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*Surprise* Great Barrier Reef has 112 tough spots that survive and replenish the rest

Coral, Greal Barrier Reef, Bleaching, Recovery, photo.

After lasting for thousands of years through wild swings of temperature, scientists could never have guessed that the Great Barrier Reef has evolved to cope with climate change.

The reef spans  2,300km and has spawning events so large that they can be viewed from space, but who knew that some parts of the reef appear to be safer and more resilient, and would repopulate the rest of the reef? (Apparently, not most of the scientists who have been selling the message of doom). Instead it made sense that 100% of the reef was at the same risk from predatory starfish and hot months, and that any day now, the reef might be polished off for good.

Perhaps some scientists had an idea, but when newspaper headlines declared the reef was on the brink of extinction, or doomed, where were they? (Possibly in hiding — afterall, Peter Ridd is one of the only ones to speak out, and he’s now fighting to save his job).

Crikey! It restores how much?

From the abstract:

The great replenishment potential of these ‘robust source reefs’, which may supply 47% of the ecosystem in a single dispersal event, emerges from the interaction between oceanographic conditions and geographic location…

Righto. This 3% of the reef matters. So lets not build coal mines on thes

e parts, yeah?

Hope for Great Barrier Reef

[Telegraph]  A new study has revealed a collection of 100 individual reefs spread throughout the 2,000 mile-long marine ecosystem that not only withstand warming seas and attacking starfish but also protect others.

… a collection of reefs lying in cooler areas able to supply their larvae – fertilised eggs – to other reefs via ocean currents.

 “The presence of these well-connected reefs on the Great Barrier Reef means that the whole system of coral reefs possesses a level of resilience that may help it bounce back from disturbances, as the recovery of the damaged locations is supported by the influx of coral larvae from the non-exposed reefs,” said Dr Karlo Hock, who led the research.

Great Barrier Reef, refuge areas. Graphic, climate change. 2017

(A) Robust sources are the reefs that possess high replenishment potential while also having low risk of bleaching and COTS outbreaks. (B) When robust sources are superimposed on estimates of acute thermal stress, the region of lower stress in the southern GBR is clearly visible. Most robust sources are located in a region where cooler oceanic water of the SCJ, and to a lesser extent the NCJ, of the South Equatorial Current flushes the GBR reef matrix. COTS, crown-of-thorns starfish; GBR, Great Barrier Reef; NCJ, North Caledonian Jet; SCJ, South Caledonian Jet.

Scientists discover “heart”

If properly protected, these cool-water reefs could supply larvae to nearly half (45 per cent) of the entire ecosystem in a single year, it said. “Finding these 100 reefs is a little like revealing the cardiovascular system of the Great Barrier Reef,” said the study’s lead author Peter Mumby, professor at the University of Queensland.

 But don’t stop panicking:

Similarly, the Queensland University academics said the 100 healthy reefs cannot be solely relied upon to mitigate the damage caused by climate change.

“These findings by no means suggest that the Great Barrier Reef corals are safe and in great condition, and there are no reasons for concern,” said Dr Hock.

Professor Peter Mumby, who also worked on the paper, said “Saving the Great Barrier Reef is possible but requires serious mitigation of climate change and continued investments in local protection.”

 With any good news story, it’s obligatory to remind everyone that we always need more concern and more money.

Great Barrier Reef, map, climate change, recovery, bleaching, crown of Thorns.

(A) Robust sources are the reefs that possess high replenishment potential while also having low risk of bleaching and COTS outbreaks. (B) When robust sources are superimposed on estimates of acute thermal stress, the region of lower stress in the southern GBR is clearly visible. Most robust sources are located in a region where cooler oceanic water of the SCJ, and to a lesser extent the NCJ, of the South Equatorial Current flushes the GBR reef matrix [35]. Data provided in S1 Data. COTS, crown-of-thorns starfish; GBR, Great Barrier Reef; NCJ, North Caledonian Jet; SCJ, South Caledonian Jet.

Press Release:

Just three per cent of the Great Barrier Reef’s corals may hold the key to regenerating reefs damaged after major disturbances, new research reveals.

Researchers from The University of Queensland, CSIROAustralian Institute of Marine Science and the University of Sheffield have pinpointed 100 reefs that have the potential to supply larvae to almost half of the Great Barrier Reef’s ecosystem in one year.

UQ School of Biological Sciences and ARC Centre of Excellence in Coral Reef Studies Professor Peter Mumby said these reefs appeared to be less at risk of the damaging effects of bleaching and starfish predation.

“They are well connected to other downstream reefs by ocean currents and can provide coral larvae (fertilised eggs), which float on ocean currents, to support the recovery of other reefs,” Professor Mumby said.

“Corals on these reefs should fare relatively well and be able to supply larvae to as many reefs as possible, without spreading the pest, crown-of-thorns starfish,” Professor Mumby said.

“Finding these 100 reefs is a little like revealing the cardiovascular system of the Great Barrier Reef.”

We knew something pumped blood, but we didn’t know exactly where it was. Now, thanks to this hard work, we have a map.

 

To alarmists it won’t bring relief,
That damage is known to be brief,
As repairs are nearby,
Through its own D.I.Y.,
Of Australia’s Great Barrier Reef.

–Ruairi

 

 REFERENCE

Hock et al (2017) Connectivity and systemic resilience of the Great Barrier Reef PLOS Biology (doi 10.1371/journal.pbio.2003355)

Image: Wikimedia, author Wise Hok Wai Lum: Flynn Reef 2014.

 

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