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Global Coral Bleaching Event: Third Ever Declared [PHOTOS]

Oct 12, 2015 11:54 AM EDT

It's official, our oceans are experiencing a coral bleaching event on a global scale. According to the National Oceanic and Atmospheric Administration (NOAA), countless simultaneous reef bleaching incidents culminated in to one massive and connected event, formally declared the third global bleaching event ever recorded.

So what exactly is coral bleaching? It may come as a surprise, but coral reefs are not plants or rocks. Colonies of unique animals called corals and their symbiotic algae partners work together to calcify a strong and vibrantly colored reef for both protection and reproductive means.

However, when corals become stressed they expel their declining algae partners in a process called bleaching. As a result, they turn 'fuzzy' and stark white. Without their little builders, the corals also lose a major source of energy (algae byproducts) and become increasingly susceptible to disease and reef deterioration. (Scroll to read on...)

(Photo : NOAA)

Worse still, rising temperatures and heightened ocean acidity (a consequence of rising C02 levels) are known coral-algae stressors. The combined effect is what many experts are calling a doomsday 'double whammy' and is attributed to some of the largest and most severe bleaching events ever seen.

That's also apparently what we can blame for this latest global event.

"The coral bleaching and disease, brought on by climate change and coupled with events like the current El Niño, are the largest and most pervasive threats to coral reefs around the world," Mark Eakin, NOAA's Coral Reef Watch coordinator, in a recent statement.

"As a result, we are losing huge areas of coral across the US, as well as internationally," he added. "What really has us concerned is this event has been going on for more than a year and our preliminary model projections indicate it's likely to last well into 2016."

That's concerning because, while reefs have been known to recover from breif bleaching events, if corals are left vulnerable and starving for more than a year, bleaching often turns fatal. What's worse, researchers revealed just last November than even mass-bleaching survivors wind up being unable to properly reproduce for years after the event.

"Even if we can fix what's killing these corals, it's going to be hard for coral populations to recover, because the surviving corals might not successfully produce enough offspring to repopulate reefs," the study's authors reported. (Scroll to read on...)

(Photo : Reproduced with Kind permission of Ove Hoegh-Guldberg, Global Change Institute at the University of Queensland) [Left] a healthy reef at Heron Island. [Right] a degraded reef off Townsville after attack from Crown of Thorns disease and bleaching.

According to the NOAA, this current bleaching event, "which began in the north Pacific in summer 2014 and expanded to the south Pacific and Indian oceans in 2015, is hitting US coral reefs disproportionately hard."

The agency found that by the end of this year, nearly 95 percent of corals in US waters will be exposed to harmful bleaching conditions.

Jennifer Koss, the NOAA Coral Reef Conservation Program's acting program manager, said that to address that issue, the US will need to "act locally and think globally."

"Locally produced threats to coral, such as pollution from the land and unsustainable fishing practices, stress the health of corals and decrease the likelihood that corals can either resist bleaching, or recover from it," she explained, adding that these immediate threats will continue to be the NOAA and other US agencies' primary concern.

"To solve the long-term, global problem, however," Koss said, "we need to better understand how to reduce the unnatural carbon dioxide levels that are the major driver of the warming." (Scroll to read on...)

(Photo : Professor Peter J Mumby, University of Queensland) Mass coral bleaching, like this event in Figi, leaves reefs brittle and starving.

That's why world powers are currently aiming limit their carbon emissions and halt the world from warming any more than an additional two degrees Celsius (3.6 °F) - known as the Copenhagen Accord. Unfortunately, many climate experts believe that the Accord's two degree limit, driven primarily through emission tax plans, is "utterly inadequate."

"We need to wake up to the idea that business as usual, even clever taxation schemes, will not act fast enough to reduce global emissions," said Ove Hoegh-Guldberg, a contributing author to the latest Intergovernmental Panel on Climate Change (IPCC) report. "This is a global emergency, which requires us to decarbonise within the next 20 years, or face temperatures that will eliminate ecosystems like coral reefs, and indeed many systems that humans depend on."

To learn more about the dire situation our ocean's corals are in, and how it's not all bad news, check out Nature World News' special report on the state of our ocean's corals. It can be read here.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

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