Claim: Local factors cause dramatic spikes in coastal ocean acidity

From Duke University

Fluctuation ‘adds insult to injury’ for marine creatures

DURHAM, N.C. – A new Duke University-led study has documented dramatic, natural short-term increases in the acidity of a North Carolina estuary.

“The natural short-term variability in acidity we observed over the course of one year exceeds 100-year global predictions for the ocean as a whole and may already be exerting added pressure on some of the estuary’s organisms, particularly shelled organisms that are especially susceptible to changes in pH,” said Zackary I. Johnson, Arthur P. Kaupe Assistant Professor of Molecular Biology at Duke’s Nicholas School of the Environment.

The short-term spikes in the acidity of the estuary were driven by changes in temperature, water flow, biological activity and other natural factors, the researchers said. And they are occurring in addition to the long-term acidification taking place in Earth’s oceans as a result of human-caused climate change.

“For vulnerable coastal marine ecosystems, this may be adding insult to injury,” said Johnson, who was lead author of the study.

When the effects of long-term ocean acidification and short-term natural variation combine, they can create “extreme events” which may be especially harmful to coastal marine life, he said.

The study was conducted at the Pivers Island Coastal Observatory at the Duke Marine Lab in Beaufort, N.C., as part of a long-term coastal monitoring program. Researchers collected seawater samples from Beaufort Inlet weekly for a year and on a daily and hourly basis for shorter periods to track changes in the water’s pH and dissolved inorganic carbon on multiple time scales.

Numerous studies have shown that increasing amounts of atmospheric carbon dioxide from human sources are finding their way into the world’s oceans. When the carbon dioxide dissolves in seawater, it reduces the water’s pH and the ability of organisms to form calcium carbonate minerals that are the building blocks of many species’ shells and skeletons. This process is known as ocean acidification.

If current trends continue, experts predict that the mean ocean pH will decrease by about 0.2 units over the next 50 years. A drop of that magnitude could have far-reaching effects on ocean ecosystems and organisms.

“We may see significant changes in biological processes such as primary production,” said Dana Hunt, assistant professor of microbial ecology, who co-authored the new study. “Some organisms, such as phytoplankton, may benefit. Many others, including shelled organisms and corals, will not.”

The Duke team’s analysis showed that a wide range of natural variables, including changes in temperature, algal production and respiration, and water movement caused by tides and storms, triggered sharp spikes in the inlet’s acidity. Some changes occurred over the course of a season; others took place on a daily or hourly basis.

“Understanding to what extent pH naturally varies in coastal ecosystems worldwide will be essential for predicting where and when the effects of increasing ocean acidity will be most profound, and what organisms and ecosystems may be most affected,” Hunt said. “Our research demonstrates we have to take into account a wide range of environmental variables, not just pH.”

The study appears in the peer-reviewed open-access journal PLOS ONE.

###

Johnson and Hunt’s co-authors were research technician Benjamin Wheeler, doctoral student Christopher Ward and former undergraduate Christina Carlson, all of Duke; and Sara Blinebry, a student intern from Carteret County Community College. Blinebry is now a research technician in Johnson’s lab. Carlson is now a policy research assistant at the Union of Concerned Scientists.

The study was funded by National Science Foundation grants to Johnson and Hunt and through private support through Duke’s Nicholas School.

CITATION: “Dramatic Variability of the Carbonate System at a Temperate Coastal Ocean Site (Beaufort, North Carolina) is Regulated by Physical and Biogeochemical Processes on Multiple Timescales,” by Zackary I. Johnson, Benjamin J. Wheeler, Sara K. Blinebry, Christina M. Carlson, Christopher S. Ward, Dana E. Hunt. PLOS ONE, Dec. 17, 2013. DOI:10.1371/journal.pone.0085117

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Sweet Old Bob

The magical CO2 strikes again. Sarc.

Stacey

“A new Duke University-led study has documented dramatic, natural short-term increases in the acidity of a North Carolina estuary.”
I assume these very clever scientists mean a reduction in alkaninity?

