Coral recovery during a prolonged heatwave offers new hope

UNIVERSITY OF VICTORIA

Research News

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IMAGE: UVIC MARINE BIOLOGIST JULIA BAUM SAMPLING PLATYGYRA COLONIES ON KIRITIMATI (CHRISTMAS ISLAND), 2019. view more CREDIT: CREDIT: KRISTINA TIETJEN.

University of Victoria biologists have discovered how some corals managed to survive a globally unprecedented heatwave, in a first-ever study that provides new hope for the long-term survival of coral reefs in the face of climate change.

“The devastating effects of climate change on coral reefs are well known. Finding ways to boost coral survival through marine heatwaves is crucial if coral reefs are to endure the coming decades of climate change,” says UVic marine biologist Julia Baum, the study’s senior author.

Published today in Nature Communications, the study presents the discoveries made by the international research team as they tracked hundreds of coral colonies on reefs around Christmas Island (Kiritimati), throughout the 2015-2016 El Niño. Heat stress from that El Niño triggered the third-ever global coral bleaching event, causing mass coral bleaching and mortality on reefs around the world. Its epicentre was Christmas Island, where the heatwave lasted an unprecedented 10 months.

Worldwide, coral reef fisheries are worth US$6.8 billion annually, and are a vital source of food and income for hundreds of millions of people in tropical island nations. In the lead-up to the United Nations Decade of Ocean Science for Sustainable Development (2021-2030), there is a renewed and global call to reverse the cycle of decline in ocean health.

“Understanding how some corals can survive prolonged heatwaves could provide an opportunity to mitigate the impact of marine heatwaves on coral reefs, allowing us to buy time as we work to limit greenhouse gas emissions,” says Danielle Claar, who led the study as a UVic doctoral student and is now a postdoctoral researcher at the University of Washington.

Climate change threatens the world’s coral reefs because corals are highly sensitive to the temperature of their surrounding waters. During a heatwave, corals release the algae that live in their tissues and produce food for them, causing the coral to turn completely white–a phenomenon known as coral bleaching. Prolonged bleaching often causes corals to die from starvation. If they can reclaim their food source within a few weeks, they can usually recover.

To date, coral recovery from bleaching has only ever been observed after heat stress subsides. With global climate models predicting that heatwaves will continue to increase in both frequency and duration, a coral’s ability to recover its food source during a prolonged heatwave is essential to its survival.

“Observing corals recovering from bleaching while still baking in hot waters is a game changer,” says Baum.

Baum adds that corals only exhibited this capacity if they were not also exposed to other types of human-caused stressors, such as water pollution. Until now it’s been unclear if local reef management could help improve corals chances of surviving climate change. “We’ve found a glimmer of hope that protection from local stressors can help corals,” says Baum.

“Although this pathway to survival may not be open to all corals or in all conditions, it demonstrates an innovative strategy for survival that could be leveraged by conservationists to support coral survival,” adds Claar.

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The research was supported by the Natural Sciences and Engineering Research Council of Canada, the US National Science Foundation, the David and Lucile Packard Foundation, The Pew Charitable Trusts’ Pew Fellows Program in Marine Conservation, the Rufford Foundation, the Canadian Foundation for Innovation and the Shedd Aquarium.

From EurekAlert!

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December 9, 2020 10:25 am

Not that this is new.

Reply to  Krishna Gans
December 9, 2020 4:51 pm

This is definitely not new. 4 years ago I blogged about how coral gained rapid tolerance of temperature changes by shifting and shuffling their symbiotic algae in an article the Coral Bleaching Debate posted here on WUWT. I got mentioned in the Australian press but then the ABC tried to denigrate me (using this paper’s co-author Ruth Gates) without ever refuting the science I presented

http://landscapesandcycles.net/coral-bleaching-debate.html

Bloke back down the pub
Reply to  Jim Steele
December 10, 2020 4:17 am

I wonder to what extent they took into account sea-level changes that are usually associated with El Niño events.

Pat from Kerbob
December 9, 2020 10:29 am

All lies
The coral reefs are dead, or dying, or dying soon.
Its sciency

Ed Zuiderwijk
December 9, 2020 10:31 am

A gobally unprecedented heatwave. That’s a new one. Next: a universally unprecedented heatwave. There, you read it here first.

