Coral reefs are aragonite structures produced by living organisms. They are homes to a variety of organisms including the coral fish and the algae that resides inside them giving them the beautiful colors.
We human beings have become the main reason because of which the corals are either getting destroyed or bleached. The main reasons are global warming, coral mining, pollution (organic and non-organic/chemical), over-fishing, blast fishing and the digging of canals and access ways into islands and bays.
The fishing practices around the world like blast fishing in which the dynamite is used to kill the fishes. Along with the fishes, the corals are also destroyed. Also selective fishing or overfishing leads to a particular species of fish being depleted and promote the growth of certain fish and organisms which damage the reef if they appear in large numbers. In countries like Philippines the fish are captured using sodium cyanide. Use of this poison kills most of the fish in the area due to extensive liver damage and also destroys coral.
The runoffs from the human activities like road construction, farming, household drainage etc. carry high amounts of carbon, nitrogen, phosphorus and minerals. This may lead to high growth of phytoplankton which reduces the oxygen contents in the water thereby harming the corals.
Apart from this Global warming caused by the green house effect is leading to the destruction of corals and also their bleaching. Bleaching is the phenomenon where the algae inside the coral die or they leave the corals. As discussed earlier the color is imparted to the corals by the algae and when they leave or die, all that remains is white structures devoid of any color. That’s why it is called bleaching. Also the increased temperatures leave the corals susceptible to various diseases like the Black band disease and the White band disease. Along with this the global warming is causing acidification of the oceans. The increase in atmospheric CO2 (a gas causing green house effect) increases the amount of CO2 dissolved in the oceans. Thus, it leads to a decrease in the pH of the ocean water.
The Coral Triangle, considered the world’s richest marine environment, spans the coasts, reefs and seas of Indonesia, the Philippines, Malaysia, Papua New Guinea, the Solomon Islands and East Timor. This Coral Triangle will be destroyed completely by the end of this century if no steps are taken to improve the present condition. According to the study commissioned by the World Wildlife Fund (WWF), this could cost the livelihoods of around 100 million people who are dependent on these corals.
Many governments are taking steps to protect the corals by declaring some specific areas containing coral reefs as Marine Protected Areas (MPAs), Biosphere reserves, Marine parks and world heritage sites.
What can be done in order to save the corals? The answer to this question is not very simple. Steps must be taken both at the governmental levels and at individual levels. Fishermen in Philippines and other such places where wrong fishing practices are being followed should be educated about the impact of their actions on the environment. As most of this is being done due to poverty government should intervene by providing them with sufficient fishing equipments. Also water should be treated before letting it run into the oceans. It is high time that we address the problem of global warming. Today we are trying to save the corals; tomorrow if the problem intensifies there will be no one to save us.