Kevin Lohse

Surely as the ocean is an alkaline solution, any change in pH should be described as a reduction or increase in alkalinity rather than in terms of acidity? Failure to do so brings into question the authors basic understanding of High School Chemistry and encourages the supposition that any science in the paper has been twisted to conform with the CAGW narrative.

R. de Haan

“Our research demonstrates we have to take into account a wide range of environmental variables, not just pH.” That’s it. They have performed a study for the BS article they produce but they have absolutely nothing.
Don’t send your kids to Duke University unless it has been your objective to breed “Morons” from the beginning.

R Babcock

I have sailed around these estuaries for years. There are innumerable swamps upstream and on the edge of these that contain enough tannic acid to stain your boat brown. A good rain or a change in wind will drive these waters out into the currents and changes can occur fairly rapidly. Plus this area is extremely shallow.
Maybe not the best place to conduct a “representative” study. Of course, Duke has their research center located there so it is much easier to go out the back door of the building and drop a water bottle in than to set up multiple locations that require someone getting in a boat on bad days.

Steve Keohane

Reduced alkalinity… Oceanic acidification always reminds me of Nektar’s second album, ‘A Tab in the Ocean’.

BioBob

What they don’t tell you:
1) aquatic organisms EAT CO2 and carbonate ions when they grow causing order of magnitude pH shifts of higher pH to 9 – 10 from ~8 of the water that surrounds them
2) sea water has massive buffering capacity so that while local water pH may shift, subsequent mixing will generally quickly restore prior equilibrium.
Conclusion: ocean life is already adapted to the usual changes in local pH far larger than the pitiful “long term .2 pH units” observed from air CO2 concentrations.
Just more tales “full of sound and fury; signifying nothing.”

Andyj

Acidity occurs around remote beach front hotels. usually where the climate kiddies have been drinking too much pop ‘n eating too much poop from the day before they scoop the water and start pushing local trees over clinging for life on the old exposed coral beds.
The fact of the matter is, the warmer the water, the less CO2 stays in solution.

R. de Haan

How stupid this article is becomes evident when you replace acidity with warming and Ph by temperature.
Claim: Local factors cause dramatic spikes in warming.
Conclusion: “Our research demonstrates to take into account a wide range of environmental variables, not just temperature”.
I think I go fishing.

knr

‘ acidification’ what a nice ‘scary ‘ word , while the scientifical more accurate ‘less base’ is rather boring. But then what matters is the ‘message’ not the data
Makes you wonder given these animals evolved and have been around for hundred of thousands or even millions year how they managed to last this long given all the past changes in ocean ‘acidification’.

hunter

The real take is that the marine environment is very robust and capable of handling a wide range of conditions, including dynamic pH.

geek49203

Better URL:
http://nicholas.duke.edu/news/local-factors-cause-dramatic-spikes-coastal-ocen-acidity
Last I checked, the Duke Foundation people had spent well north of $1 billion on global warming stuff.

M Courtney

The natural short-term variability in acidity we observed over the course of one year exceeds 100-year global predictions for the ocean as a whole…

Sounds like the ocean can buffer the effects of the river quite effectively then. Which is a positive sign.

John

Scientists are just now beginning to discover just how variable pH can be in different marine ecosystems. For example, on the west coast, depending on whether there is substantial upwelling or not (it varies), pH can vary from about 7.8 to about 8.1. A few years ago, nobody knew this could happen, at least in the published literature. The Scripps Institute study which made the findings above sampled something like 18 sites worldwide, and found that even in the least variable parts of the oceans, pH wasn’t constant.
You can say that it isn’t the natural variability that is the problem, but the small added CO2-induced reduction in pH. That certainly seems backwards: if natural organisms can tolerate wide swings in pH, it speaks to resiliency, not to fragility.
We need long term studies, such as are now happening in the Great Barrier Reef, where you take a natural system with all its complexity, and then you add CO2 with bubblers, so that you get an area with pH that is lower by about .2 points, with the effect diminishing with distance from the bubbler. You can then look at what happens in the natural world, with the pH of 2100 or thereabouts. THAT is when you can find out if there are any deleterious effects.
The reason you have to do this is partly that lab studies won’t get you the answer, but partly because many of these sea creatures, whether with shells or not, were around at the end of the Eocene, when CO2 levels were about 1,100 ppm, plus or minus. They survived then, so they may well have the genetic capability to deal with 600 ppm of CO2 and the pH that results. Of course, there are likely to be some CHANGES, yes. But do we take apart western economies because of changes in ecosystems that let all creatures survive, but just change the balance? Let’s see what capabilities these creatures really do have. We need real science.
And despite the attempt at fear mongering from these scientists (or perhaps their PR people), they are doing real science, their problem isn’t the science, but the fear mongering in the press statement.

