Ocean Acidification: Global Warming's evil twin
If you’ve seen one envirokook rant on ocean acidification, you’ve seen a hundred. Due to the failure of satellite temperature data to keep the global warming dream alive, as well as an ever-growing mountain of paleo-climatological evidence displaying that our current climate is neither without precedent or a “tipping-point”, a harbinger of mankind’s eventual extinction—Progressive ecokooks, who seek a mandate to control your life—are looking to ocean acidification as their savior.
Ocean acidification is going to destroy marine life & cause irreparable damage to our biosphere, this is something that must be addressed (with a slew of heavy-handed mandates from Washington & trillions in wealth redistributed of course) or we will regret it.
If global temperatures continue to fail to cooperate, look for ocean acidification to play a larger role in the ecokook playbook. One thing that needs to be mentioned first is the apparent Democrat/Collectivist/Ecokook failure to understand Freshman science. A pH migrating from 8.0 to 7.5 for example, is not acidifying. Far from it—have these clowns taken a gander at a pH scale? Apparently not. Going from a pH of 7.3 to 7 for example, is also not acidification.
It’s moving towards acidification, but 7.5 & 7 are not an acid. Unless of course you’re an ecokook & then you can make up your own science. So, if anyone tells you that X is acidifying, ask them to show you the peer-reviewed evidence of a pH <7.0.
Now, let’s get to numerous examples in peer-reviewed literature demonstrating that ocean acidification isn’t happening (even to the extent the ecokooks say it is), nor is it a problem for mankind or the wildlife in our oceans & seas. Neither is this “ocean acidification” unprecedented.
A history of pH levels in the South China Sea. Recent decades have to be unprecedented, right? These low pH values have never happened before, never happened before man’s evil inventions began wreaking havoc on the planet. You see, you have to give up this lavish lifestyle “for the greater good.” This will require sacrifice folks, this will require a lot less freedom & if you’re an entrepreneur, probably a lot more of your money.
It’s for the collective good you see; Washington has a good track-record with this power & you should just trust them. What does the science say?
- Working with eighteen samples of fossil and modern Porites corals recovered from the South China Sea, the nine researchers employed 14C dating using the liquid scintillation counting method, along with positive thermal ionization mass spectrometry to generate high precision δ11B (boron) data, from which they reconstructed the paleo-pH record of the past 7000 years that is depicted in the figure below.
- As can be seen from this figure, there is nothing unusual, unnatural or unprecedented about the two most recent pH values. They are neither the lowest of the record, nor is the decline rate that led to them the greatest of the record. Hence, there is no compelling reason to believe they were influenced in any way by the nearly 40% increase in the air's CO2 concentration that has occurred to date over the course of the Industrial Revolution. As for the prior portion of the record, Liu et al. note that there is also "no correlation between the atmospheric CO2 concentration record from Antarctica ice cores and δ11B-reconstructed paleo-pH over the mid-late Holocene up to the Industrial Revolution."
- Further enlightenment comes from the earlier work of Pelejero et al. (2005), who developed a more refined history of seawater pH spanning the period 1708-1988 (depicted in the figure below), based on δ11B data obtained from a massive Porites coral from Flinders Reef in the western Coral Sea of the southwestern Pacific. These researchers also found that "there is no notable trend toward lower δ11B values." Instead, they discovered that "the dominant feature of the coral δ11B record is a clear interdecadal oscillation of pH, with δ11B values ranging between 23 and 25 per mil (7.9 and 8.2 pH units)," which they say "is synchronous with the Interdecadal Pacific Oscillation."
- Going one step further, Pelejero et al. also compared their results with coral extension and calcification rates obtained by Lough and Barnes (1997) over the same 1708-1988 time period; and as best we can determine from their graphical representations of these two coral growth parameters, extension rates over the last 50 years of this period were about 12% greater than they were over the first 50 years, while calcification rates were approximately 13% greater over the last 50 years.
- Most recently, Wei et al. (2009) derived the pH history of Arlington Reef (off the north-east coast of Australia) that is depicted in the figure below. As can be seen there, there was a ten-year pH minimum centered at about 1935 (which obviously was not CO2-induced) and a shorter more variable minimum at the end of the record (which also was not CO2-induced); and apart from these two non-CO2-related exceptions, the majority of the data once again fall within a band that exhibits no long-term trend, such as would be expected to have occurred if the gradual increase in atmospheric CO2 concentration since the inception of the Industrial Revolution were truly making the global ocean less basic.
Wait, there’s more on the South China Sea & pH variability over long time-frames:
- Hoping to add at least some insight into the dearth of knowledge surrounding historic pH trends, Wei et al. set out to develop an annually-resolved long-term seawater pH record for the region of the northern South China Sea. They did this by analyzing the annual rings for 159 years in a Porites coral, coral growing in Longwan Bay, 2 km off the east coast of Hainan Island (19.29°N, 110.66°E). The ratio of Boron-11 to Boron-10 (the two stable isotopes of Boron) in the growth rings is related to the acidity of the surrounding water.
- As shown in the figure below, Wei et al. note their seawater pH reconstruction reveals the presence of large decadal-scale variability, with significant periodicities at approximately 18 and 5.6 years as revealed by power spectral analysis. The mean pH over the 159-year period was 8.04 and annual pH values ranged from 7.66 to 8.40. Additionally, they report an insignificant linear trend in the data of -0.00039 ± 0.00025 pH unit per year, amounting to a decline of 0.062 pH unit across the length of the record. Statistically, “Insignifcant” means the trend cannot be distinguished from zero.
- Several important points can be made in regard to Wei et al.’s reconstruction. First, model-based reconstructions have calculated a theoretical 0.1 pH drop in oceanic seawaters in response to the CO2 that has been emitted into the atmosphere since pre-industrial times. The changes measured in the Porites coral were not significantly different from zero, which is what real-world data shows. This suggests the models may well be overestimating the amount of CO2 that is being dissolved into the oceans and thus inflating the potential impacts of so-called ocean acidification. Second, it is clear from viewing Figure 1 that there are numerous natural swings in pH that occur over relatively short time intervals (1-3 years) in which the pH either rises or falls by more than 0.3 unit. Indeed, it is not uncommon for the pH to rise or fall by twice this amount over a period of 1 to 2 years to a decade. The significance of this second point is noted in the fact that marine life is clearly able to survive and thrive under natural swings in oceanic pH over the course of two or three year periods that are twice as large as the pH decline that is predicted to occur by theoretical models over the course of the next century. The fact that they can successfully endure these rapidly recurring events in so short a time interval gives considerable pause to alarmist concerns that they can’t endure or adapt to the much smaller pH change predicted to occur over the next century or more.
- The authors write that "natural variability in pH is seldom considered when effects of ocean acidification are considered," and they suggest that this omission is disturbing, because "natural variability may occur at rates much higher than the rate at which carbon dioxide is decreasing ocean pH," which is about 0.0017 pH unit per year according to Dore et al. (2009) and Byrne et al. (2010). And because of this fact, they contend that "ambient fluctuation in pH may have a large impact on the development of resilience in marine populations," noting that "heterogeneity in the environment with regard to pH and pCO2 exposure may result in populations that are acclimatized to variable pH or extremes in pH."
- To further explore this possibility, Hofmann et al. recorded continuous high-resolution time series of upper-ocean patterns of pH variability with autonomous sensors deployed at fifteen different locations stretching from 40.7303°N to 77.8000°S latitude and from 0 to 166.6712°E longitude and 0 to 162.1218°W longitude, over a variety of ecosystems ranging from polar to tropical, open-ocean to coastal, and kelp forest to coral reef.
- The eighteen researchers report that their measurements revealed "a continuum of month-long pH variability with standard deviations from 0.004 to 0.277 and ranges spanning 0.024 to 1.430 pH units," which variability was "highly site-dependent, with characteristic diel, semi-diurnal, and stochastic patterns of varying amplitudes."
- Directly quoting Hofmann et al., "these biome-specific pH signatures disclose current levels of exposure to both high and low dissolved CO2, often demonstrating that resident organisms are already experiencing pH regimes that are not predicted until 2100." And these facts suggest that the current real-world heterogeneity of the world's oceans with regard to pH and pCO2 exposure may indeed "result in populations that are acclimatized to variable pH or extremes in pH," such as those that have been predicted to be the new norm in 2100.
I don’t think I need to add anything to that other than many of the “end time” proclamations uttered by organizations such as the Sierra Club, Greenpeace, the Nightly Snooze shows (antique media) & a number of taxpayer-funded government institutions are generalized & purposely-packaged to elicit fear. Here’s another factor in ocean pH variance, ocean upwelling.
- In 2002, Scripps’ esteemed oceanographer Walter Munk argued for the establishment of an Ocean Observation System reporting, “much of the twentieth century could be called a “century of undersampling” in which “physical charts of temperature, salinity, nutrients, and currents were so unrealistic that they could not possibly have been of any use to the biologists. Similarly, scientists could find experimental support for their favorite theory no matter what the theory they claimed.” Due to that undersampling MIT’s oceanographer Carl Wunsch (2006) likewise noted, “Among the more troublesome distortions now widely accepted, one must include the notion that the ocean circulation is a simple “conveyor belt” and that the Gulf Stream is in danger of ‘turning off’.”
- Another such favorite theory, mistakenly offered as a fact, speculates we are now witnessing increasing anthropogenic ocean acidification, despite never determining if current pH trends lie within the bounds of natural variability. Claims of acidification are based on an “accepted scientific paradigm” that “anthropogenic CO2 is entering the ocean as a passive thermodynamic response to rising atmospheric CO2.” Granted when all else is equal, higher atmospheric CO2 concentrations result in more CO2 entering the oceans and declining pH. But the ever-changing conditions of surface waters exert far more powerful effects. Whether we examine seasonal, multi-decadal, millennial or glacial/interglacial time frames, ocean surfaces are rarely in equilibrium with atmospheric CO2. Relative to atmospheric CO2, seasonal surface water can range up to 60% oversaturated due to rising acidic deep water. Due to the biological pump, CO2 concentrations can be drawn down, leaving surface waters as much as 60% under‑saturated (Takahashi 2002). Thus we cannot simply attribute trends in surface water pH to equilibration with atmospheric CO2. We must first fully account for natural ocean cycles that raise acidic waters from deeper layers and the biological responses that pump CO2 back to ocean depths.
- [note: in this essay I use “acidic” in a relative sense. For example, although the pH of ocean water is 7.8 at 250 meters depth and is technically alkaline, those waters are “more acidic” relative to the surface pH of 8.1.] […]
- In Bates 2014, A Time-Series View of Changing Surface Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification, they simplistically argued declining ocean pH is “consistent with rising atmospheric CO2”. But a closer examination of each site used in their synthesis suggests their anthropogenic attribution is likely misplaced. For example, at the Hawaiian oceanic station known as HOT, based on 10 samplings a year since 1988, researchers reported a declining pH trend. But that trend was not consistent with invasions from atmospheric CO2. An earlier paper (Dore 2009) had observed, “Air-sea CO2 fluxes, while variable, did not appear to exert an influence on surface pH variability. For example, low fluxes of CO2 into the sea from 1998–2002 corresponded with low pH and relatively high fluxes during 2003–2005 were coincident with high pH; the opposite pattern would be expected if variability in the atmospheric CO2 invasion was the primary driver of anomalous DIC accumulation.” (DIC is the abbreviation for Dissolved Inorganic Carbon referring to the combined components derived from aqueous CO2, including bicarbonate and carbonate ions.)
- Those higher fluxes of CO2 into the surface likely stimulated a more efficient biological pump resulting in higher pH. That rise in pH is consistent with experimental evidence demonstrating CO2 is often a limiting nutrient (Riebesell 2007), and adding CO2 stimulates photosynthesis. That most photosynthesizing plankton have CO2 concentrating mechanisms suggests CO2 is often in chronic short supply.
- The greatest concentrations of CO2 upwell from depth to invade surface waters. As seen below in the illustration by Byrne 2010 from the northern Pacific, the ocean’s pH (thus the store of DIC) rapidly drops from 8.1 at the surface to 7.3 at 1000 meters depth. Dynamics such as upwelling bring deeper waters to the surface reducing pH, while dynamics such as the biological pump shunt carbon back to deeper depths and raise surface pH. At the risk of oversimplifying a myriad of complex dynamics, oceans basically undergo a 4-phase cycle that determines the average annual surface pH. Any adjustments to this cycle will alter trends in pH over decadal to millennial time periods. […]
- As illustrated in the Evans et al graph below, coastal upwelling can over‑saturate the surface waters to 1000 matm, 2.5 times above atmospheric pCO2 (represented by dashed horizontal line). Within weeks the biological response sequesters and exports that carbon so that concentrations of surface water CO2 fall as low as 200 matm; a concentration that would still be under-saturated relative to the Little Ice Age’s atmosphere. Relative to these rapid seasonal changes in pH, fears that marine organisms cannot adapt quickly enough to the relatively slower changes wrought by anthropogenic CO2 seem overblown.
- Still such fears filter researchers’ interpretations. Along the west coast of North America, planktonic sea snails called pteropods, begin life feeding on algal blooms ignited by seasonal coastal upwelling. As illustrated in scanning electron micrograph “a”, shown below from (Bednarsek 2014), pteropod shells are heavily dissolved during the first few weeks of life due to acidic upwelled water. Picture “b” shows a larger more mature shell with the outer part of the shell experiencing no dissolution. As the snails matured, either upwelled acidic waters subsided or the snail was transported seaward to less acidic waters by the same currents that promoted upwelling. The result is pteropod shell dissolution is a very localized, short duration phenomenon.
