Coral reefs are fragile ecosystems, and even a slight change in their marine habitat could drastically impact the corals, and other marine life too. One of the main threats to the reefs is climate change. As global warming occurs through out the world, the ocean waters will also start to get warmer, which is what is known as ocean warming. Even 2 degrees Celsius change in the water can have a massive impact on the corals. This is because the corals can feel this slight change and will start to feel stressed, and their first natural reaction is to expel their symbiotic zooxanthellae since this algae is not a part of them. The corals at this stage are now hopeless without their symbiotic partner, and will not be able to survive without oxygen and food. The now starving corals will turn into a ghostly white and perish.
Since humans need healthy coral reefs to be able to get fish, it makes sense that they would want to protect the reefs. But instead, overfishing and destructive fishing has become another threat to the marine ecosystem. Not only do corals protect the fish, the fish also protect the reefs by keeping them clean and giving them nutrients and food to thrive. If there weren’t enough fish in the reefs to do so, the corals would not be able to survive. Destructive fishing also does massive damage to the reefs because in some reefs, people have large nets to catch fish in. This technique is not only pointless, but also harmful because the nets will only get caught in the corals, smashing them and the fish too. Some fishermen pour a chemical into the water to stun the fish so they can catch them, but the chemical is very harmful to the corals, and will eventually kill them. Natural disasters occur only once in a while, and so...
... middle of paper ...
...conditions eventually led to the bleaching of a tremendous amount of corals, and caused a total of 70% to 80% of all shallow-water corals deaths.
Although, weather isn’t the only threat nature brings to the coral reefs. Invasive species and predators of the corals are also threats to the corals. The crown-of-thorns Starfish (Acanthaster planci) is one of the corals predators. They slowly crawl over corals and literally “eat the life out of them” as they consume all of the corals living tissues, then move on to the next coral. Other predators of corals include fish, barnacle, marine worms, snails and crabs. During 1978, a massive amount of Crown-of-Thorns Starfishes invaded the reefs in the Fagatele Bay National Marine Sanctuary in American Samoa. This was an extreme case of predation and had devastating results as 90% of all corals at the sanctuary were destroyed.
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
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
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.
Corals provide shelter for nearly one quarter of all known marine species. The reefs are home to over 4000 species of fish, 700 species of coral, and thousands of other forms of plant and animal life. Living coral reefs are the foundation of marine life, and this also means that they are essential for human life, but all over the world they are dead or dying because people are destroying them at a very fast rate. Already 10% have been lost, and there are predictions that 705 of all corals on the planet will be destroyed in 20 to 40 years unless people stop doing what they are doing now – i.e., pollution, sewage, erosion, cyanide fishing, bad tourism.
...of sodium cyanide is released into a target area in order to stun fish. This method of fishing is used mainly for the capture of aquarium fish, to be sold to wealthier countries, but it is also used for catching food fish. Hundreds of thousands of pounds of cyanide are released into the Pilipino reefs each year. As you can imagine, pumping large quantities of toxins into a fragile ecosystem has negative effects. Even low concentrations of cyanide inhibits photosynthesis in zooxanthellae, a genus of algae with which coral grows symbiotically. The death of the algae removes the major food source of the coral, causing bleaching and death. The cyanide also harms the coral directly, blocking the oxygen-transporting proteins, and preventing oxygen from reaching the cells, causing death.
All over the world coral reefs play an important part in our environment. Not only are the reefs colorful and beautiful to look at but the coral reefs house several different types of fish and other sea creatures. Coral reefs have started to decline over the years due to “climate change, El Nino events, overfishing, pollution and other pressures” (Newnham 1). A healthy coral reef can also collapse due to a natural disaster (Newnham 2). There can be several different reasons why a coral reef has started to decline or has been destroyed.
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.
Humans have a very large effect on the ecosystems of coral reefs. Sensitivity of coral reefs causes them to be more susceptible to harmful anthropogenic practices. Some of these are sedimentation, global warming, recreational activities, poison fishing, blast fishing practices, water pollution, and coral mining. All of these very different practices can effectively end up with the same results; the mortality of coral reefs around the world. Coral reefs are an important ecosystem of the world, and support many different industries and millions of people.
Coral bleaching is the loss of a corals’ zooxanthellae that lives in the tissues of the coral and because of this loss the corals turn completely white. Coral bleaching is mostly caused by the warm temperatures of the water which means that climate change can have an effect on the coral reefs. Corals live in very nutrient poor waters and have certain zones of tolerance to water temperature, salinity, UV radiation, opacity, and nutrient quantities (Jason Buchheim). Because most coral reefs are found in clear, shallow tropical waters, light is able to pass through and heat up the water and coral beneath it. Most reef-building corals normally contain around 1-5 x 106 zooxanthellae cm-2 of live surface tissue and 2-10 pg of chlorophyll a per zooxanthella. When corals bleach they commonly lose 60-90% of their zooxanthellae and each zooxanthella may lose 50-80% of its photosynthetic pigments (Jason Buchheim). Because of climate change, the water temperatures change in various locations and regions of the world that may not be used to that certain type of climate. Areas with coral reefs are affected by ...
Imagine a lush underwater place. Beautiful structures colorful animals and places that would never have been thought of before. In reality that's not what it really looks like, really the ocean is a desolate place that is barren like a desert. Many marine species have been lost by as much as 49%.(seeker) A big part of that reason is because of coral bleaching which causes as stated above a decline in species that depend on the coral as there home. Coral bleaching is a serious problem that could cause problems for everyone if we don’t fix it.
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.
This website gives a large historical overlook and possible conclusion to the issue of coral reef bleaching. Since the 1980’s episodes of coral reef bleaching and death have occurred almost every year in one or more of the world's tropical or subtropical seas. Bleaching happens in episodes, with the most severe typically accompanying coupled ocean–atmosphere phenomena. Bleaching episodes have resulted in loss of coral
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).
Located in tropical ocean waters, coral reefs provide priceless resources to both human and marine life. The leading natural cause of destruction among the coral reefs is global warming. Other natural causes are earthquakes, hurricanes, cyclones, and typhoons. The destruction to the coral reefs from these natural disasters is minimal compared to the dangers caused by man. Man-made destruction has a much wider impact on the health of the coral reefs. This destruction includes over-fishing, damage from anchors, aquarium industry, overgrowth of seaweed, and being smothered by sediments.
In conclusion, I would like to say that before writing this paper, I had no idea how important coral reefs were to the earth. I have learned a lot and I think that if more people were informed about the positive capabilities of them, humans wouldn't be so careless about them.