Guest Post by Willis Eschenbach
I love the coral reefs of the planet. In my childhood on a dusty cattle ranch in the Western US, I decorated my mental imaginarium of the world with images of unbelievably colored reefs below white sand beaches, with impossibly shaped fish and strange, brilliant plants. But when I finally first got to dive on the reefs, some forty years ago now, I found that my wildest imagination was only a pale, sickly phantasm compared to the real reef, the real beach, and the real sea life around it. It is a marvel of rioting color and exploding life where I have spent many happy hours, mesmerized.
Figure 1. Thousands of different types of living creatures together form the coral reef environment. SOURCE
Unfortunately, coral reefs are supposed to be threatened by increasing CO2. It’s supposed to make the various animals’ carbonate skeletons and shells dissolve, by decreasing the “pH” of the ocean (pH is a measure of relative alkalinity/acidity) and thus making the seas more neutral than they are today. Careful chemical calculations based on the complex carbonate chemistry of the ocean are said to prove that, no question. Aquarium tests are said to have shown it beyond a doubt, with statistically significant results. The claim has been repeated ad nauseam … and yet the reefs are thriving where they are not impacted by true threats like pollution and coral mining and curiously, the killing of parrotfish.
I have long held that the chemistry of the ocean was not ruled by the chemical energetics of the hundreds of various reversible reactions. That is the generally held view, that the ocean is ruled by chemistry. I hold the contrasting view, that the chemistry is not the last link in the chain. I say that the chemistry of the ocean is in turn ruled by life, and not the other way around as is the common assumption.
An early piece of evidence that shaped this view was when I found out that the pH of the water over a reef is not driven by chemistry, nor by the partial pressure of CO2 in the air. It is driven by the reef itself, which is a net producer of CO2. In other words, the biological products of the reef creatures themselves cause the water over the reef to move from more to less alkaline, often on a short time span. In one study the pH of the reef water changed by one full pH unit (1000% change) in 12 hours … and yet climate researchers breathlessly forecast dire consequences from much smaller pH changes than that spread out over a century, not 12 hours. From my experience with life in the ocean, and from my research, I am much more confident in the adaptability and tenacity of life than those researchers seem to be.
Figure 2. Cross section through a coral colony showing the living polyps, along with the carbonate skeleton built by the polyp. SOURCE
So I was interested to come across a research paper (paywalled, alas) with the unwieldy name of “Acclimation to ocean acidification during long-term CO2 exposure in the cold-water coral Lophelia pertusa.”
Abstract
Ocean acidity has increased by 30% since preindustrial times due to the uptake of anthropogenic CO2 and is projected to rise by another 120% before 2100 if CO2 emissions continue at current rates. Ocean acidification is expected to have wide-ranging impacts on marine life, including reduced growth and net erosion of coral reefs. Our present understanding of the impacts of ocean acidification on marine life, however, relies heavily on results from short-term CO2 perturbation studies.
Here we present results from the first long-term CO2 perturbation study on the dominant reef-building cold-water coral Lophelia pertusa and relate them to results from a short-term study to compare the effect of exposure time on the coral’s responses. Short-term (one week) high CO2 exposure resulted in a decline of calcification by 26-29% for a pH decrease of 0.1 units and net dissolution of calcium carbonate.
In contrast, L. pertusa was capable to acclimate to acidified conditions in long-term (six months) incubations, leading to even slightly enhanced rates of calcification. Net growth is sustained even in waters sub-saturated with respect to aragonite. Acclimation to seawater acidification did not cause a measurable increase in metabolic rates. This is the first evidence of successful acclimation in a coral species to ocean acidification, emphasizing the general need for long-term incubations in ocean acidification research. To conclude on the sensitivity of cold-water coral reefs to future ocean acidification further ecophysiological studies are necessary which should also encompass the role of food availability and rising temperatures.