- Nonetheless in a study sponsored by NOAA’s Ocean Acidification Program Bednarsek 2014 argued those examples of shell dissolution were caused by anthropogenic carbon writing, “We estimate that the incidence of severe pteropod shell dissolution owing to anthropogenic OA has doubled in near shore habitats since pre-industrial conditions across this region and is on track to triple by 2050.” But such “conclusions” are unsupported speculation at best. The study failed to determine if upwelled waters were any more acidic now than during any other seasonal or La Nina upwelling event. Most studies suggest upwelling declined during the Little Ice Age, and the resumption of stronger upwelling is the result of a natural cycle. But Bednarsek (2014) simply used a formula equilibrating past and present atmospheric CO2 to compute surface water pH. But such methodology is meaningless. No net CO2 diffusion from the atmosphere to surface waters occurs when upwelling has oversaturated surface pCO2, and as shown in the Evans et al graph, due to the biological pump surface waters remained undersaturated relative to both current and LIA atmospheric CO2. Shame on those NOAA scientists for such biased interpretations.
And we have this as well:
- The oceans are dying, says . . . just about everyone. Well at least the New York Times, which reported last month that “Ocean Life Faces Mass Extinction, Broad Study Says.” And the Times never makes any factual mistakes; I checked to make sure this story wasn’t from Gail Collins. But to my amazement, there’s a broad study out in the latest issue of BioScience, a premier journal in the Oxford University family, written by eight scientists from universities on several continents, that bravely takes issue with the conventional wisdom. “Reconsidering Ocean Calamities” argues that there is an “absence of robust evidence” for many of the most common claims about ocean perils. Even though the article is written in the usual dry and technical language of scientific journal articles, it is not hard to make out that the authors think a lot of the popular claims, such as ocean acidification, are exaggerated or badly overestimated. It takes direct aim at some of the leading catastrophist journal articles: […]
- The authors walk through a number of purported ocean calamities, debunking or qualifying them one by one. Of special note is their argument about ocean acidification from CO2: “[T]here have been a few claims for already realized impacts of ocean acidification on calcifiers, such as a decline in the number of oysters on the West Coast of North America (Barton et al. 2012) and in Chesapeake Bay (Waldbusser et al. 2011). However, the link between these declines and ocean acidification through anthropogenic CO2 is unclear. Corrosive waters affecting oysters in hatcheries along the Oregon coast were associated with upwelling (Barton et al. 2012), not anthropogenic CO2. The decline in pH affecting oysters in Chesapeake Bay (Waldbusser et al. 2011) was not attributable to anthropogenic CO2 but was likely attributable to excess respiration associated with eutrophication. Therefore, there is, as yet, no robust evidence for realized severe disruptions of marine socioecological links from ocean acidification to anthropogenic CO2, and there are significant uncertainties regarding the level of pH change that would prompt such impacts.”
The author of that N.Y. Times rag (Carl Zimmer) did make a feeble attempt (see the comments section at the Powerline post I linked to) to paint the authors of “Reconsidering Ocean Calamities” as those who rigidly-support the “hair-om-fire” doomsday scenarios.
Sure, they recognize that overfishing could be a huge problem, but if you read through their entire paper, their conclusions are nowhere near (despite Zimmer attesting that he contacted two of the authors, but I only see quotes from one) Zimmer’s apocalyptic themes. I find it funny when some of these people look through the fossil record (chock-full of mass extinctions) to find evidence that we’re on the verge of an extinction level event.
Carl Zimmer will vomit-forth some catchy-quotes, some “we may see some reaalllly bad stuff by 2100” nonsense, but when one considers the items I’ve already covered (as well as the upcoming material)—I think it’s reasonable to conclude the Zimmer has a central-planner’s approach, he has an agenda. I also find it funny & irritating when they assert “corals have declined by 40%” but not time-frame is given. A lot of things have hit peaks & valleys over many millennia, but not to get off the subject.
Here’s the vaunted IPCC on ocean acidification:
- For this issue, I looked at the topic of ocean acidification and fish productivity. The SPM [Summary for Policy Makers] asserts on Page 17 that fish habitats and production will fall and that ocean acidification threatens marine ecosystems.
- “Open-ocean net primary production is projected to redistribute and, by 2100, fall globally under all RCP scenarios. Climate change adds to the threats of over-fishing and other non-climatic stressors, thus complicating marine management regimes (high confidence).” Pg 17 SPM
- “For medium- to high-emission scenarios (RCP4.5, 6.0, and 8.5), ocean acidification poses substantial risks to marine ecosystems, especially polar ecosystems and coral reefs, associated with impacts on the physiology, behavior, and population dynamics of individual species from phytoplankton to animals (medium to high confidence).” Pg 17 SPM.
- So, the IPCC agrees that ocean acidification is a serious problem due to rising CO2 emissions from burning fossil fuels. What does it say in the Working Group Reports? But wait a minute. Let’s see what is in the working group reports that are written by scientists, not politicians.
- WGII Report, Chapter 6 covers Ocean Systems. There we find a different story with more nuance and objectivity: “Few field observations conducted in the last decade demonstrate biotic responses attributable to anthropogenic ocean acidification” pg 4
- “Due to contradictory observations there is currently uncertainty about the future trends of major upwelling systems and how their drivers (enhanced productivity, acidification, and hypoxia) will shape ecosystem characteristics (low confidence).” Pg 5
- “Both acclimatization and adaptation will shift sensitivity thresholds but the capacity and limits of species to acclimatize or adapt remain largely unknown” Pg 23
- “Production, growth, and recruitment of most but not all non-calcifying seaweeds also increased at CO2 levels from 700 to 900 µatm Pg 25
- “Contributions of anthropogenic ocean acidification to climate-induced alterations in the field have rarely been established and are limited to observations in individual species” Pg. 27
- “To date, very few ecosystem-level changes in the field have been attributed to anthropogenic or local ocean acidification.” Pg 39…
- Contrast the IPCC headlines with the Senate Testimony of John T. Everett, in which he said: “There is no reliable observational evidence of negative trends that can be traced definitively to lowered pH of the water. . . Papers that herald findings that show negative impacts need to be dismissed if they used acids rather than CO2 to reduce alkalinity, if they simulated CO2 values beyond triple those of today, while not reporting results at concentrations of half, present, double and triple, or as pointed out in several studies, they did not investigate adaptations over many generations.”
- “In the oceans, major climate warming and cooling and pH (ocean pH about 8.1) changes are a fact of life, whether it is over a few years as in an El Niño, over decades as in the Pacific Decadal Oscillation or the North Atlantic Oscillation, or over a few hours as a burst of upwelling (pH about 7.59-7.8) appears or a storm brings acidic rainwater (pH about 4-6) into an estuary.” […]
- Scientists have had pH meters and measurements of the oceans for one hundred years. But experts decided that computer simulations in 2014 were better at measuring the pH in 1910 than the pH meters were. The red line (below) [at the link] is the models recreation of ocean pH. The blue stars are the data points — the empirical evidence. What we have here is one of the basic foundations of the climate change scare, that is falling ocean pH levels with increased atmospheric CO2 content, being completely dismissed by the empirical ocean pH data the alarmist climate scientists didn’t want to show anyone because it contradicted their ‘increasing ocean acidity’ narrative.
And here’s a bit more on the NOAA hiding historical data on pH levels because a short-trend that validates their doomsaying is a lot more effective than a century’s worth of data that doesn’t validate their taxpayer-funded tripe.
- The science and engineering website Quest, recently posted: “Since the Industrial Revolution in the late 1700s, we have been mining and burning coal, oil and natural gas for energy and transportation. These processes release carbon dioxide (CO2) into the atmosphere. It is well established that the rising level of CO2 in our atmosphere is a major cause of global warming. However, the increase in CO2 is also causing changes to the chemistry of the ocean. The ocean absorbs some of the excess atmospheric CO2, which causes what scientists call ocean acidification. And ocean acidification could have major impacts on marine life.”
- Within the Quest text is a link to a chart by Dr. Richard A. Feely, who is a senior scientist with the Pacific Marine Environmental Laboratory (PMEL)—which is part of the National Oceanic and Atmospheric Administration (NOAA). Feely’s climate-crisis views are widely used to support the narrative.
- Feely’s four-page report: Carbon Dioxide and Our Ocean Legacy, offered on the NOAA website, contains a similar chart. This chart, titled “Historical & Projected pH & Dissolved Co2,” begins at 1850. Feely testified before Congress in 2010—using the same data that shows a decline in seawater pH (making it more acidic) that appears to coincide with increasing atmospheric carbon dioxide…
- The December edition of the scientific journal Nature Climate Change features commentary titled: “Lessons learned from ocean acidification research.” However, an inquisitive graduate student presented me with a very different “lesson” on OA research.
- Mike Wallace is a hydrologist with nearly 30 years’ experience, who is now working on his Ph.D. in nanogeosciences at the University of New Mexico. In the course of his studies, he uncovered a startling data omission that he told me: “eclipses even the so-called climategate event.” Feely’s work is based on computer models that don’t line up with real-world data—which Feely acknowledged in email communications with Wallace (which I have read). And, as Wallace determined, there is real world data. Feely, and his coauthor Dr. Christopher L. Sabine, PMEL Director, omitted 80 years of data, which incorporate more than 2 million records of ocean pH levels.
- Feely’s chart, first mentioned, begins in 1988—which is surprising as instrumental ocean pH data has been measured for more than 100 years since the invention of the glass electrode pH (GEPH) meter. As a hydrologist, Wallace was aware of GEPH’s history and found it odd that the Feely/Sabine work omitted it. He went to the source. The NOAA paper with the chart beginning in 1850 lists Dave Bard, with Pew Charitable Trust, as the contact.
- Wallace sent Bard an email: “I’m looking in fact for the source references for the red curve in their plot which was labeled ‘Historical & Projected pH & Dissolved Co2.’ This plot is at the top of the second page. It covers the period of my interest.” Bard responded and suggested that Wallace communicate with Feely and Sabine—which he did over a period of several months. Wallace asked again for the “time series data (NOT MODELING) of ocean pH for 20th century.” Sabine responded by saying that it was inappropriate for Wallace to question their “motives or quality of our science,” adding that if he continued in this manner, “you will not last long in your career.” He then included a few links to websites that Wallace, after spending hours reviewing them, called “blind alleys.” Sabine concludes the email with: “I hope you will refrain from contacting me again.” But communications did continue for several more exchanges.
- In an effort to obtain access to the records Feely/Sabine didn’t want to provide, Wallace filed a Freedom of Information Act (FOIA) request. In a May 25, 2013 email, Wallace offers some statements, which he asks Feely/Sabine to confirm: “…it is possible that Dr. Sabine WAS partially responsive to my request. That could only be possible however, if only data from 1989 and later was used to develop the 20th century portion of the subject curve.”
- “…it’s possible that Dr. Feely also WAS partially responsive to my request. Yet again, this could not be possible unless the measurement data used to define 20th century ocean pH for their curve, came exclusively from 1989 and later (thereby omitting 80 previous years of ocean pH 20th century measurement data, which is the very data I’m hoping to find).”
- Sabine writes: “Your statements in italics are essentially correct.” He adds: “The rest of the curve you are trying to reproduce is from a modeling study that Dr. Feely has already provided and referenced in the publication.”
- In his last email exchange, Wallace offers to close out the FOIA because the email string “clarified that your subject paper (and especially the ‘History’ segment of the associated time series pH curve) did not rely upon either data or other contemporary representations for global ocean pH over the period of time between the first decade of 1900 (when the pH metric was first devised, and ocean pH values likely were first instrumentally measured and recorded) through and up to just before 1988.” Wallace received no reply, but the FOIA was closed in July 2013 with a “no document found” response.
- Interestingly, in this same general timeframe, NOAA reissued its World Ocean Database. Wallace was then able to extract the instrumental records he sought and turned the GEPH data into a meaningful time series chart, which reveals that the oceans are not acidifying. (For another day, Wallace found that the levels coincide with the Pacific Decadal Oscillation.) As Wallace emphasized: “there is no global acidification trend.”
I don’t think these ecokooks like FOIA much, do you? This specifically covers The New York Times & an editorial they ran on ocean acidification. Even the NOAA told them they were blowing it out of proportion [Shallin Busch NOAA]:
- “OA is more of a future problem than a problem right now for the Great Barrier Reef. I think it is really important to resist the NYT editor’s impulse to say that OA is wreaking all sorts of havoc RIGHT NOW, because for ecological systems, we don’t yet have the evidence to say that. OA is a problem today because it is changing ocean chemistry so quickly. The vast majority of the biological impacts of OA will only occur under projected future chemistry conditions. Also, the study of the biological impacts of OA is so young that we don't have any data sets that show a direct effect of OA on population health or trajectory… It might be good to mention that some species will be harmed by OA, some will benefit, and some won’t respond at all!
Not exactly a ringing-endorsement of “the sky is falling” OA scenario is it? Do lower pH levels always depress calcification? Uh, no. We are worried about other marine organisms, but the ones that calcify (barnacles, coral, mollusks) are the primary concern as pH levels drop.
- In introducing their study, the authors write that "calcifying marine organisms such as molluscs and foraminifera, crustaceans, echinoderms, corals and coccolithophores are predicted to be most vulnerable to decreasing oceanic pH (ocean acidification)." They also, however, say there is a possibility for "increased or maintained calcification under high carbon dioxide conditions," and they go on to experimentally demonstrate the reality of this phenomenon in five different types of calcifying marine animals.
