Coral Reef Degradation

Coral reefs have been in danger of going extinct for quite some time, but right now is a pivotal time in stopping the damages that are occurring every single day. It is predicted that all coral reefs may die by 2050 if we don't make changes to protect them (McCarthy, 2018). As the world has become more urbanized and technologically advanced, many risk factors for coral reefs have arisen and it has already made a huge impact on coral reefs across the world.

The three main risk factors for coral reefs that I will focus on in this project are global warming, global pollution levels, and tourism/overfishing. In the first section we will focus on answering the question: how does global warming affect coral reefs around the world? In section 2, we will look at: how do global pollution levels play a part in coral reef degradation? Finally, we will answer the last research question: how does tourism and overfishing cause damage to coral reefs?

I chose to focus on this topic because it combines themes of geography, environment and sustainability, and can also be applied to many other themes we have learned about in this course. It applies to the theme of geography because each coral reef location has a story behind it of why these damages are occurring and sometimes the cause of the damage can be explained by its geographical factors. It applies to the theme of environment and sustainability for a similar reason since we can explain most causes of coral reef degradation by going into detail about its surrounding environment and the sustainability of its environment. Also, this topic is especially interesting to me because I really enjoy snorkeling and it's sad when you visit a coral reef over your lifetime and can slowly see parts of it dying each time you come back.

The first cause of coral degradation that we will look at is the main cause of damage to coral reefs: global warming. Global warming is the long term increase that has been observed in the global annual temperature and it has caused a lot of negative effects on our environment (Turrentine, 2021). One effect that impacts our coral reefs is coral bleaching.

The article: “Everything You Need to Know about Coral Bleaching—And How We Can Stop It” gives a lot of good information about what coral bleaching is, how it happens and how it affects coral reefs overall. 

Citation: Hancock, L. (2021). Everything You Need to Know about Coral Bleaching-And How We Can Stop It. WWF.  https://www.worldwildlife.org/pages/everything-you-need-to-know-about-coral-bleaching-and-how-we-can-stop-it . 

This article explains that coral bleaching is when coral loses it’s bright vibrant colors and turns completely white due to environment changes that affect the algae living inside of the coral. The bright color of live coral comes from microscopic algae called zooxanthellae that live within the coral and help it survive. However, when the environment changes such as with global warming and sea temperatures rising, the coral “stresses out and expels the algae”. Then, as the algae is no longer living inside the coral, the coral dies and fades into a white color. The algae could return to the coral and bring it back to life, but when the temperature stays too high, the algae never goes back and both the coral and algae die. This temperature change can be as little as 2 degrees fahrenheit which may seem like a big change, but “average global sea surface temperature has increased about 1.5 degrees F since 1901” (Bradford 2021). 

This relates to our topic of coral reef degradation because once coral bleaching occurs due to global warming, it is detrimental to coral reefs since once the coral dies in some parts of the reef, it rarely ever comes back to life. Then, usually the rest of the reef dies because the necessary algae is no longer there to keep it alive. In the article it explains, “According to the National Oceanic and Atmospheric Association, between 2014 and 2017 around 75% of the world’s tropical coral reefs experienced heat-stress severe enough to trigger bleaching. For 30% of the world’s reefs, that heat-stress was enough to kill coral” (Hancock 2021).

Below is a sad before and after picture of the Seychelles Coral Reef which has been heavily affected by coral bleaching due to global warming.

Although many coral reefs have been affected by coral bleaching, I think it is important to look at specific one to really understand the impacts it has on the reef life. In this next article called "Great Barrier Reef has lost half of its corals since 1995" it explains in depth how coral bleaching has impacted The Great Barrier Reef.

Citation: BBC. (2020, October 14). Great Barrier Reef has lost half of its corals since 1995. BBC News. https://www.bbc.com/news/world-australia-54533971. 

This article explains how the largest coral reef in the world, The Great Barrier Reef, has always been protected due to its size since as we talked about previously, the environment of the coral is what keeps it alive so a larger environment creates a healthier reef habitat. However, even the largest reef in the world has seen a great increase in its decline. According to scientists, there were mass bleaching episodes in 2016 and 2017 due to an increase of greenhouse gas emissions that severely damaged the reef and caused the coral sizes and species to drop more than 50%. This caused much of the habitat to die along with it since it was home to many fish and other marine wildlife. The effects of this back to back bleaching was the greatest damage to the reef to this date and the chances of the reef ever recovering are slim to none. In the article it explains that, "Last year, the Australian government's official agency on the reef confirmed that human-driven warming remained the biggest threat to the reef's long-term survival" (BBC, 2020). Scientists state that if we cannot reduce the greenhouse gas emissions that are causing this coral bleaching then 90% of the coral in all of the world will be wiped out.

