Ocean acidification climate change fears overblown, studies show

March 31, 2012 iwishart New Zealand 3

By Ian Wishart
Author of Air Con

The UN IPCC has tried to drum up panic by suggesting rising CO2 absorption in the oceans is affecting the pH balance, making the seas more “acidic” and killing coral and other marine life. But the latest scientific studies are actually suggesting other factors may be at play.

“An international team of scientists has solved a mystery that has puzzled marine chemists for decades,” explained the University of Miami in 2009.(footnote 440) “They have discovered that fish contribute a significant fraction of the oceans’ calcium carbonate production, which affects the delicate pH balance of seawater. The study gives a conservative estimate of three to 15 percent of marine calcium carbonate being produced by fish, but the researchers believe it could be up to three times higher.”

Now this is an exceptionally important study. Rising CO2 levels in the oceans cause chemical reactions that can start to harm shellfish and other marine life by dissolving their shells and exoskeletal structures. In theory. However, it appears fish can and do use the surplus CO2 in the oceans, along with calcium-rich surface waters, to create calcium carbonates, which help keep the oceans alkaline.

If you’ve owned a fish tank you’ll know fish quickly create their ideal pH level, and the same thing applies on a much bigger scale in the oceans.

“Until now,” continues the University of Miami study, “scientists believed that the oceans’ calcium carbonate, which dissolves in deep waters making seawater more alkaline, came from marine plankton.

The recent findings published in Science explain how up to 15 percent of these carbonates are, in fact, excreted by fish that continuously drink calcium-rich seawater. The ocean becomes more alkaline at much shallower depths than prior knowledge of carbonate chemistry would suggest which has puzzled oceanographers for decades.

The new findings of fish-produced calcium carbonate provides an explanation: fish produce more soluble forms of calcium carbonate, which probably dissolve more rapidly, before they [are able to] sink into the deep ocean.”

This is important, because the UN IPCC study teams have claimed the calcium carbonates produced by plankton (which sink to the ocean floor) take millions of years to re-balance the oceans, but this new study shows fish produce a much more rapidly acting form of the alkaline that can benefit the upper layers of the oceans immediately.

“The digestive systems of fish play a vital role in maintaining the health of the oceans and moderating climate change,” reported Reuters news agency on the peer-reviewed study.

“Bony fish produced a large portion of the inorganic carbon that helps maintain the oceans’ acidity balance and was vital for marine life, they said.

“The world’s bony fish population, estimated at between 812 million and 2 billion tons, helped to limit the consequences of climate change through its effect on the carbon cycle.

“ ‘This study is really the first glimpse of the huge impact fish have on our carbon cycle – and why we need them in the ocean’, researcher Villy Christensen and colleagues wrote.

“Calcium carbonate is a white, chalky material that helps control the acidity balance of sea water and is essential to the health of marine ecosystems and coral reefs.”

The probable reason for decreasing alkalinity, then, is overfishing, not CO2 emissions.(footnote 442) If we strip-mine the seas of alkaline-producing fish, we should hardly act surprised when we find less alkalinity in the seawater after a few decades of bad fishing practice. (footnote 443)

Then there’s this recent bombshell published in the journal Geology: that increasing levels of CO2 in the ocean are actually helping some shellfish thrive: (footnote 444)

In a striking finding that raises new questions about carbon dioxide’s (CO2) impact on marine life, Woods Hole Oceanographic Institution (WHOI) scientists report that some shell-building creatures – such as crabs, shrimp and lobsters – unexpectedly build more shell when exposed to ocean acidification caused by elevated levels of atmospheric carbon dioxide (CO2).

Because excess CO2 dissolves in the ocean – causing it to “acidify” – researchers have been concerned about the ability of certain organisms to maintain the strength of their shells. Carbon dioxide is known to trigger a process that reduces the abundance of carbonate ions in seawater – one of the primary materials that marine organisms use to build their calcium carbonate shells and skeletons.

The concern is that this process will trigger a weakening and decline in the shells of some species and, in the long term, upset the balance of the ocean ecosystem.

But in a study published in the Dec. 1 issue of Geology, a team led by former WHOI postdoctoral researcher Justin B. Ries found that seven of the 18 shelled species they observed actually built more shell when exposed to varying levels of increased acidification. This may be because the total amount of dissolved inorganic carbon available to them is actually increased when the ocean becomes more acidic, even though the concentration of carbonate ions is decreased.

