Coral Reefs Come Back to Life After Shutdown Caused by Climate Change
Nearly 2,500 years ago, the coral reefs along Panama's Pacific coast completely collapsed due to natural climate change, according to researchers who say the shutdown corresponds to dramatic swings in El Niño-Southern Oscillation weather patterns.
The history of the reefs shows that the coral organism can bounce back from devastating climate changes, the likes of which the world hasn't seen for millennia. Until now.
"As humans continue to pump greenhouse gases into the atmosphere, the climate is once again on the threshold of a new regime, with dire consequences for reef ecosystems unless we get control of climate change," said study co-author Richard Aronson, a biology professor at Florida Institute of Technology.
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To see how climates affected tropical reefs, a multi-institutional research team took core samples of dead coral reefs along the Pacific coast of Panama and analyzed the cross-sections to reconstruct the history of the reefs over the past 6,000 years.
"We jammed 17-foot-long irrigation pipes down into the reef and pulled out a history, a section of the reef, that told us what the ups and downs of the reef had been," Richard Aronson of the Florida Institute of Technology told NPR.
"We were shocked to find that 2,500 years of reef growth were missing from the frameworks," said doctoral student Lauren Toth. "That gap represents the collapse of reef ecosystems for 40 percent of their total history." When she and Aronson examined reef records from other studies across the Pacific, they discovered the same gap in reefs as far away as Australia and Japan.
They say the effects of El Nino and La Nina, two weather events which can drastically change the ocean temperature, are the cause of the lost years in coral growth. And once the global climate moderated those extremes, the reefs began growing again.
"What [this study] tells me is that these reefs do have hope, and if we are able to get a handle on climate change, then we might be able to save coral reefs," Aronson told CBS News.
But that doesn't mean human-caused climate change won't do coral reefs any harm.
"It is quite the opposite," Aronson told MSNBC. "Environmental pressure caused the reef ecosystems to collapse, and relieving that pressure allowed recovery."
"The same message," he added, "applies to human-caused climate change: by changing the climate we are stressing corals and coral-reef ecosystems, and we will have to stop doing that if we are going to save the reefs."
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