Latitude
Reply to  Ed Zuiderwijk
December 9, 2020 10:45 am

missed the big one…..it’s only the 3rd bleaching event….even though it’s something they and their zoox have evolved to do

“Heat stress from that El Niño triggered the third-ever global coral bleaching event,”

peer review and publishing has turned into a world class lying competition

Rud Istvan
Reply to  Latitude
December 9, 2020 1:52 pm

Dunno about the global part. The coral reef here in Fort Lauderdale didn’t bleach at all.

Joel O'Bryan
Reply to  Ed Zuiderwijk
December 9, 2020 10:48 am

Considering corals have been around hundreds of millions of years thru a lot worse, and that the researchers must know that, the use of “unprecedented” is a just a tad bit disingenuous.

Newminster
Reply to  Joel O'Bryan
December 9, 2020 11:28 am

The whole thing is disingenuous, Joel, and that’s the polite version. These people have no claim on the word “scientist”.

They start from a pre-conceived premise drip-fed into them by the activists that pass for scientists in modern universities and then produce awe-struck papers when they find situations that don’t match with the received wisdom. They then find ever more unlikely reasons for this anomaly and invent “cures” which inevitably “work” because the anomaly never existed in the first place.

One day the scales will fall from their eyes and they will realise that their life’s work has been a fraud because their teachers and mentors lied to them.

Mark Luhman
Reply to  Newminster
December 9, 2020 7:23 pm

“These people have no claim on the word “scientist”.” yep all they are is educated idiots.

Gerry, England
Reply to  Mark Luhman
December 10, 2020 6:21 am

Are you sure about the ‘educated’ bit?

Opus
Reply to  Ed Zuiderwijk
December 9, 2020 1:24 pm

Anton Petrev had a video on Youtube recently the the entire Universe is warming up. AGW is worse than we thought.

AndyHce
Reply to  Opus
December 9, 2020 3:41 pm

The eventual heat death of the universe is an idea that has been around longer than the AGW frenzy.

Stephen Skinner
December 9, 2020 10:32 am

“a globally unprecedented heatwave” – Really? Within what timeframe and I’m assuming it will be spanning the entire time that corals have been in existence? 160 million years?
And…
“The devastating effects of climate change on coral reefs are well known.” No no no. This assertion has just been repeated endlessly so that it is well known in the sense of familiar. That is not the same as it being correct.

Reply to  Stephen Skinner
December 9, 2020 11:03 am

Meanwhile the Grand Solar Minimum begins to take its toll, as the planet just keeps cooling down, with no stopping in sight. Welcome to yet one more glaciation phase of this 2.58my ice age(Pleistocene)

Peter W
Reply to  John L. Kelly
December 9, 2020 12:10 pm

But it is all the fault of that soot we are putting into the atmosphere, remember? That is what we were told back in the 1970’s. Climate change is ALWAYS the fault of the human race.

Dave Fair
Reply to  Stephen Skinner
December 9, 2020 1:08 pm

“The devastating effects of climate change on coral reefs are well known.” Fascinating that the study authors’ would say that, since their study’s conclusion was that the reefs (at least a significant portion) survive extended heatwaves quite well. [Oh well … keep sending money until I retire to a coral atoll.]

Climate believer
December 9, 2020 10:52 am

“The devastating effects of climate change on coral reefs are well known…..”

They’re obviously not because you are just about to explain something you didn’t know about it.

“where the heatwave lasted an unprecedented 10 months….”

Unprecedented – like never having happened or existed in the past. Like, in the last 500 million years that these things have been around.

“the third-ever global coral bleaching event….”

Again I think you might have the blinkers on.

“With global climate models predicting…”

very little that comes to pass?

……..OMG… have we got something for the “better than we thought” file?

Mr.
Reply to  Climate believer
December 9, 2020 3:58 pm

“The devastating effects of climate change on coral reefs are well known…..”

Yep. And even more devastating are the observed effects of atom bombs on coral reefs – Bikini Atoll lagoon – totally obliterated in the 1950s.

Yet, ~ 70 years later, there they are back to their former glory, with no “assistance” from “science”

WattsUpWithThat??

