Increase in acidity may not be harmful to coral reefs after all

November 10, 2015 by Bob Yirka report
Close up of polyps are arrayed on a coral, waving their tentacles. There can be thousands of polyps on a single coral branch. Credit: Wikipedia

(Phys.org)—A combined team of researchers affiliated with the Scripps Institution of Oceanography and the Bermuda Institute of Ocean Sciences has found, via a five year study, that increased ocean acidification may not pose the threat to coral reefs that scientists have thought. In their paper published in Proceedings of the National Academy of Sciences, the team describes their study and why they now believe that an increase in green house gas emissions many not have the devastating impact on coral reefs that most in the field have assumed would occur.

To better understand what might happen with if more carbon dioxide makes its way into the oceans due to an increase of the gas in the atmosphere caused by human emissions, the researchers set up monitoring devices along a coral reef offshore from Bermuda—information from the sensors was monitored for five years (2007 to 2012). The team also had access to data from an ocean chemistry monitoring station approximately 80 kilometers from their study site. The combined data offered a unique perspective on coral activity.

In studying the data, the researchers noticed that spikes of occurred during 2010 and again in 2011—those blooms made their way to the coral reef offering more food than normal for the coral. The coral responded by growing which caused them to pull more alkaline carbonate from the surrounding water, making it more acidic. Eating more also resulted in the corals emitting more carbon dioxide into the water. The result was a big increase in acidity—to levels higher than have been predicted for the future due to human emissions—yet, the coral continued to flourish.

These observations contrast sharply with the prevailing view that an increase in acidity is harmful to coral—leading to death if it goes too far. But the levels seen by the researchers with this new effort suggest that is not the case at all, and therefore muddles theories regarding the impact on the oceans of higher levels of carbon dioxide and warmer temperatures. Another team with Western Australia noted that the results found by this new team appeared to agree with those of a small study they conducted where they put boxes around some and piped in , to no detrimental effect.

Explore further: Coral growth in Western Australia found to be thriving in warmer water

More information: K. L. Yeakel et al. Shifts in coral reef biogeochemistry and resulting acidification linked to offshore productivity, Proceedings of the National Academy of Sciences (2015). DOI: 10.1073/pnas.1507021112

Abstract
Oceanic uptake of anthropogenic carbon dioxide (CO2) has acidified open-ocean surface waters by 0.1 pH units since preindustrial times. Despite unequivocal evidence of ocean acidification (OA) via open-ocean measurements for the past several decades, it has yet to be documented in near-shore and coral reef environments. A lack of long-term measurements from these environments restricts our understanding of the natural variability and controls of seawater CO2-carbonate chemistry and biogeochemistry, which is essential to make accurate predictions on the effects of future OA on coral reefs. Here, in a 5-y study of the Bermuda coral reef, we show evidence that variations in reef biogeochemical processes drive interannual changes in seawater pH and Ωaragonite that are partly controlled by offshore processes. Rapid acidification events driven by shifts toward increasing net calcification and net heterotrophy were observed during the summers of 2010 and 2011, with the frequency and extent of such events corresponding to increased offshore productivity. These events also coincided with a negative winter North Atlantic Oscillation (NAO) index, which historically has been associated with extensive offshore mixing and greater primary productivity at the Bermuda Atlantic Time-series Study (BATS) site. Our results reveal that coral reefs undergo natural interannual events of rapid acidification due to shifts in reef biogeochemical processes that may be linked to offshore productivity and ultimately controlled by larger-scale climatic and oceanographic processes.

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31 comments

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zorro6204
4 / 5 (9) Nov 10, 2015
Maybe not, but ocean temperature sure is harmful. I went out yesterday on a reef on the Kohala coast of the Big Island, and it was destroyed. I'd say 90% of the coral is either dead, and covered with algae, or bleached. For all practical intents and purposes, there is no reef left.
antigoracle
2.2 / 5 (10) Nov 10, 2015
One more nail in the AGW Cult's CO2 filled coffin of lies.
barakn
4 / 5 (8) Nov 10, 2015
This study showed that well-fed coral can survive higher acidity at current temperatures, not the elevated temperatures anticipated in the future. It also didn't show how starving coral would respond to higher acidity.
Bongstar420
2.1 / 5 (7) Nov 10, 2015
Seeing as how CO2 has been above 1000ppm in the past..

This does not surprise me.
Are coral a new species or what?

Me thinks not
jeffensley
2.6 / 5 (10) Nov 10, 2015
A great example of why models/predictions need to be relegated to their true status as only somewhat useful tools. We need to stop using things that have yet to happen as scientific evidence or as catalysts for taking drastic action.
jeffensley
1.7 / 5 (6) Nov 10, 2015
Maybe not, but ocean temperature sure is harmful. I went out yesterday on a reef on the Kohala coast of the Big Island, and it was destroyed. I'd say 90% of the coral is either dead, and covered with algae, or bleached. For all practical intents and purposes, there is no reef left.


