is over 12, the coral reefs will have devastating effects (Ove, 395). The DHW model calculates all hot spots over a 12 week period, whereas measuring just hot spot product is a measure of instantaneous heat (chap 4). The DHW shows where widespread coral bleaching occurs along with severity (Ove). When a value of 2DHW is given, this means that the hotspot is 1˚C warmer for 2 weeks, or 2˚C for 1 week (chap 2). Refer to Figure….to examine the global DHW
Coral reefs around the world are in danger. One of the causes is global warming, which has been increasing the temperature of the ocean water resulting in coral bleaching. This essay will focus on damage occurring to the Great Barrier Reef.
Baker, Andrew c. “Climate change and coral reef bleaching: An ecological assessment of long-Term impacts, recovery trends and future outlook.” Estuarine, Coastal and Shelf Science, Academic Press, 17 Sept. 2008, www.sciencedirect.com/science/article/pii/S0272771408003405.
Coral Reefs are said to be the “tropical rainforest” of the sea. They are home to over 25% of all marine life (http://coralreefalliance.org.stories/storyReader$77). Over the past few decades they have been subjected to destructive anthropogenic practices. Some of the major threats to coral reefs include sedimentation, water pollution, harmful recreational activities, and global warming. All of these things cause stress on corals and can potentially cause mortality. Corals are made up of two parts, a polyp and zooxanthellae. A polyp is a calcerous body that grows from a hard part of the ocean floor. Zooxanthellae is a photosynthetic algae which lives in the polyp and provide energy for themselves and the coral. In many cases, corals undergo “bleaching,” which is a process where corals lose the zooxantheallae or chlorophyll pigment, and turn white (Wilkinson et all). After bleaching corals can survive for several months. It is possible for corals to recover by hosting more zooxantheallae, but it can take between 5 and 50 years for them to recover completely (Wilkinson et all, 1999).
Leading scientists advise climate change will cause increases to the frequency and intensity of extreme weather events. Rising sea levels pose a significant risk to coastal communities, while the world’s oceans could become too acidic to support coral reefs and other calcifying marine organisms. Coral reefs contain only six per cent of the area of the Great Barrier Reef, yet they provide critical habitat and food for numerous species in the ecosystem. However, climate change has already impacted coral reefs in the Great Barrier Reef as corals are very helpless against its potential impacts. Eight mass coral bleaching events has occurred since 1979, triggered by unusually high water temperatures. And because of this, zooxanthellae (photosynthetic algae) leave their tissues and corals will have no more colours hence ‘bleaching’. Without the zooxanthellae, the corals that remain gradually starve to death. Once the coral dies, fish and a multitude of other marine species are soon affected. Rising sea levels and more frequent and intense storm surges will see more erosion of Australia’s coastline, causing community and residential
Given how important coral reefs are, the increasingly disappearance of our coral reef ecosystems will continue to have a detrimental impact on marine biodiversity with in these ecosystems. In addition to the decline of the animal species, job opportunities for many staff members that keep our parks open and healthy for everyone to enjoy, revenue be lost due to the decline in coral reefs. To help ensure this downward spiral in eliminated before it is too late, park officials and scientist conduct continuous research on the effects of ocean acidification and global warming on marine organisms and overall health and longevity of these ecosystems. Ultimately, the goal is to develop ways to intervene before it is to late in hopes that we can reverse the damage already inflicted on our coral reefs and allow these ecosystems to re grow once
Bleaching is when the ocean water become too warm, “corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality.” (Cave and Gillis). When a coral bleaches, it is more of like a self defense mode, which makes it turn white. The coral loses its food source as well. The downfall of this is that without the cooler waters, the corals could die of starvation or disease. Cooler waters from below can help a bleached coral bounce back to its natural state. However, if the water stays too warm for an extended period of time, “the corals don't just bleach, they cook and they die very quickly,.” (Westcott). Throughout time, much of the corals near Cairns and northward have lost the most corals. Hughes states that, “near Cairns, the Great Barrier Reef has lost 47 percent to 83 percent of their coral and as you go northward, the Great Barrier Reef has lost 11percent to 35 percent of its corals.” (Cave and Gillis). In another report, “a study last year found the largest die off of corals ever recorded with about 67 per cent of shallow water coral found dead in a survey of a 700km stretch.” (Johnston). In 2016 and 2017, there were back to back bleaching events. According to CNN reports, “back to back bleaching events in 2016 and 2017 have devastated a 1,500 km (900 miles) stretch of the UNESCO World Heritage Site.” (Westcott). Before the 2016 bleaching event of the Great Barrier Reef, there have only been two bleaching events, 1998 and 2002. According the Hughes, “only 9 percent of the reef has avoided bleaching since 1998.” (Cave and Gillis). That means that over 90 percent of the Great Barrier Reef has been affected by coral bleaching at least once in the past 19 years.