- What was done: Working with five different calcifying organisms - two gastropods (the limpet Patella vulgata and the periwinkle Littorina littorea), a bivalve mussel (Mytilus edulis), one crustacean (the cirripede Semibalanus balanoides) and one echinoderm (the brittlestar Amphiura filiformis) - Findlay et al. say they "measured either the calcium (Ca2+) concentration in the calcified structures or shell morphological parameters as a proxy for a net change in calcium carbonate in live individuals exposed to lowered pH," where the lower pH of the seawater employed was created by the bubbling of CO2 into header tanks.
- What was learned: "Contrary to popular predictions," as the six scientists remark, they found that "the deposition of calcium carbonate can be maintained or even increased in acidified seawater." In fact, they say that four of the five species they studied actually exhibited increased levels of calcium in low pH conditions. In the case of Littorina littorea, for example, they indicate that all morphological shell parameters - width, height, thickness, area, perimeter, aperture area and aperture perimeter - "increased in low pH treatments compared to the control," while noting that "there was ~67% more growth in shell height, ~30% more growth in shell width and ~40% more growth in shell thickness under low pH conditions compared to the control." And in another part of their study, they observed there was a large amount of dissolution taking place on isolated shells and arms of the creatures they studied; but they found that "the presence of a live animal within its calcium carbonate structure offset this dissolution."
- What it means: Findlay et al. say their findings demonstrate that "there is a great degree of biological control on calcification with complex links to other physiological processes," and that "increasing evidence in the literature agrees with the results of this [i.e., their] study," noting that: "McDonald et al. (2009) showed calcification in another barnacle species (Amphibalaus amphitrite) to continue, and possibly even increase, under low pH conditions (pH 7.4); Arnold et al. (2009) demonstrated larval lobsters (Homarus gammarus) were able to lay down calcium carbonate structure in pH conditions 0.3 units below the control levels; Checkley et al. (2009) showed young fish have enhanced aragonite otolith growth when grown under elevated CO2; Maier et al. (2009) showed that, although there was a decrease in calcification in cold-water corals, overall they showed a positive net calcification at aragonite saturation states below 1, and longer-term experiments suggest that these corals may actually maintain or even increase calcification over longer timescales at low pH (Schubert et al., 2010)."
Now let’s take a gander at Coccolithophores & their response to lower pH levels. They are a very important link in the biological food chain in the world’s oceans.
- The authors write that "laboratory studies are unrealistic in many respects and, because of their typically short timescales, preclude the possibility of evolutionary adaptation to the imposed change, a key uncertainty in OA [ocean acidification] research," citing Gattuso and Buddemeier (2000), Langer et al. (2006) and Ridgwell et al. (2009). And, therefore, they say it is "vital to complement laboratory experiments with observational studies of coccolithophores living in the natural habitats to which they are evolutionarily adapted."
- What was done: Focusing on two morphotypes (over-calcified and normal) of the world's most abundant coccolithophore species (Emiliania huxleyi), Smith et al. assessed their numbers, along with seawater carbonate chemistry and other environmental variables, at monthly intervals between September 2008 and August 2009 along a 1,000-km route, including over deep oceanic waters in the Bay of Biscay.
- What was learned: The fourteen researchers say their data "clearly show" that "there is a pronounced seasonality in the morphotypes of E. huxleyi," reporting "surprisingly" that "the over-calcified morphotype was found to dominate the E. huxleyi population in winter," in spite of the fact that seawater pH and CaCO3 saturation were lowest in winter. And the heavily-calcified form of E. huxleyi dominated dramatically, shifting from less than 10% of the total E. huxleyi population in summer to more than 90% of the population in winter.
- What it means: Smith et al. say they "do not suggest that the changing carbonate chemistry was necessarily responsible for this shift in morphotypes." However, they suggest that "if it was not, then the alternative is that carbonate chemistry is not the sole and overriding control over coccolithophore calcification," which should, in their words, "seriously call into question" the contention of some that "ocean acidification will lead to a replacement of heavily-calcified coccolithophores by lightly-calcified ones."
- Coccolithophores—tiny calcifying plants that are part of the foundation of the marine food web—have been increasing in relative abundance in the North Atlantic over the last 45 years, as carbon input into ocean waters has increased. Their relative abundance has increased 10 times, or by an order of magnitude, during this sampling period. This finding was diametrically opposed to what scientists had expected since coccolithophores make their plates out of calcium carbonate, which is becoming more difficult as the ocean becomes more acidic and pH is reduced. These findings were reported in the November 26th edition of Science and based on analysis of nearly a half century of data collected by the long-running Sir Alister Hardy Foundation (SAHFOS) Continuous Plankton Recorder sampling program…
- Gnanadesikan said the Science report certainly is good news for creatures that eat coccolithophores, but it’s not clear what those are. “What is worrisome,” he said, “is that our result points out how little we know about how complex ecosystems function.” The result highlights the possibility of rapid ecosystem change, suggesting that prevalent models of how these systems respond to climate change may be too conservative, he said.
- Coccolithophores are often referred to as "canaries in the coal mine." Some of the key coccolithophore species can outcompete other classes of phytoplankton in warmer, more stratified and nutrient-poor waters (such as one might see in a warming ocean). Until this data proved otherwise, scientists thought that they would have more difficulties forming their calcite plates in a more acidic ocean. These results show that coccolithophores are able to use the higher concentration of carbon derived from CO2, combined with warmer temperatures, to increase their growth rate…
- “In the geological record, coccolithophores have been typically more abundant during Earth’s warm interglacial and high CO2 periods. The results presented here are consistent with this and may portend, like the “canary in the coal mine,” where we are headed climatologically,” said Balch.
As they say on TV, “Wait, there’s more.”
- The authors write that "the predicted drop in pH, in the following referred to as 'ocean acidification (OA),' is considered to affect a variety of biological and biogeochemical processes in the oceans with potentially far-reaching consequences on the community and ecosystem level," citing Riebesell et al. (2007); and they say that they "wanted to test whether Arctic coastal plankton communities will be in any way affected by high pCO2/low pH and thus susceptible to ocean acidification."
- What was done: To investigate the impact of OA on a natural Arctic plankton community, Aberle et al. state that "a mesocosm experiment was conducted in Kongsfjorden, Svalbard, over a period of about one month in June/July 2010," where nine polyethylene mesocosms were deployed and moored, and where CO2-enriched seawater was injected into them to achieve three different degrees of CO2 equilibrium concentrations - low (175-250 ppm), intermediate (340-600 ppm) and high (675-1085 ppm) - and where 13 days later, nutrients were added to all three mesocosm treatments to ensure a sufficient nutrient supply for bloom development."
- What was learned: The six scientists report that they "found almost no direct effects of OA on microzooplankton composition and diversity," and that "both the relative shares of ciliates and heterotrophic dinoflagellates as well as the taxonomic composition of microzooplankton remained unaffected by changes in pCO2/pH."
- What it means: In the concluding paragraph of their paper, Aberle et al. state that their hypothesis that a high CO2 concentration would alter microzooplankton community structure, carrying capacity or phenology must be rejected on the basis of their mesocosm experiment, while noting that the findings of their study point to "a relatively high robustness of microzooplankton towards elevated CO2 in coastal waters."
Along those same lines this was done:
- In a paper published in Biogeosciences, Leu et al. (2013) write that "ocean acidification occurs as a consequence of increasing atmospheric CO2 concentrations, and is thought to represent a major threat for some groups of marine organisms," in that polyunsaturated fatty acids or PUFAs - which are essential metabolites that are synthesized only by algae and therefore have to be acquired via their ingestion by all other organisms - may not be as prominent in Arctic plankton in a high-CO2 world as they are nowadays, leading to a degradation of planktonic food quality. But is this really so?
- In a study designed to answer this important question, the five researchers studied the effect of ocean acidification of a natural plankton community in the Arctic in a large-scale mesocosm experiment that was carried out in Kongsfjorden (Svalbard, Norway at 79°N), where nine mesocosms of ~50 m3 each were exposed to eight different CO2 levels (from natural background conditions to ~1420 ppm, yielding pH values ranging from ~8.3 to 7.5). And what did they find?
- Leu et al. report that "no indications were found for a generally detrimental effect of ocean acidification on the planktonic food quality in terms of essential fatty acids." In fact, they say that from an ecological point of view, "it is remarkable that the overall community response with respect to the relative amount of PUFAs to increased CO2 concentrations was rather positive." And thus they further conclude that "findings about detrimental effects of ocean acidification on single species in laboratory studies (as, for instance, Riebesell et al. (2000) or Tsuzuki et al. (1990)), and even their consequences for grazers (Rossoll et al., 2012) are probably less relevant in a natural situation where other, more CO2-tolerant species take over."
- In the end, therefore, Leu et al. state that "the overall availability of essential PUFAs for higher trophic levels seems not to be affected negatively, although the specific fatty acid composition may change." This is because, as they describe it, "the overall amount of essential PUFAs available to the entire community (or at least within a certain size class) is the important measure for the algal food quality," which fact "also holds true for the implications for trophic transfer efficiency and consequences for phytoplankton-zooplankton ratios," as discussed by Brett and Muller-Navarra (1997).
- Thus, as a result of these several encouraging observations, we should all be able to sleep a little better at night, knowing that atmospheric CO2 enrichment likely will not lead to a degradation of planktonic food quality in Arctic waters, in contradiction of what many environmental pessimists have ardently postulated.
- With respect to the effects of ocean acidification on the marine nitrogen cycle, the authors write that "the current hypothesis, based on the manipulation of water column pH in laboratory studies, states that decreasing pH will impact the nitrogen cycle by decreasing nitrification," and this decrease in the microbial conversion of ammonium to nitrate would likely negatively impact both marine phytoplankton composition and production.
- What was done: Fulweiler et al. record that they "compiled an existing unique data set of concurrent water column nitrification rates and water column pH values from a temperate New England estuary (Narragansett Bay, Rhode Island, USA)," which had been obtained and reported previously by Berounsky (1990) and Berounsky and Nixon (1985a,b, 1990, 1993).
- What was learned: The four researchers say they "found the exact opposite trend to the current hypothesis: water column nitrification rates were highest at low pH and decreased significantly as pH increased," and they note that "these results are in direct contradiction to some of the more recently published studies examining the impact of ocean acidification on marine nitrification (Huesemann et al., 2002; Beman et al., 2011)." However, they indicate that their findings "are consistent with previous studies from three decades ago," citing the work of Anthonisen et al. (1976) and Focht and Verstraete (1977).
- What it means: Fulweiler et al. emphasize that their results "highlight that nitrifying organisms in coastal systems tolerate a wide range of pH values," adding that "the degree of negative correlation with pH may depend on site-specific environmental conditions." And in a grand understatement, they conclude by saying their findings indicate that "the current hypothesis of the negative impacts of ocean acidification on nitrification, at least for the coastal ocean, might need reevaluation."
What about Arctic copepods (crustaceans) such as Calanus glacialis?
- The authors write that the Arctic copepod Calanus glacialis "can comprise up to 70-80% of the zooplankton biomass in Arctic shelf seas (Blachowiak-Samolyk et al., 2008; Conover, 1988; Hirche and Mumm, 1992), and is a key herbivore (Mumm et al., 1998; Soreide et al., 2008; Tande, 1991) as well as an important prey item for other zooplankton species (Falk-Petersen et al., 2002, 2004), fish (Fortier et al., 2001), and seabirds (Karnovsky et al., 2003; Weslawski et al., 1999; Wojczulanis et al., 2006)." And, therefore, they say that "testing the potential impacts of ocean acidification on C. glacialis reproduction is vital."
- What was done: Weydmann et al., as they describe it, investigated "how the reduction of sea surface pH from present day levels (pH 8.2) to a realistic model-based level of pH 7.6, and to an extreme level of pH 6.9, would affect the egg production and hatching success of C. glacialis under controlled laboratory conditions," where "reduced pH seawater was prepared by bubbling compressed CO2 through filtered seawater, until the appropriate level of pH was reached."
- What was learned: The four researchers report that "CO2-induced seawater acidification had no significant effect on C. glacialis egg production," and that a reduction in pH to 6.9 only delayed hatching at what they called that "extreme level of pH." They also state there was no significant effect "on the survival of adult females," which observation, in their words, "is in agreement with previous studies on other copepod species," citing Mayor et al. (2007) and Kurihara and Ishimatsu (2008).
- What it means: In reference to their several findings, Weydmann et al. state that their results are "in agreement with previous studies on other copepod species and would indicate that copepods, as a group, may be well equipped to deal with the chemical changes associated with ocean acidification."
- [T]he team of five researchers conducted a short (5-day) experiment in which they subjected adults of two copepod species (the calanoid Acartia grani and the cyclopoid Oithona davisae) to normal (8.18) and reduced (7.77) pH levels in order to assess the impacts of ocean acidification (OA) on copepod vital rates, including feeding, respiration, egg production and egg hatching success. At a pH value of 7.77, the simulated ocean acidification level is considered to be “at the more pessimistic end of the range of atmospheric CO2 projections.” And what did their experiment reveal?
- In the words of the authors, they “did not find evidence of OA effects on the reproductive output (egg production, hatching success) of A. grani or O. davisae, consistent with the numerous studies demonstrating generally high resistance of copepod reproductive performance to the OA projected for the end of the century,” citing the works of Zhang et al. (2011), McConville et al. (2013), Vehmaa et al. (2013), Zervoudaki et al. (2014) and Pedersen et al. (2014). Additionally, they found no differences among pH treatments in copepod respiration or feeding activity for either species. As a result, Isari et al. say their study “shows neither energy constraints nor decrease in fitness components for two representative species, of major groups of marine planktonic copepods (i.e. Calanoida and Cyclopoida), incubated in the OA scenario projected for 2100.” Thus, this study adds to the growing body of evidence that copepods will not be harmed by, or may even benefit from, even the worst-case projections of future ocean acidification.