This is relevant to the topic because it is important to look closely at a specific reef to really analyze and understand how reefs are being impacted by coral bleaching. Especially in the case of the largest reef in the world, The Great Barrier Reef, if this reef is losing its habitats and coral species then you can only imagine how smaller reefs are being completely wiped out across the world due to these same effects. If we continue to increase greenhouse gas emissions, then we may lose coral reefs forever which will severely impact the marine life, the overall health of our oceans and create disarray within the natural predator/prey food cycle.

Along with coral bleaching, global warming has a lot of other impacts on coral reefs such as changes in the fish and overall ecosystem due to temperature changes. In this next section we will look at how global warming affects the ecosystem within a coral reef and how this affects the coral reef overall.

The article “Global warming may disproportionately affect larger adults in a predatory coral reef fish” explains all the ways that global warming impacts ecosystems within coral reefs.

Citation: Oregon State University Libraries. (2016, November 3). Global warming may disproportionately affect larger adults in a predatory coral reef fish. Global Change Biology. https://login.ezproxy.proxy.library.oregonstate.edu/login?qurl=https://onlinelibrary.wiley.com%2fdoi%2ffull%2f10.1111%2fgcb.13552

In this article, it explains how one of the main effects of global warming is our rising sea temperatures and increased levels of CO2 in the ocean which both have a huge impact on the ecosystems living within coral reefs around the world. When temperatures increase in the ocean, then it completely changes the ecosystem because it creates smaller bodies of fish and decreases the size of the ecosystem in that area. This is because the fish can survive longer in cold water, so more fish are dying and the fish are overall smaller in size due to decreased metabolic rates due to the higher temperature. This changes the dynamic of the entire ecosystem because smaller fish have a much lower energy demand which causes the natural flow of the ecosystem (predator/prey circulation) to slow down and get backed up. Once the cycle is thrown off enough, the ecosystem will fail and there will no longer be any life within the reef.

Another point the article brought up was that since there is an increase of CO2 levels in the ocean, that means there is a decrease of oxygen in the water and many fish within an ecosystem rely on a fresh source of oxygen in order to survive. With decreased levels of oxygen, more fish will die and the cycle within the ecosystem will slow/eventually stop and the reef will ultimately die.

This source is important for our research because it explains two big ways that coral reefs are dying and what is causing it to die. This adds to what we already know about coral bleaching and provides another explanation of how organisms and ecosystems are failing in coral reefs due to global warming. Since we are concerned with the overall degradation of coral reefs, it is important to consider all of the damages that coral reefs are facing so we can come up with an educated plan on how to save the remaining reefs from becoming extinct.

The second cause of coral degradation we will explore in this story map is global pollution levels and how they have impacted coral reefs. Global pollution levels have increased drastically over time with an increase in urbanization and new technologies, but the impacts of these increased levels on the environment is often overlooked.

Here in this infographic we explore global pollution levels over time and analyze how this is affecting our coral reefs, and what we need to do about it.

Citations for infographic above:

OECD (2021), Air pollution exposure (indicator). doi: 10.1787/8d9dcc33-en (Accessed on 23 May 2021)

Lamb, J. B. (2018, January 26). Plastic waste associated with disease on coral reefs. ScienceMag.Org. https://science.sciencemag.org/content/359/6374/460

First, we will look at this article called “Towards protecting the Great Barrier Reef from land-based pollution” by authors from Global Change Biology which gives a great explanation of how land-based pollution has impacted coral reefs greatly and also gives some insight and ideas on how to protect coral reefs from the damages of land based pollution. 

Citation:    Global Change Biology (2016) 22, 1985–2002, doi: 10.1111/gcb.13262

This article talks about how land-based pollution such as dumping of excess resources into oceans or the discharge of land based pollutants into waters have heavily impacted coral reefs and caused a lot of damage to its ecosystem and the reef health itself. Pollutants from adjacent land often end up in oceans because it is an easy way to get rid of garbage without having to think about it, however people don’t understand or think about the amount of damage it is doing to our ocean environment. By dumping our waste into the ocean, we are degrading the water quality, eliminating the necessary oxygen within the water and killing sea life by giving them the wrong impression that plastic is food. As we have talked about in the earlier section, a healthy ecosystem needs a source of fresh oxygen in order to survive and by dumping waste into the water, it is being polluted with all sorts of harmful chemicals that are not sustainable for sea life. In this article, it goes into great detail about all the different chemicals that are being dumped into our oceans by activities such as farming and production and how this is affecting not only the animals in the ocean, but also the coral, plants and animals who live around the water. “The overall decline in GBR ecosystem condition is generally considered to be caused by the cumulative impacts of climate change, poor water quality in inshore areas from land-based run-off, large-scale modification of coastal habitats and fishing pressure (Great Barrier Reef Marine Park Authority, 2014).” The entire ecosystem is made up of the animals and its surrounding wildlife, so when all forms of life are being attacked within the ecosystem, it is unlikely for it to survive as a whole. 