Louis Hooffstetter

This looks like a non-issue to me. One local factor I didn’t see mentioned is the presence of natural tannic acids in the tributaries that flow into these estuaries. Swamps and rivers in the southeast are typically the color of coffee/cola with pH values in the range of 3 to 5. This is due to relatively high levels of tannic acids released during the decomposition of plant matter in the surrounding forests and marshes. It’s nothing new and nothing bad. Estuarine ecosystems evolved with these natural influxes of acidic water. As a result, estuarine organisms have likely adapted to these natural pH fluctuations. One would expect Duke University Ph.Ds who study these environments to know that.

Leo Morgan

My stars! This is as scary as if long term Global Warming was compounded by horrific things called ‘winter’ and ‘summer’. Or maybe just ‘day’ and ‘night’. How will the ecosystem survive?
Oh wait. What they’re calling acidification is just neutralisation. The sophistry of shysters does not will intellectual assent from any honest person.

Gail Combs

R Babcock says: @ January 3, 2014 at 5:25 am
I have sailed around these estuaries for years. There are innumerable swamps upstream and on the edge of these that contain enough tannic acid…
>>>>>>>>>>>>>>
Tannic acid is just one of the organic acids found in swamps.
I had the displeasure of titrating water from the Merrimack river (MA) (aka swamp water) to figure out how much KOH to add to the deionized water for each batch to bring the pH into the correct range. Since we were in a drought fresh rain water caused the swamps to be ‘Flushed’ every time it rained. so the amount changed wildly from day to day and even batch to batch on the same day.
My boss insisted I come up with a standard amount to add and fired me when I refused to do the impossible.
Reality bit her but good when she came up with a standard amount, ruined a large number of batches and joined me in the unemployment as the VP of manufacturing got back from vacation.
Don’t you love Karma? :>)

JFB

Oh God! Now that the first card of the annual pack failed (Antarctic melting) they soon come to the second card, played every year in November and March (ocean acidification)
Look at the two annual peaks clearly here: http://www.google.com/trends/explore#q=ocean%20acidification
This is getting too predictable…
Later came: tornadoes, permafrost, hurricanes, ocean acidification again, blah, blah, blah

Leo Morgan

Oops re typo. Should have read:
…Does not earn intellectual assent from any honest person.

Myron Mesecke

If a reduction in alkalinity is called acidification then I want to see Minute Maid advertize its reduced acid orange juice as alkalized orange juice.

Leon Brozyna

When I see phrases such as “long-term ocean acidification,” I see the purported study as being nothing but eco-activism run amok. I would be more receptive to the message if it used such terms as “long-term ocean neutralization.”
But then, science has prostituted itself to keep the funding spigot open, so they choose the “correct” hot-button phrases. Just keep on pushing the panic mode … eventually the wolf will eat the boy.

Roberto

Call this stuff “Tabloid” publication. Fact light, and emotion heavy. “What your acidity reveals about your bio-future.”
That’s not necessarily bad. As Mark Steyn pointed out one time, at least the tabloids are recognizing that they can’t take their audience for granted. They have to write in an interesting style.

wolfman

North Carolina has blackwater and brownwater rivers/estuaries, and I believe that the Duke laboratory is near the confluence of both of those types of rivers. The changes relate to lots of factors, and the study notes that the observed changes are natural. Then, the speculation begins on adding CO2 to the process. The assumption is that there will be incremental impacts from a trend to lower pH for the estuaries and ocean. However, as noted above, this doesn’t account for the dynamics of ocean current, upwelling, or biological responses and adaptations. They assert that shellfish will definitely be harmed, which needs to be studied in real estuaries and oceans–not just in the lab. The suggested study around the Great Barrier reef is a great suggestion, but it also needs to be done in other marine environments with different geological and biological components and biological systems.
As noted above, the study is useful, but the speculation exceeds what was shown.