What about the Arctic sea snail (Limacina helicina)? Is Ocean Acidification going to render it extinct?
- Citing Hunt et al. (2008), the authors write that "pteropods are pelagic mollusks that play an important role in the food web of extensive oceanic regions, particularly at high latitudes, where they are a major dietary component for zooplankton and higher predators, such as herring, salmon, whales and birds."
- What was done: In the words of Comeau et al., "the effect of ocean acidification was investigated using juveniles of the Arctic pteropod Limacina helicina from the Canada Basin of the Arctic Ocean," where they caught and extracted overwintering individuals from depths of 100 to 200 meters through a hole in the ice, which captives they then maintained at three pH levels (8.05, 7.90 and 7.75) for eight days, after which they assessed them for mortality and shell growth.
- What was learned: The three researchers found that pH did not impact the mortality of the pteropods; but they note that the degree of linear extension of their shells decreased as pH declined. Nevertheless, they discovered that the pteropods were able to extend their shells at an aragonite saturation state as low as 0.6, which led them to speculate that "the presence of a thin periostracal layer covering the calcareous surface, as shown on the Antarctic pteropod Limacina helicina antarctica (Sato-Okoshi et al., 2010), might, among other mechanisms, protect the shell from a corrosive environment."
- What it means: Although much remains to be known about pteropod responses to a potential decline in seawater pH, it would appear that they already possess a certain degree of adaptability to low pH levels; and the results of many similar studies of other calcifying sea creatures suggest that, like them, pteropods may be able to evolve in their ability to successfully cope with declining seawater pH at a rate commensurate with realistic rates of ocean acidification, especially within the context of the acidification analysis of Tans (2009).
Now let’s take a look at corals reefs & the effects pH levels have had on them because there’s a lot of scaremongering out there in the literature about “coral reefs gonna die off unless we get some-sort of transnational agreement to save them & control your carbon footprint.” As H.L. Mencken said, “The urge to save humanity is almost always a false front for the urge to rule” and the global warming/climate change charade (and when I say charade I mean it’s as-if they’ve never done any research into climatological changes prior to the Industrial Age) is part-and-parcel of that. Without further ado, coral reefs have had it rough:
- According to a paper published this week in Science, natural climate change 4,000 years ago drove coral reefs to "total ecosystem collapse lasting 2,500 years" for "40 percent of their total history" over the past 6,000 years. The authors believe "an intensified ENSO regime" was responsible, but then erroneously assume AGW will lead to a similar reef collapse, despite extensive peer-reviewed literature showing that changes in greenhouse gases have not and will not affect ENSO intensity:
All without Wal-Mart, Exxon-Mobil & the evil automobile, coral reefs were on the ropes, but they’re a tough lot—easy to knock down, but they don’t stay down.
- The authors write that octocorals possess "an internal calcium carbonate skeleton comprised of microscopic sclerites embedded in their tissue," citing Fabricius and Alderslade (2001), Jeng et al. (2011) and Tentori and Ofwegen (2011). They also note that they are "the second most important faunistic component in many reefs, often occupying 50% or more of the available substrate." And in light of these facts, they say "it is important to predict their response to a scenario of increased pCO2."
- What was done: Gabay et al. studied three species of octocorals from two families found in the Gulf of Aqaba at Eilat, including the zooxanthellate Ovabunda macrospiculata and Heteroxenia fuscens (family Xeniidae) and Sarcophyton sp. (family Alcyoniidae), which they maintained for five months under normal (8.2) and reduced (7.6 and 7.3) pH conditions, while they assessed their pulsation rate, protein concentration, polyp weight, density of zooxanthellae and chlorophyll concentration per cell.
- What was learned: In the words of the three Israeli scientists, their results indicated "no statistically significant difference between the octocorals exposed to reduced pH values compared to the control."
- What it means: Quoting once again the words of Gabay et al., "these findings indicate that octocorals may possess certain protective mechanisms against rising levels of pCO2," and in this regard they suggest that "their fleshy tissues act as a barrier, maintaining a stable internal environment and avoiding the adverse effects of the ambient elevated pCO2," in line with the similar thinking of Rodolfo-Metalpa et al. (2011), while noting that "this suggestion is further supported by our finding that the ultrastructural features of O. macroscipulata sclerites are not affected by increased ambient seawater acidity." And so it is that they ultimately conclude that "octocorals might be able to acclimate and withstand rising levels of ocean acidification, even under conditions that are far beyond what is expected to occur by the end of the present century (pH 7.9)."
We’re not done with coral yet folks:
- The authors write that "according to the IPCC (2007) models, atmospheric CO2 is predicted to rise to 540-970 ppm by the end of this century and reach a maximum of approximately 1,900 ppm when the world's fossil fuel reserves are fully exploited," while noting that "a substantial number of laboratory studies have suggested a decline in coral calcification with a rise in seawater pCO2." However, they say that recent studies "have postulated that the sensitivity of corals to elevated levels of CO2 is potentially more diverse than previously considered," citing the works of Fabricius et al. (2011), Pandolfi et al. (2011) and Rodolfo-Metalpa et al. (2011).
- What was done: Intrigued by these new and diverse findings, Takahashi and Kurihara measured the rates of calcification, respiration and photosynthesis of the tropical coral Acropora digitifera - along with the coral's zooxanthellae density - under near-natural summertime temperature and sunlight conditions for a period of five weeks.
- What was learned: The two Japanese researchers found that these "key physiological parameters" were not affected by either predicted mid-range CO2 concentrations (pCO2 = 744 ppm, pH = 7.97, Ωarag = 2.6) or by high CO2 concentrations (pCO2 = 2,142 ppm, pH = 7.56, Ωarag = 1.1) over the 35-day period of their experiment. In addition, they state that there was "no significant correlation between calcification rate and seawater aragonite saturation (Ωarag)" and "no evidence of CO2 impact on bleaching."
- What it means: Contrary to what many climate alarmists have long contended, there is mounting evidence that suggests that the negative consequences they predict for the world's marine life in a future high-CO2 world are by no means assured, nor are they likely to be widespread.
What about coral reefs on Papua New Guinea?
- At several locations in Papua New Guinea there are submarine geothermal vents in shallow water where concentrated CO2 continually bubbles up from the substrate amidst healthy coral growth. Although well known to recreational divers, this natural experiment in the effects of enhanced CO2 seems not to have yet been investigated by researchers concerned with ocean acidification. Perhaps the cogitative dissonance with alarmist belief has deterred them. Recently Mr Jeff McCloy of Newcastle, NSW invited me to join him on his yacht Seafaris in PNG. When told of my interest in the geothermal vents there, he generously offered to take me to them.
- I will digress briefly to comment on Seafaris as it is a truly unique vessel. In 2008 she was awarded both the Australian and World Superyacht of the Year awards. Jeff managed the building project himself and every detail reflects both elegance of design and craftsmanship as well as practical functionality, something rare in superyachts. I will mention only one of many superb features. This is a hydraulic cradle which carries a 9m water jet driven tender which can be launched and recovered at the touch of a button.
- Observations: On 14 February 2010 we visited two geothermal areas in the D’Entrecasteaux Islands, Milne Bay Province, PNG. One is located near the north end of Normanby Island about 30 m S.E. of the outer end of the wharf at the village of Esa’Ala. The other is a well known dive site known as the “Bubble Bath”. It is located about 20 m offshore near the mid-north coast of Dobu Island, an extinct volcano.
- At Esa’Ala the area of bubble venting is scattered along the inner edge of a fringing reef which is about 10 -15 m in width. The outside edge slopes steeply into deep water and the inside edge is bordered by grass beds (Thalassia sp.) on silty bottom of mixed reef and volcanic sediments. The bubbling is near continuous small trickles at numerous points scattered amid both grass and coral areas in water depths of 3 – 5 m. The location is sheltered from prevailing wind and wave action. Both coral and plant growth were unusually luxuriant. In the grass beds small juvenile rabbitfish (Siganus sp.) are abundant feeding on the epiphytic algae growing on the grass blades.
- At the “Bubble Bath” location near Dobu I. the bubbling was much more vigorous. In addition to more numerous and larger bubble streams amid both coral and grass beds, there was a main vent which emits a large volume of gas not unlike a Jacuzzi bubble bath in volume (around a cubic metre a minute). From the only mild odour of hydrogen sulphide it seemed apparent that the main gas being emitted was CO2. Both plant and coral growth seemed more luxuriant than at Esa’Ala. Water depths were 2-3 m and the location was again a fringing reef protected from prevailing wind and waves. The grass beds were dense to within a meter of the main vent and the coral reef began about 10 m away. Both locations were sheltered from currents and would have a poor supply of planktonic food. It seemed apparent in both that the unusual profusion of both grass and coral growth was most likely attributable to the gas vents.
- The pH of water samples was measured using a Pacific Aquatech PH-013 High Accuracy Portable pH Meter with a resolution of 0.01 pH. It was calibrated with buffered solutions at pH 6.864 and pH 4.003 immediately before measuring the samples. The Esa’Ala sample was taken immediately adjacent to a Porites coral and about 10 cm from a small bubble stream. The pH was 7.96. A sample from next to a Porites coral at the “Bubble Bath” measured 7.74. This was also about 10 cm from a somewhat larger bubble stream and about 12 m from the main gas vent. A sample next to the main vent measured 6.54. A sample from the open ocean just outside Egum Atoll about 100 Km N.E. of Dobu read 8.23 which is near typical for open ocean in this region. It seems that coral reefs are thriving at pH levels well below the most alarming projections for 2100. The biggest threat we face isn’t to Barrier Reef tourism. The whole modern economy is founded on cheap abundant energy. High energy liquid fuel is essential to all mobile heavy machinery. Trucks, tractors, trains, ships, planes and earth moving equipment cannot be run on sunbeams and summer breezes. The International Energy Agency along with virtually all oil industry analyst groups now recognise that future global oil supplies are likely to be increasingly tight and more expensive.
On the same subject, even Nature admitted:
- Here we show that as pH declines from 8.1 to 7.8 (the change expected if atmospheric carbon dioxide concentrations increase from 390 to 750 ppm, consistent with some scenarios for the end of this century) some organisms benefit, but many more lose out. We investigated coral reefs, seagrasses and sediments that are acclimatized to low pH at three cool and shallow volcanic carbon dioxide seeps in Papua New Guinea. At reduced pH, we observed reductions in coral diversity, recruitment and abundances of structurally complex framework builders, and shifts in competitive interactions between taxa. However, coral cover remained constant between pH 8.1 and ~7.8, because massive Porites corals established dominance over structural corals, despite low rates of calcification. Reef development ceased below pH 7.7 [NOTE: As we have already covered, coral reefs taking it on the chin isn’t unprecedented in earth’s history]. Our empirical data from this unique field setting confirm model predictions that ocean acidification, together with temperature stress, will probably lead to severely reduced diversity, structural complexity and resilience of Indo-Pacific coral reefs within this century.
Coral reefs on the Palau Rock Islands:
- The Palau Rock Islands lagoons are naturally acidic from subsurface venting. The lagoons are known for their natural diversity species and corals. The Wood’s Hole study is the latest of a number of studies of this lagoon. The abstract from the Science article is below.
- “Ocean acidification threatens the survival of coral reef ecosystems worldwide. The negative effects of ocean acidification observed in many laboratory experiments have been seen in studies of naturally low-pH reefs, with little evidence to date for adaptation. Recently, we reported initial data suggesting that low-pH coral communities of the Palau Rock Islands appear healthy despite the extreme conditions in which they live. Here, we build on that observation with a comprehensive statistical analysis of benthic communities across Palau’s natural acidification gradient. Our analysis revealed a shift in coral community composition but no impact of acidification on coral richness, coralline algae abundance, macroalgae cover, coral calcification, or skeletal density. However, coral bioerosion increased 11-fold as pH decreased from the barrier reefs to the Rock Island bays. Indeed, a comparison of the naturally low-pH coral reef systems studied so far revealed increased bioerosion to be the only consistent feature among them, as responses varied across other indices of ecosystem health. Our results imply that whereas community responses may vary, escalation of coral reef bioerosion and acceleration of a shift from net accreting to net eroding reef structures will likely be a global signature of ocean acidification.”
- They found a pH range from ~8.0 to ~7.6 standard units and Ω-aragonite ranges from ~3.7 to ~1.9. They found some species variations that couldn’t really be assigned to pH differences and were similar to other reefs. In general, they found a healthy, thriving coral system. The negative seems to be increased “macrobioerosion” with decreasing pH.
- Bioerosion is caused by organisms and can be supplemented by physical and chemical processes of erosion. The article doesn’t discuss the biological causes but states that it correlated with pH. It seems that bioerosion hasn’t stopped the reef from being healthy and striving and the authors don’t spend much time discussing bioerosion’s other potential causes or how other reefs compare. Ω is an index of saturation calculated from calcium and carbonate ions and the solubility product (Ksp). An Ω = 1.0 indicates the solution is saturated. Ω>1 is supersaturated and the greater the number the more likely calcium carbonate will precipitate and the better for shell formation. Ω=4 is supposedly ideal.
