Trouble in paradise: Ocean acidification this way comes

Jan 05, 2012 By Cheryl Dybas
Something wicked this way comes: ocean acidification arrives in paradises like Mo'orea.Credit: NSF Moorea Coral Reef LTER Site

Double, double toil and trouble; Fire burn, and caldron bubble.---Shakespeare, Macbeth

Mo'orea, it's called--this island in French Polynesia that's been dubbed the most beautiful island in the world.

Here Tahitian breezes dance across crystal and beneath the tropical seas lies a necklace of that encircles Mo'orea like a string of brightly colored jewels.

Extensive reefs of a named Porites and other species form atolls, or reefs that ring Mo'orea's lagoons.

Porites are colonial corals, also known as Scleractinians, found in shallow tropical waters throughout the Indo-Pacific and Caribbean regions.

Think tropical reef and your mind's eye is likely seeing Porites.

These corals and other calcifying marine life, such as coralline algae, are also the world's primary reef-builders.  And therein lies the trouble.

The seas in which these calcifying species dwell are turning acidic, their pH slowly dropping as Earth's oceans acidify in response to increased carbon dioxide in the atmosphere.

As atmospheric carbon rises in response to human-caused carbon dioxide emissions, carbon in the ocean goes up in tandem.

Marine life that depends on calcium carbonate can no longer form shells or, in the case of coral reefs, skeletons.  Such marine life are found in waters that are more basic with a higher pH rather than a lower pH, which is more acidic.

Porites reefs, say scientists Peter Edmunds and Robert Carpenter of California State University at Northridge, are among the most sensitive of all corals.

Carpenter and Edmunds are two of the lead scientists at the National Science Foundation's (NSF) Mo'orea Coral Reef Long-Term Ecological Research (LTER) site, one of 26 such LTER sites around the globe.

Mo'orea is the only coral reef site in NSF's LTER network. It is funded by NSF's Divisions of Ocean Sciences and Environmental Biology.

To study the effects of ocean acidification on corals and other calcifying organisms, the biologists have been awarded an NSF SEES (Science, Engineering, and Education for Sustainability) Ocean Acidification grant.

We need to understand the chemistry of ocean acidification and its interplay with other marine processes--while Earth's seas are still hospitable to life as we know it, according to David Garrison, director of NSF's Biological Oceanography Program.

Carpenter and Edmunds hope to learn how fast--and the specific mechanisms by which--ocean acidification is affecting Mo'orea's corals and calcified algae, before the island's pristine reefs join dead and dying corals lining tropical coastlines around the world.

"Is there a way of sustaining healthy coral reefs when our oceans are acidifying?" asks Edmunds.

"Marine animals and plants from pteropods--delicate, butterfly-like plankton--to hard corals and coralline algae are affected by ocean acidification, as are the microbes that fuel ocean productivity and influence the chemical functioning of seawater.

"Corals like Porites, with their extensive distribution in tropical waters, may be ocean 'canaries in the coal mine.'"

At the current rate, he and Carpenter believe, coral reefs could disappear by the turn of the next century.

"The loss of biodiversity," says Carpenter, "would be devastating to the world's oceans--and to all of us. Tourism and fishing, in fact, entire economies, depend on coral reefs."

The scientists' recent findings are cause for hope, however. Porites, it turns out, may be developing an ability to counteract the effects of ocean acidification.

When Edmunds exposed Porites to different water temperatures and pH levels, and to plankton called brine shrimp as a food source, he found that increasing the amount of plankton in the coral's diet reduced the effects of ocean acidification.

The results are published in a recent issue of the journal Limnology & Oceanography.

"It's an intriguing mechanism," says Edmunds. "As seawater became more acidic, the corals continued to deposit calcium carbonate [new hard skeleton]. Although ocean acidification reduced the overall ability of coral tissue to calcify, the corals responded to more food by adding more tissue."

Edmunds thinks that the extra plankton food may allow the coral to "bulk up," thereby changing its internal structure and increasing its ability to manufacture skeleton even in acidifying waters.

"It's a very important finding that corals can mitigate the effects of ocean acidification," says Garrison. "It will be important to uncover the specific mechanism, and to establish whether other species have this ability."

And whether, says Edmunds, it might allow Porites to survive in the more acid oceans of the future.

