Coral Bleaching: Destroying the Great Barrier Reef

By: Emma Giles

Coral bleaching is a serious environmental issue which is not spoken about enough. As one of the most important ecosystems in the world, coral reefs foster major biodiversity. Located off the coast of Queensland in Australia, the Great Barrier Reef is the largest reef in the world, and it is 2299.75 kilometers in size. This area is home to thousands of animal species, including fish, starfish, sea birds, sharks, stingrays, and more. However, this ecosystem is being significantly destroyed by coral bleaching, which leaves animals without homes and in a dying environment. Coral bleaching is a consequence of climate change, and it could eventually result in the catastrophic extinction of coral. 

Coral bleaching can occur for numerous reasons. For instance, storm-generated precipitation can dilute ocean water while runoff can carry pollutants, and both processes bleach corals near the shorelines. Additionally, high temperatures, overexposure to sunlight, and exposure to the air during extreme low tides contribute to bleached corals in shallow waters. However, one of the primary causes of bleaching is the rising of ocean temperatures. If the oceans are too warm for too long, the coral releases Zooxanthellae, which are tiny algae plants living inside the tissue of a coral that provide the coral’s color among other things. During bleaching, coral expels this algae. This drains the coral’s color, which leaves behind a skeleton of the coral and allows its tissue to become transparent. Since rising ocean temperatures are a direct effect of climate change, so is coral bleaching by association. This means that human behavior accelerates the destruction of coral reefs as well. 

Fortunately, coral can recover from bleaching. However, the damage may be permanent if the bleaching is prolonged in warmer water for over eight weeks. As a result, the coral may become liable to disease. The Great Barrier Reef has been increasingly susceptible to coral bleaching recently, and large expanses of it contain mostly bleached coral. These wasted ecosystems are no longer fit to house the many animal species who inhabit and depend on the Reef.  

As previously mentioned, coral bleaching is a consequence of climate change, which is exacerbated by humans yet affects every living thing. Many species of fish rely on living coral for food and homes, and bleached coral doesn’t provide fish with either of those things. As large expanses of the reef consist of bleached coral, it becomes abandoned. This forces fish and marine animals to migrate in search of new homes and food sources. In short, these bleached reefs are the aquatic equivalent of a ghost town. Bleaching decreases growth or the speed of growth, and it also causes coral to reproduce less. Even more, if bleached coral disappears completely, biodiversity may dwindle to near none. 

Coral bleaching predominantly affects marine life, but its economic impacts on society cannot be ignored either. For instance, bleached reefs do not attract tourism as healthy reefs do. Though diving on reefs can negatively impact their conservation, the lack of tourism hurts coastal economies, as many areas rely on tourist attraction to sustain the local economy.  

For the past five years, coral bleaching has been at its worst. According to the World Wildlife Fund, 91% of coral has been bleached at least once, and the bleaching on the Great Barrier Reef ranges from none to the highest severity. The Australian Institute of Marine Science uses a protocol that measures bleaching, allows scientists to monitor reef health and status, and compares bleaching over time in the Great Barrier Reef World Heritage Area. According to the research, in 2016, the Reef experienced the worst bleaching and die-off when approximately 1,100 kilometers of coral were affected. As temperatures rise, bleaching as such will not only become increasingly common, but also more deadly in the form of mass coral die-off. Large ocean expanses that were once lively could soon become utterly neglected and uninhabitable. 

Fortunately, the Australian government is prioritizing the coral crisis and allocating funds to find solutions. According to the Department of Agriculture, Water and the Environment, the Australian Government is investing $700 million to the Reef Trust, which is the government’s primary investment program to support the execution of the Reef 2050 Long-Term Sustainability Plan. This plan employs a long-term framework to protect and manage the Great Barrier Reef. There is also a six-year grant in place to help maintain and monitor the reef and hopefully conserve what hasn’t been bleached yet. 

Nevertheless, coral bleaching is deeply concerning. The only way that this phenomena can end is by preventing ocean temperatures from rising further. Climate change is wreaking large-scale havoc that is damaging the planet, and coral bleaching is one of the consequences that could cause the eventual extinction of coral. The Great Barrier Reef is home to thousands of species that would have no home or food source if all coral were to die off, and according to CNN, this reef is also one of the seven natural wonders of the world. Many wish to see reefs lively and healthy, but this may not be possible due to the urgent threats of coral bleaching.

How to Help:

- Donate to the Great Barrier Reef Foundation

- Plant a coral by joining the Coral Nurture Program

- Adopt a coral with the Reef Restoration Foundation

- Share this article and educate family and friends

Art Work Credits: Becca Stadtlander