But the current environmental troubles facing the iconic reef could be the sixth and possibly final death event, researchers warn. This event, reports ScienceMag, killed vast stretches of the Reef.
Over millennia, the reef has adapted to sudden changes in environment by migrating across the sea floor as the oceans rose and fell.
By analyzing data of fossil reef cores from 16 sites of the Great Barrier Reef, scientists could tell the reef grew slower when the whole system had finished its "migration".
The 10-year, multinational effort has shown the reef is more resilient to major environmental changes such as sea-level rise and sea-temperature change than previously thought but also showed a high sensitivity to increased sediment input and poor water quality.
"I have grave concerns about the ability of the reef in its current form to survive the pace of change caused by the many current stresses and those projected into the near future", he said. Webster and an global team wanted to view the reef's current plight within a longer-term context. Also, three times from 10,000 to 17,000 years ago, when glacial melt caused sea levels to rise rapidly, they were nearly killed off. At that time, the sea was 118 meters lower than current levels.
Two of what the scientists dubbed death events happened 30,000 and 22,000 years ago and were caused by subaerial exposure, which is when the reef becomes exposed to air.
Changing sea levels and drops in water quality have caused the reef to fight for its life five times through thousands and thousands of years, but it turns out, the reef is incredibly tough and adept at recovery.
Two more death events occurred at the deglaciation period 17,000 and 13,000 years ago, this time brought about by the sea levels rising rapidly. In response, the reef had to move seaward in order to survive. In addition, due to the sharp increase in the level of water in the sea about nine thousand years ago, BBR began its movement towards the land, as when the depth influenced the increase in the level of education of sedimentary rocks.
However, the rapid increases in temperature and sea-level due to current changes in climate may be too much for the reef to properly adapt as it has before.
Today, the Great Barrier Reef is 2,300 km long and can be seen from space, lounging off the coast of Queensland, Australia.
A new controversy has emerged, with the Greens demanding to know why $444 million in taxpayers' money was handed to a small charity without using a competitive process. Peter Whish-Wilson said. "And why the government bypassed the specially designed public bodies that are already doing this work".