coral reef The great barrier coral reef extends on more than 2000 km in the North-East of the Australian coast, and covers a surface of 350.000 km ². The 2500 coral solid masses which make it up in make a single unit registered with the world inheritance of humanity. This natural wonder is in danger.

In question: the global warming, which involves also the rise in the temperature of the oceanic masses. According to a report of the intergovernmental group of experts on the evolution of climate (GIEC), which must be published on April 5, a rise in temperature of 2°C compared to the averages of 1990 would involve a generalized whitening of the corals of the Large Reef, and a degree more would cause important mortalities.

The cause of deterioration is perfectly known. The corals live in symbiosis with microscopic algae, the zooxanthelles ones, which bring their food to them. A rise in temperature causes the expulsion of these organizations by the corals, which become exhausted and die quite simply of hunger. Their internal skeleton, exposed, explains the white color which replaces their usual colours chatoyantes then.

The process had already occurred in 1998 and 2002, where 60 to 95% of the coral populations had been touched. The situation had been restored at the end of a few weeks, but approximately 10% perished. Less lucky were the coral reefs surrounding Maldives, which were almost completely destroyed.

But the marine warming is not alone in question. Among the harmful effects of human origin, it is also necessary to consider the increase in the discharge of the sediment of the rivers and rivers in the ocean, and the images of the satellites are eloquent on this subject: the currents of water fresh charged with opaque matter, which formerly were diffused slowly close to the coasts, not only reach, but cross the reef, blocking photosynthesis. Moreover, those are also charged with pesticides and other chemical substances coming from the intensive sugar cane cultures, which do nothing but worsen the situation.

Several solutions are considered. Partnerships were tied with the farmers in order to them responsabiliser and to reduce the harmful practices to the environment. Since 2004, some 30% of the surface of the Large Reef are classified in “green zone” and of many warnings the access prohibits some, with an encouraging result.

In the tourist zones, various solutions are tried to try to slow down the increase in the watery temperature. Parasols were installed, and of automatic waterings were implemented to cool surface. But, explains Paul Marshall, person in charge for change the climatic team of Great Reef Reef Marine Park Authority (GBRMPA), in charge of the management of the zone, tourism in this area generates an annual sales turnover of some 4 billion euros…

Let us recall that Australia is currently the only rich country, with the United States, to have refused to sign the draft-agreement of Kyoto. And that Australian the Prime Minister, John Howard, have just admitted the existence of the climatic phenomenon of warming.