Or perhaps you could leave the AGW doom narrative behind briefly and lay the blame where it belongs...

Unfortunately, many visitors do not understand what coral is and how they can minimize their impact on coral and the other organisms found on the reef. Research has confirmed that overuse and trampling of live corals degrades these delicate ecosystems.


http://kohalacent...eefteach
SamB
3 / 5 (6) Nov 10, 2015
Good article. These silly butterfly predictions need to stop.
barakn
4 / 5 (8) Nov 10, 2015
Seeing as how CO2 has been above 1000ppm in the past..

This does not surprise me.
Are coral a new species or what?

Me thinks not

Coral comprise an entire biological class composed of 7 orders containing over 7000 species. Your naive question suggests you were unaware there was more than one. But to answer it, some are new and some are not. And as for 1000 ppm CO2, the question is - how fast did it rise? We would expect many species to survive slow changes.
Captain Stumpy
3.8 / 5 (10) Nov 10, 2015
A great example of why models/predictions need to be relegated to their true status as only somewhat useful tools
@jeffen
this is completely ridiculous!
would you say the same thing to the investigator that was there to examine your vehicle accident?

how about one that is trying to catch the murderer who killed your family?

and the forensics technicians who actually process the evidence?
Or perhaps you could leave the AGW doom narrative behind briefly and lay the blame where it belongs
conspiracist ideation is for those who can't produce evidence and use the scientific method
you know, like zephir, jvk, viko and the electric universe clan

http://www.ploson...tion=PDF

tommo
3.3 / 5 (6) Nov 11, 2015
While this may sound promising it doesn't to me bring acidification rates into play substantially thus misleading by far the headline, "Increase in acidity may not be harmful to coral reefs after all".

We are 10-times the rate of a mass-extinction, that's impossible for corals to overcome so I'm wondering here why this is important at this time to posit when the capacity given is far below the acidification rate.

Is that a scientific headline or a FoxSnoozer ???
tommo
1 / 5 (1) Nov 11, 2015
I will distinctly point out that we jumped a major greenhouse gas over 40% in a blink of the geologic time-scale eye.

The air CO2 off the NW Washington coast at the NVS-Shellfish Growers platform is 418.1-ppm and the ocean 341-ppm.

That's the acidification forcing, the growers can't take in seawater during upwelling events or they can't grow spat, that's where the platform & buoy system came from, this posit is so bunk long-term I object, I think this is bullshit not science.
antigoracle
2.1 / 5 (7) Nov 11, 2015
And as for 1000 ppm CO2, the question is - how fast did it rise?

So, why don't you tell us?
unrealone1
1.4 / 5 (9) Nov 11, 2015
Jurassic PERIOD WAS 3000PPM TO 2000 PPM life was in fact Jurassic! in the ocean and out, End of story really.. Carbon is not pollution, prize winning horticulturist all use CO2 enrichment in there hot houses.
bertibus
3.7 / 5 (3) Nov 11, 2015
@Captain Stumpy
"This is ridiculous". No it isn't.
He said that models are a somewhat useful tool; he didn't dismiss them out of hand.
All of your 'examples' confirm his comment.
Using a model to find a murderer is simply the use of a tool...detectives still need to find and arrest someone, and then there's a court case.
Ditto the forensic examiner; plenty of whom have been proven to be less than 100% accurate to put it politely.
Why be so dismissive?
unrealone1
1 / 5 (3) Nov 11, 2015
Common Sunscreen Chemical Kills Coral
http://news.disco...1021.htm
The truth is sunscreen is killing more coral than CO2 will ever do.
Captain Stumpy
3.7 / 5 (6) Nov 11, 2015
Why be so dismissive?
@bertibus
because of his historical arguments like
models attempt to account for many climate-related variables and I respect the effort but I have no confidence in the values chosen
an emotional appeal (non-evidenciary) to the data- basically saying "nice try but... i don't like it therefore it must be wrong"