- The reef is supposedly a natural lab to look at the future of ocean acidification since the pH range and Ω and a predictor of future ocean acidification from climate change. The results seem to be opposed to the standard scare, but the article would have us believe otherwise. The Wood’s Hole news release says the corals are thriving despite acidification. In the news release they use the standard 0.1 pH unit decrease is a 30% increase in acidification. This is a (rounded) calculation straight from the definition of pH (pH=-log[H+] which, on rearrangement, gives the hydrogen ion concentration. Any 0.1 decrease in pH is a 26% increase in hydrogen ion concentration (acidity). On the pH scale, 7 standard units is neutral, below 7 is acidic and above 7 is basic. Since the ocean pH is generally >7, it is basic. Climate science needs to claim “acidification” so they have defined less basic as acidic. Adding acid to a basic solution to decrease the pH was once called neutralization. If I added acid to reduce the pH below 7, I was acidifying the solution. It looks like definitions change to suit the need.
The Science article says specifically:
- Shifts in ocean chemistry are likely occurring more rapidly now than in the past 300 million years. Excess CO2 released from fossil fuel emissions and deforestation is absorbed by the surface oceans, driving down seawater pH and calcium carbonate (CaCO3) saturation state (Ω), a process termed ocean acidification (OA) (2). Coral reefs are considered especially vulnerable to OA. Reefs are made of CaCO3 produced by calcifying organisms, including corals and coralline algae, and laboratory experiments have shown that biogenic calcification is slowed and its destruction is accelerated at levels of OA projected for the end of this century. Some experiments have raised key questions regarding the potential for coral reef organisms to adapt to OA or for covarying environmental factors, such as light, water flow, and nutrient availability, to modulate the impacts of OA. However, most studies of naturally low-pH reefs, including CO2 vents in Papua New Guinea (PNG) and Japan, freshwater seeps in Mexico, and upwelling regions of the eastern tropical Pacific, have yielded no evidence to support either scenario…
- Characterization of Palau’s carbonate chemistry environment was achieved by discrete water sampling at 11 study sites during multiple tidal cycles, seasons, and years from dawn (6:00 a.m.) to dusk (6:00 p.m.), combined with continuous, 4-day-long pH sensor deployment and water sampling to characterize diurnal variability at a subset of these sites (Fig. 1, fig. S1, and tables S1 and S2). Site average dawn-to-dusk pH and Ω of the CaCO3 mineral aragonite (Ωar) are typically within error of 24-hour mean values and are thus considered representative of the full diel range in carbon system chemistry. Average pH/Ωar ranged from 8.05 (±0.04 SD)/3.7 (±0.3) at the highest-pH/Ωar barrier reef site to 7.84 (±0.03)/2.3 (±0.2) at the lowest-pH/Ωar Rock Island site, falling as low as 7.61/1.86 in the early hours of the morning…
- Despite the pH and Ωar conditions already at predicted end-of-century open ocean levels and pCO2 up to 720 μatm, the Rock Islands support high coral cover, richness, and diversity and very low macroalgae cover. This observation counters expectations based on some laboratory CO2 manipulation experiments and studies of other naturally low-pH reefs in which severe declines in coral richness and coralline algal cover and increases in macroalgae are signature impacts of OA. In general, coral cover on Palau’s high-pH barrier reefs (28 to 37%) was lower than that of the low-pH bay reefs (32 to 63%), a trend likely exacerbated by a bleaching event in 1998 that caused declines in coral cover on the barrier reef but not the bays. Nevertheless, the relatively high cover and diversity in the low-pH reefs cannot be solely attributed to differential bleaching-induced mortality: the pre-1998 cover on the barrier (50% in 1992) was already lower than the current coral cover on Palau’s lowest-pH reefs (63%). The skeletal extension, density, and calcification rates of Porites and Favia corals did not change significantly with declining pH and Ωar, indicating that the rates of CaCO3 production, a physiological process considered one of the most sensitive to OA, are maintained across Palau’s OA gradient. In contrast, many laboratory CO2 manipulation experiments with Porites and Favia corals have shown significant declines in calcification of these genera with declining pH/Ωar.
Well gosh, I guess if the real-world results are different than the laboratory then you assume something in the laboratory is not mimicking what’s happening in the wild. Bio-erosion is likely occurring in spite of pH levels, not because of pH levels. Here’s another case of natural pH variations in a thriving marine community.
- In an effort to fill this knowledge gap [of organism response to pH variance], this team of researchers embarked on a journey to “characterize the patterns and magnitudes of diel [daily], seasonal, and interannual fluctuations in pH and dissolved oxygen (DO) in an undisturbed tidal salt marsh adjacent to Long Island Sound, using a multiyear, high-frequency data set.” Flax Pond (40.96°N, 73.14°W), a one square kilometer tidal salt marsh located on the north shore of Long Island Sound, served as the specific study site where data were collected between April 2008 and November 2012. And what did those data reveal?
- As shown in Figure 1 [at the link], large fluctuations in pH occurred at Flax Pond on both daily and seasonal time scales. The daily pH range varied from a low of 0.22 unit during the winter to a high of 0.74 unit in the summer. Seasonally, the highest pH values occurred in February (average of 8.19) and the lowest values (average of 7.59) occurred in August. Thus, average pH conditions in Flax Pond “decline from early spring until late summer by approximately 0.6 units” and “average diel [daily] pH fluctuations exceed 0.7 units and commonly approach one unit of magnitude in July and August.” Yet even more extreme fluctuations in pH were found to occur within a single tidal cycle. The right panel of Figure 1 presents a three-day record of detailed measurements that reveal a pCO2 fluctuation “between ~350 µatm and nearly 4,000 µatm within one tidal cycle.” Thus, within a few short hours, the marine life within Flax Pond was subjected to a pH fluctuation that reached values as low as 6.9, which is nearly 1 full pH unit below the predicted decline by the end of this century.
- With respect to the cause of these large variations, Baumann et al. they are chiefly biologic, the magnitude of which is “modulated by tides and the time of day, with the most acidic and hypoxic conditions occurring during low tide at the end of the night” due to community respiration. During the day, the pH rises as photosynthetic marine life assimilate CO2 and incoming water of a higher pH from the open ocean flows into the marsh from the incoming tide.
- In discussing the implications of their findings, the American researchers note that the highly variable pH conditions observed in Flax Pond, though higher in magnitude, are characteristic of observations made in other coastal locations. However, such fluctuations have “yet to be adequately represented” in laboratory ocean acidification experiments, where the pH change is near unanimously held at a constant value and may falsely project a marine organism’s response to ocean acidification out in the real world of nature.
- Perhaps the most significant finding to be gleaned from this analysis, however, is that fact that despite current daily and seasonal pH fluctuations that often exceed – and by more than two-fold – the projected 0.3 unit decline that acidification alarmists expect to wreak havoc on marine ecosystems between now and the end of the century. This salt marsh is teeming with life.
Again, we have a case where 1) The laboratory is not only wrong but 2) they aren’t even mimicking what’s occurring in nature adequately, which means the experiment is a moot point. Here’s another interesting example that correlates with the above:
- In further expanding the scientific knowledge on this important topic, the six American researchers set out to conduct a “short, high-resolution physical and biogeochemical pilot field study” on the back reefs of Ofu, American Samoa, where they measured a number of hydrodynamic and biogeochemical parameters there over a seven-day period in November, 2011. The specific study location was Pool 100 (14.185°S, 169.666°W), a shallow lagoon containing 85 coral species and various kinds of crustose coralline algae and non-calcifying algae. Koweek et al. selected Pool 100 because, as they state, shallow back reefs “commonly experience greater thermal and biogeochemical variability owing to a combination of coral community metabolism, environmental forcing, flow regime, and water depth.”
- Results of their data collection and analysis revealed that temperatures within the shallow back reef environment were consistently 2-3°C warmer during the day than that observed in the offshore environment. In addition, and as expected, the ranges of the physical and biogeochemical parameters studied in Pool 100 greatly exceeded the variability observed in the open ocean. Inside Pool 100, the pH values fluctuated between a low of 7.80 and a high of 8.39 across the seven days of study, with daily ranges spanning between 0.5 and 0.6 of a unit (Figure 1). What is more, Koweek et al. report that the reef community in Pool 100 spent far more time outside of the offshore pH range than within it (pH values were between 8.0 and 8.2 during only 30 percent of the observational period, less than 8.0 for 34 percent of the time and greater than 8.2 for the remaining 36 percent of the observations). Additional measurements and calculations indicated that these fluctuations in pH were largely the product of community primary production and respiration, as well as tidal modulation and wave-driven flow.
- Commenting on these and other of their findings, Koweek et al. write that “our measurements have provided insight into the physical–biogeochemical coupling on Ofu.” And that insight, they add, “suggests a significantly more nuanced view of the fate of coral reefs” than the demise of global reef systems that is traditionally forecast under the combined stresses of climate change and ocean acidification. Indeed, if these ecosystems presently thrive under such variable (and more severe) environmental conditions than those predicted for the future—which conditions are largely derived and modulated by themselves—why wouldn’t they persist?
What about the Sea Urchin (Psammechinus miliaris)? What is a lower pH doing to this species?
- The authors write that "the reproductive processes and early life-stages of both calcifying and non-calcifying animals are believed to be particularly vulnerable to a reduced pH environment," but they say "there is as yet no clear and reliable predictor for the impacts of ocean acidification on marine animal reproduction."
- What was done: As their contribution to the scientific quest for this important knowledge, Caldwell et al. say they "investigated the combined effect of pH (8.06-7.67) and temperature (14-20°C) on percent sperm motility and swimming speed in the sea urchin Psammechinus miliaris using computer assisted sperm analysis (CASA)," while working with specimens they collected from the Isle of Cumbrae (Scotland).
- What was learned: "Surprisingly," in the words of the six scientists, "sperm swimming performance benefited greatly from a reduced pH environment," as "both percent motility and swimming speeds were significantly enhanced at pHs below current levels." And in light of the additional fact that sperm-activating peptides - which are believed to have evolved some 70 million years ago during a period of high atmospheric CO2 concentration - are fully functional from pH 6.6 to 8.0 (Hirohashi and Vacquier, 2002), they state that "the combined data on motility, swimming speed and SAP function at reduced pH indicates that sperm are sufficiently robust to allow functionality at pHs that would have been experienced in the paleo-ocean (ca pH 7.4-7.6) and which are within projections for near-future climate change scenarios."
- What it means: The UK researchers conclude that "current ocean pH levels are suboptimal for P. miliaris sperm-swimming speed and that reproductive success for certain marine species may benefit from a reduced pH ocean."
In other words, there’s no doomsday scenario for our friend, the Sea Urchin. We’re not done with our friendly neighborhood Sea Urchin though.
- The authors write that "the Southern Ocean, a region that will be an ocean acidification hotspot in the near future, is home to a uniquely adapted fauna that includes a diversity of lightly-calcified invertebrates," and, hence, they felt it important to investigate how the early life stages of one of these life forms are impacted by the levels of atmospheric CO2 enrichment being predicted to occur within the current century.
- What was done: Yu et al., as they describe it, utilized the sea urchin Sterechinus neumayeri to test the effects of high CO2/low pH on early development and larval growth by exposing them to environmental levels of CO2 in McMurdo Sound (control: 410 ppm) and mildly elevated CO2 levels, both near the level of the aragonite saturation horizon (510 ppm), and to under-saturating conditions (730 ppm).
- What was learned: The six scientists report that over the course of development from egg to late four-arm pluteus, they found that "(1) early embryological development was normal with the exception of the hatching process, which was slightly delayed, (2) the onset of calcification as determined by the appearance of CaCO3 spicule nuclei was on schedule, (3) the lengths of the spicule elements, and the elongation of the spicule nuclei into the larval skeleton, were significantly shorter in the highest CO2 treatment four days after the initial appearance of the spicule nuclei, and (4) finally, without evidence of true developmental delay, larvae were smaller overall under high CO2 treatments; and arm length, the most plastic morphological aspect of the echinopluteus, exhibited the greatest response to high CO2/low pH/low carbonate conditions."
- What it means: After all was said and done, Yu et al. concluded, in the final sentence of their paper's abstract, that "effects of elevated CO2 representative of near future climate scenarios are proportionally minor on these early development stages."
Indeed, despite the following conditions, it’s not all gloom-and-doom:
- Seawater conditions in the Crary Lab aquarium were fairly representative of water conditions in McMurdo Sound. The salinity was almost invariant (Fig. 2A), remaining at 34.8–34.9‰ over the course of the 30-day experiment. The alkalinity values (Fig. 2B) were slightly more variable, but were not significantly different between treatments over the time-course (n = 30, ANOVA, p>0.1) with the average alkalinities of the three reservoirs running at 2328.5 (±13.0 SD), 2330.5 (±10.5) and 2331.3 (±15.5) for the 410 µatm (control), 510 µatm and 730 µatm pCO2 treatments respectively. While the environmental seawater temperature was −1.9°C in McMurdo Sound, the incoming seawater in Crary Lab was consistently over a degree warmer, especially given the controlled air temperature within the lab. Water temperatures (Fig. 2C) averaged −0.3 (±0.2), −0.3 (±0.2) and −0.4 (±0.2) °C (n = 5 each treatment, ± SD) for the three treatment levels (410 control, 510 and 730 µatm respectively), with the overall average over time being −0.3°C (±0.2 SD). Averaged pHTS (Fig. 2D) and pCO2 (Fig. 2E) (n = 5 each treatment, ± SD) over the time course of the experiment showed acceptable consistency within each treatment despite the variation in alkalinity and temperature over time. Average in-situ pHTS values over the duration of the experiment were 8.027 (±0.005 SD), 7.937 (±0.005) and 7.793 (±0.007) for the 410 µatm (control), 510 µatm and 730 µatm pCO2 treatments respectively. Average pCO2 levels over the duration of the experiment were 408.6 (±6.2 SD), 512.0 (±7.0) and 730.2 (±14.0) µatm for the 3 treatments. Average aragonite saturation values (Ωara) for the three treatments were 1.35 (±0.02 SD), 1.12 (±0.01), and 0.82 (±0.01)… Early embryos were indistinguishable in appearance between all CO2 treatment groups, demonstrating a lack of effect on basic cell-division and morphogenesis. One study reported deleterious CO2 effects on early cell divisions only at sub-optimal sperm concentrations ; other evidence demonstrates an overall negative effect of elevated pCO2 but that responses can be variable between male-female pairs. Elevated temperature has deleterious effects on early cleavages , but not with synergistic effects of low pH. Another study on the possible mechanism of delays at first cleavage in Strongylocentrotus purpuratus under highly elevated CO2/low pH (pH 7.0/4000 ppm pCO2) demonstrated no deleterious effects on cell cycle checkpoints.
