Global-warming: A nail in the coffin of Coral Reefs

Corals and coral-reefs are one of the most magnificent creations of the marine lives. For an ordinary man it is beyond his imagination to figure out their beauty of world of colours. They are the major under-sea tourists' attraction, enhancing local economic activity. Moreover, coral reefs, like mangroves, act as buffers against erosion in coastal areas, protecting the human habitation and their livelihoods. They are rich source of seafood
Coral reefs are the ridge-like structure formed primarily by the accumulation of the calcareous skeletal material of marine animals along with other organisms that grow in situ in them.  The commonest reef-building organisms are the corals; hence the reefs are called the "coral reefs". In a favourable environment, colonies of millions of coral polyps (shells) grow plentifully. The colonies house varieties of mollusks and other animals and also microorganisms like calcareous algae and bryozoans. The shells of the microorganisms facilitate cementation of the bigger skeletons.
According to the International Union for the Conservation of Nature (IUCN) and Conservation International, warming up of the seawater due global warming and dumping of toxic wastes, corals and hundreds of other animal species are fast facing extinction. The odds against the coral reefs have greatly amplified by the rapid increase in sea levels due to global warming.
A recent report of  UK's Hadley Centre for Climate Prediction, says that before the end of the century, a warming of at least 3 degrees Celsius may eventually trigger the melting of the of entire Greenland ice sheets, raising the sea levels by at least six metres. Corals are very sensitive to the environment--especially temperature, extent of turbidity and the depth of seawater. They thrive only in mud-free marine environment from near the sea levels to the depth of 120-150 feet and temperatures not below 25 degrees Celsius.
The increase in the sea levels and temperatures would greatly jeopardize the survival of coral reefs and thousands of marine animal species that depend on reefs for sustenance. These animals, in turn, act as a fodder to the fisheries. With their food in short supply, fisheries would also get affected adversely. As the forests and the tigers are the indicator of the health of the terrestrial environment; of the oceans, coral reefs are pivotal to the health of under water ecosystems. Their degradation would adversely affect under sea-water life.
It is believed that if no counter measures were undertaken, about third of the coral reefs are feared to become extinct in next ten years.  Another effect of global warming is their discoloration. The bleaching effect is immensely visible in many localities, as Seychelles, Mauritius, Sri Lanka, and Great Barrier Reef, Australia.
Carbon dioxide acts as a raw material for the growth of the coral reefs. That way, in the past, oceans acted as giant carbon sinks. However, acidic oceans saturated with CO2 might reverse the whole process of carbon absorption. In a few hundred years, the oceans may become a net source of CO2 emissions, as the acidic seawater would react with the calcareous skeletons, releasing carbon dioxide into the atmosphere much like vehicles do on land.
Coral reefs are the home for world's quarter of all marine species. The rising acidity adversely impacts the entire shell-forming seal life, as acid reacts with the calcareous skeletons causing osteoporosis and their degeneration. Acidity also kills off reef algae and deprives reefs of calcium, thus, hindering their growth. Degeneration is visible in bleached and weakened reefs. At least 231 species of the atoll-building polyps have been classified as critically endangered under IUCN's red list because of osteoporosis.
The environmentalists of the world are worried as how to save this most wonderful creation of nature. We must understand that the ability of the oceans to maintain their chemical equilibrium depends on the smooth orchestration of hundreds of thousands of factors. However, due to excessive carbon dioxide and other greenhouse gases emissions and consequent global warming, the chemical equilibrium has gone severely off balance putting the entire marine animal kingdom into the struggle for their survival.
Therefore, nothing, however, can be more effective in saving the coral reefs than taking all those steps that cause global warming, as reducing carbon footprints, primarily by changing energy use and opting for less polluting vehicles, as well as, releasing less sewage and effluents into the sea.
Dr RP Mishra
Contact: Mob. 9993006190