I don’t have the full paper yet, but let me briefly discuss the abstract. The main message I see there is, the reef abides. The plants and animals of the ocean abide. The creatures that form carbonate shells and structures are tough and tenacious, they can do things we haven’t imagined. Their lifespan is often short enough to allow for evolution in human rather than geological time. They are able to change and modify, to adapt in response to changing water conditions. In addition, a healthy reef contains not just the dominant species in any given ecological niche, but a host of competing species. If it gets a bit warmer or colder, this alters the balance of the reef’s major simbionts, emphasizing a better-adapted competitor, and the reef keeps going. Even the “bleaching” events so feted by doomsayers are only minor occurrences in the reef’s geological history. Drill down, this has happened in the past. It is the extreme end of the scale of how the reef adapts to changing conditions. It gets rid of its symbionts wholesale, and starts over again. But the reef abides.
Next, a nitpick. The correct description for their claim is that the ocean waters have become more neutral. They have not become “more acidic” as the paper claims. They have moved towards neutrality. They have to pass through neutrality before they can start getting “more acidic”, and the ocean is a long ways from that.
Finally, I doubt greatly that we have anywhere near enough data to make the statement that “Ocean acidity has increased by 30% since preindustrial times”. See the second link above (repeated here http://wattsupwiththat.com/2010/06/19/the-electric-oceanic-acid-test/ ) for some of the very scarce real data.
I’ll update this if I can get a copy of the paywalled paper from my undersea connections …
[UPDATE—A denizen of the sub-aquatic world has tapped a trans-oceanic undersea fiber optic cable and sent me the paper, my thanks as always to Davey Jones. My comments follow.]
First, their statement about the so-called increase in ocean acidity is repeated in the body of the paper, but without citation … not good. They assert, without any evidence, that:
Presently the ocean takes up about 25 % of man-made CO2, which has led to a decrease in seawater pH of 0.1 units since 1800.
As mentioned above, that’s sketchy, observations of ocean pH are very scarce. Other than that, however, it is a fascinating paper. The experiment is very well described. They went down in a submersible and picked the coral branches, to assure good specimens and avoid damaging the reef. And also because it would be an awesome trip. They grew the specimens in their lab. Care to know what coral eat? Brine shrimp babies, that’s what, and not only that, they eat them alive, the heartless monsters.
The corals were fed twice a week with live Artemia franciscana (Premium, Sanders) nauplii and once a week with defrosted Cyclops (AD068, amtra Aquaristik) or ground fish flakes (TetraMarine Flakes, Tetra).
So. They did the short-term experiment using air with different amounts of CO2 above the water. The levels they chose were 509, 605, 856, and 981 µatmospheres (approximately, ppmv). This range starts with CO2 levels at about twice the pre-industrial values, and ends at around a thousand ppmv, a level which is extremely unlikely to be reached in this century.
In the short-term experiment (a week), the coral polyps fared very poorly. They failed to thrive, and at the higher levels, the corals’ carbonate skeletons were being eaten away by the high-CO2 water.
Then they did the long-term experiment, ramping up to the higher levels over a period of a few months. In this regard, there is a very revealing comment.
At the beginning, all CRS [the “closed recirculating systems” containing the coral] were supplied with ambient air with a pCO2 level of approx. 406 µatm. After taking water samples for TA [total alkalinity], DIC [dissolved inorganic carbon], and nutrients and measurements of the physicochemical water parameters (temperature, pH, salinity), sampling, the physicochemical parameters (salinity, pH, temperature) of each reactor were monitored by inserting a multi sensor device (Multi350i, WTW) into a small opening in the lid. During incubations, pH and pCO2 [partial pressure of CO2] can change differently in each bioreactor depending on rates of respiration and calcification of the enclosed coral branches. Therefore, the carbonate system parameters (pH, pCO2, ΩAr) and growth rates were calculated separately for each bioreactor.
In other words, what I said above—chemistry is being ruled by life, and not the other way around. The pH and the pCO2 are not simply functions of the amount of CO2 in the overlying air. They are functions of the reef and the reef life itself.
There were other interesting outcomes. In the short-term experiments, there is a statistically significant correlation between increasing CO2 and decreasing calcification rates (growth rates). As CO2 went up, growth went down, and coral skeletons were actually being eroded at the highest CO2 levels. This is a great example of how a statistically significant result can be entirely wrong because the experiment itself is conceptually flawed. The results are statistically significant … but meaningless.