Here's more on Sterechinus neumayeri:
- The authors write that "the effects of concurrent ocean warming and acidification on Antarctic marine benthos warrant investigation as little is known about potential synergies between these climate change stressors."
- What was done: Ericson et al. "examined the interactive effects of warming and acidification on fertilization and embryonic development of the ecologically important sea urchin Sterechinus neumayeri reared from fertilization in elevated temperature (+1.5°C and 3°C) and decreased pH (-0.3 and -0.5 pH units)." [NOTE: The aquarium system maintained three pH/pCO2 levels (pH 8.0/450 ppm, pH 7.7/850 ppm, pH 7.5/1,370 ppm), within the range projected for Antarctic waters over coming decades (IPCC
2007; McNeil and Matear 2008).]
- What was learned: Ericson et al. report that "fertilization using gametes from multiple males and females, to represent populations of spawners, was resilient to acidification at ambient temperature (0°C)," and they say that development to the blastula stage was "robust to levels of temperature and pH change predicted over coming decades."
- What it means: The sea urchins studied by the seven scientists appear well equipped to successfully deal with IPCC-predicted near-future increases in seawater temperature and acidification; and whatever may happen beyond the current century should prove to be of little problem as well. Working with another sea urchin species (Strongylocentrotus franciscanus), for example, Sunday et al. (2011) found significant levels of phenotypic and genetic variation for larval size in future CO2 conditions; and they say that "a genetic basis for variation in CO2 responses has been found in the three previous studies in which it has been sought," citing the work of Langer et al. (2009), Parker et al. (2011) and Pistevos et al. (2011), which findings support the notion that "genetic variation exists at some level for almost all quantitative characters (Roff, 1997)."
Now the Mediterranean Sea Urchin (Paracentrotus lividus):
- The authors write that "ocean acidification is predicted to have significant effects on benthic calcifying invertebrates, in particular on their early developmental states," and they note that "echinoderm larvae could be particularly vulnerable to decreased pH, with major consequences for adult populations."
- What was done: Martin et al. explored the effect of a gradient of decreasing pH from 8.1 to 7.0 -- corresponding to atmospheric CO2 concentrations of ~400 ppm to ~6630 ppm -- on the larvae of the sea urchin Paracentrotus lividus, a common but economically and ecologically important species that is widely distributed throughout the Mediterranean Sea and the northeast Atlantic from Ireland to southern Morocco. This they did, as they describe it, by using "multiple methods to identify the response of P. lividus to CO2-driven ocean acidification at both physiological (fertilization, growth, survival and calcification) and molecular (expression of genes involved in calcification and development) levels."
- What was learned: The eleven researchers found that "Paracentrotus lividus appears to be extremely resistant to low pH, with no effect on fertilization success or larval survival." They did, however, discover that "larval growth was slowed when exposed to low pH," but they report that there was "no direct impact on relative larval morphology or calcification down to pH 7.25," which equates to an atmospheric CO2 concentration of ~3560 ppm. In addition, they found that "genes involved in development and biomineralization were upregulated by factors of up to 26 at low pH."
I should also add this related to pH levels & fertilization:
- The fertilization success of P. lividus was high (>97%) and was not affected by a decrease in pH. This broad tolerance to changes in pH is consistent with previous observations made for other species of sea urchin. Comparative data on the effects of decreased pH on sea urchin fertilization showed either no effect (Byrne et al., 2009a; Byrne et al., 2009b; Byrne et al., 2010) or an effect restricted to pH<7.4 (Bay et al., 1993; Kurihara and Shirayama, 2004). In Heliocidaris erythrogramma, fertilization success was similar in control and lower pH treatments (>90% from pH 7.9 to 7.6) (Byrne et al., 2009a). It dropped from ≥90% in controls to 70% at pH 7.4 in Echinometra mathaei (Kurihara and Shirayama, 2004) and to 60% at pH 7.0 in Hemicentrotus pulcherrimus and Strongylocentrotus purpuratus (Bay et al., 1993; Kurihara and Shirayama, 2004). In P. lividus, fertilization remained unaffected in the lowest pH treatments (pHT 7.25 and 7.0). The robustness of sea urchin fertilization to decreased pH is likely related to the low pH that is naturally associated with echinoderm reproduction, i.e. the low internal pH of activated sperm and the release of acid by eggs at fertilization (Byrne et al., 2009a). This suggests that sea urchin fertilization is highly tolerant to ocean acidification within the range of pH values projected in the next decades, or even below model predictions. However, because of favorable fertilization conditions in most laboratory experiments with no sperm-limiting conditions, fertilization success could be overestimated relative to natural systems. Recent studies revealed a 25% reduction in fertilization success at pH 7.7 in H. erythrogramma (Havenhand et al., 2008) and a 72% drop in fertilization efficiency at pH 7.8 in S. franciscanus (Reuter et al., 2010), which may be attributed to decreased sperm motility.
Those statements may be used by ecokooks to present a doom-and-gloom scenario, but that’s not necessarily true. 1) Yes, the laboratory can only do so much & it goes both ways. If the lab is not replicating what it done in the wild, one cannot use it to be optimistic or pessimistic 2) The reliance on projections & models can be highly dubious.
Now the Sea urchin (Arbacia dufresnei):
- The authors write that "increased atmospheric CO2 emissions are inducing changes in seawater carbon chemistry, lowering its pH, decreasing carbonate ion availability and reducing calcium carbonate saturation state," which phenomenon (known as ocean acidification) is said by them to be "happening at a faster rate in cold regions, i.e., polar and sub-polar waters," where marine biologists are beginning to look for early indications of what may be in store for earth's many calcifying forms of sea life, as the declining trend in seawater pH continues.
- What was done: Catarino et al. studied the development of larvae produced by adults of the sea urchin Arbacia dufresnei - which they collected from a sub-Antarctic population in the Straits of Magellan near Punta Arenas, Chile - when immersed in high (8.0), medium (7.7) and low (7.4) pH seawater.
- What was learned: The five scientists state that "the proportion of abnormal larvae did not differ according to [pH] treatment," with the result that although "lower pH induced a delay in development" - which has also been noted by Dupont et al. (2010) - it "did not increase abnormality." They additionally indicate that "even at calcium carbonate saturation states <1, skeleton deposition occurred," and they further note in this regard that specimens of Heliocidaris erythrogramma also "seem not to be affected by a pH decrease (until 7.6)," citing Byrne et al. (2009a,b), while likewise noting that the Antarctic Sterechinus neumayeri is also thought to be "more robust to ocean acidification than tropical and temperate sub-tidal species," citing Clark et al. (2009) and Ericson et al. (2010).
- What it means: The findings of Catarino et al., as well as those of the other researchers they cite, suggest that "polar and sub-polar sea urchin larvae can show a certain degree of resilience to acidification." And they conclude that because of this fact, A. dufresnei has the potential to "migrate and further colonize southern regions."
The Sea Anemone (Anemonia viridis) vs. lower pH levels.
- The authors write that "non-calcifying anthozoans such as soft corals and anemones, play important ecological and biogeochemical roles in reef environments (e.g. Fitt et al., 1982; Bak and Borsboom, 1984; Muller-Parker and Davy, 2001)," and as with reef-forming scleractinian corals, they note that in order to supplement their nutritional requirements, "many anemones harbor symbiotic algae (Symbiodinium spp.)." Yet in spite of these significant similarities, they indicate that little is known about how these organisms would respond to a future acidification of the world's oceans.
- What was done: Focusing on this particular dearth of information, Suggett et al. collected pertinent data from the 11th to the 26th of May 2011 on a sea anemone (Anemonia viridis) along a natural seawater pH gradient of 8.2-7.6 - such as would be expected to prevail across an atmospheric CO2 gradient of 365-1425 ppm - which was produced by a shallow cold vent system (Johnson et al., 2011, 2012) that released CO2 to coastal waters near Vulcano, Italy, about 25 km northeast of Sicily.
- What was learned: The nine researchers say their physiological measurements revealed an increase in gross maximum photosynthesis and respiration rates, but with the increase in photosynthesis being greater than the increase in respiration, as well as increased dinoflagellate endosymbiont abundance (but unchanged diversity) with increasing CO2, with the result that sea anemone abundance increased with CO2 and "dominated the invertebrate community at high CO2 conditions."
- What it means: Suggett et al. say that the enhanced productivity they observed in the sea anemones they studied implies "an increase in fitness that may enable non-calcifying anthozoans to thrive in future environments, i.e. higher seawater CO2." And, therefore, they declare in the title of their paper that "Sea anemones may thrive in a high CO2 world."
Now let’s talk oysters, specifically the Pacific Oyster (Crassostrea gigas) larval & post-larval:
- The authors write that it is widely believed that" human-caused pH change is posing serious threats and challenges to the pacific oyster (Crassostrea gigas), especially to their larval states." However, they note that "our knowledge of the effect of reduced pH on C. gigas larvae presently relies presumptively on four short-term (< 4 days) survival and growth studies." And they clearly feel that this paucity of experimental data is insufficient to draw such strong conclusions.
- What was done: Based on multiple physiological measurements made during various life stages of the oysters, Ginger et al. studied "the effects of long-term (40 days) exposure to pH 8.1, 7.7 and 7.4 on larval shell growth, metamorphosis, respiration and filtration rates at the time of metamorphosis, as well as the juvenile shell growth and structure of C. gigas.
- What was learned: The seven scientists discovered that (1) "mean survival and growth rates were not affected by pH," that (2) "the metabolic, feeding and metamorphosis rates of pediveliger larvae were similar, between pH 8.1 and 7.7," that (3) "the pediveligers at pH 7.4 showed reduced weight-specific metabolic and filtration rates, yet were able to sustain a more rapid post-settlement growth rate," and that (4) "no evidence suggested that low pH treatments resulted in alterations to the shell ultra-structures or elemental compositions (i.e., Mg/Ca and Sr/Ca ratios)."
- What it means: In light of these several positive findings, Ginger et al. concluded that "larval and post-larval forms of the C. gigas in the Yellow Sea are probably resistant to elevated CO2 and decreased near-future pH scenarios." In fact, they opine that "the pre-adapted ability to resist a wide range of decreased pH may provide C. gigas with the necessary tolerance to withstand rapid pH changes over the coming century."
Here's some more pertinent info from the study:
- In the oyster collection site, the Yellow Sea, in annual time scale, the sub-surface seawater pH varied between 8.11 to 7.67 due to seasonal changes in salinity and temperature. For example, in winter the pH ranged between 7.67 and 7.92 but in summer it raised to 8.06. The peak summer average pH 8.11 was however found in late summer months (August). Notably, the carbonate system in the oyster collection site (Yellow Sea) is substantially influenced by globally rising anthropogenic CO2 when compared to natural CO2 input through respiration and mineralization. The pH 8.1 is representing current global surface average as well as average pH at the time of adult oyster collection for this study. The two decreased pH treatments, pH 7.7 and pH 7.4, represented the extreme carbonate system variables (such as pCO2 and carbonate ion concentration) experienced by oysters today and the average future projected for the year 2100 or beyond. These two decreased pH levels are in fact environmentally realistic in naturally fluctuating estuarine and coastal environments, where the Pacific oyster larvae likely to develop…
- A decrease in pH did not affect either the mean larval shell size or relative composition of the different development stages on days 11 or 16 pre-settlement. The pH 7.4 treatment resulted in a more rapid post-settlement growth, suggesting a selective pressure posed by decreased pH on the more tolerant individuals within a population. Pre- and post-settlement growth and survival seemed to be resistant to the projected decrease in pH. Although the effects of pH on fertilization success and embryonic development were not examined, both responses have been found to be quite unaffected by a decreased pH of 7.6 in the western Sweden population. A similar insignificant pH effect on fertilization and embryo development has been found in the Oregon and Northwestern U.S. populations. Nevertheless, oyster embryo growth as a function of pH deserves further study. With over 45 days of pH exposure involving multiple developmental stages, this study further suggests that the larval growth and development of Yellow-Sea-population may be resistant and tolerant to the detrimental effects of a decreased pH (7.4). Similar to our results, the pH did not affect the larval growth and development of the Suminoe oyster at pH 7.8 or the Portuguese oyster at pH 7.5.
Again, the sky is not falling chicken little ecokooks. The Portuguese oyster (Crassostrea angulate):
- Citing Lapegue et al. (2004), the authors write that the Portuguese oyster is "an important ecosystem engineer" that is "extensively cultivated" and that lives in significant numbers in the coastal environments of South China, France and Portugal.
- What was done: In a number of laboratory studies designed to see how the larval growth stage of this particular species of oyster responds to various "climate change stressors," as they describe them, Thiyagarajan and Ko examined the effects of low pH (7.9, 7.6, 7.4) at ambient salinity (34 ppt) and low salinity (27 ppt), while they say "the combined effect of pH (8.1, 7.6), salinity (24 and 34 ppt) and temperature (24°C and 30°C) was examined using factorial experimental design."