This relates to our general topic of coral degradation because as we looked at in the first section, coral relies on its environment and surrounding organisms to keep it alive so when all life forms are dying within it, the coral will die and never be recovered. Since pollution levels have stayed high for a long time, many coral reefs have already been destroyed and soon enough they will become extinct if we do not make changes and control the waste being dumped into our oceans. This article suggests creating catchment mechanisms to stop the pollutants from entering the water and find other ways to dispose of excess resources that will not harm the ocean environment.

In this next article called "Future habitat suitability for coral reef ecosystems under global warming and ocean acidification" by authors from Global Change Biology, it talks about how air pollution is affecting our ocean ecosystems and coral reefs.

Citation: Global Change Biology (2013) 19, 3592–3606, doi: 10.1111/gcb.12335

In this article it explains that the rising levels of CO2 concentrations in the ocean have had a large impact on the world's tropical coral reefs by affecting the ocean temperatures (as we talked about above) and ocean acidification. This article goes over how coral bleaching is caused by increased levels of CO2 in the ocean and how the severity of these bleaching levels will lead to a mass decline in coral reef habitats. Additionally, ocean acidification is "the chemical consequence of the excess dissolution of CO2 derived from fossil fuel combustion in surface seawater" (Global Change Biology, 2013). Ocean acidification lowers the pH of the water which results in weaker reef structures that are more prone to physical damage. Also, it raises the sea temperatures and we know from above, a healthy ecosystem cannot be sustained with these higher temperatures. The article explains that if ocean acidification continues to occur due to increased air pollution levels, then the sea temperature will continue to rise to a level that is not sustainable by any ocean ecosystem and the coral will continue to degrade and become weaker and weaker until it eventually just dies.

This is important information for our research because we have looked at global warming overall and we have looked at land pollution, but when you break down the effects that air pollution has on coral reefs, you gain a better understanding of how human activities are causing damage to coral reefs. Also, ocean acidification is a new topic that was discussed in this article and it explains yet another threat that coral reefs face.

Finally, in this next section we will explore our last research question of how tourism and overfishing has caused great damage to coral reefs around the world. Tourism and overfishing cause physical damages to coral reefs and ecosystems by interfering with the the ecosystems predator/prey cycle and physically breaking down reef structures with anchorage, fishing nets, human activities such as snorkeling and other tourist activities where people come to admire the reef without knowing how to properly take care of it.

To learn more about this cause of coral reef degradation, we will look at the article embedded below called "Physical Damage" by authors from CoralDigest.org.

Citation: PhysicalDamage - coraldigest. (2014). CoralDigest.Org. https://www.coraldigest.org/index.php/PhysicalDamage

This article goes over all the physical damages that coral reefs around the world encounter and what they are caused by. It starts out by explaining that physical damage done to coral reefs is significant and it heavily impacts the health and sustainability of the reefs. It states "30% of percent of coral reefs are in critical condition and may die within the next decade. By the year 2050 it is estimated that over 60% of reefs will have died off completely" (CoralDigest, 2014). It also explains that some damages are natural such as storms and natural disasters, but most are caused by human activity. Coastal development causes a lot of damage to coral reefs because as the coastlines become more developed, there is more land based pollutants entering the water, more docks and piers are built that sometimes are built right into a reef and an increase in fishing because as the more people live there, the higher the demand is for seafood. Also, tourism and entertainment has caused a lot of physical damage to coral reefs because the boating, snorkeling and diving can interfere with the sea's ecosystem and disrupt the natural food cycle, and much of the physical damage comes from tourists who come and are not educated on how to safely observe coral reefs, so they end up causing great damage to it. Also, when anchoring next to a coral reef, many boats will place their anchor on top of reef structures and completely destroy it. Lastly, it talks about how destructive fishing practices have a big impact on coral reefs because fishing is such a big business that has a very high demand so when the fishing practices are not reef safe, it will destroy the reef structures and interfere with the ecosystem.

This information is relevant to my main topic of coral reef degradation because it provides more ways that coral reefs are being destroyed around the world and it gives insight into how human activities are causing great damages to coral reefs all around the world. This information needs to be talked about more because tourism, overfishing and destructive fishing practices and coastal development are some of the easiest ways we can stop coral reef destruction since they are all causing physical damage rather than natural damages.

