Ngorongoro part 2
Planet Doc Full Documentaries
The corals of the Great Barrier Reef have begun to bleach because of he global warming of the atmosphere.
▶ Spanish video: http://planetdoc.tv/documental-barrera-de-coral-de-australia
Northeast Australia is protected from the pounding of the sea by the greatest barrier reef in the world. Millions and millions of tiny coral polyps have, with their calcareous skeletons, helped form a barrier of 348,700 km2, a structure so incredible that it can be seen from space as a beautiful white line in the blue immensity of the ocean.
The 2,500 reefs that make up the Great Barrier Reef in Australia form a stable ecosystem that has maintained continuity over extremely long periods of time. For thousands of years, only gradual changes have altered this submarine world and the result of this situation is unprecedented biodiversity.
The coral reefs constitute the oldest natural communities on our planet.
All this explosion of life, this entire range of incredible biodiversity, is the result of an evolutionary continuity unaltered for millions of years; the reward for constancy, the patent demonstration of the biological potential of our planet.
But, starting just a few years ago, this biological continuity has suddenly been altered; and what appeared to be an unchangeable world has seen its ancient foundations crumble.
The corals of the Great Barrier Reef have begun to bleach.
Some external factor is killing the polyps, interrupting the growth and renewal of the reefs. And if the polyps are not renewed, the entire ecosystem simply dies.
All the biodiversity of the ecosystem is based on the most delicate, tiny organisms of the reef: the coral polyps. These small architects are responsible for the construction and renovation of the Great Barrier Reef and for this they produce over 100 million tonnes of calcium carbonate a year; this production serves to repair the inevitable wear and tear of acting as a brake on the sea and generates sufficient limestone to construct 17 pyramids like that of Giza.
But in order for the polyps to construct their fabulous calacareous armour-plating, they need the zooxanthelae, single-cell algae that live inside them and thanks to which they are able to feed.
The global warming of the atmosphere caused by contaminating gases is heating up the water of the seas. This increase kills the zooxanthelae, causing the death of the corals. And without corals, the coasts of northeast Australia will be left defenceless against the brutal pounding of the waves.