Rates of coral calcification on the Great Barrier Reef and many other reef systems around the world have declined by 15-20% since 1990 due to increasing thermal stress (De’ath 2012). It has already been mentioned that the oceans absorb almost all of the excess heat from climate change. This affects coral reef systems in what is known as coral bleaching. The term bleaching refers to the loss of corals’ colors. A coral’s color is the result of the zooxanthellae present.
The leading natural cause of destruction among the coral reefs is global warming. Global warming causes the bleaching of coral reefs to occur. Bleaching is a response to stress by the coral reef that happens when the water becomes to warm. The coral then put out a brownish zooxanthelle which causes them to lose their color. Without the zooxanthelle, the corals cannot provide nourishment for itself and th...
Climate change has been affecting coral reefs in a negative way. If the climate continues to get warmer more of our coral reef become bleached, the structure of the reefs will become weak, and algae that keeps coral healthy will die. In the essay, “A framework for understanding Climate change impacts on Coral Reefs” by Joshua Clinner (2016), he emphasizes our climate change has become one of the long-term threats to coral reef. The article “Climate change and human impacts are damaging the world’s coral reefs”, which didn’t include an author (2001), states that the sea temperatures throughout the tropics has increased dramatically leaving much of the coral unhealthy. Spencer Hall (2008), discussed in his article “Coral Reefs and Climate Change”, how the increase in climate change puts a lot of stress on coral reefs because they are very sensitive to the change of temperature. Rigel B (2003) states in his essay, “Climate Change and Coral Reefs”, that coral reef has already been negatively impacted by
Coral reefs are well known for their colorful array of marvelous sights including a parade of exotic flora and fauna. They are said to be the foundation for a quarter of marine species, and are a crucial support for human life as well. The coral reef ecosystem is a diverse collection of species (ranging from microscopic to larger-than-life in size) that interact with each other and their physical environment. If any piece of a coral reef is harmed or removed the entire community can be seriously affected, even to the point of collapse. Unfortunately, human impact has resulted in long-term stresses that, unlike the short-term stress of natural disasters, coral reefs are not as capable to recover from. “Approximately half of the world’s coral reef ecosystem resources are considered by scientists to be in 'poor' or 'fair' condition and have declined over time due to several anthropogenic threats” (“Status of Corals” par. 2). Through poorly administered commercial practices, carelessness and ignorance among the common people, and human aggravated natural processes coral reef destruction has become a serious issue afflicting the world’s biodiversity and it’s intricate biosphere mechanics (“Human Impact on the Great Barrier Reef” 1) (“What Are Coral Reefs?” 1).
Research from the University of California San Diego Scripps Institution of Oceanography said that species in the ocean consume a projected 12,000 to 24,000 tons of plastic every year in the Pacific Ocean (Nall, 2014). Pollution of recyclable materials in the oceans is one of the leading causes of why some marine species are nearing extinction. Many authors of articles and books analyzing this topic tend to agree that pollution of our oceans is a problem. The future of this problem is where their ideas tend to differ. The following four literature reviews attempt to demonstrate and support my belief that pollution is getting worse in the ocean and more marine life ecosystems are being affected, but there are things that we as humans can do to change this. Imagine a world where we didn’t have to constantly worry about the vicious cycle of humans affecting animals and then animals in turn affecting us through consumption.
They are one of the most complex ecosystems on the planet, and are home to over 4,000 different types of fish, 700 species of coral and thousands of other plants and animals. A good way to imagine a coral reef is to think of it as a bustling city or community, with the buildings made of coral, and thousands of inhabitants coming and going, carrying out their business. In this sense, a coral reef is like a metropolis under the sea. What is a coral reef? Although coral is often mistaken for a rock or a plant, it is actually composed of tiny, fragile animals called coral polyps.
Coral reefs need to be preserved for many reasons. In this paper, I will discuss a few of them. First of all, they house a collection of diverse organisms, and contribute to fisheries which provide food items such as fish, crustaceans, and mollusks. Furthermore, coral skeletons are being used as bone substitutes in reconstructive bone surgery and may be able to provide important medicine, including anti-cancer drugs and a compound that blocks ultra-violet rays, they even help reduce global warming by taking carbon dioxide out of the air. These reefs provide a habitat for many species.
A coral reef is scientifically defined as limestone ridges that are created out of coral animals. These types of tiny animals are called coral polyps. Overtime, coral polys produce and accumulate into limestone. Inside the cracks and chinks of the limestone reside thousands of species. Since there are so many diverse species that live in the limestone, coral reefs make up some of the most diverse ecosystems on the Earth. These ecosystems can only function in clear, warm salt water, which is usually located in tropical regions. These reefs are usually located in shallow waters so that they are close to the surface. They are situated in this environment so that there is enough sunlight for photosynthesis which is important for the growth and development of the reefs.