Edmunds and Carpenter found that the response of tropical reefs to may be species-specific, with some species of corals and coralline algae affected more than others.

They've also discovered that more acid oceans may lead to changes in patterns of biodiversity in a high-carbon dioxide world.

If the tropical seas cauldron continues to bubble with waters turning to acid, the scientists say, it will indeed lead to double, double toil and trouble--for the most beautiful island in the world, and for coral reefs around the globe.

Ultimately, it will affect the sustainability of life on a planet that--made up of 70 percent oceans--might better be called Water than Earth.

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tadchem
2.7 / 5 (12) Jan 05, 2012
As long as the pH is above 7.0 the ocean is not 'acidic.' It is alkaline. What is being called 'acidification' is actually 'neutralization' - a shift of pH towards 7.
Carbon dioxide and water form a buffer system. The effect of the addition of acid or alkali is muted by the shifts in the equilibria between carbonic acid, bicarbonate, and carbonate, according to Le Chatelier's Principle.
Adding CO2 only increases the buffer strength of the system, while formation of calcium carbonate decreases the buffer strength.
As long as the pH lies between 6.37 and 9.19 the predominant form of caron in the oceans will be as bicarbonate - the most biologically available form of carbon, and the one used by coral to form reefs.
Xbw
1.8 / 5 (23) Jan 05, 2012
I think I remember reading somewhere that when carbon dioxide in the ocean increases, the algae and various plantlife that feed on it increase as well. It's balance in nature. Go figure.
kaasinees
3.2 / 5 (17) Jan 05, 2012
I think I remember reading somewhere that when carbon dioxide in the ocean increases, the algae and various plantlife that feed on it increase as well. It's balance in nature. Go figure.

Yeah except these are harmful algae that damage other organisms, go figure, the green algae and plankton levels are too low.
NotParker
1.7 / 5 (24) Jan 05, 2012
Measuring present and past pH levels are no more than a wild ass guess.
GSwift7
2 / 5 (24) Jan 05, 2012
A study released in December showed that coral reefs have a natural daily fluctuation in Ph, due to the sun and the daily cycle of the living things there. They checked multiple locations at multiple reefs. They found that the Ph value swings up and down in response to that daily cycle. The daily max and min values already exceede the predicted level due to man made co2 over the next century. From that, it is obvious that coral can easily adapt to a small change made by man over a long time frame. They also found that coral exposed to more acidic water (lower Ph) actually increases its rate of shell production to compensate.

Those organisms are very old. They have survived extreme climate change many times. This should be obvious to anyone who studies them. The above article is pure propaganda, and I suspect they know it. They HAD to see the report about the daily Ph fluctuations.
Vendicar_Decarian
3.6 / 5 (17) Jan 05, 2012
Have you been a Moron all your life ParkerTard?

"Measuring present and past pH levels are no more than a wild ass guess." - ParkerMoron
Caliban
3.3 / 5 (12) Jan 05, 2012

I recommend checking (at the very least) wiki for "ocean acidification" for the facts, before making any judgements or pronouncements regarding the mechanism and effects of it based on this shoddily written article.

Skepticus_Rex
2.2 / 5 (18) Jan 06, 2012
Many of the corals we see today originated during the Middle Triassic period.

rCO2 levels ppm of atmosphere (based on Ekhart et al. 1999):

Early Triassic: 1000 ppm

End Triassic: 2500-3000 ppm

Many species of corals survived the End Triassic extinction event. It took them a long time to recover from that one but recover many of them did. A few new species even came out of that evolutionary stressor.

Many of the same species of corals survived through the period 10,000 years after the Cretaceous-Tertiary period, with pCO2 levels estimated at 2,300 ppm. (See Beerling et al. 2002).

We are in no real danger of reaching CO2 levels that high from mankind's contribution of CO2 to the atmosphere via so-called fossil fuels.
GSwift7
2.2 / 5 (17) Jan 06, 2012
Here's the reference for my previous comment:

http://www.ploson....0028983

It was done by Scripps Institute and several different branches of University of California, so not exactly a big oil funded, conservative group here. They are saying that natural variability is larger than AGW effects, and that nobody knows what effect AGW might have. Here's a quote:

Natural variability may occur at rates much higher than the rate at which carbon dioxide is decreasing ocean pH, about 0.0017 pH/year. This ambient fluctuation in pH may have a large impact on the development of resilience in marine populations, or it may combine with the steady effects of acidification to produce extreme events with large impacts


Their figure 2 shows graphs of the pH at various locations. Very informative.

