A Colorless World: Coral Bleaching
I’m sure you’ve all heard of bleaching. You bleach clothes to make them whiter, you bleach bathrooms and kitchens to disinfect them, but have you ever thought about how bleaching may occur in the ocean? There is an event that occurs in coral reef ecosystems called coral bleaching which is a result of prolonged exposure of coral to extreme temperatures in the ocean.
Certain symbiotic algae (zooxanthellae) attach to coral and actually give the coral its color. When temperatures get too hot the symbiotic algae pack up their bags and leave the coral, resulting in a bleaching effect on the coral.
Most of the time these bleaching events will end up killing the corals which is a big part of the coral reef
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This event resulted in an outbreak of coral disease and macro algae, ultimately reducing reef quality.
Still recovering, Tobago was struck again in 2010.
After this event, researchers Jahson Berhane Alemu I and Ysharda Clement were curious to find out what corals could survive and which ones could not. They set out to analyze the effects of mass coral bleaching on four main reef building taxa at three popular reefs in Tobago, West Indies. Basically they were trying to find out which corals were able to withstand bleaching.
The three reefs that were analyzed were Buccoo reef, Culloden reef, and Speyside. Buccoo Reef Marina Park is the only marine protected area in Trinidad and Tobago. The researchers were granted permission for every visit to the reef. There was no need to contact or remove and species from the area. The authors collected data in three categories: ocean temperature monitoring, a coral bleaching assessment, and a benthic assessment.
First of all, they monitored the oceanic temperature using a combination of meters and sea surface temperature using remote sensing
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
Coral bleaching happens when there is a decrease of zooxanthellae involved in the symbiotic relationship with their coral host. This also causes a loss of the coral's beautiful colors that sometimes can be seen to human eye. Bleaching leads to death of coral over time. Some causes of bleaching have been tied to salinity of the ocean and sedimentation. The main reasons known to cause severe coral bleaching are climate change and radiation. These two elements are extremely harmful to coral especially when they’re working together at the same time (Fitt et al. 2001).
Overfishing is also a reason why the coral reefs are turning white. There are fishing techniques that include explosives so when you explode an object in the water, it will disrupt the coral and will explode into pieces. About 55% of the world's coral reefs are threatened by overfishing and destructive
Coral bleaching can be caused when coral is stressed by many things including pollution, overexposure to sunlight and extreme low tides however, it primarily occurs when corals are stressed due to unusually high sea temperatures (National Oceanic and Atmospheric Administration, 2015). Unusually high temperatures cause coral 's colourful, symbiotic algae (zooxanthellae) to separate from the coral leaving it to appear white (De 'ath, Fabricius, Sweatman & Puotinen, 2012; Baker, Glynn & Riegl, 2008). Coral bleaching is not isolated to one select reef, but rather many reefs all around the world. Mass coral bleaching has become more widespread and frequent over the recent decades, often resulting in high mortality rates (Pandolfi, Connolly, Marshall
Coral bleaching is when the tiny algae that lives in the coral which causes it to be bright and colourful, gets so stressed out when the water temperature exceeds the limit that it can handle, which then makes the algae
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.
Coral Reefs are said to be the “tropical rainforest” of the sea. They are home to over 25% of all marine life (http://coralreefalliance.org.stories/storyReader$77). Over the past few decades they have been subjected to destructive anthropogenic practices. Some of the major threats to coral reefs include sedimentation, water pollution, harmful recreational activities, and global warming. All of these things cause stress on corals and can potentially cause mortality. Corals are made up of two parts, a polyp and zooxanthellae. A polyp is a calcerous body that grows from a hard part of the ocean floor. Zooxanthellae is a photosynthetic algae which lives in the polyp and provide energy for themselves and the coral. In many cases, corals undergo “bleaching,” which is a process where corals lose the zooxantheallae or chlorophyll pigment, and turn white (Wilkinson et all). After bleaching corals can survive for several months. It is possible for corals to recover by hosting more zooxantheallae, but it can take between 5 and 50 years for them to recover completely (Wilkinson et all, 1999).
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.
The coral reefs of the world are of vast importance because they host 25% of all marine life on the planet. Now that corals have been briefly described, we can see why the effects of climate change damage coral reef systems. Ocean acidification is a result of climate change. Acidification is caused by an increase in carbon dioxide in our oceans and leads to a decrease in the pH levels of seawater. This pH decrease reduces the ability of corals to make their hard skeletons.
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).
... the world's reefs died due to increased water temperature. Bleaching leaves corals susceptible to disease, while severe bleaching kills them. An estimated 10% of the world's coral reefs are dead, and 60% of the world’s coral reefs are at-risk, due to tourism.
Coral Reefs need to be preserved for many reasons. In this paper I will discuss a
Today many people do not see the need to preserve corals reefs. Hence because of the lack of appreciation for the reefs, they are slowly disappearing. Many citizens do not realize the importance of these reefs, the species they hold, and the food webs that connect the ecosystems. Our American government has stated many times that they are doing all they can to preserve and to replenish our coral reefs. However, how accurate is that statement? To answer these questions, we first have to understand what a coral reef is and how it can be saved.