The Australian Great Barrier Reef, suffering from severe stress in a warmer, more acidic ocean, has returned five times over the past 30,000 years, researchers said Monday.
Reefs could be more resilient than previously thought, it's probably never been as bad as they are today, they added.
"I have grave concerns about the ability of the reef in its present form to survive the pace of change. Due to the many current burdens and those projected in the near future," said Jody Webster from the University of Sydney, who along with one Article in the journal Nature Geoscience wrote.
In the past, the reef moved along the seabed to English: www.dlr.de/en/desktopdefault.aspx/t…1
This rate may not be enough to withstand the current flood of environmental problems. At the SST (sea surface temperature) and at the hyperacidity the speed did not change ", so Webster opposite AFP. The rates of change "are probably much faster now – and in future projections."
The World Heritage Site, which attracts millions of tourists, suffers from frequent coral bleaching due to climate change-induced warming of sea temperatures.
Webster and an international team wanted to look at the current plight of the reef in a longer-term context.
For more than 10 years, they examined how they had responded to changes in continental ice sheets that expanded and declined over 30 millennia. 196590000] Fish farming
Their research covers a period from before the "Last Glacial Maximum" or LGM – the freezing point about 21,000 years ago during the last Ice Age.
The average sea level at the time was about 120 meters lower than today.
When sea levels dropped to LGM, there were two massive "deaths" – 30,000 and 22,000 years ago, the team found.
These were caused by the reef bone g exposed in the air. What was left, climbed seaward, to recover later.
When ice sheets melted after the LGM, two deaths – 17,000 and 13,000 years ago – were attributed to sea-level rise, the team found. In these cases, the reef moved landward.
The fifth death event occurred about 10,000 years ago, apparently because of a massive sediment basin at a higher sea level.
Webster said that the GBR "will likely be in the next few thousand years anyway, if it follows its geological pattern," as it is believed that the earth is eligible for another ice age.
"But whether human-induced climate change will accelerate remains to be seen."
In April 2016, a study reported that during a violent heatwave in 2016, nearly a third of the reef coral died in a "catastrophic death." has been.
Changes in sea temperature and acidity can "fade" coral – emit algae that live in their tissues and provide them with food.
Bleached corals are more susceptible to disease, and without enough time to recover can disappear forever.
Coral reefs are home to about a quarter of marine life, and act as a nursery for many species of fish.