MarkW

LEt me see if I have this right. There are huge natural variations in acidity that organisms have no trouble dealing with. On the other hand the small changes caused by CO2 are going to cause everything to die?

papertiger

@ Gail Combs says: January 3, 2014 at 6:07 am
Sounds like your boss was a Duke alumna.
Duke must have run short on students to abuse.

Merrick

pH is, by definition, the measure of hydrogen ions in concentration and therefore, by definition, the measure of acidity. There is absolutely nothing wrong with saying that the alkalinity is decreasing (technically, that would be measured by pOH), but there is also nothing wrong with saying the acidity is increasing – when pH goes down (and therefore hydrogen ion concentration goes up) the acidity is increasing. Critisize the work on it’s merits.

Bryan A

I can see the Ships now…Ships…Jobs…
A Fleet of tankers whose purpose is to traverse the seas, sucking up low PH water into processing tanks, increasing the PH to slightly above “normal levels”, then expelling the treated water back into the oceans. The process could even be what propells the ships.
someone slap me, I’m in a geoengineering nightmare

Tom J

Well, the following two paragraphs in this posting pricked my curiosity:
‘Johnson and Hunt’s co-authors were research … and former undergraduate Christina Carlson, all of Duke; and Sara Blinebry, a student intern from Carteret County Community College. Blinebry is now a research technician in Johnson’s lab. Carlson is now a policy research assistant at the Union of Concerned Scientists.
The study was funded by National Science Foundation grants to Johnson and Hunt and through private support through Duke’s Nicholas School.’
Now, maybe it indicates a bias of mine, but I think a student intern from a community college is, perhaps, in a little over their head when they’re involved in research that’s intended to impact national and global policy. But, then again, it must be an inspiring thing to be involved in changing the world. Except of course when it all goes wrong. And, also taking part in this research we have Christina Carlson who’s now a policy research assistant at that important world bettering organization; Union of Concerned Scientists. But of particular satisfaction to my curiosity was to discover some things about one of the funders of this research (or, should I say several funders since it was all of us): the National Science Foundation. On NSF’s own website was the following:
‘NSF Notice of Intent to Revise American Recovery and Reinvestment Act (ARRA) Award General Terms and Conditions to Ensure Project Completion by September 30, 2013’
For whatever reason was the NSF a part recipient in the nearly trillion dollars in stimulus funds that was thrown to the winds back in 2009? And, was this research one of the ‘shovel ready’ projects designed to get us all re employed? I don’t know. But, before anybody puts too much stock in this science I think it’s a question worthy of being asked. And, out of the legions of students leaving college with no job prospects, at least the stimulus may have employed two, eh?

johnmarshall

Ocean water has the same chemistry for 400Ma through extreme CO2 changes without causing acidification. pH has remained within its natural variability above pH 7.0.
Estuary waters will have enormous variations because of the fresh water feed. Nothing to do with CO2.

michael hart

Typical.
Neither “insult” nor “injury” is in the published article, because the authors know full well that they are not justified. But they can say what they want in the press release.
A bit of perspective from the article

If the carbonate system was in equilibrium and the sole driver of changes in pH, elevated levels of DIC would directly lower pHT. However, based on time-lagged correlation the summer minimum in pHT precedes the maximum in DIC by ~2 months pointing to different mechanisms driving their respective extremes (Figure S2). Over the annual cycle pHT is strongly correlated with temperature (r2=0.68), whereas DIC is most strongly correlated with salinity (r2=0.69) (Figures 1 and S3).

They have measured nothing that looks strikingly new, nor anything that looks alarming. Pretty much what you would expect from the text books. If they are just learning how to use the instrumentation and practice their techniques, then fair enough.

Michael Jankowski

What an incredible finding…short-term variability exceeds long-term trends and projections! I wonder if we can apply this to temperature, precipitation, and other parameters, lol. Eureka…it works!

