The Great Barrier Reef in Australia is experiencing bleaching. According to France-Presse, bleaching of a reef is “coral...that has been stressed by the heat” (France-Presse). When a coral has been “stressed by heat,” (France-Presse) the coral discards the algae that lives within itself which causes the coral to be more susceptible to disease. It can take up to several decades for a coral to recover from bleaching. Because of that fact that most coral does not have enough time to recover, it dies.
Atmospheric carbon dioxide is a greenhouse gas, meaning it traps solar radiation in the atmosphere. This is done by either absorbing or reflecting infra-red waves, thereby trapping them in the Earth’s atmosphere for longer, contributing to global warming. Rising sea surface temperature has a large effect on coral, due to their low range of tolerance of 23°–29°Celsius. Large-scale bleaching events can occur from a temperature change as little as 1-2°Celsius (Brown 1997). Bleaching is the loss of colour from the coral and can be due to two reasons, the symbiotic zooxanthellae plankton either leave the coral
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
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):
A Synthesis of Selected Literature on The Impact of Climate Change on Coral Reefs This is an explanatory synthesis on the impacts of climate change on coral reefs. Climate change is affecting coral reefs in a negative way. Due to the increase of sea temperatures, coral reefs are becoming bleached. When a coral reef becomes it causes them to expel the algae, leaving the corals white1,2,3,4. In the essay, “A framework for understanding Climate Change Impacts on Coral Reefs” by Joshua Clinner (2016), he addresses that when coral reefs become bleached they have reduced growth rates. The article, “Five Species We Stand to Lose if Coral Reefs are Destroyed and What You Can Do About it” by Jenna Bardroof (2014), emphasizes that coral bleaching is a serious threat to coral colonies and specific mammals
“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
The bleaching of coral reefs is when warm water forces algae to leave the reef. Once the algae disappear, the coral goes from a vibrant color to a pale white. As one marine biologist said, “You go from a vibrant, three-dimensional structure teeming with life, teeming with color, to a flat pavement...” This bleaching makes the coral more vulnerable to diseases and a greater risk of death. The biggest bleaching events to have occurred in
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 bleaching research was led by the UNSW Professor Peter Steinberg, Director of the Sydney Institute of Marine Science, and Professor Madeleine van Oppen of the Australian Institute of Marine Science and the University of Melbourne. Their heat-stress experiment conducted in the laboratory, showed that tiny algae have more genes than humans do. That's why the algal genes are able to activate or de-activate needed reaction on the
Lubofsky begins his article by explaining that “climate It is estimated that by the end of the century, climate change and warmer oceans will kill coral reefs. Lubofsky follows the studies of graduate student Hannah Barkley in this article. Hannah Barkley has been studying coral health in the western Pacific. She investigates how coral reefs respond to climate change and which corals can survive in this climate change. Coral reefs “provide habitats for 25 percent of all marine species” (Lubofsky 28) and protect shorelines from storm damage. Barkley moved her research from “Cape Cod to the Rock Islands of Palau to study reef communities” (Lubofsky 28) since temperature and acidity have risen in some Palauan bays. To obtain the temperatures in the Palauan reefs, Barkley and her colleagues set up a network of underwater temperature sensors around the barrier reef and inside the lagoons. One of Barkley’s advisors, Cohen, found that “ocean warming affects coral reefs in at least two ways” (Lubofsky 29). First, an increase in temperature by 1oC can break down the symbiotic relationship between the coral and algae causing the corals to become bleached and die. Coral bleaching happens when the symbiotic relationship is gone and photosynthesis ceases to occur. Second, warming “stratifies the ocean into warmer surface layers and denser,
Coral Bleaching Abstract Coral reefs have been called the rainforests of the ocean and are one of the most diverse and important ecosystems on the planet. This paper will explore how global warming has effected these fragile ecosystems. It will focus on the impact of increasing ocean temperatures on coral reefs.
Global climate change is one of the greatest threats to the long run future of coral reefs. In combination with other natural and human-induced pressures, warming seas pose a serious risk to the world's coral reef ecosystems. Summer sea temperature increases of just 2-3°C for a week or two, or 1-2°C for a month or two, are enough to kill sensitive corals.
What's Happening? 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.
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
What is Bleaching? 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.