Reduction of Coral Reef Ecosystems

Coral reefs are often coined as the rainforests of the sea, and they are one of the most diverse ecosystems on the planet. Although they cover less than 1 percent of the Earth's surface, coral reefs house about one-third of all marine species. It is estimated that there are about 3.2 million species that inhabit coral reef ecosystems. The coral reefs not only provide biodiversity, they also play a vital role in the local economies. Tourism is one of the ways that nearby countries benefit from coral reefs. Coral reef fisheries produce about 6 million metric tons of fish annually and they provide for one-quarter of the fish that is caught in developing nations. Coral reefs are also associated with building materials, coastal protection, and pharmaceutical discoveries. However, coral reefs have been declining mainly due to stresses that result from human activity like overfishing and pollution. The rises in carbon emissions from the increased fossil fuel combustion and cement production have resulted in the acidification of the ocean and global warming, which both inhibit the growth of coral reefs.
Reef habitats might appear to be robust enough to withstand anything, but they are extremely fragile. Most corals are not only brittle, but they require pristine, warm, clear, relatively nutrient-free waters in order for them to survive. It is estimated that over the last 50 years, humans have put enormous pressure on coral reef ecosystems by altering the waters and tearing up the coral reef foundations. It is reported that approximately 27 percent of the monitored reef formations have been lost and we are at risk of losing 32 percent in the next couple of years (De’ath, Fabricius, Sweatman, & Puotinen, 2012). The interesting part of all the reports and studies conducted that analyze coral reef ecosystems decline is that they all note that human activity is the primary reason for the decline. There are half a billion people who are currently living within fifty miles of the reef habitats and there are much more who are on their way, which is likely to make the situation worse.
There are many different ways that human activity assaults the coral reef. For example, in Florida people drain their septic tanks directly into the ocean. This results in algae growing on top of the coral structures and deprives the coral polyps’ sunlight. Fishermen from Sri Lanka use dynamite to catch fish. When they blow up the dynamite it also blows up the reefs into bits. Around the islands of Japan and Philippines overfishing of the natural predators has allowed the starfish to run rampant and devastate the coral reefs in the area (Graham et al., 2008). All over the world, global warming that is mainly caused by human greenhouse gas emissions has been warming up the top layers of the oceans and this causes the corals to turn white and lose their polyps. This condition is referred to as bleaching.
The decline of coral reefs from global warming and ocean acidification takes a toll on marine species. Declines in coral cover have been associated with a decline in fish biodiversity. In areas where the coral reefs have declined it has been noted that 75 percent of the reef species fell in population and 50 percent of the species also exhibited lower counts as compared to their originals. Researchers have found that species whose juveniles depend on the coral reefs declined in greater scale. There is also a prediction that some species might become extinct if the coral reef ecosystem decline continues. Therefore, there is need to develop intervention strategies that will reverse the damage that has already been afflicted on the coral reef ecosystems. This will allow the ecosystems to grow once again and the marine ecosystem will be restored.


References
De’ath, G., Fabricius, K. E., Sweatman, H., & Puotinen, M. (2012). The 27–year decline of coral cover on the Great Barrier Reef and its causes. Proceedings of the National Academy of Sciences, 109(44), 17995-17999.
Graham, N. A., McClanahan, T. R., MacNeil, M. A., Wilson, S. K., Polunin, N. V., Jennings, S., . . . Letourneur, Y. (2008). Climate warming, marine protected areas and the ocean-scale integrity of coral reef ecosystems. PLoS ONE, 3(8), e3039.