Gail Combs

papertiger says: @ January 3, 2014 at 6:53 am
…Sounds like your boss was a Duke alumna…
>>>>>>>>>>>>>
Actually it gets even better.
She had a recent degree in Chemistry from a MA school. The poor troubleshooter from the DI equipment company did analysis on several samples of the water from different times I collected for him. Therefore we KNEW there were all sorts of nasty organics in the water like Putracine and that they changed over short periods of time. Unfortunately the woman was only looking at how to advance up the corporate ladder and did not realize all the toes she had stepped on would come back to bite her.
According to a friend, a chem engineer, who attended the high level meeting on why the plant was losing so much $$$, the VP asked where I was and why I had not fixed the problem. When he found out I was fired he stated. “I knew I should have gotten rid of that B…h – Fire her!”
(I was the person they assigned sticky production problems to at that plant and others.)
I think Prof. Chris(tmas) Turkey is looking at a very similar situation. He has stepped on a lot more toes than he realizes.
MORE Popcorn!

The report said;
‘If current trends continue, experts predict that the mean ocean pH will decrease by about 0.2 units over the next 50 years. A drop of that magnitude could have far-reaching effects on ocean ecosystems and organisms.’
The mean average means that there will be measurements substantially above and substantially below. If someone would like to confirm the actual ph obtained in this study I will find out the ph of our local estuary. I suspect there will be a substantial difference which the marine eco systems haven’t noticed. Can I get funding for this?
tonyb

Jim Clarke

John says:
January 3, 2014 at 5:53 am
“That certainly seems backwards: if natural organisms can tolerate wide swings in pH, it speaks to resiliency, not to fragility.”
John is exactly right. This story parallels the whole global warming crisis. The alarmist argue that the small change produce by humans will be a catastrophe, while ignoring or remaining willfully ignorant of the much larger, natural variability that already exists, in which organisms survive quite nicely.
This study clearly reveals the resiliency of these environments and indicates that the small changes that humans will produce will probably have no noticeable impact, but such a conclusion would certainly result in the end of all funding for study. The funders are simply not interested in non-issues, so the authors have to spin their conclusions 180 degrees to remain relevant and active scientists.
This all stems from one of the main myths of modern environmentalism, which holds that the biosphere was in perfect balance and harmony until the nasty human creatures came along and started mucking around with the Divine Gaea. The reality is that the Earth has always been a dynamic place to live, and it is that dynamic that makes life on Earth so resilient.
Modern environmentalists do not like change, but this study (along with all other similar studies) indicates that change (in the form of large, natural variability) is inevitable and vitally important to the environment. Consequently, we must conclude that modern environmentalism is fundamentally anti-environment.

Steve

Does anyone still understand the difference between “interpolation” and “extrapolation”? When I was in engineering school years ago they taught us that while interpolation usually worked, extrapolation gives unreliable results. Duke has started a nice study but to extrapolate as they did is completely irresponsible.

Kevin Kilty

Leo Morgan says:
January 3, 2014 at 6:07 am
My stars! This is as scary as if long term Global Warming was compounded by horrific things called ‘winter’ and ‘summer’. Or maybe just ‘day’ and ‘night’. How will the ecosystem survive?

Exactly! Here is a related thought I found amusing …“For vulnerable coastal marine ecosystems, this may be adding insult to injury,” said Johnson, who was lead author of the study…. Which is the insult and which is the injury, here? Are the natural variations the insult or injury? A tsunami of group-think possibly overwhelms the trickle of new knowledge.

Richard Sharpe

The real take is that the marine environment is very robust and capable of handling a wide range of conditions, including dynamic pH.

Since the dominant paradigm in Biology and related fields is evolution and natural selection, surely the organisms in those environment have already been selected to handle such fluctuations.