Graemethecat
December 9, 2020 10:58 am

Perhaps the clowns responsible for this “scientific” paper could address the fact that corals have survived far warmer periods in the geologically-recent past.

December 9, 2020 11:03 am

Meanwhile the Grand Solar Minimum begins to take its toll, as the planet just keeps cooling down, with no stopping in sight. Welcome to yet one more glaciation phase of this 2.58my ice age(Pleistocene)

Ron Long
December 9, 2020 11:24 am

“…first ever study that provides new hope for the long-term survival of coral reefs in the face of climate change.” What demonstrably false nonsense. Coral reefs, and both the debris from them and their intact remains, are LIMESTONE, the fifth commonest sedimentary rock on the exposed part of the earth. Geologists have been understanding these reef-records since 1879, when “The Structure and Origins of Limestone” was published. The Exxon Research adaption of “Sequence Stratigraphy”, from the late 1970’s, shows how reefs/limestone migrates along with a changing environment. Reefs have lived almost 600 million years on our planet, through snow-ball earth to the really hot Age of the Dinosaurs. Can we guess that reefs will find someplace to flourish no matter what?

Robert of Texas
December 9, 2020 11:28 am

Hmm, so if you do not pollute the waters the corals grow in they live, and if you heavily pollute the waters the corals die…

Sounds like to me that heat has nothing to do with it…it’s water pollution. That actually sounds very plausible to me.

Lance Flake
December 9, 2020 11:29 am

“Unprecedented”
Inigo Montoya: You keep using that word, I don’t think you know what it means.

Zigmaster
December 9, 2020 11:41 am

Who would’ve thought .Something that has survived Millenia can survive a local heatwave!
Wow!

Mr.
December 9, 2020 11:42 am

But what a wonderful holiday from a BC winter in Victoria to tropical Christmas Island.
Next year- the Great Barrier Reef
(or at least the inshore fringing coral clumps, where most visiting students do their GBR “research”)

saveenergy
December 9, 2020 11:51 am

Could be better than we thought, so Peter Ridd was right all along !!!

Here’s an interesting 2013 PDF with the catchy title …
‘Impact of seawater acidification on pH at the tissue-skeleton interface and calcification in reef corals’
https://www.academia.edu/12907704/Venn_et_al_2013_PNAS_acidification_and_coral_pH?email_work_card=view-paper

Saying things like – “Overall,our findings suggest that reef corals may mitigate the effects of seawater acidification by regulating pH in the SCM (subcalicoblastic medium).

Don’t let alarmists see it … unless you want to upset them (:-))

michael hart
December 9, 2020 12:15 pm

“…a globally unprecedented heatwave”

Complete and utter twaddle.

RickWill
December 9, 2020 12:24 pm

The Lord be praised – It is not as bad as we thought.

UVIC need to be defunded for spreading this heresy. Where are the high priests of Climate Change when they are needed!

December 9, 2020 12:32 pm

The Chinese broke up some reefs in the South China Sea to build their military islands….don’t worry….they are supposedly restoring the reefs now….so, call the Chinese if you are having reef problems….caused by climate not being static – rather being changing.

Peter Fraser
December 9, 2020 12:58 pm

I would not have thought there was much “human caused stressors such as pollution” around Christmas Island where the research was done.

Howard Dewhirst
December 9, 2020 1:04 pm

El Ninos are not caused by human CO2 emissions so how are they caused by climate change?

fred250
Reply to  Howard Dewhirst
December 9, 2020 1:36 pm

Two things happen in the GBR region during a strong El Nino.

1 Sea levels drop, exposing coral to excess direct sunlight..

2. Currents slow or reverse, meaning that the normal food supplies are greatly diminished.

Of course the little coral critters go looking for somewhere for a holiday.

n.n
December 9, 2020 1:13 pm

Evidence recovered in a limited frame of reference, about a problem observed in a limited frame of reference. Progress.

Gordon A. Dressler
December 9, 2020 1:21 pm

Hmmm . . . the above paper questions “how some corals managed to survive a globally unprecedented heatwave . . . with subsequent implication that this was during the interval of the 2015-2016 El Niño.

