Coral Reefs : A Major Role Of Marine Ecosystems

Corals dislike warm water about as much as acidity. When oceans get typically warm, corals can eject the algae that symbiotically live in their skeletons, providing food in exchange for shelter. The ejection process is called bleaching, named by the white skeleton left behind when the coral gets sick and, in some cases, dies.

Elevated sea temperatures caused by climate change and extra-bright sunlight can result in coral bleaching. As the water gets warmer, corals will expel the algae known as zooxanthellae that lives in their tissues causing the coral to turn completely white. When temperatures drop, the corals can recover, but they might be vulnerable to disease and when

Coral reefs are found in shallow tropical waters along the shores of islands and continents. Coral bleaching is a topic that gets left in the dust. Not many people really pay attention or show much interest in it. Widespread bleaching, involving major coral reef regions and resulting in mass coral mortality has raised concerns about linkage of the events to global phenomenons including global warming or climate change and increased UV radiation from ozone depletion. Corals provide a lot not just for us humans but for marine life as well. Marine Biology provides information about how bleaching happens and how it affects the coral. Buchheims’ article is full of logos and a few pathos while the other source is full of ethos. In The Nature Conservancy’s director Stephanie Wear provides us with lots of professional opinions

The ocean is two-thirds of our planet a vast blue landscape home to many biomes which according to Boyce Thorne-Miller “(ecosystem types) corresponding to sets of environmental conditions that vary with depth, latitude, and longitude” (16). However, the ocean and its biomes is under attack from the changing environment. We can see this through coral reef biomes as they make their home near the shores. Through coral reefs we can view the effects that these changes have on the ocean through how the coral reef biome is affected. Humans are a danger to the coral reefs and the wildlife that resides in the biome. The pollution being released into the environment is poisoning the coral and causes death and malformation to the wildlife. The ocean is changing due to global warming which is causing a change in the temperature and rising water levels leading to a change in the stabile areas coral can survive. The increasing acidification of the ocean is causing the coral reefs to die. I will be looking at the effects these issues cause to coral reefs biomes and the ocean to see the similarities in how they affect both.

Coral bleaching is normally characterized by the expulsion of the zooxanthellae algae, loss of algal pigmentation, or both. Coral bleaching events have had serious effects on corals and reefs worldwide. What is crucial to the understanding of zooxanthellae expulsion and bleaching is how the density of zooxanthellae within the coral is changing, if at all, under the prevailing range of environmental conditions (Gates and Edmunds, 1999). Over the last twenty years, there has been a dramatic increase in both the frequency and intensity of coral bleaching events. Sixty major bleaching events have been reported between 1960 and 1979, whereas only nine were reported prior to 1979 (Huppert and Stone, 1998). Given the dependence of the coral on this symbiotic algae, it is important to determine the cause of these bleaching events. According to Helvarg (2000, p.12):

Since early 1998, climate change has been demonstrating its effects in increasing the ocean 's temperature (West & Salm, 2003). Warm water stress corals causing the phenomenon known as coral bleaching, by which expulsion of colourful symbiotic algae the zooxanthellae, vital for

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.

Change in ocean Temperature: increased ocean temperature drastically caused by climate change is the leading cause of coral bleaching.

“Unusually high water temperatures have caused many coral species to lose their zooxanthellae, turn white, and die prematurely, thereby leading to a decline in reef building. Scientists predict bleaching will reduce diversity among corals and the creatures that depend on them” (“Great” World Book). Additionally, changes in the salinity of the water affects the Great Barrier Reef. Salinity is changing because of changes in climate. This is because warmer air from climate change can absorb more water than cooler air, therefore changing evaporation cycles. In places where there is more rainfall than evaporation, rainfall is increasing. In places where evaporation exceeds rainfall, evaporation is increasing. This process is widening the gap between humid and arid regions. This proves to scientists that climate change is affecting salinity (Calif). Furthermore, diseases are produced among coral because of climate change as well as pollution. Increasing temperatures are so effective on the reef that the only disease that can be treated is black-band disease (“Coral”). Ultimately, the coral in the Great Barrier Reef becomes brittle and pale because of these

Although bleaching can be found in animals, it is most notable in corals. These species have a symbiotic relationship with the yellow-brown colored zooxanthellae from the genus Symbiodinium (Douglas ). Figure 3 shows the

Coral bleaching may seem new and a strange topic, but it has been around and wreaking havoc for many of years. Bleaching starts to happen when the water temperatures rise slightly above average temps for more than several days, which then kills the vibrant coral (“Global Warming”). The coral reefs get their vivid color from algae and other small organisms. They are found in the coral’s tissue. Algae helps supply food for the reef through carbohydrates. The algae creates the carbohydrates through photosynthesis (“Coral Reefs”). Coral bleaching

Coral reef ecosystems around the globe are threatened by human interferences and climate change. This has led to many scientists conducting studies on global coral reef ecosystems to gain a better understanding of the cause and effects of coral reef damage. In both Hodgson’s (1999) and Carpenter et al.’s (2008) studies, they are aware of the continuous degradation of global coral reef ecosystems. Hodgson's study involved conducting a survey on global coral reef ecosystems to see whether human actions were affecting the health of supposed pristine Coral reefs. Carpenter et al. incorporated Hodgson’s study into a compiled study about the possible extinction of reef building corals due to climate change and anthropogenic effects. Carpenter’s

Coral reefs are threatened by global warming. They can only live in waters between 18 C and 30 C. Therefore, with the increase in temperature of the surrounding water, there has been an unprecedented increase in the number of coral bleaching events during the past 2 decades (which have had some of the warmest years in history). When ocean temperatures get too high, coral polyps lose the symbiotic algae inside them, causing them to turn white, or "bleach," and eventually die.

In an article by Ray and Perry, they explain several events that have occurred in coral over the past hundred years. Most people do not realize how damaging the climate can be to plants. The warmer the water the higher the temperatures will become and this puts stress on the corals. They are very sensitive to changes in temperature and if the water keeps changing, bleaching will become more common and the health of the coral reef will begin to decline. In 1998, an enormous underwater heat wave hit and killed 16% of the coral on reefs around the world. This was caused by the El Nino and became known as the first major coral bleaching event to occur. The next major coral bleaching event took place in 2010 and it was triggered by the El Nino again. Currently coral is going through another bleaching event that began in 2015 and is still going on now. This event is the largest of its kind and has impacted several reefs through the years. The bleaching is caused by the climate change heat that is absorbed by the water, it is estimated that 93 percent is absorbed into the water. This bleaching causes risk to five hundred million peoples livelihood and could cause a loss in income up to thirty billion dollars. During the last two periods of bleaching, humans didn’t have the knowledge or technology to survey the coral reefs and see what was going

Coral reefs contain symbiotic algae called zooxanthellae which gives the coral its healthy brownish color. The algae "utilizes sunlight and the coral animal's respired CO2 to produce energy rich compounds that feed the coral host" (AIMS, 2003). When stress factors such as "heat, solar radiation, pollution, reduced salinity and changes in oxygenation" occur around the coral, bleaching can begin (Dennis). When bleaching occurs, the algae, which create nutrients for the coral to feed from, is released due to stresses to the reef. Thus the coral starves and its white calcium carbonate skeleton of the coral becomes visible (AIMS, 2003). But one of the main stresses that contributes to the lifeless white appearance of the coral is the warmer temperatures of the sea surface water.