Guest myth-busting by David Middleton

From the American Association of Science of America [1]…

Ocean acidification could boost shell growth in snails and sea urchins By Katie Camero Jul. 23, 2019 , 2:00 PM The world’s oceans are acidifying rapidly as they soak up massive amounts of the carbon dioxide (CO 2 ) released from burning fossil fuels. That’s bad news for tiny marine critters like coral and sea urchins that make up the base of the ocean food chain: Acidic water not only destroys their shells, but it also makes it harder for them to build new ones. Now, scientists studying sea snails have discovered an unexpected side effect of this acid brew—it can help some of them build thicker, stronger shells by making their food more nutritious. Often called climate change’s “evil twin,” acidification happens when the ocean absorbs atmospheric CO 2 . As CO 2 dissolves, the process releases hydrogen ions, lowering the water’s pH and increasing its acidity. That acidic water… […] To find out what is happening in the wild, Sean Connell, an ecologist at the University of Adelaide in Australia, and colleagues traveled to underwater CO 2 vents off the coast of New Zealand’s White Island (Whakaari). Water near the vents is about as acidic as most of the ocean is predicted to be by the end of the century. The researchers collected five sea snails (Eatoniella mortoni), along with five samples of turf algae, a staple of the sea snails’ diet. […] Despite the idea that some marine organisms can resist the dangers of climate change, Riebesell says biodiversity is still decreasing, especially at CO 2 vents, and that could make ecosystems less resilient. “Even if some organisms benefit from warming and acidification, there are still losers,” Riebesell says, “and evolutionary adaptation is not fast enough to compensate for the loss of these losers.” Science! As in, “she blinded me with…”[2]

The phrase “ocean acidification” was literally invented out of thin air in 2003 by Ken Caldiera to enable liberal arts majors to sound sciencey when scaring the bejesus out of the scientifically illiterate masses. The geochemical process has been well-understood for about 100 years… But didn’t get a crisis-monger nickname until 2003.

When the pH of seawater decreases, calcium carbonate dissolves. In warm, shallow seas, at a pH of about 8.3, dissolution of aragonite and calcite particles by inorganic processes is almost nonexistent. However, since the classical studies of the Challenger expedition, it has been known that the proportion of calcium-carbonate particles in seafloor sediments decreases as depth of water increases (Table 5-1). Such decrease is particularly rapid at depths between 4000 and 6000 m. Although the reasons for this decrease have been debated, the evidence suggests that calcium carbonate dissolves because the CO 2 concentration increases with depth. The control on CO 2 appears to be part biological; it results from biological oxidation of organic-carbon compounds. Also, the water masses at greater depth were derived from the polar region; their temperature is lower and the water contains more dissolved CO 2 . Increased concentration of CO 2 is in turn reflected by lower pH, which leads to calcium carbonate dissolution. However, the increase of pressure with depth may also be involved; such increase affects the dissociation of carbonic acid (Eqs. 5-11 and 5-12). The depth at which the calcium-carbonate decreases most rapidly is known as the carbonate-compensation depth, defined as the depth at which the rate of dissolution of solid calcium carbonate equals the rate of supply. Friedman and Sanders, 1978, pages 133-134

Friedman and Sanders, 1978, pages 133-134

Friedman and Sanders, 1978, pages 133-134

Why do you think the Science! journalist is a Liberal Arts major?

Well… There’s this…

Katie Camero

Katie Camero is a Diverse Voices in Science Journalism intern for the News section of Science in Washington, D.C. Science! As in, “she blinded me with…”[2]

Then there are the things she wrote in this article…

Note: Most of my rebuttals are from these two WUWT posts:

The world’s oceans are acidifying rapidly… Katie Camero, Liberal Arts major

Horst schist!

Figure 1. Station ALOHA, Hawaiian Ocean Time Series (HOTS) calculated pH (at 25 °C) trend (Oct. 1988 – Nov. 2016). Adapted from: Dore, J.E., R. Lukas, D.W. Sadler, M.J. Church, and D.M. Karl. 2009. Physical and biogeochemical modulation of ocean acidification in the central North Pacific. Proc Natl Acad Sci USA 106:12235-12240

While the Station ALOHA pH trend does exhibit a negative slope and correlates well with pCO 2 (R² = 0.8646), most of the values fall within 2δ of the 1994-2005 mean. Over the past 29 years the pH has dropped from 8.1 to 8.1, rounded to 1 decimal place.

Acidic water not only destroys their shells, but it also makes it harder for them to build new ones. Katie Camero, Liberal Arts major

Good fracking grief! Seawater can’t become acidic, at least not under real world conditions. A study of seawater pH near active volcanic CO 2 vents in the Mediterranean (Kerrison et al., 2011) found that the pH immediately adjacent to the vent was still alkaline, despite being subjected to the equivalent of nearly 5,600 ppm CO 2 .

Figure 2. CO 2 fugacity vs pH. Data from Kerrison et al., 2011.