Again, to really understand the physical damages that coral reefs face I think it is important to look at specific cases where coral reef have been damaged by outside physical impacts to fully grasp the importance of preventing it.

To do so, we will analyze the article "Marine pollution, coastal development: Coral reefs need to be saved" which goes in depth on how specific coral reefs have been impacted by physical damages and how we can stop these damages from occurring.

Citation: Sundararaju, V. (2021, April 5). Marine pollution, coastal development: Coral reefs need to be saved. Down To Earth. https://www.downtoearth.org.in/blog/wildlife-biodiversity/marine-pollution-coastal-development-coral-reefs-need-to-be-saved-76298.

This article starts off by explaining that coral reefs in the Indo-Malayan region have existed for over 200 million years and that it took the coral about 50 years to reach its present level of diversity. And yet, if the right measures to protect these coral reefs aren't taken, they could disappear within the next 40 years. The current rate of degradation is extremely high right now and if we do not protect these reefs, they will become extinct. These coral reefs acts as a barrier against waves, help prevent coastal erosion and are a breeding ground for many marine species. They also provide revenue and job opportunities for recreation and tourism. "It has been assessed that one square kilometre of coral reef produces 20-35 mega tonnes of fishes sufficient to feed about 600 people annually" (Sundararaju, 2021). However, with enjoying the benefits from coral reefs comes a lot of responsibility that is not being taken seriously. For example, due to changes in the coral, an entire island has disappeared in the Thoothukudi region of Tamil Nadu. Coral reefs have been deteriorating faster than ever due to coastal development, destructive fishing techniques and domestic and industrial sewage. In this article it provides ways to help stop the destruction of coral reefs and it is important that the world is educated on these measures so that we can all come together to save our coral reefs. It states that "Fishing by using dynamite, cyanide and explosives in the areas where coral reefs are found should be banned", pollution caused by domestic and industrial sewage needs to be monitored and restricted, the destruction of mangrove forests near the reefs should be banned and the collection of marine animals living in these reefs should be prohibited (Sundararaju, 2021).

This article was helpful for this topic because many articles explain the damages, but this one provided ways to fix these damages that can be put into action now. Lawmakers around the world need to be educated on the destruction of coral reefs since many of the ways to prevent it can be easily put in place. Even the general public should be education on this issue because many of the physical damages are from the public and can also be easily remedied. If we do not start putting these actions into place we may lose coral reefs for good and it is important to notice the small details that are changing rather than just the big picture and this article helped to put things into perspective.

By analyzing these 5 main articles, we have learned about all the ways that coral reef degradation occurs. Our first research question "how does global warming affect coral reefs around the world?" can be summarized as follows: Global warming causes great damages to coral reefs due to increased sea temperatures that cause coral bleaching and major changes to the ecosystem. Coral cannot withstand these increased temperatures because it kills the organisms that keep coral alive and it kills the fish and entire ecosystem surrounding the reef so that no life can be sustained within it.

The second research question of "how do global pollution levels play a part in coral reef degradation?" is explained within my third and fourth articles because it gives information on pollution levels around the world, and talks about how both land pollution and air pollution causes damages to coral reefs in their own ways. Land pollution causes more physical damage and degrades the quality of water to a point where an ecosystem can no longer be sustained within it and the air pollution causes increases in sea temperatures and ocean acidification which harms both the coral and the ecosystem within it.

Finally, the third research question of "how does tourism and overfishing cause damage to coral reefs?" is answered by the last article which explains that human activities such as overfishing, tourism, coastal development and seafood demand causes great physical damages to the coral reef structures and the ecosystem. Also, there will always be natural disasters that cause damage to reef structures, but for the most part, it is human activity that causes the physical damage.

All of these causes of coral reef degradation that we have learned can be tied into themes and concepts we have covered in class such as geography, environment and sustainability. Geography is very important to tie into this information because all of the damages are based on where certain human activities occur and the proximity to coral reefs. It also applies to environment because all of these damages occur by damaging the environment of the coral reef and it not only affects coral reefs, but also the environment in general. Finally, it is all based on sustainability because in order to save our coral reefs, we must make changes and commit to sustainable practices because that is the only way that we can stop these damages from occurring and try to save the remaining coral reefs.

This topic is related to the geography of the western world in general because if we do not make changes to save our coral reefs, then they will be gone forever and our geography will change dramatically. The causes and impacts of global warming are important to analyze when learning about the geography of the entire western world because if it gets too late and no changes are made, then there will be many geographical changes that will impact the rest of the world. We rely on our planet to provide life, but we must take care of our planet in all geographical aspects because if we do not, then our world will no longer be the beautiful place we know it as.