Because in the long-term experiment (six months), the opposite occurred. The corals, once they had time to adapt to the change in pH and CO2 levels, did very well. The study reports:
Growth rates in the long-term experiment (LTE) did not follow the negative trend with increasing pCO2 observed in the short-term incubation. Instead, growth rate, which was comparable to that of the control treatment in the short-term experiment, stayed high at elevated CO2 levels. … Surprisingly, corals maintained in waters sub-saturated with respect to aragonite (CRS3, Tables 4 & 5) displayed the highest average Gr of 1.88 ± 1.34 × 10-2 % d-1. Positive net calcification in waters corrosive to aragonite was also confirmed by measurements of total alkalinity repeatedly performed over the course of the incubation, showing a continuous decrease during the long-term incubation in the highest CO2 treatment. There was no statistically significant relationship between average growth rates and pCO2 concentrations (Kruskal-Wallis ANOVA on ranks, H = 1.46, P = 0.482).
I want to expand on a couple of their statements. First, even when the chemistry predicted that the ocean waters would actively erode and dissolve the coral skeleton … it didn’t happen. In waters where it should have dissolved, it didn’t.
But the most important finding was the final one, which I can paraphrase as:
Coral growth rates are not related to CO2 levels.
It’s not even that CO2 doesn’t affect growth levels much. They’re not related at all. As the paper said,
There was no statistically significant relationship between average growth rates and pCO2 concentrations
Even the highest CO2 levels tested, far above anything in the coming century, couldn’t stop the corals from growing, heck, it didn’t even slow them down. In other words, life wins out once more, against all odds. Gotta love it.
w.
PS—for those interested in the carbonate chemistry of the ocean, there’s a great calculator here.
I have a friend who worked for CSIRO (she no longer works there). Her team did a study a couple of years ago on the Great Barrier Reef and their conclusions were very interesting. And so was CSIRO Board’s response to the study.
Her team found that there was no evidence of damage to the GBR from lowering alkalinity (rising CO2 in the water) and found that in scenarios where alkalinity dropped, sea temperature rose and sea levels rose that the GBR actually flourished and would increase in size and diversity. They found the only evidence of damage was due to tourism, fishing and storms (cyclones). A further conclusion was that cyclones act as a “vacuum cleaner” of sorts on the GBR and cleans up the reef allowing a faster and stronger bounce-back (sort of like how bushfires rejuvenate forests).
The CSIRO Board refused the paper to go public or published, cancelled the study and threatened dismissal if any on the team went public. They did not want the study to become publicly available and wanted to maintain their public message that human CO2 will destroy the GBR. I’m very happy to see reef studies like this coming out now as it validates the work my friend did whilst at CSIRO. I’m sure she will be very happy to hear of this.
How did they lower pH with CO2 and still maintain bicarbonate levels high enough for the corals to lay down calcium carbonate?
If the bicarbonate levels are high enough for that, you can’t lower pH with CO2.
What the must be saying is that when CO2 levels rise high enough, long enough for the oceans to deplete all of it’s bicarbonate, corals don’t grow as fast………../snark
….or, in an aquarium, we can blast it with enough CO2 to deplete the buffer, and eventually lower the pH
Do these morons realize that in order to lower the pH of the oceans, the oceans would have to run out of buffer ….and that won’t happen unless denitrification stops first…and if denitrification stops…no one will care what the pH is
Alas, with Australia being home to the Great Barrier Reef, we are also home to the annual “the reef is dying” or “the reef will be dead in x years” from our well nurtured and very well funded Professor Ove Hoegh Guldberg.
In 1999, Hoegh-Guldberg warned that the Great Barrier Reef was under pressure from global warming, and much of it had turned white.
In fact, he later admitted the reef had made a “surprising” recovery.
In 2006, he warned high temperatures meant “between 30 and 40 per cent of coral on Queensland’s great Barrier Reef could die within a month”.