P.S. The wiki pages on environmental stuff suck. Stick to official sources if you want the truth.
GSwift7
1.8 / 5 (19) Jan 06, 2012
Notice the rate of AGW pH change: .0017 pH/year.

Then compare that to the natural variability: .024 at the most stable site, and 1.43 at the most variable site.

So the most stable site (an outlier) saw 14 times more variability in just 30 days than the predicted annual AGW change. The least stable site (another outlier) saw 841 times more variability in 30 days than the AGW annual change. It looks like the mean for the "normal" (non-outlier) sites is somewhere around .5 pH over the 30 day period, and that's 294 times more than the AGW annual change.

Keep in mind that natural rain water is slightly acidic (pH below 7), so every time it rains the ocean gets way more acidic (for a short time) than any amount of co2 could cause.

The article above is highly misleading, and it only took me a few minutes to figure that out. Too bad most people are too lazy to cross-reference sensational articles and fact check them.
Skepticus_Rex
1.7 / 5 (17) Jan 07, 2012
Most people will not check the facts and will be frightened back into believing in spite of the new data that contradict portions of this study. The IPCC and others of their ilk will see to that.

Mankind's contribution of CO2 will never reach the levels of the End Triassic and Cretaceous-Tertiary periods and if the corals survived levels as high as that of those periods, they will survive the paltry levels that eventually will get there by the influence of man.
gregor1
1.3 / 5 (14) Jan 08, 2012
Please read this and then decide for yourself which article is the more rational
http://online.wsj...028.html
Ronan
4 / 5 (12) Jan 08, 2012
GSWift: I'm physically capable of surviving repeated, temporary exposure to air tainted with 400 ppm of hydrogen sulfide, but force me to breath it 24-7, and I'm going to croak. Likewise for the corals; they're capable of surviving repeated, daily exposures to conditions under which carbonate sequestration is difficult--because those unpleasant conditions are punctuated by more favorable ones.

Skepticus Rex: I'd point out that in the circumstances you mention, CO2 levels were not merely high, but had been high for a prolonged period of time, and had not been suddenly boosted to those levels. As a result, the organisms of the time--corals included--had had time to evolve the necessary adaptations to live in such a world. Transplant a Triassic coral into today's seas, and it would likely be fine and dandy with a drop in oceanic pH; in fact, it might even welcome it. But the today's corals haven't evolved to deal with the conditions that we're throwing at them.
Skepticus_Rex
1.9 / 5 (17) Jan 08, 2012
Ronan,

Many of the same corals today also were Triassic species. They evolved during this period and continue to exist with little change to the present day. They still carry the same genes to survive high CO2. I highly doubt that any species that came through the Triassic period--and they are most species alive today--will be killed off by today's conditions.

As I have written elsewhere, mankind's contribution of CO2 to the atmosphere never will reach Triassic and K/T levels. It is not possible with current supplies of fossil fuels. It is most likely they will be gone long before anything like that happens.

For the longest time, people thought that warming seas would wipe out certain corals but they surprised us. They expelled their symbiotic algae and took up other species in response and ended up surviving and recovering.
Ronan
4.5 / 5 (2) Jan 09, 2012
Skepticus Rex: Hm. Full caveat, here; I am by no means an expert on the evolutionary history of corals, so my knowledge on this subject comes from what I can find by scrounging about on the internet, and it is wildly possible that I may be misinterpreting what I'm finding. However, http://coral.aims...ion.html this seems to indicate that your statement about the longevity of coral species is incorrect; it shows extensive speciation between now and the Triassic-Jurassic extinction, and even explicitly notes that a full 3/4ths of modern coral genera did not exist before the Eocene. Where are you getting your information?
Ronan
5 / 5 (1) Jan 09, 2012
As for your latter point, I'm still attempting to find information on the total carbon reserves (coal, oil, tar sands, etc.), so I've no immediate response--although I do know that there's very great uncertainty in the quantities of some sources of carbon (methane clathrates, particularly; there are estimates for how much methane is lying out there, locked in ice, but unless things have changed recently I know that they aren't very good estimates). Furthermore, like I said before the issue is not necessarily the absolute values of either temperature or CO2 that are reached, but the rate at which they change. I have no doubt whatsoever that given proper time to acclimate, Earth life would be fine and dandy with five or more degrees of warming, relative to now--If it had time to evolve to deal with it. But we're not giving it time, and that's the problem.
GSwift7
2 / 5 (8) Jan 09, 2012
Ronan, if you choose to argue against the Scripps Institute, which I quoted above, then I can't help you. Scripps are experts in marine biology, and strong supportes of marine ecosystem conservation. If anyone wanted to lie and say that the coral was safe when it actually isn't, Scripps wouldn't be the ones to do it. The same goes for the University of California. In fact, with so many different branches of UC involved, I find it hard to imagine how you can think to argue against all of those people. I linked to cutting edge, current, published, peer reviewed scientific literature, and you respond with some nonsense analogy? You think that makes sense?