The point (that you made, and i not-so-clearly made) was that a tool is a highly useful means of finding answers
jeffe has argued against this in the past

now, whereas i can understand the argument that we can't perfectly model this highly complex system, and we might not have all of the necessary data, that doesn't mean the models are wrong or that we can't use them as tools (as he's intimated in the past). in fact, the models have not only been pretty accurate, but also incredibly helpful (directly refuting his arguments)

it doesn't matter what his confidence levels are in the data
MikPetter
3.7 / 5 (3) Nov 11, 2015
An interesting study but should be taken in context of corals evolutionary pattern. There is likely to be different responses between Caribbean species and Indo-pacific species.
"The central Indo-Pacific centre of diversity has an average generic age of 30 million years, about half that of the Caribbean...."
http://coral.aims...tion.jsp
"Such CO2 concentrations in the atmosphere have likely not been seen since at least the end of the Oligocene 23 million years ago..."
http://www.scient...c-highs/
antigoracle
1.9 / 5 (9) Nov 11, 2015
HEAR YE! HEAR YE! READ ALL ABOUT IT!
CORALS FLOURISH IN CO2!
Ignorant AGW Chicken Littles in disbelief that their cult has been deceiving them.
SuperThunder
3.7 / 5 (3) Nov 11, 2015
how about one that is trying to catch the murderer who killed your family?


You would if you were the one who killed your family.
TiagoTiago
not rated yet Nov 12, 2015
Hm, so what does cause coral bleaching?
Vietvet
4 / 5 (4) Nov 12, 2015
"What is coral bleaching?"

http://oceanservi...ach.html
TiagoTiago
1 / 5 (1) Nov 12, 2015
"What is coral bleaching?"

http://oceanservi...ach.html


Oh, so not a chemical reaction between the acid and the hard stuff on corals? Hm, interesting...
MMM
3.7 / 5 (3) Nov 12, 2015
I would be curious if the science writer actually interviewed the authors of the study, because I feel like this phys.org story goes beyond any statements made in the underlying research article. The reason that increasing acidity and aragonite undersaturation negatively impacts corals is that it makes calcification more energetically difficult. This study shows that the process of calcification makes the water more acidic, which says nothing about the implications of water that starts more acidic.

An analogy: I claim that CO2 is good for growing plants. Someone releases a study showing that CO2 levels above forests during seasons with high plant growth are actually much lower than background CO2 levels. Does this study show that in fact plants like low CO2 conditions? No, it does not.
gkam
2.3 / 5 (6) Nov 12, 2015
"Jurassic PERIOD WAS 3000PPM TO 2000 PPM life was in fact Jurassic! "
--------------------------------

Oh, . . . and how many people were there enjoying it?

None? Not possible for us to live in that environment?

Oh, . . .
TheGhostofOtto1923
2.6 / 5 (5) Nov 12, 2015
"Jurassic PERIOD WAS 3000PPM TO 2000 PPM life was in fact Jurassic! "
--------------------------------

Oh, . . . and how many people were there enjoying it?

None? Not possible for us to live in that environment?

Oh, . . .
So what are you saying george? That there were no people back then because the CO2 was too high?

Ahaahaaaahaaaaaaaa.

5000 ppm is considered low-level.

"At CO2 levels greater than 0.5%, adverse health affects are present in humans, animals, and plants."
http://www.blm.go...apxC.pdf
Uncle Ira
4 / 5 (8) Nov 12, 2015
Oh, . . . and how many people were there enjoying it?


Why you not look him up like you are always telling peoples to do you?

None?


Are you guessing or did you look him up?

Not possible for us to live in that environment?


Maybe we could or maybe we could not. Why you don't look up what the conditions were back then and then see if there is somebody around to day living in conditions like somewhere. Choot, we got jungles and rain forests and swamps all over the place where peoples can live just fine.

You new-agey types always miss the big picture. You dance around with your slogans and pet ideas that will make the world wonderful. But you miss the root cause and don't realize that until you get that root cause taken care of, all your new-agey stuffs are doomed to fail.

It is not rocket science.THERE ARE TOO MANY PEOPLES IN TOO LITTLE SPACE FOR US TO NOT BE DOOMED.That is what the world should focus on to preserve the future for humanity.
Uncle Ira
3.9 / 5 (7) Nov 12, 2015
I would be curious if the science writer actually interviewed the authors of the study, because I feel like this phys.org story goes beyond any statements made in the underlying research article.


Well read him your self and report back to us.

http://www.pnas.o...full.pdf
Whydening Gyre
3.7 / 5 (3) Nov 15, 2015
It is not rocket science.THERE ARE TOO MANY PEOPLES IN TOO LITTLE SPACE FOR US TO NOT BE DOOMED.That is what the world should focus on to preserve the future for humanity.

Careful, Ira. You're gonna sound like a doomsdaying anarchist...:-)
gkam
1 / 5 (6) Nov 15, 2015
He can stop breeding, . . .
Whydening Gyre
4 / 5 (4) Nov 15, 2015
He can stop breeding, . . .

Why? Sex is the reason we have a lot of happy people running around. NO sex is the reason we have a lot of unhappy, frustrated and even angry people running around.
Wanna win a war with terrorists? Send in a bunch of uninhibited hot chicks...
snoosebaum
not rated yet Nov 15, 2015
I thought suntan lotion was the problem ?

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