In fact, he later admitted this bleaching had “a minimal impact”.
In 2007, he warned that temperature changes of the kind caused by global warming were again bleaching the reef.
In fact, the Global Coral Reef Monitoring Network last week said there had been no big damage to the reef caused by climate change in the four years since its last report, and veteran diver Ben Cropp said this week that in 50 years he’d seen none at all.
jae says:
October 25, 2011 at 6:29 pm
Well, as a chemist (although only a specialist in a very distant area), I would be very surprised if the CO2 levels in the air can make ANY significant difference to the pH of the oceans, considering the enormous buffering that is available in those oceans.
===============
You could well be right. However, you need to keep in mind that the ocean is apparently near saturation in Ca++. And Calcium Carbonate is less soluble in warm water than cold but is also more soluble in acidic solutions than basic. So we potentially have this situation where warm oceans are trying to precipitate solid calcium carbonate while they absorb CO2 from the atmosphere forming 2H+ plus CO2– except that some of that is bicarbonate HCO3- and there are two crystal forms of CaCO3 with biological agents preferring to use the less stable form — Aragonite as well as or instead of Calcite.
If you are somewhat smarter than I, you may be able to work all that out, make everything balance, and figure out exactly what the consequences of increasing atmospheric CO2 would be for shell forming organisms. I have to say that I don’t have the slightest idea on a purely chemical/physical state basis what will happen.
I believe that once we get past the folks trying to simulate ocean acidification by adding Hydrochloric acid (not dumb exactly, but it won’t work), and get into experiments with injecting CO2 into sea water, we do find some affect on skeleton formation in corals — which is what Willis’ article is about, I believe. His point being that the corals quickly adjust to the new environment and go back to happily doing whatever it is that corals do.
Don K
October 25, 2011 at 4:24 pm
crosspatch says:
October 25, 2011 at 3:09 pm
When did modern corals first appear?
===========
What’s a “modern coral”? FWIW, The oldest known reef forming corals are Middle Ordovician (480 million years ago). There’s no reason to believe that their behavior re CO2 is any different than “modern” corals.
###
Modern corals show up in the record during the Triassic.
well did you ever – dry ice in tap water to change the pH
thanks but in my little lagoon I’m having trouble getting my hands on enough C because not only is there so much much buffer but then all these other little critters are floating getting a better deal.
And mind you I only want to do a home renovation.
Can they do dry ice takeaway ?
Good work Willis,
This shows once again that careful analysis over the required (longish) time frame always disproves the scary fairy stories told by AGW avocates.
“Over and over and over again, my friend,
We’re certainly NOT on the eve of destruction”
John M:
Your link shows up as this:
http://www.jodc.go.jp/info/ioc_doc/Experts/120608eo.pdf#8**
Right now that doesn’t download.
Any advice? Looks like it would be super to have!
Max
IIRC from readin a couple of papers on the subject, that Hoegh-Guldberg and his group(ies) are monitoring about 30 square metres of the GBR (Great Barrier Reef) to arrive at their conclusions. You have to read the paper to see the methodology.
The GBR is made up of thousands of individual reefs stretching well over 2500 km, covering an area of over 300,000 square km. The monitoring sample isn’t even 1 ppm. it’s 0.0001 ppm. or one in 10 thousand million. There aren’t enough people on the planet to take a sample that small from the human population.
BTW Willis: In Australia, the Prime Minister stated that the Great Barrier Reef is in danger of “assification”.
And we’re supposed to pay a tax on carbon to prevent that. Culling feral donkeys in the region.would seem to be a more effective, direct approach. That would leave only the tourist asses to threaten the reef.
The GBR will be dead as a doornail in a few thousand years anyway when a dropping sea level exposes it to the air. As we slide into the next glaciation, we will see sea levels drop and practically every single coral reef known today will be high and dry. Of course, new reefs will form, probably in the same places they existed in the last glaciation. But at the peak of the next glaciation, the current GBR will be some hundred meters above sea level.
Don K, what you say may be true but it is completely irrelevant to the discussion. The point is that regardless of what the exact CO2 number was in the Triassic, it is agreed by all that it was significantly higher than it is now, about 5x higher is the generally agreed to number.