You want to see what kills coral? Look at the Bahamas and surrounding islands where tourism has exploded in the past few decades (same in tropical pacific). Waste water from humans is causing massive outbreaks of disease in aquatic species (not just coral). It has nothing to do with co2. They need waste water treatment, not co2 traps.
Ronan
5 / 5 (1) Jan 09, 2012
Hm...You're right. No, I don't think that makes sense. In looking over what I wrote, the certainty with which I phrased that analogy was definitely unjustified. I would point out, though, that the basic idea is not unjustified, nor was it an example of "arguing against (Scripps and UC)." In the paper itself, they are careful to note:
Ronan
5 / 5 (2) Jan 09, 2012
For all the marine habitats described above, one very important consideration is that the extreme range of environmental variability does not necessarily translate to extreme resistance to future OA. Instead, such a range of variation may mean that the organisms resident in tidal, estuarine, and upwelling regions are already operating at the limits of their physiological tolerances (a la the classic tolerance windows of Fox see [68]). Thus, future acidification, whether it be atmospheric or from other sources, may drive the physiology of these organisms closer to the edges of their tolerance windows. When environmental change is layered upon their present-day range of environmental exposures, they may thereby be pushed to the guardrails of their tolerance [20], [68].


They do, of course, also emphasize that the wide ranges of pH observed may indicate that corals are more robust than thought, as you noted. That is not, however, necessarily a safe conclusion to jump to.
GSwift7
1 / 5 (4) Jan 09, 2012
In regard to coral, on the bright side, there's been some promising results in the past few years!

A handful of places in the Bahamas, where they were having notable problems with aquatic disease outbreaks, actually installed some simple (cheap) water quality control measures. The ecosystems in those places rebounded immediately. The rate of turnaround was remarkable (one year), and encouraging, because such dramatic success leads to funding to do the same in other places (unless you want to base your resort on the concept of being a museum of dead coral reefs?)
StarGazer2011
1 / 5 (4) Feb 07, 2012
Skeptikus_Rex, GSwift7: Congratulations, you got Ronan to think for a moment :)
@Ronan: Keep digging, you will find nothing is as it seems in the world of post normal science.
StarGazer2011
1.4 / 5 (9) Feb 07, 2012
In other hilarious 'coldWarming' news (warming is cooling now you know)... Actual observations of actual coral show their growth has increased by 23%. And to a greenie pseudo-scientist coral growing is just as unsustainable as coral dying, so its bad whatever happens, and demands more funding :)
http://www.abc.ne...3899.htm

Note the completely speculative doomsaying at the end:
"There will be a threshold beyond which the corals are not happy with and they'll just slow their growth down."

How could he know? Before he did the research he expected coral to by dying, instead its growing 23% faster, note the 'pathological science' where he is unable to consider that his theory may be wrong.

97% of published american climate scientists are wrong.
barakn
1 / 5 (1) Mar 02, 2012
Stargazer posted a link to a story about southern hemisphere corals growing at the southernmost (coldest) edge of their range, in the Indian ocean. Then, by not noting any of these facts, lets everyone reading his/her/its post assume that all corals are experiencing this 23% growth. How did the scientist know "There will be a threshold beyond which the corals are not happy with and they'll just slow their growth down?" Because that's exactly what happened further north in the same ocean, especially the 1998 event that killed up to 90% of the coral in some shallow Indian reefs.