Causes Of Coral Bleaching

Coral Reefs are known as the “Tropical Rainforests of the Oceans.” They are called thus because of the “tight resource coupling and recycling, allowing coral reefs to have extremely high productivity and biodiversity” (Coral Reef bleaching, no date). Coral Bleaching has always been a part of the natural circle of life, but only over the last forty years’ have Marine Biologist seen a rapid increase of the onset of coral bleaching. Coral reefs are severely threatened by the combination of natural causes and human activities. Natural causes include climatic events such as El Niño and La Niña events, whereas the human activities include the dramatic effects of the coastal development along the reefs, agricultural overflow into the sea and marine

The need for food and livelihood has lead the people living there to fish and survive off of the natural resources that the reef has to offer them. As coral reefs are among the most diverse fishing grounds, this has caused overfishing and multiple other drastic events to occur. The coral fish are being fished for food, sport and for live fish art such as tanks and aquariums. Chemical fishing, which includes the use of cyanide to stun and capture live fish, causes the coral polyps to be killed and it also degrades the reef habitat. This causes coral bleaching and “re-establishment of the symbiosis may take from six months to one year or more” (Threats to coral reefs: The effects of chemical pollution - Marine Biodiversity Wiki, no date). Another method of fishing that can cause a devastating impact on coral is dynamite fishing. This way of fishing shatters coral colonies and kills the coral tissues on adjacent colonies (The Nature Conservancy, 2016). Over time, other types of algae will replace the ejected dead and poisonous zooxanthellae in the coral. Changes in the algae living on the coral will lead “to changes in the species of fish and other animals living on the reef.” (Coral bleaching, no