Is this a search for a pH Hockey Stick?
When natural variation is large and some scientist goes looking for a trend, it takes some very hard work to get a significant result. Not happening in this case, I think.

tadchem

“When the carbon dioxide dissolves in seawater, it reduces the water’s pH and the ability of organisms to form calcium carbonate minerals that are the building blocks of many species’ shells and skeletons.”
How in heck are the organisms supposed to form carbonate minerals *without* CO2?
Also the actual pH of the water is not mentioned. A ‘pure’ aqueous CO2 solution has a pH of 6.37; any lower pH must come from some other acid such as the humic and fulvic acids formed by the action of O2 and water on organic materials.

knr

Merrick so why do you think they go for ‘acidification’ rather than ‘alkalinity is decreasing ‘?
The data be dammed its all about the message , could be climate ‘science’ motto , and ‘acidification’ gives nice scary message.

de_mol

In the Cambrian, CO2 levels were way up, in the atmosphere around 7000 ppm. Since there was presumably equilibrium over these million of years (Henry’s law), the levels were way up in the oceans as well.
http://www.klimaatfraude.info/images/smallCO2-600k.jpg
The Cambrian is known as the period when live exploded. So I can not see any problem with any acidification of the oceans. Life in the oceans are proven to be very resilient.

Matt Skaggs

Huge swings in coastal pH were also documented during the sleuthing as to what was causing commercial oyster die-offs off Washington state. Turns out that the native Olympic oysters thrive under these conditions, the imported Japanese oysters not so much.

Keitho

My take is that the hourly/daily/monthly and annual variations in ocean pH measured by this team exceed the change expected from MMCO2 over a century.
Pffft.

Ivor Ward (aka Disko Troop)

How do you “insult” a shellfish?

Aussiebear

Lets get this straight. They put their instruments into the estuary for a YEAR, and got readings that went up and down. Their readings were local and different “and exceeds 100-year global predictions for the ocean as a whole”. Apples and Oranges folks. Local variations will always trump some modelled/projected mean.

richard

classic stupidity ,
so lets take a look at what the EPA rules and regulations allow in North Carolina.
http://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/upload/oa_state_info_nov2010.pdf
North Carolina: “Saltwater pH: shall be normal for the waters in the area, which generally shall range
between 6.8 and 8.5 except that swamp waters may have a pH as low as 4.3 if it is the result of natural
conditions.”

richard

it would help if they stated what they measured that PH to be at the moment.

Kevin Kilty

Gail Combs says:
January 3, 2014 at 6:07 am

Very amusing story. Even in well educated nations only about a sixth of the college educated people have any acquaintance with science. I assume you are a chemist. Your bad boss was a recent chemistry grad with much lesser ability; but to the average person you are both chemists and what the bumbler says and thinks has weight equal to yours. This is the origin of much bad policy.

rgbatduke

I have sailed around these estuaries for years. There are innumerable swamps upstream and on the edge of these that contain enough tannic acid to stain your boat brown. A good rain or a change in wind will drive these waters out into the currents and changes can occur fairly rapidly. Plus this area is extremely shallow.
Maybe not the best place to conduct a “representative” study. Of course, Duke has their research center located there so it is much easier to go out the back door of the building and drop a water bottle in than to set up multiple locations that require someone getting in a boat on bad days.