- What was learned: In the words of the two researchers, "surprisingly, the early growth phase from hatching to 5-day-old veliger stage showed high tolerance to pH 7.9 and pH 7.6 at both 34 ppt and 27 ppt," while they report that "larval shell area was significantly smaller at pH 7.4 only in low-salinity." Then, in the 3-factor experiment, they observed that "shell area was affected by salinity and the interaction between salinity and temperature but not by other combinations [italics added]." And they discovered that "larvae produced the largest shell at the elevated temperature in low-salinity, regardless of pH."
- What it means: In light of these several positive findings, Thiyagarajan and Ko conclude that "the growth of the Portuguese oyster larvae appears to be robust to near-future pH level (>7.6) when combined with projected elevated temperature and low-salinity in the coastal aquaculture zones of [the] South China Sea."
- Ocean acidification is considered by climate alarmists to be detrimental to nearly all sea creatures; and the early life-stages of these organisms are generally thought to be the most sensitive stages to this environmental change.
- What was done: In a study designed to explore these assumptions, the authors tested the effects of seawater acidification by CO2 addition, leading to reductions of 0.3 and 0.6 pH units, on six-month-old juvenile mussels (Mytilus galloprovincialis), which they obtained from a mussel raft on the Ria de Ares-Betanzos of Northwest Spain, focusing their attention on growth, calcification and mortality.
- What was learned: The eight researchers, all from Portugal, report that the growth of the mussels, measured as relative increases in shell size and body weight during the 84 days of the experiment, "did not differ among treatments." In fact, they say that a tendency for faster shell growth under elevated CO2 was apparent, "at least during the first 60 days of exposure." In the case of calcification, however, they indicate that this process was reduced, but by only up to 9%. Yet even here they state that "given that growth was unaffected, the mussels clearly maintained the ability to lay down CaCO3, which suggests post-deposition dissolution as the main cause for the observed loss of shell mass." Last of all, with respect to mortality, Range et al. write that "mortality of the juvenile mussels during the 84 days was small (less than 10%) and was unaffected by the experimental treatments."
- What it means: In summing up the implications of their findings, the Portuguese scientists say that they further support the fact that "there is no evidence of CO2-related mortalities of juvenile or adult bivalves in natural habitats, even under conditions that far exceed the worst-case scenarios for future ocean acidification (Tunnicliffe et al., 2009)."
- The authors write that "coastal ocean acidification is expected to interfere with the physiology of marine bivalves." In fact, they state that CO2-induced changes in pH are expected by some scientists to negatively affect the physiology of all marine life. But since bivalves dominate the macrofauna of many estuaries and coastal embayments, they decided to target the mussel Mytilus galloprovincialis for further study, since it is a species that is distributed worldwide and that dominates the extensive cultures of the Galician rias (bays and inlets) of northwest Spain.
- What was done: Working with juvenile M. galloprovincialis specimens that were obtained from a mussel raft in the Ria de Ares-Betanzos, and that were reared in an experimental bivalve hatchery in Tavira, Portugal, Fernandez-Reiriz et al. tested the effects of three levels of seawater acidification caused by increasing concentrations of atmospheric CO2: a natural control level plus two lesser levels of pH, one reduced by 0.3 pH unit and another reduced by 0.6 pH unit. This they did by measuring several responses of the mussels after 78 days of exposure to the three sets of pH conditions, focusing on clearance and ingestion rate, absorption efficiency, oxygen consumption, ammonia excretion, oxygen to nitrogen ratio, and scope for growth.
- What was learned: The five researchers report that significant differences among treatments were not observed for clearance, ingestion and respiration rates. However, they say that the absorption efficiency and ammonium excretion rate of the juvenile mussels were inversely related to the 0.6 pH reduction, while the maximal scope for growth and tissue dry weight were also observed in the mussels exposed to the pH reduction of 0.6 unit.
- What it means: Fernandez-Reiriz et al. conclude their report by stating that their results suggest that Mytilus galloprovincialis "could be a tolerant ecophysiotype to CO2 acidification, at least in highly alkaline coastal waters," while noting that "mytilids are also able to dominate habitats with low alkalinity and high pCO2," citing the work of Thomsen et al. (2010) in this regard. And so it would indeed appear that juvenile mussels may well be able to survive - and possibly even thrive - in a CO2-enriched world of the future.
This is interesting & demonstrates the pre-programmed resilience of some organisms-- Mussel (Bathymodiolus brevior) thriving in horrid conditions:
- The authors discovered "dense clusters of the vent mussel Bathymodiolus brevior in natural conditions of pH values between 5.36 and 7.29 on the northwest Eifuku volcano, Mariana arc, where liquid carbon dioxide and hydrogen sulfide emerge in a hydrothermal setting," which they studied along with mussels from "two sites in the southwestern Pacific: Hine Hina in the Lau backarc basin and Monowai volcano on the Kermadec arc," where "the same mussel species nestles in cracks and rubble where weak fluid flow emerges."
- What was learned: Tunnicliffe et al. identified four-decade-old mussels that had learned to cope with the extreme acidity of these hellish conditions, although their shell thickness and daily shell growth increments were "only about half those recorded from mussels living in water with pH > 7.8." Nevertheless, the mussels were alive and doing what most climate alarmists have claimed such creatures should not be able to do in such conditions. And the six researchers note that the mussels were accompanied by "many other associated species," as reported in the study of Limen and Juniper (2006).
- What it means: Tunnicliffe et al. conclude that these several findings attest to "the extent to which long-term adaptation can develop tolerance to extreme conditions." And just how extreme were the conditions in which the mussels lived? Caldeira and Wickett (2003) have calculated the maximum level to which the air's CO2 concentration might rise due to the burning of earth's post-21st century fossil-fuel reserves (2000 ppm), the point in time when that might happen (AD 2300), and the related decline that might be expected to occur in ocean-surface pH (0.7 unit). These results give a time frame of 300 years for organisms to adapt to a pH decline from about 8.1 to 7.4; and considering the much lower pH range in which the mussels studied by Tunnicliffe et al. and the many species studied by Limen and Juniper were living (5.36 to 7.29), there is ample reason to believe that even the worst case atmospheric CO2-induced acidification scenario that can possibly be conceived would not prove a major detriment to most calcifying sea life. Consequently, what will likely happen in the real world should be no problem at all, as is additionally suggested by the many items we have archived in our Subject Index under the headings of Calcification and Evolution.
Some of the folks who wring their hands over OA & falling pH values—the same folks who believe clams & sheep have a common ancestor (yes, a naturalist has to believe that)—don’t have the ability to fathom that these organisms will adapt to falling pH levels, even if those pH declines are of the Doomsday variety they want you to believe in. Just some food for thought.
The Seastar (Parvulastra exigua) come on down:
- The authors write that "Parvulastra exigua is a conspicuous member of the intertidal fauna of southeast Australia with a distribution spanning 7000 km of shoreline and is an important grazer on microalgae," citing Branch and Branch (1980), Arrontes and Underwood (1991), Stevenson (1992) and Jackson et al. (2009). In addition, they say that it is "also found in South Africa and has the broadest distribution recorded for the Asteroidea," citing Hart et al. (2006).
- What was done: Working with adult P. exigua specimens collected from Little Bay, Sydney (Australia), McElroy et al. measured the metabolic rates of the seastars at conditions characteristic of high tide (ca. 18°C and pH 8.2), as well as at 3 and 6°C warmer conditions and at additional pH values of 7.8 and 7.6 "in all combinations," as they put it.
- What was learned: The three Australian researchers report that "the metabolic response of P. exigua to increased temperature (+3°C and +6°C) at control pH [8.2] indicates that this species is resilient to periods of warming as probably often currently experienced by this species in the field." And they also report that they "did not observe a negative effect of acidification on rate of oxygen consumption at control temperature, a combination of stressors that this species currently experiences at night time low tide."
- What it means: Although the metabolic response of P. exigua is resilient to current levels of extreme temperature and pH stress - which are equivalent to mean conditions predicted for the end of the 21st century - it is possible that the extreme seawater temperatures and pH levels at that future time (if IPCC predictions prove true) will be greater than the extreme levels of today, which could prove to be a real challenge for the seastars. However, McElroy et al. write, in the concluding paragraph of their research report, that "species such as P. exigua with a broad distribution from warm to cold temperate latitudes may possess scope for adaptation (evolutionary change) and/or acclimation via phenotypic plasticity (Visser, 2008), as suggested for sympatric echinoid and ophiuroid species (Byrne et al., 2011; Christensen et al., 2011)." And based on the information archived under the heading of Evolution (Aquatic Life) in our Subject Index, that possibility is beginning to look like a real likelihood.
- Habitat warming and acidification experienced by intertidal invertebrates are potentially detrimental to sensitive early post-larvae of benthic marine invertebrates. To determine the potential impact of acidification and warming on a conspicuous component of the temperate intertidal fauna of the southern hemisphere, the response of newly metamorphosed juvenile (ca. 450 μm [micrometer] diameter) sea stars (Parvulastra exigua) to increased acidification and temperature was investigated with respect to conditions recorded in the habitat (− 0.4–0.6 pH units, + 2-4 °C), in all combinations of stressors. In situ monitoring was used to generate data on environmental conditions. The pH of the tide pools varied from 7.54 (pCO2 2045 μatm) at predawn to 8.91 (pCO2 28 μatm) in the afternoon and temperature varied from 10 °C at night to 24 °C during the day, conditions that fluctuated from baseline sea surface conditions of pH 8.2 and 16 °C. P. exigua was used as a model tolerant intertidal species to generate insights into stress tolerance of the early benthic life stage. After a 4-week incubation in experimental conditions, negative effects on juvenile development and growth were only observed at pH 7.2 (− 1.0 units/pCO2 4430–4601μatm; Ωcal 0.6, Ωar 0.4). Our results indicate that juvenile P. exigua is physiologically acclimatised to tolerate extreme conditions indicating that it may be robust to near future (ca. 2100) change in ocean conditions. Although it is difficult to know how tide pools will change in the future, pulses of the deleterious level of acidification (pH 7.2) may occur in the intertidal in future night time low tides.
- Little is known about how fishes and other non-calcifying marine organisms will respond to the increased levels of dissolved CO2 and reduced sea water pH that are predicted to occur over the coming century. We reared eggs and larvae of the orange clownfish, Amphiprion percula, in sea water simulating a range of ocean acidification scenarios for the next 50–100 years (current day, 550, 750 and 1030 ppm atmospheric CO2). CO2 acidification had no detectable effect on embryonic duration, egg survival and size at hatching. In contrast, CO2 acidification tended to increase the growth rate of larvae. By the time of settlement (11 days post-hatching), larvae from some parental pairs were 15 to 18 per cent longer and 47 to 52 per cent heavier in acidified water compared with controls. Larvae from other parents were unaffected by CO2 acidification. Elevated CO2 and reduced pH had no effect on the maximum swimming speed of settlement-stage larvae. There was, however, a weak positive relationship between length and swimming speed. Large size is usually considered to be advantageous for larvae and newly settled juveniles. Consequently, these results suggest that levels of ocean acidification likely to be experienced in the near future might not, in isolation, significantly disadvantage the growth and performance of larvae from benthic-spawning marine fishes…
- Additional CO2 reacts with water to form carbonic acid, which through a series of reactions leads to a decline in pH and a shift in the carbonate–bicarbonate ion balance (Feely et al. 2004), a process known as ocean acidification. Global ocean pH is estimated to have dropped 0.1 U since pre-industrial times and is predicted to drop another 0.3–0.4 U by 2100 owing to existing and future emission of CO2 into the atmosphere [NOTE: Remember all the scenarios we’ve already covered where organisms were either shrugging-off or thriving in lower pH environments] … We tested the effects of CO2-induced ocean acidification on the embryonic and larval life histories of a tropical marine fish, the orange clownfish Amphiprion percula. We used a range of treatments relevant to predicted future atmospheric CO2 concentrations (current day, 550, 750 and 1030 ppm). The upper levels of our treatments (750 and 1030 ppm CO2) were based on the IPCC A2-SRES emission trajectory, in which atmospheric CO2 concentrations are predicted to range between 730 and 1020 ppm in the year 2100 and ocean pH is predicted to decline by 0.3–0.4 U between 2000 and 2100… The average pH of unmanipulated sea water in the parental breeding area was 8.15 ± 0.07 (s.d.). Treatment sea water was adjusted to a pH of 7.8 ± 0.05 using an automated CO2 injection system… The well-developed capacity for acid–base regulation in fishes may explain why exposure to approximately 1030 ppm CO2 and a pH of 7.8 had little obvious effect on the life-history traits of A. percula embryos. Another important difference is that many invertebrates are broadcast spawners where the eggs are released directly into the ocean. In contrast, A. percula is a benthic spawner and the eggs are retained on the reef for approximately one week after laying. The pH of reef water can vary substantially throughout the day, sometimes reaching levels below 8.0 in the early morning due to accumulated respiration of reef organisms in shallow water overnight (Ohde & van Woesik 1999; Kuffner et al. 2008). The eggs of benthic spawners might be adapted to such variation in ambient CO2 and pH levels and this may increase their tolerance to mild hypercapnia. The majority of small reef fish are demersal spawners (Munday & Jones 1998) and perhaps, like A. percula, they might be more tolerant to CO2 and pH fluctuations than are the eggs of pelagic spawners.
