This paper reviews what we currently know about coral bleaching and its impact on coral reef ecosystems. It analyses the scientific evidence linking coral bleaching to climate change and other anthropogenic activities. It also focuses on the importance of ecosystem services provided by coral reefs, and the socio-economic and environmental impacts of coral bleaching. The paper concludes with a set of recommendations and mitigation strategies to slow down the rate of coral bleaching, thus allowing coral reefs to adapt and develop resilience in the face of climate change.
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):
Change in ocean Temperature: increased ocean temperature drastically caused by climate change is the leading cause of coral bleaching.
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 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 is a somewhat recent phenomenon that has prompted many communities and countries around the world to enact policies and legislation that deal with their dying coral reefs. In early 1998, a mass coral bleaching event took place on the Australian Great Barrier Reef, and broad scale aerial surveys confirmed that most of the inland reefs had experienced at least some bleaching (Lally 1999). The following analysis of the Great Barrier Reef will illustrate that a successful policy process must incorporate the people who live, work, and depend on the fragile environment into the decision-making about
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.
That's very bad for marine ecology and size of Great Barrier Reef, notes student Rachel Levin. On a genetical level, there have some reactions too. "We found they can switch on genes to produce proteins that neutralize the toxic chemicals," explains Levin, whose article on coral bleaching was published in the Molecular Biology and Evolution.
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 usually occurs when the surface of a sea with coral in it becomes too warm for the coral. When the water heats to as little as one degree higher than normal, coral expels the algae living in its tissue, which causes it to turn completely white. The rise in temperature of the sea surface has been linked mainly to global warming. Other causes of coral bleaching include oxygen starvation caused by an increase in zooplankton, increased solar irradiance, increased sedimentation, bacterial infections, changes in salinity, herbicides, low tide and exposure, cyanide fishing and elevated sea levels. Bleaching events in 2016 were unprecedented, nearly 90% of the coral in the Great
Australia’s scientists have released its comprehensive map of the Great Barrier Reef’s bleached corals revealing that less than 36% of the areas explored have not been severely bleached yet. The bleaching is caused by abnormally hot waters due to El Niño and climate change. These high temperatures cause corals’ symbiotic algae, which is their crucial food source, to become scarce and toxic, forcing the corals to expel it. Removing the algae turns the coral bone white and the coral begins to starve. Of the 911 individual reefs that researchers surveyed, a large 93%-843 reefs-experienced some kind of bleaching. Furthermore, the Great Barrier Reef is home to more than 1,500 different kinds of fish, 6 of the worlds remain seven marine turtle species
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.
Whenever someone hear about bleaching, they automatically think about this strong potent chemical used for clothing to make it stain-free, the pungent smell when they open the door to a pool, or when someone plans on dyeing their hair to a lighter color. Bleaching is very useful for humans, but is it good for the environment? Has anyone heard of coral bleaching? Coral bleaching has nothing to do with chemicals at all, in fact it is called coral bleaching because when coral is bleached, it becomes white like when a t-shirt is bleached (though too much bleach can eat a hole). Coral bleaching has been a problem these past few years on the East coast of Australia’s Great Barrier Reef. It has been declining in its beautiful
There are many causes that contribute to the ghostly image of bleached corals, pollutants in the water, natural events - hurricanes, waves, and human activities - commercial scuba diving, heavy tourism in highly biodiversed aquatic areas. Yet the one major factor that causes this bleaching is the increase in the sea surface temperatures. The warmer temperatures are results of global warming, the rising concentrations of the greenhouse gases in the atmosphere, mainly carbon dioxide.