And regardless of exactly how it came to be, the point is that corals of today’s sort of species first appear in the Triassic. You are attempting to drag bits of irrelevant information into the discussion to muddy the water when the fundamentals are quite clear and not in dispute. It doesn’t matter if modern corals appeared earlier or not, in fact, it would bolster my point because CO2 levels were even HIGHER earlier. In fact, it might have been a decline in CO2 levels that lead to some “great dying” if some fundamental bottom of the food chain species went extinct from lack of enough CO2.
In fact, it will be CO2 depletion in the atmosphere that results in life on earth perishing long before the Sun becomes too hot. As Earth cools and volcanism declines, less CO2 is emitted into the atmosphere. CO2 is relentlessly scrubbed from the atmosphere and once the scrubbing rate exceeds the emission rate, the amount of CO2 declines with some variations due to ocean warming and cooling but overall in decline. As the CO2 declines, plant species become less productive. As the plant species become less productive, the animal species which live on them become less productive and it progresses all the way up the food chain. At some point the plants can no longer support a self-sustaining population of animals and the animals die off one species at a time. Finally at some point life as we know it no longer exists save some extremophiles in various places. Life as we know it depends on at atmosphere with CO2 and the richer the CO2 content, generally the better conditions are for life as long as there is adequate oxygen. Now there will be bursts of CO2 injected as long as there is volcanism and plate tectonics but once the plates stop subducting, it is pretty much over. No CO2 bound up as limestone, marble, coal, or oil will be released into the atmosphere though volcanic activity once plate tectonics stop.
We are expected to reach that condition in less than 1 billion years. One estimate is that CO2 will start its unstoppable downward spiral in about 250 million years. In other words, we have one more cycle of crust turnover and that is it, it’s all over. Without the heat inside the earth driving plate tectonics, the life on the surface dies from lack of CO2. Humans are, effectively, natures way of boosting the carbon cycle and retuning CO2 to the atmosphere to give the Earth maybe a few million more years of life.
Let’s say a solution rises from pH 3.5 to pH 4. We’d describe it as becoming less acidic, rather than more alkaline, wouldn’t we? And we’d describe the process as de-acidification, not alkalization or basification, wouldn’t we? Therefore …
Here’s what I posted earlier on this matter:
Willis – It gets rid of its symbionts wholesale, and starts over again. But the reef abides.
L. pertusa is a “black” coral that resides at depths where the sun don’t shine, and thus it has no photosynthetic symbionts.
======
The most common and well-known deep-sea coral (DSC) species is Lophelia pertusa.
[…]
It has been suggested that there is a link between L. pertusa distribution and the presence of microseepage of light hydrocarbons (mostly methane) (Hovland et al., 1998). The frequent occurrence of L. pertusa at cold seep sites has been documented in the North Atlantic (Hovland and Thomsen, 1997) and on the upper Louisiana slope of the Gulf of Mexico (Schroeder, 2002; MMS PIs unpublished data). This may be a result of hard substrate availability from authigenic carbonate precipitation as a byproduct of anaerobic oxidation of methane (Aharon and Fu, 2000; Boetius et al., 2000). It may also be due to increased food availability as a result of locally enhanced chemosynthetic productivity. This possibility is currently under study by Fisher and Cordes as part of the ongoing MMS deep coral project on the ULS. Chemosynthetic production appears to constitute a small component of L. pertusa diet in relatively shallow Norwegian fiords, based on stable carbon isotope evidence (Mikkelsen et al., 1982). However, the importance of seep chemosynthetic production to corals may be significantly greater at greater water depth, where the input of good quality photosynthetically produced organic matter is greatly reduced.
http://www.tdi-bi.com/what's_new/sept05/chemoIII/Chemo write up.pdf
======
I guess that makes the rapid adaption more interesting.
I have spent a good part of my career finding buried fossil reefs on seismic profiles obtained by the dreaded companies. They were formed in a vast variety of geologic times and settings, and I would presume a vast variety of temperatures and ph’s.