Partial pressure and fugacity (μatm) are a little lower than what the mixing ratio (ppm) would be, depending on temperature and humidity. However, they are close. A partial pressure (pCO 2 ) of 350 μatm generally equates to about 350 ppm in the atmosphere. At nearly 5,600 ppm CO 2 the seawater was still alkaline, not acidic.

To find out what is happening in the wild, Sean Connell, an ecologist at the University of Adelaide in Australia, and colleagues traveled to underwater CO 2 vents off the coast of New Zealand’s White Island (Whakaari). Water near the vents is about as acidic as most of the ocean is predicted to be by the end of the century. Katie Camero, Liberal Arts major

“An ecologist at the University of Adelaide in Australia” is not an upgrade relative to a Liberal Arts major at Boston University, if they really think that the water near CO 2 “vents is about as acidic as most of the ocean is predicted to be by the end of the century.”

The pH of the water nearest to the Mediterranean CO 2 vents ranged from 7.01 to 7.15. At least one study from White Island, found “reduced mean pH levels (7.49 and 7.85) relative to background levels of 8.06” (Brinkman & Smith, 2014). Without a reference to pCO 2 of the seawater, these numbers are useless.

Atmospheric CO 2 is on a trajectory to reach 550-600 ppmv by the end of this century. There is no scientific basis to assert that this will drop the average pH of he open ocean from 8.1 to less than 7.5. Atmospheric CO 2 would have to rise to 1,000 to 2,000 ppmv to drive average seawater pH below 7.5.

Figure 3. Cenozoic seawater pH from boron isotopes in planktonic foraminifera (modified after Pearson & Palmer, 2000). Note that pH was lower than the PETM 51.5 (EECO) and 59.5 Mya. HOTS Station Aloha is added for reference.

Figure 4. Cenozoic CO 2 atmospheric mixing ratio and seawater partial pressure. Notice the huge difference between atmospheric CO 2 and pCO 2 . Also notice that pCO 2 was higher before and after the PETM and that stomata data indicate that CO 2 was about what it is today, apart from a short duration spike to about 800 ppmv 55.2 Mya. Talk about settled science! The Mauna Loa instrumental record (MLO) is added for reference. Note: Tirpati should be Tripati.

Besides, it’s not the pH that matters!

All that matters are the aragonite (Ωarg) and calcite (Ωcal) saturation states.

Figure 5. Station ALOHA Aragonite and Calcite saturation state trends (Oct. 1988 – Nov. 2016). Adapted from: Dore, J.E., R. Lukas, D.W. Sadler, M.J. Church, and D.M. Karl. 2009. Physical and biogeochemical modulation of ocean acidification in the central North Pacific. Proc Natl Acad Sci USA 106:12235-12240

While the addition of CO 2 to seawater will lower the Ωarg and Ωcal, increasing the temperature will increase the saturation states. And temperature dominates pCO 2 .

In situ Ωarg vs. pCO 2 …

Figure 6. Station ALOHA aragonite saturation vs pCO 2 in situ. Adapted from: Dore, J.E., R. Lukas, D.W. Sadler, M.J. Church, and D.M. Karl. 2009. Physical and biogeochemical modulation of ocean acidification in the central North Pacific. Proc Natl Acad Sci USA 106:12235-12240

Note that In situ Ωarg has a much better correlation to SST than to in situ pCO 2 …

Figure 7. SST vs aragonite saturation. Adapted from: Dore, J.E., R. Lukas, D.W. Sadler, M.J. Church, and D.M. Karl. 2009. Physical and biogeochemical modulation of ocean acidification in the central North Pacific. Proc Natl Acad Sci USA 106:12235-12240

Despite the idea that some marine organisms can resist the dangers of climate change, Riebesell says biodiversity is still decreasing, especially at CO 2 vents, and that could make ecosystems less resilient. “Even if some organisms benefit from warming and acidification, there are still losers,” Riebesell says, “and evolutionary adaptation is not fast enough to compensate for the loss of these losers.” Katie Camero, Liberal Arts major

Well… Duh! Ries et al., 2009 conducted a laboratory experiment on a representative sample of marine calcifiers (oceanic critters that make shells, tests, carapaces, etc. out of CaCO 3 )…

To investigate the impact of ocean acidification on a range of benthic marine calcifiers, we reared 18 calcifying species for 60 d in isothermal (25 °C; see the Data Repository for discussion) experimental seawaters equilibrated with average pCO 2 values (±SD) of 409 (±6), 606 (±7), 903 (±12), and 2856 (±54) ppm, corresponding to modern pCO2, and ~2, 3, and 10 times pre-industrial levels (~280 ppm), respectively, and yielding average seawater saturation states (±SD) of 2.5 (±0.4), 2.0 (±0.4), 1.5 (±0.3), and 0.7 (±0.2) with respect to aragonite (see the Data Repository for detailed methods). These carbonate system parameters were selected to represent the range of values predicted for the coming millennium (Brewer, 1997; Feely et al., 2004) and to span those reported to have occurred since mid-Cretaceous time (ca. 110 Ma; Royer et al., 2004; Tyrrell and Zeebe, 2004). The organisms’ net rates of calcifi cation (total calcification minus total dissolution) under the various pCO2 treatments were estimated from changes in their buoyant weight and verified with dry weight measurements after harvesting. Ries et al., 2009

The aragonite saturation data from Station ALOHA indicate that critical levels would occur at much higher pCO 2 levels than Ries’ formulations. Most of the marine calcifier taxa were relatively unaffected below the equivalent of 600-900 ppm CO 2 .