I actually teach at the Marine Lab in the summers, and usually live in a house right next to Pivers Island that looks out through the inlet gap into the Atlantic. The rocks around the island are covered with oysters. There are oyster reefs lining the estuary. Barnacles grow on any hard surface immersed in the water for as little as a week — a folding chair of ours blew into the creek at the beginning of one summer and I hooked it while fishing three weeks later and dragged it back up — now decorated with barnacles. What they are really doing is noting that local hard shelled organisms such as barnacles, clams (also abundant and prolific), and oysters are remarkably tolerant to variation in ocean pH, and of course this is a good thing because the ocean pH can vary substantially seasonally, daily, hourly depending on the rain, the wind, the temperature, and more.
It seems to me that they’ve basically shown that if the worst-case projections of GCMs are correct, the globe warms, and the ocean’s overall pH drops by 0.2 that many of the organisms that might be threatened are evolved to tolerate that because that is within the range of the “noise” of natural variation. If the change occurs slowly, over years, there is plenty of time for natural selection to further enhance their tolerance, because these species are highly prolific. There is even time for UN-natural selection to work — at this point we could go in and tinker with the genes of these animals to enhance their tolerance of lower pH or could actively breed tolerant organisms in the lab.
This is old news, anyway. It verifies what was reported by Scripps last year:
http://joannenova.com.au/2012/01/scripps-blockbuster-ocean-acidification-happens-all-the-time-naturally/
There are two important points here. One is that the change in the pH of the open ocean (as opposed to coastal pH that can easily change due to multiple factors) is so small that it is difficult to observe at least on the comparatively few graphs I’ve seen of it. Global pH change appears to be like global SLR or global warming — more often observed as local pH change, where any systematic worldwide effect is completely swamped in all sorts of noise and local chemical dynamics. The other is that in most of the places where pH does change dramatically over comparatively short timescales, usually driven by alterations of e.g. ocean upwelling of CO_2-rich colder water — if organisms couldn’t tolerate the change they wouldn’t exist there. And in many cases, they don’t! This is much more an issue of marginal local habitats than it is a global issue.
Could this be a serious issue? Sure. Even small changes in water chemistry or ecology could be fatal for sensitive organisms living in a marginal habitat. We’ve certainly wiped out species by polluting inland waters with agricultural runoff or by accidentally introducing competing species from around the globle. Humans have had a major impact on global microecologies time and again, and have without question directly driven numerous species to extinction. Is it a bad idea to drive species to extinction? Sure. They are part of the genetic wealth of the world. We are just beginning to realize how valuable the little chemical factories various species have evolved to solve local problems really are. Also, while local ecologies as a whole are rather tolerant (they have to be!) if you tear enough holes in them they can certainly collapse, and that is usually going to be bad.
But like SLR, it is observed more in the predictions of future disaster than in some immediately apparent observable/measurable change that can be definitively attributed to anthropogenic CO_2.
Oh, by the way — to the nice individual above who asserted that children sent to Duke are destined to become morons — if any of your children are fortunate enough to be the one applicant in ten that is accepted at the University, I think that it is almost certain that a) they are not a moron; b) they ain’t never gonna be a moron, barring accidents that damage their brains; c) they are going to get a world-class education. The University is tolerant of dissenting opinions and diverse viewpoints. I have stood on Pivers Island and expressed my personal doubts about the predictive skill of GCMs and the possibility that the scientific case for catastrophe is being overstated for political reasons to my students. They have listened, in some cases expressed their own doubts, in others raised points that support the possibility of catastrophe. That is called reasoned discourse, and it does not produce morons, it produces individuals who aren’t afraid to doubt accepted beliefs and who are capable of making up their own minds before deciding things.
Lots of research like this is currently being done at Pivers Island by undergraduates. That by itself is impressive — undergraduates participating in actual research is awesome, as by doing so they MUST confront critical issues, learn to understand the variability of data, learn to deal with confirmation bias. Yes, the work so far is far from systematic even locally, but it is a decent first step. The knowledge they have gained and presented is useful, and whether or not their “interpretation” of that knowledge survives the test of time is really beside the point. This serves to reinforce the Scripps observations linked above that local estuarine pH often varies — perhaps even usually varies — by amounts as great or greater than the proposed worst-case acidification projected by the IPCC. Their paper might, in other words, eventually prove part of the evidence that undermines their own interpretation (or not!) but that, too, is the point of research. If you already knew the answer, why would you look?
rgb

R. de Haan says:
January 3, 2014 at 5:22 am
Don’t send your kids to Duke University unless it has been your objective to breed “Morons” from the beginning.

And while you are at it, make sure to cheer against the university’s basketball and football teams all the time. To give you motivation (as if you need any), there is an excellent book on why everyone hates Duke, especially Duke basketball: http://www.google.com/search?tbo=p&tbm=bks&q=isbn:1250008190.
Being serious, although I hate the Duke athletic department because I am a UNC fan, do not let this one report affect your viewpoint on the education you receive at Duke. It really does provide some of the best education money can buy. Duke is one of the best medical colleges in the US and thus has one of the best hospitals in this country. If I needed major surgery, Duke hospital is the first place I would want to be. Do not judge the many by the actions of a few.