AGW has been blamed for the decline of many of the planet’s reefs. It has always bothered me that when snorkeling on these reefs one encounters a huge range of temperatures, from cold upwellings to bathwater hot backreef flows. Can the coral really be that sensitive to a degree or two of temperature change? A minuscule change in acidity?
Recent articles document a string of events initiated by over fishing which inevitably damages a reef. I suspect that perturbation will prove to be much more important than subtle changes in temperature and chemistry.
Great read – including the comments 🙂
I haven’t had time to read all the comments, but this statement is suburb: “…That is the generally held view, that the ocean is ruled by chemistry. I hold the contrasting view, that the chemistry is not the last link in the chain. I say that the chemistry of the ocean is in turn ruled by life…”
It is not merely an aquarium which is too small to duplicate Nature. They have attempted to build “bubble” environments for humans, (in order to study problems that might occur in long distance space travel,) and they simply cannot get it right. Either CO2 levels or O2 levels or the levels of trace gases go all out of whack in their “bubble.” They try to tweak the levels of gasses by growing more or less alge in their “bubble,” but have to open the door and step out after not so long, because the air becomes unfit to breathe.
In other words, at this point our smartest thinking cannot do what nature does without thinking.
I am suspicious of any experiment which uses the “bubble” of an aquarium, and makes the claim it duplicates the vastness of the sea.
crosspatch says:
October 25, 2011 at 9:16 pm
Don K, what you say may be true but it is completely irrelevant to the discussion. The point is that regardless of what the exact CO2 number was in the Triassic, it is agreed by all that it was significantly higher than it is now, about 5x higher is the generally agreed to number.
=========
OK, I’ll tell you one more time and you can believe me or not as you choose. 5x is probably NOT a reliable number. It’s not impossible for it to be correct, or even for it to be an underestimate. But it most certainly is not agreed to by “all”. But yes, significantly higher than now is a very defensible position. It’s how I’d bet if I had to bet.
My experience over the past 70 years has been that when people tell me X is true and everyone agrees with it, much of the time, not only does everyone not agree with it, within a few decades, “everyone” agrees on something quite different. I’d say that about half of what I “knew” when I graduated from High School in 1956 is no longer operative. That is, in fact, why I don’t have much use for “climate science” Too much conjecture and “soft science” and not enough hard science to support the structure. The fact that they don’t seem to have a clue what caused the last glaciation, can’t persuade the ice core data to align with their theories, and can’t predict the next glaciation doesn’t help.
But don’t let me discourage you. You could be right, and I’d say that your chances of being right are considerably better than, say, James Hansen’s.
Willis, I do not have access to the paper
. Do they talk about the symbiotic organisms at all?
A simple minded explanation of why the first week and the increase in CO2 showed deterioration might hinge on the number of symbiotic organisms that they carried off with the samples. It may very well be that it took them a week to come up to the necessary populations for the health of the colony and CO2 has nothing to do with the deterioration.
So I guess my question is about control of the experiment. Did they keep a sample in a water tank with just what they thought original water/temperature conditions as a control? If yes, was the control healthy? If they are not discussing a control they have designed a bad experiment.
I like “less caustic”. 🙂
A final thought. I suspect that if one defined a three dimensional space with ocean pH (or atmospheric CO2 concentration) on one axis, ocean temperature on another, and exposure duration on the third, the region of the space where coral reefs can thrive would form a rather large blob. There would no doubt be areas where adding a little CO2 would push a given reef out of the “blob” and probably others where more CO2 might permit new reefs to form. Unless the “blob” shrinks dramatically or becomes distorted in some weird fashion when one of the parameters is altered , it’s likely that we (humans and corals alike) are somehow gonna survive.
Actually, there are. To one significant digit, it rounds to 1. Care to volunteer? Warning: vivisection is involved.
>;-p
Max;
That link worked fine for me; the 13MB file d/l’d in a few seconds.
And, to add to the fun, >3X thicker; hence pteranodons and giant dragonflies.
” Don’t be bitter!”, said Tom acidly.