Holy smokes Batman, doesn’t sound like a marine apocalypse to me. Again, notice the references to pre-coded adaptation in these organisms to deal with an IPCC predicted scenario. Larval growth of walleye Pollock (Theragra chalcogramma):
- The authors write that "rising atmospheric concentrations of CO2 are predicted to decrease the pH of high-latitude oceans by 0.3 to 0.5 units by 2100," and they say that "because of their limited capacity for ion exchange, embryos and larvae of marine fishes are predicted to be more sensitive to elevated CO2 than juveniles and adults."
- What was done: In a study designed to explore these particular predictions, Hurst et al. (2013) examined the direct effects of projected levels of ocean acidification on the eggs and larvae of walleye pollock in a series of laboratory experiments that focused on determining the effects of elevated CO2 levels on size-at-hatch and early larval growth rates, where treatments were selected to reflect ambient conditions and conditions predicted to occur in high latitude seas in the next century (a 400-600 ppm increase), as well as a significantly higher CO2 treatment (~1200 ppm).
- What was learned: The three U.S. researchers found that "ocean acidification did not appear to negatively affect size or condition of early larval walleye pollock." In fact, they say there was "a trend toward larger body sizes among fish reared at elevated CO2 levels," while noting that this trend toward faster growth rates among larvae reared at elevated CO2 levels has also been observed in experiments with orange clownfish (Munday et al., 2009), as well as in the study of juvenile walleye pollock conducted by Hurst et al. (2012).
- What it means: In the words of Hurst et al. (2013), their findings suggest that "the growth dynamics of early life stages of walleye pollock are resilient to projected levels of ocean acidification."
- Due to atmospheric accumulation of anthropogenic CO2 the partial pressure of carbon dioxide (pCO2) in surface seawater increases and the pH decreases. This process known as ocean acidification might have severe effects on marine organisms and ecosystems. The present study addresses the effect of ocean acidification on early developmental stages, the most sensitive stages in life history, of the Atlantic herring (Clupea harengus L.). Eggs of the Atlantic herring were fertilized and incubated in artificially acidified seawater (pCO2 1260, 1859, 2626, 2903, 4635 μatm) and a control treatment (pCO2 480 μatm) until the main hatch of herring larvae occurred. The development of the embryos was monitored daily and newly hatched larvae were sampled to analyze their morphometrics, and their condition by measuring the RNA/DNA ratios. Elevated pCO2 neither affected the embryogenesis nor the hatch rate. Furthermore, the results showed no linear relationship between pCO2 and total length, dry weight, yolk sac area and otolith area of the newly hatched larvae. For pCO2 and RNA/DNA ratio, however, a significant negative linear relationship was found. The RNA concentration at hatching was reduced at higher pCO2 levels, which could lead to a decreased protein biosynthesis. The results indicate that an increased pCO2 can affect the metabolism of herring embryos negatively. Accordingly, further somatic growth of the larvae could be reduced. This can have consequences for the larval fish, since smaller and slow growing individuals have a lower survival potential due to lower feeding success and increased predation mortality. The regulatory mechanisms necessary to compensate for effects of hypercapnia could therefore lead to lower larval survival. Since the recruitment of fish seems to be determined during the early life stages, future research on the factors influencing these stages are of great importance in fisheries science.
So, if CO2 levels skyrocket beyond even projected levels, we could see some issues with larval development of this particular species of Atlantic Herring. If climate sensitivity isn’t nearly as high as thought (and there’s a growing-body of literature suggesting it is not), then we’re not in for the wild ride climate alarmists suggest we are. What about Juvenile Atlantic Cod (Gadus morhua)?
- The subject of Jutfelt and Hedgärde’s analysis was Atlantic cod (Gadus morhua), which they describe as an “ecologically and economically important species that has a history of being exposed to overfishing (Rose, 2004) and cod populations may therefore be sensitive to the effects of additional stressors such as ocean acidification.” For their analysis, the two researchers reared juvenile Atlantic cod for 30 days in control water (~500 μatm) or water with elevated CO2 levels (~1,000 μatm), during which time the juveniles were subjected to three separate behavioral experiments: (1) swimming activity, measured by the number of lines crossed per minute (12-19 days after exposure), (2) emergence from shelter, assessed by how long it took the fish to exit a shelter after a disturbance (26 days post exposure), and (3) lateralization, measuring turning side preference and the strength of behavioral symmetry (29-30 days post exposure). The purpose of the experiments was to determine whether or not these specific behaviors were affected by exposure to elevated CO2, as they “were previously reported to be affected by CO2 exposure in tropical reef fish.”
- When all was said and done, however, Jutfelt and Hedgärde report they found no effect of CO2 treatment on any of the behaviors tested, writing that “behavioral effects of CO2 are not universal in teleosts” and that “the behavior of Atlantic cod could be resilient to the impacts of near-future levels of water CO2.” Ruminating on why this may be the case, the authors note that Atlantic cod have been observed to forage in deep waters with low pH, and, therefore, may be “physiologically adapted to be tolerant to high environmental CO2 levels.” [NOTE: There’s that adaptation issue that these scientific wizards (ecokooks) often forget to mention]
- Whatever the reason, one thing is clear. As stated by the two researchers in the final sentence of their paper, “the results obtained in this study complicate the prediction of future effects of ocean acidification on fish, suggesting that behavioral effects could be negligible in some species and that we might not be able to make good predictions until more species from representative geographical and phylogenetic groups are tested and published.” Ocean acidification alarmists—take note!
- The authors write that "the bay barnacle Amphibalanus improvisus is (1) "a prominent filter-feeder in many fouling communities," (2) "globally widespread, occurring in shallow, tidal areas in both salty and brackish waters," and (3) "common throughout the Baltic Sea system, extending from near-full-salinity waters of the Skagerrak to nearly fresh waters of the Bay of Tothnia."
- What was done: In two separate experiments conducted over two successive years, Pansch et al. first assessed larval survival and development while rearing nauplius larvae in 6-well plates over ten days in response to three different pH treatments (8.02, 7.80 and 7.59), while in the second experiment larval stage and size were assessed by rearing nauplius larvae in 5-l glass bottles over 6 days in response to two different pH treatments (8.09 and 7.80).
- What was learned: Quoting the three scientists, "larval development of the barnacle was not significantly affected by the level of reduced pH that has been projected for the next 150 years," for "after 3 and 6 days of incubation, we found no consistent effects of reduced pH on developmental speed or larval size at pH 7.8 compared with the control pH of 8.1." Likewise, they say that "after 10 days of incubation, there were no net changes in survival or overall development of larvae raised at pH 7.8 or 7.6 compared with the control pH of 8.0." In all of their many individual trials, however, they determined "there was significant variation in responses between replicate batches (parental genotypes) of some larvae," with some batches actually responding positively to reduced pH."
- What it means: Pansch et al. say their results suggest that "the non-calcifying larval stages of A. improvisus are generally tolerant to near-future levels of ocean acidification," and that "this result is in line with findings for other barnacle species and suggests that barnacles do not show the greater sensitivity to ocean acidification in early life history reported for other invertebrate species," while adding that the barnacle's "substantial genetic variability in response to low pH may confer adaptive benefits under future ocean acidification."
- We expand upon the narrow taxonomic scope found in the literature today, which overlooks many life history characteristics of harvested species, by reporting on the larvae of Rachycentron canadum (cobia), a large, highly mobile, pelagic-spawning, widely distributed species with a life history and fishery value contrasting other species studied to date. We raised larval cobia through the first 3 weeks of ontogeny under conditions of predicted future ocean acidification to determine effects on somatic growth, development, otolith formation, swimming ability, and swimming activity. Cobia exhibited resistance to treatment effects on growth, development, swimming ability, and swimming activity at 800 and 2100 μatm pCO2. However, these scenarios resulted in a significant increase in otolith size (up to 25% larger area) at the lowest pCO2 levels reported to date, as well as the first report of significantly wider daily otolith growth increments. When raised under more extreme scenarios of 3500 and 5400 μatm pCO2, cobia exhibited significantly reduced size-at-age (up to 25% smaller) and a 2-3 days developmental delay. The robust nature of cobia may be due to the naturally variable environmental conditions this species currently encounters throughout ontogeny in coastal environments, [NOTE: there’s that adaptation factor again] which may lead to an increased acclimatization ability even during long-term exposure to stressors.
How are those Polychaetes (segmented worms) faring in the era of man’s evil inventions & unchecked CO2?
- Polychaetes are a class of segmented worms that live under a wide range of oceanic conditions. Often, they are the dominant organisms found living in the sea floor, but they also thrive in the open ocean. According to Ricevuto et al. (2015), although knowledge of the potential response of these organisms to ocean acidification is growing, much remains to be learned, including “how their trophic behavior might change in response to low [less basic, or more acidic] pH [NOTE: the low pH for this study was 7.7-7.8].” In an effort to fill this informational void, Ricevuto et al. thus set out to examine food-chain interactions of three polychaete species (Platynereis dumerilii, Polyophthalmus pictus and Syllis prolifera) and their organic matter (food) sources (macroalgae, seagrass and epiphytes) in a naturally acidified region of the Mediterranean Sea.
- The location for their study was a shallow water reef area on the north-eastern coast of Ischia, an island off the coast of Italy known for volcanic features, including underwater vents that release copious quantities of CO2. The vents produce a pH gradient in the area that provides “a natural laboratory for ocean acidification studies, [NOTE: See Table 1 at Ricevuto el al. for the pH variance]” which the researchers further describe as “an ideal model system to conduct experiments investigating the effect of climate changes (particularly ocean acidification) on benthic community composition and structure, as well as on functional aspects, such as tropic interactions,” which was the focus of this study. And what did the study show?
- After collecting data and conducting a series of complex analyses, the three Italian researchers report “increased pCO2 did not alter the trophic interactions dramatically,” adding “there seems to be a resilience in the trophic pattern, possibly due to the tolerance of the target species to acidification and potential local acclimatization and/or adaptation (see Calosi et al., 2013).” Such “phenotypic plasticity” (the ability to alter biochemical reactions based on environmental changes such as increasing temperature or acidity) observed in the three polychaete species studied, according to Ricevuto et al., “may allow them to respond well to alterations in the environment and eventually offset near-future ocean acidification scenarios.” Thus, as the researchers ultimately conclude, “for some species, like the ones considered in this study, ocean acidification may not represent a dramatic stress.” And that’s good news worth reporting.
Got green marine algae (Stichococcus cylindricus and Stichococcus minor)?
- From pre-industrial times to the present, the atmosphere's CO2 concentration has risen well in excess of 100 ppm, leading to a drop of 0.1 pH unit in earth's seawater, while anticipated CO2 increases to the end of the current century are suggestive of a further drop of 0.3-0.5 pH unit, according to Caldeira and Wickett (2003, 2005). So what do these projections portend for the productivity of the world's marine algae?
- What was done: In a study of two such green marine algae (Stichococcus cylindricus and Stichococcus minor), Moazami-Goudarzi and Colman measured their growth rates while growing them in artificial seawater - as per Berges et al. (2001) - within 125-ml Erlenmeyer flasks at pH values of 5.0, 6.0, 7.0, 8.2, 9.0 and 9.5, as well as at a variety of salinity levels (25, 50, 100, 200 and 470 mM).
- What was learned: The two Canadian researchers report that "both species were found to have similar growth rates and grew over the range of pH 5.0 to 9.5 with optimal rates at pH 8.2," with cells grown at pH 5.0, 6.0 and 7.0 showing no significant difference in growth rates. Likewise, they similarly report that "both species were found to have similar growth rates and to grow over a range of salinities at sodium chloride concentrations of 25, 50, 100, 200 and 470 mM."
- What it means: With Moazami-Goudarzi and Colman determining that S. minor and S. cylindricus "were able to tolerate a broad range of pH from pH 5.0 to 9.5," as well as the broad range of salinities they investigated, it would appear that even the worst nightmare of the world's climate alarmists would not be a great impediment to the continued wellbeing of these two green marine algae, even without the positive influence of evolutionary forces that would likely come into play over the timespan involved in the seawater transformations envisioned by Caldeira and Wickett.
- We exposed berried Norway lobsters (Nephrops norvegicus), during 4 months to the combination of six ecologically relevant temperatures (5–18°C) and reduced pH (by 0.4 units). Embryonic responses were investigated by quantifying proxies for development rate and fitness including: % yolk consumption, mean heart rate, rate of oxygen consumption, and oxidative stress. We found no interactions between temperature and pH, and reduced pH only affected the level of oxidative stress significantly, with a higher level of oxidative stress in the controls. Increased temperature and % yolk consumed had positive effects on all parameters except on oxidative stress, which did not change in response to temperature. There was a difference in development rate between the ranges of 5–10°C (Q10: 5.4) and 10–18°C (Q10: 2.9), implicating a thermal break point at 10°C or below. No thermal limit to a further increased development rate was found. The insensitivity of N. norvegicus embryos to low pH might be explained by adaptation to a pH-reduced external habitat and/or internal hypercapnia during incubation. Our results thus indicate that this species would benefit from global warming and be able to withstand the predicted decrease in ocean pH in the next century during their earliest life stages. However, future studies need to combine low pH and elevated temperature treatments with hypoxia as hypoxic events are frequently and increasingly occurring in the habitat of benthic species.
Nope, doesn’t sound like the old Norway Lobster will be going the way of the Dodo due to pH fluctuations. And again, did you notice the allusion to adaptation? So, for you naturalist Progressive Democrats who claim to be scientifically-adept—quit acting as if you’ve never heard of (micro)evolution and/or adaptation. Unless you attended a decaying public school in Illinois, New Jersey or California—then I may excuse your ignorance.