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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strange how the cookie crumbles.
Global Garden Gets Greener – NASA Earth Observatory
earthobservatory.nasa.gov/Study/GlobalGarden/
For the most part, these changes were favorable for Earth’s vegetation. … impact of the last two decade’s climate changes on Northern Hemisphere vegetation, …
Merrick says:
January 3, 2014 at 7:13 am
“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.”
I would add that the foregoing applies to strong acid solutions, but not for sea water in the pH 8 range. Acidity is a measure of reactivity to hydroxide ion and in the case of sea water at pH 8 it is dominated by bicarbonate. Hydrogen ion concentration is so small at pH 8 that of course small changes in pH yield huge changes in hydrogen ion concentration on a percentage basis. That is how the bogus claim that we’ve increased the acidity of sea water by 30%. Of course on that basis, one could say that tap water is a 1000% more acidic than sea water.
So what they are saying is that local pH levels can vary wildly due to purely natural causes, and they are unable to find any actual damage to any organism as a result (or else they would have said so).
We should however be very alarmed about a far smaller, very long term change in the same parameter, because….
Are these guys familiar with the term “own goal”?
What I take away from this is that the reported natural, dramatic sic pH swings have little effect on quality of life in the estuaries. Therefore, the wringing of hands, gnashing of teeth, and declarations that “may be” we’re all gonna die because of ocean acidification is just more nonsense from these money grubbing parasites.
Oh, you mean fertilizin’ them ‘baccy fields does more than CO2? How can it be?
Thanks rgb, I’ve been trying to be more objective when it comes to reviewing studies and reports that appear. I recently completed a program in water engineering with an environmental monitoring component – part of my re-education since my retirement from the Canadian Navy – so I can easily relate to the complexity of water chemistry, especially when it comes to seawater.
BTW, when it comes to discussing acidification of the oceans, Oceanographers seem to forget that fresh water lakes will be the first to acidify and act as canaries to assess the impact of CO2 on acidification. What do the Limnologists say is happening?
It would be bad enough if a school associated itself with research publications that made excursions from their declared and ostensible goals to draw confident but flawed and feeble conclusions about global warming. It is egregious if that was why the paper slid past the referees and editors into print, and was just yet another obligatory declaration of fidelity and fealty to the dominant group-think meme and funding bias.
On the evidence, it was one or the other.
The focus on the Amazon which is so popular might have to draw in its horns, a little. Gas-exchange sats now indicate that it is not the “lungs of the world”; over a diurnal cycle, it produces as much CO2 and O2 as it absorbs. Its contribution is indirect: riparian and other runoff fertilizes ocean phytoplankton which consume the former and release the latter on balance. And it is apparently, however variegated, far from pristine and “fragile”: earthworks beneath the canopy now indicate widespread agricultural clearing before the Hibernian Holocaust destroyed the local economies. The current rainforest is mostly post-Columbian. Give the jungle an inch, … >;p
Could somebody please help me. I often argue these points with relatives. These relatives include a PHD scientist for EPA that tests water quality. Her description of her test equipment was “it can detect a grain a salt in an Olympic size pool.” Others include a graduate student of physics, an NIH research assistant to a Nobel laureate biochemistry scientist, a couple of graduate level students of biochemistry, and… I think you get my drift.
I, on the other hand, went into the Navy after High School. I’ve learned in the military and over the years (mostly self-taught) how to become a pretty fair programmer, systems analyst, and systems administrator. Therefore, I’m not at their educational level. I do have the countervailing influence that all of them will admit that I’m their intellectual equal.
I don’t like to argue from ignorance. If I don’t know – I don’t know. These are heavy weight people I debate with so I can’t afford to be wrong on the science. Especially in their field of specialty.
My understanding is that ph drops through several levels of alkalinity until it achieves base. From there it descends to acidity. It is my understanding that a decrease in alkalinity in no way, shape, or form, implies an increase in acidity. It is also my understanding that our ability to measure ph is not very accurate, that any measurement too far right of the decimal point is meaningless.
Is my understanding correct? Does it require re-learning or modification?
“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.”
Not according to what I have read on this excellent site. The cause is not certain and if humans are contributing it is a small proportion at best.
Merrick says: January 3, 2014 at 7:13 am “pH is, by definition, the measure of hydrogen ions in concentration….”
Not quite. The definition I was taught related to hydrogen ion activity, which can be a rather different figure in the presence of high concentrations of other ions and even suspended particles. Like in the sea.
Were these the studies in fish tanks with unrealistic levels of co2 added or the In situ studies? Here are some more studies showing how damaging ocean acidification can be to sea creatures. Hold onto your hats!
One year! Wow! This is indeed a very startling result. The evidence is clear and we must act now before we see large changes over ONE MONTH and even ONE DAY! Now what’s this?
H/t
http://joannenova.com.au/2012/01/scripps-blockbuster-ocean-acidification-happens-all-the-time-naturally/
http://joannenova.com.au/2012/2011/11/the-chemistry-of-ocean-ph-and-acidification/
“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.”
No, it reduces the ability of only SOME organisms to secrete aragonite from seawater. I believe that most of the studies using CO2 as the acidifier (not HCl or some other proton donor) have shown that most shelly fauna benefit, that is, make thicker or larger shells. Reasons for this may simply that more bicarbonate is available to the organisms, or that living shelly organisms actively modify the pH in the immediate vicinity of their tests, an adaptation one might expect for organisms dealing with large natural pH swings.
Hey Anthony, how come you never post the full link when you write “From Duke University” or from wherever? I always have to look it up. Not much work to do but it would be nice to have the full link to the actual article when you write “From XYZ”…
[Reply: Best to put this post in ‘Tips & Notes’. ~ mod.]
A reply from Zachary Johnson to me,
Hi Richard,
Thanks for the note. You’re right, there is quite a range currently allowed by the EPA in North Carolina (and many other states). And our measurements of pH did not exceed that range, so with the current regulations and observations I don’t think the EPA would take any action. Indeed, one of our goals was to get a good estimate of what normal natural variability is and how this compares to longer term (decadal) projections of increasing acidity (decreasing pH). With additional monitoring including at other sites in North Carolina and beyond, the EPA and other regulatory agencies will be able to better establish what is ‘normal’ to establish better guidelines to maintain a healthy environment for the long term. One of the broader goals of this type of study is to provide the best data and science available so that we (our society) can make informed choices.
All the best, Zackary