“Most likely the organisms that responded positively were somehow able to manipulate…dissolved inorganic carbon in the fluid from which they precipitated their skeleton in a way that was beneficial to them,” said Ries, now an assistant professor in marine sciences at the University of North Carolina.

“They were somehow able to manipulate CO2…to build their skeletons.”

In truth, it’s a simple reminder of something the climate changers either forget or deliberately ignore when crafting their dumbed-down scary soundbites: when one species can no longer take the heat in the kitchen, another one rises up from the shadows swiftly to take its place that’s more resilient and even thrives in the new conditions.

The moral of the story? Life appears far more adaptable than you hear about on the TV news. The next time you hear a Greenpeace lobbyist, or a TV reporter for that matter, sensationally warning of the dangers of ocean acidification, you can be forgiven if you choose to roll all over the floor in fits of laughter.

440 “Fishdunnit! Mystery solved”, University of Miami news release, based on a study published in Science, 16 January 2009
441 “Fish digestions help keep oceans healthy”, Reuters 16 January 2009,
442 More evidence that this is the case is provided by Australian geology researcher Tim Casey, who found that decreasing alkalinity in the oceans was not being matched in fresh water systems like rivers and lakes. If CO2 were the culprit, acidification should be happening in all open air water sources across the planet. The fact that it isn’t suggests something other than atmospheric CO2 is to blame, and marine overfishing or submarine volcanism are far more likely explanations. See Casey’s paper.
443 Additionally, if coral atolls are being severely overfished that could explain why decreasing alkalinity might be impacting coral structures.
444 “In CO2-rich Environment, Some Ocean Dwellers Increase Shell Production”, Woods Hole Oceanographic Institute, Dec 1 2009

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3 Comments

  1. Nice try, but FAIL. You are using papers that were published 3 years ago. And yet you ignore the most recent papers which show that yes, the oceans are acidifying, and yes, it is starting to hurt oysters and other shellfish that rest of the ocean food change depend on.

  2. Yeah…depends on how good the studies you haven’t actually cited are. Species adaptation through micro evolutionary measures is actually quite rapid after a few generations. The seas have been far less alkaline in the past than they are today, and marine life has been around a billion years or more. But here are some recent studies that don’t get mentioned on the Chicken Little websites:

    Abstract

    Ocean acidity has increased by 30% since preindustrial times due to the uptake of anthropogenic CO2 and is projected to rise by another 120% before 2100 if CO2 emissions continue at current rates. Ocean acidification is expected to have wide-ranging impacts on marine life, including reduced growth and net erosion of coral reefs. Our present understanding of the impacts of ocean acidification on marine life, however, relies heavily on results from short-term CO2 perturbation studies. Here, we present results from the first long-term CO2 perturbation study on the dominant reef-building cold-water coral Lophelia pertusa and relate them to results from a short-term study to compare the effect of exposure time on the coral’s responses. Short-term (1 week) high CO2 exposure resulted in a decline of calcification by 26–29% for a pH decrease of 0.1 units and net dissolution of calcium carbonate. In contrast, L. pertusa was capable to acclimate to acidified conditions in long-term (6 months) incubations, leading to even slightly enhanced rates of calcification. Net growth is sustained even in waters sub-saturated with respect to aragonite. Acclimation to seawater acidification did not cause a measurable increase in metabolic rates. This is the first evidence of successful acclimation in a coral species to ocean acidification, emphasizing the general need for long-term incubations in ocean acidification research. To conclude on the sensitivity of cold-water coral reefs to future ocean acidification further ecophysiological studies are necessary which should also encompass the role of food availability and rising

    – Acclimation to ocean acidification during long-term CO2 exposure in the cold-water coral Lophelia pertusa

    Armin U. Form*,
    Ulf Riebesell

    Article first published online: 23 NOV 2011

    DOI: 10.1111/j.1365-2486.2011.02583.x

    HERE’S ANOTHER:

    Summary

    Rising anthropogenic CO2 emissions acidify the oceans, and cause changes to seawater carbon chemistry. Bacterial biofilm communities reflect environmental disturbances and may rapidly respond to ocean acidification. This study investigates community composition and activity responses to experimental ocean acidification in biofilms from the Australian Great Barrier Reef. Natural biofilms grown on glass slides were exposed for 11 d to four controlled pCO2 concentrations representing the following scenarios: A) pre-industrial (∼300 ppm), B) present-day (∼400 ppm), C) mid century (∼560 ppm) and D) late century (∼1140 ppm). Terminal restriction fragment length polymorphism and clone library analyses of 16S rRNA genes revealed CO2-correlated bacterial community shifts between treatments A, B and D. Observed bacterial community shifts were driven by decreases in the relative abundance of Alphaproteobacteria and increases of Flavobacteriales (Bacteroidetes) at increased CO2 concentrations, indicating pH sensitivity of specific bacterial groups. Elevated pCO2 (C + D) shifted biofilm algal communities and significantly increased C and N contents, yet O2 fluxes, measured using in light and dark incubations, remained unchanged. Our findings suggest that bacterial biofilm communities rapidly adapt and reorganize in response to high pCO2 to maintain activity such as oxygen production.

    Effects of ocean acidification on microbial community composition of, and oxygen fluxes through, biofilms from the Great Barrier Reef

    Verena Witt1,2,*,
    Christian Wild2,
    Kenneth R. N. Anthony1,
    Guillermo Diaz-Pulido3,
    Sven Uthicke1

    Article first published online: 12 SEP 2011

    DOI: 10.1111/j.1462-2920.2011.02571.x

  3. ANd in fact, as if to prove my point about evolutionary adaptation, here’s a recent paper concerning your oysters entree:

    Abstract

    It is essential to predict the impact of elevated Pco2 on marine organisms and habitats to anticipate the severity and consequences of future ocean chemistry change. Despite the importance of carry-over effects in the evolutionary history of marine organisms, few studies have considered links between life-history stages when determining how marine organisms will respond to elevated Pco2, and none have considered the link between adults and their offspring. Herein, we exposed adults of wild and selectively bred Sydney rock oysters, Saccostrea glomerata to elevated Pco2 during reproductive conditioning and measured the development, growth and survival response of their larvae. We found that elevated Pco2 had a negative impact on larvae of S. glomerata causing a reduction in growth, rate of development and survival. Exposing adults to elevated Pco2 during reproductive conditioning, however, had positive carry-over effects on larvae. Larvae spawned from adults exposed to elevated Pco2 were larger and developed faster, but displayed similar survival compared with larvae spawned from adults exposed to ambient Pco2. Furthermore, selectively bred larvae of S. glomerata were more resilient to elevated Pco2 than wild larvae. Measurement of the standard metabolic rate (SMR) of adult S. glomerata showed that at ambient Pco2, SMR is increased in selectively bred compared with wild oysters and is further increased during exposure to elevated Pco2. This study suggests that sensitive marine organisms may have the capacity to acclimate or adapt to elevated Pco2 over the next century and a change in energy turnover indicated by SMR may be a key process involved.

    Adult exposure influences offspring response to ocean acidification in oysters

    Laura M. Parker1,*,
    Pauline M. Ross1,
    Wayne A. O’Connor2,
    Larissa Borysko1,
    David A. Raftos3,
    Hans-Otto Pörtner4

    Article first published online: 27 OCT 2011

    DOI: 10.1111/j.1365-2486.2011.02520.x

    ANOTHER STUDY THIS YEAR has found big discrepancies in measurements of pCO2 in studies, with the implication that people are overestimating the sensitivity of marine organisms to CO2:
    “…if calculated pCO2 values are underestimated by up to 30 %, an organism’s respective sensitivity to acidification might be severely overestimated.”
    See Implications of observed inconsistencies
    in carbonate chemistry measurements for
    ocean acidification studies
    C. J. M. Hoppe, G. Langer, S. D. Rokitta, D. A. Wolf-Gladrow, and B. Rost
    Alfred Wegener Institute for Polar and Marine Research, 27570 Bremerhaven, Germany
    Received: 23 January 2012 – Accepted: 24 January 2012 – Published: 14 February 2012
    Correspondence to: C. J. M. Hoppe (clara.hoppe@awi.de)
    Published by Copernicus Publications on behalf of the European Geosciences Union.

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