Well, if we look at the trend in the UAH satellite-based temperature of the global lower atmosphere (ref: https://wattsupwiththat.com/2020/12/06/uah-global-temperature-update-for-november-2020-0-53-deg-c/ ), and furthermore conservatively just look at the trend line since 2007, we can easily see the the interval of 2015-2016 had a positive anomaly from the average slope of about 0.15 C.

Now let’s compare that to the fact that we are currently at CENTURY-DURATION-AVERAGED global temperatures that are around 0.5 C cooler than the Holocene peak temperature, which occurred about 8,000 years ago (ref: comment image )

Of course, the massive thermal inertia of Earth’s oceans compared to Earth’s atmosphere means that oceans (with the coral under discussion) will respond much less temperature-wise to the two year El Nino than the centuries-long 0.5 C hotter atmospheric temperatures associated with Holocene.

So, a “globally unprecedented heatwave” that ocean corals have had to withstand? . . . I think not.

But then again, perhaps those University of Victoria biologists that authored the above-cited “research news” think coral biology versus the stresses from NORMAL climate change need only consider the period since they were born.

To the Natural Sciences and Engineering Research Council of Canada, the US National Science Foundation, the David and Lucile Packard Foundation, The Pew Charitable Trusts’ Pew Fellows Program in Marine Conservation, the Rufford Foundation, the Canadian Foundation for Innovation and the Shedd Aquarium:
you’re not getting your money’s worth . . . but on second thought, maybe you are indeed getting EXACTLY what you paid for.

Rory Forbes
December 9, 2020 1:40 pm

First they must show that the climate in that location has changed at all, with respect to the prevailing conditions. Then they must provide evidence that such changes have never caused similar effects in the corals in past warming events (for which there are numerous examples during the Holocene Interglacial … particularly the post Younger Dryas warming.

Andre Den Tandt
December 9, 2020 2:22 pm

I guess we should be thankful for small mercies. These biologists have a hard time summoning the courage to go against the GW consensus. Given that they are from Victoria, where coral reefs are unknown, it must be tough to challenge the catastrophic consensus centered in Townsville, Queensland. Personal experience tells me that a wintertime dive on the Great Barrier Reef requires a wetsuit after half an hour, and that a summertime snorkel experience on the east coast of Madagascar in December is quite unpleasant on account of the soup-like temperature of the water. Yet the corals in both places were in splendid health. Tahiti and Moorea were disastrous because a hurricane had destroyed nearly all signs of coral life. The Ningaloo Reef on Australia’s west coast is on average 2 C degrees warmer than the Great Barrier reef. Yet that’s the best reef I ever saw. All the people who are so certain in their appraisals of what makes a healthy reef need to spend more time on a greater variety of reefs, and under varying conditions. It’s complex and far from well-understood.

Mike
December 9, 2020 2:38 pm

Oh when will this junk science stop!!? What ever happened to learning? What ever happened to critical thinking?
Are the universities no longer teaching it? Is this high school level garbage state of the art ecology now?
Do these people actually believe what they write? Who the hell are these people!?

Mad Mac
Reply to  Mike
December 9, 2020 5:23 pm

I agree Mike it seems that critical thinking has been lost in many academic disciplines.

Mike
Reply to  Mad Mac
December 9, 2020 5:49 pm

I’m far from an academic but even I can see that their methods are feeble, incomplete, dismissive, incompetent, preposterous.

Paul Johnson
December 9, 2020 7:53 pm

“a first-ever study that provides new hope for the long-term survival of coral reefs”

It only give hope to people deluded into thinking there is a risk to coral reefs long-term survival in the first place.

Shaun
December 9, 2020 8:54 pm

“With global climate models predicting ….”

Well this statement alone means that we can all rest easy. None of their ‘crap-data-in/crap-data-out’ models has EVER made a correct prediction, why would this one be any different?

Dave Andrews
December 10, 2020 9:21 am

Some 23 nuclear weapons,including one H bomb, were detonated on Bikini Atoll between 1946 and 1958. That’s almost 2 a year.

The temperatures reached during nuclear explosions equal those of the interior of the sun. Yet in 2008 researchers found that 70% of the atoll’s coral reef species had resettled the lagoon and there was evidence that the coral had begun to grow again as soon as 10 years after the tests ended.

Seems to me the reefs are perfectly able to accommodate the small temperature changes occuring now.

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