Taxa without a strong preference for aragonite over calcite, that had a higher degree of organic cover and those that utilized photosynthesis tended to fare better under high CO 2 conditions. Some of the best seafood (crab, shrimp & lobster) thrive in under high CO 2 conditions.

Figure 8. Figure 1 from Ries (Left), red boxes approximate current calcification rate range. (Right) Letters indicate the pCO 2 level at which the calcification rate drops below the current range. Adapted from: Dore, J.E., R. Lukas, D.W. Sadler, M.J. Church, and D.M. Karl. 2009. Physical and biogeochemical modulation of ocean acidification in the central North Pacific. Proc Natl Acad Sci USA 106:12235-12240 and Ries, Justin B., Anne L. Cohen, Daniel C. McCorkle; Marine calcifiers exhibit mixed responses to CO 2 -induced ocean acidification. Geology ; 37 (12): 1131–1134. doi: https://doi.org/10.1130/G30210A.1

The only marine calcifier which appears to be in peril at pCO 2 levels likely to be reached in the next few centuries is the soft clam, Mya arenaria,… And this is fracking HILARIOUS!!!

The high tolerance of environmental factors is reflected in two statements made by Hidu & Newell (1989) about clam culture: “Mya larvae are among the most hardy that we have reared; one has to work overtime with incompetence to destroy a brood.” and “If Mya are hardy as larvae they are even more hardy as juveniles.” Strasser, 1998

Do I need to explain this?

Ries et al., 2009 tried as hard as they could to wipe out marine calcifiers with “ocean acidification.” The only taxa, they were able to even remotely imperil was Mya arenaria (called “steamers” where I grew up)… possibly the hardiest of all hardy marine calcifiers. This bit can’t be repeated too often…

“Mya larvae are among the most hardy that we have reared; one has to work overtime with incompetence to destroy a brood.”

You really couldn’t make this schist up if you were trying. Mya arenaria is possibly the most successful invasive species of the Phanerozoic Eon… It was an invasive species before Adam met Eve… Long before Adam met Eve. Yet, it is the only taxa that Ries et al., 2009 managed to “work overtime with incompetence to destroy a brood.”

References

Brinkman T. J., Smith A. M. (2014) “Effect of climate change on crustose coralline algae at a temperate vent site, White Island, New Zealand”. Marine and Freshwater Research 66, 360-370.

Dore, J.E., R. Lukas, D.W. Sadler, M.J. Church, and D.M. Karl. 2009. “Physical and biogeochemical modulation of ocean acidification in the central North Pacific”. Proc Natl Acad Sci USA 106:12235-12240

Friedman, G.M. and Sanders, J.E. (1978) “Principles of Sedimentology”. Wiley, New York.

Kerrison, Phil & Hall-Spencer, Jason & Suggett, David & Hepburn, Leanne & Steinke, Michael. (2011). “Assessment of pH variability at a coastal CO2 vent for ocean acidification studies.” Estuarine and Coastal Marine Science. 94. 129-137. 10.1016/j.ecss.2011.05.025.

Pagani, M., J.C. Zachos, K.H. Freeman, B. Tipple, and S. Bohaty. 2005. “Marked Decline in Atmospheric Carbon Dioxide Concentrations During the Paleogene”. Science, Vol. 309, pp. 600-603, 22 July 2005.

Pearson, P. N. and Palmer, M. R.: “Atmospheric carbon dioxide concentrations over the past 60 million years”. Nature, 406, 695–699,https://doi.org/10.1038/35021000, 2000.

Ries, Justin B., Anne L. Cohen, Daniel C. McCorkle; “Marine calcifiers exhibit mixed responses to CO 2 -induced ocean acidification”. (2009). Geology ; 37 (12): 1131–1134. doi: https://doi.org/10.1130/G30210A.1

Royer, et al., 2001. “Paleobotanical Evidence for Near Present-Day Levels of Atmospheric CO 2 During Part of the Tertiary”. Science 22 June 2001: 2310-2313. DOI:10.112

Strasser M, 1999. “Mya arenaria: an ancient invader of the North sea coast”. Helgolander Meeresunters 52:309–324.

Tripati, A.K., C.D. Roberts, and R.A. Eagle. 2009. “Coupling of CO 2 and Ice Sheet Stability Over Major Climate Transitions of the Last 20 Million Years”. Science, Vol. 326, pp. 1394 1397, 4 December 2009. DOI: 10.1126/science.1178296

Pop Culture References

[1] American Association of Science of America

[2] Science! As in, “she blinded me with…”

Thomas Dolby – She Blinded Me With Science from Mad Hatter on Vimeo.

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