Spread out over an area of more than 280000 square kilometers, the coral reefs offer support to several marine species including fish that graze and live in it, zooxanthellae, and algae. They guard the shores against storms and waves, provide medicines and food to humans, and promote tourism. However, in the recent few years, the economically beneficial corals have been threatened by several global changes, a majority of which are man-made (Shah). Indeed, approximately 25 percent of the coral reefs around the world are regarded as irreversibly damaged and another 60 percent is said to be under significant threat (WWF).
Global Changes Impacting the Coral Reefs
Key global changes adversely affecting the coral reefs include development in the coastal regions, invasive species, excessive fishing, pollution, climate change, acidification of the ocean, mining of the corals, and reckless tourism (WWF).
Off late, humans have been developing the coastal regions for industrial, tourism, transportation, and urban use. For this, the coral reefs have been mined and reclaimed, and forests have been destroyed leading to the dumping of excess sediments in the ocean and suffocation of coral life. Humans have also fished excessively owing to market demands, used harmful fishing methods such as blast and cyanide fishing, and dropped anchors along the coasts thereby destroying the reefs. They have polluted the water bodies by dumping sewage, industrial and agrochemical wastes, and spilling oil, which encourage growth of algae stifling coral growth. Further, tourists have handled the corals reefs, and boated and snorkeled carelessly (Shah).
Perhaps the biggest threat that the coral reefs face is from the climate change worldwide. Global warming, owing to increased atmospheric carbon dioxide levels, has increased ocean temperatures, which is unfavorable for coral survival. At warm sea temperatures, corals expel colorful zooxanthellae and algae that survive in them, which is termed as coral bleaching, and become susceptible to ailments such as white pox and black band disease. This results in the death of the corals and the ecosystem they supported (National Wildlife Federation).
Global warming also impacts corals indirectly by altering the ocean chemistry. Oceans absorb the increased amount of atmospheric carbon dioxide and become acidic thereby inhibiting coral skeleton formation and growth. It also increases sea levels, which makes the water too deep for the corals to receive sufficient sunlight for optimum growth (National Wildlife Federation).
Reefs are known to survive isolated bleaching events. However, global threats impacting the corals today cause large scale bleaching, making it difficult for them to recover and survive (Shah). Moreover, persistent rise in atmospheric carbon dioxide levels keeps the ocean pH low and provides very little opportunity for the corals to counter and recover from its impact (Biello).
Several organizations around the world including the National Oceanic and Atmospheric Administration, World Wide Fund, and National Wildlife Federation are working towards preserving this diverse ecosystem by cleaning the water bodies, monitoring the causative factors, and educating people as to how they can prevent reef destruction. That said, unless a strong legal and political action by way of creating Marine Protected Areas and reducing greenhouse gas emission is taken, these ‘rainforests of the sea’ shall continue to remain threatened by the ever-increasing global changes (National Ocean Service).
Works Cited
Biello, David. “Coral Reefs Show Remarkable Ability to Recover from Near Death.” Scientific American. Scientific American, 15 Jan. 2015. Web. 25 Feb. 2016. < http://www.scientificamerican.com/article/coral-reefs-show-remarkable-ability-to-recover-from-near-death/ >.
National Ocean Service. “Corals: Protecting Coral Reefs.” Ocean Service. National Oceanic and Atmospheric Administration, 22 June 2015. Web. 25 Feb. 2016. < http://oceanservice.noaa.gov/education/tutorial_corals/coral11_protecting.html >.
National Wildlife Federation. “Global Warming and Coral Reefs.” NWF. National Wildlife Federation, n.d. Web. 25 Feb. 2016. < https://www.nwf.org/Wildlife/Threats-to-Wildlife/Global-Warming/Effects-on-Wildlife-and-Habitat/Coral-Reefs.aspx>.
Shah, Anup. “Coral Reefs.” Global Issues. Global Issues, 3 Mar. 2013. Web. 25 Feb. 2016. < http://www.globalissues.org/article/173/coral-reefs>.
WWF. “Coral Reefs: Threats.” WWF. World Wide Fund for Nature, 2016. Web. 25 Feb. 2016. < http://wwf.panda.org/about_our_earth/blue_planet/coasts/coral_reefs/coral_threats/>.
