Acid Oceans? & Oyster Shells

What’s Natural?

Guest post by Jim Steele

Published July 14, 2020 in the Pacifica Tribune

(I wrote a white paper for the CO2  Coalition, providing more details and references to peer reviewed science regards how marine life counteracts ocean acidification. That paper can be downloaded here )

Search the internet for “acid oceans” and you’ll find millions of articles suggesting the oceans are becoming more corrosive due the burning of fossil fuels, and “acid oceans” are threatening marine life. Although climate modelers constantly claim the oceans’ surface pH has dropped since the 1800s, that change was never measured, as the concept of pH was not created until the early 1900s by beer-makers.

In 2003 Stanford’s Dr. Ken Caldeira coined the term “ocean acidification” to generate public concern about increasing CO2  . As New Yorker journalist Elizabeth Kolbert reported, “Caldeira told me that he had chosen the term ‘ocean acidification’ quite deliberately for its shock value. Seawater is naturally alkaline, with a pH ranging from 7.8 to 8.5—a pH of 7 is neutral—which means that, for now, at least, the oceans are still a long way from actually turning acidic.” Nonetheless Caldeira’s term “ocean acidification” evoked such undue fears and misunderstandings, we are constantly bombarded with catastrophic media hype and misdiagnosed causes of natural change.

For example, for nearly a decade the media has hyped the 2006-2008 die-off of larval oysters in hatcheries along Washington and Oregon. They called it a crisis caused by rising atmospheric CO2  and the only solution was to stop burning fossil fuels. But it was an understanding of natural pH changes that provided the correct solutions. Subsurface waters at a few hundred meters depth naturally contain greater concentrations CO2  and nutrients and a lower pH than surface waters. Changes in the winds and currents periodically bring those waters to the surface in a process called upwelling. Upwelling promotes a burst of life but also lowers the surface water pH.  Not fully aware of all the CO2  dynamics, the hatcheries had made 3 mistakes.

First, they failed to recognize not all oyster species are well adapted to the low pH of upwelled water. The larvae of native Olympia oysters naturally survive intense upwelling events along the Washington coast because that species “broods” its larvae. The larvae initiate their shells protected inside their parents’ shells where pH is more controlled. However, the Olympia oysters were over-harvested into near extinction in the 1800’s.

So, fishermen imported the Japanese oyster, which is now the mainstay of the Washington and Oregon fisheries. Japanese oysters did not evolve within an intense upwelling environment similar to Washington’s coast. Each Japanese oyster simply releases over 50 million eggs into the water expecting their larvae to survive any mild changes in pH during initial shell formation. Hatcheries didn’t realize the Japanese oyster’s larvae had a 6-hour window during which the larvae’s initial shell development and survival was vulnerable to low pH.

Second, because cooler waters inhibit premature spawning, hatcheries pumped cool water from the estuary in the early morning. As measured in coral reefs, photosynthesis raises pH during the day, but nighttime respiration drops pH significantly. By pumping early morning water into their tanks, they imported estuary water at its lowest daily pH. Finally, they failed to recognize natural upwelling events transport deeper waters with naturally low pH into the estuary, further lowering the pH of water pumped into their tanks.

Now, hatcheries simply pump water from the estuary later in the day after photosynthesis has raised pH. Scientists also developed a metering device that detects intrusions of low pH waters, so hatcheries avoid pumping water during upwelling events. As for most shellfish, once the shell is initiated, a protective layer prevents any shell corrosion from low pH conditions. Problem easily solved and crisis averted!

The simplistic idea that burning fossil fuels is causing the surface ocean to become more acidic is based on the fact that when CO2  interacts with water a series of chemical changes results in the production of more hydrogen ions which lowers pH. Unfortunately, all catastrophic analyses stop there. But living organisms then reverse those reactions. Whether CO2  enters the surface waters via the atmosphere or from upwelling, it is quickly utilized by photosynthesizing plankton which counteracts any “acidification”. A percentage of the organic matter created in the sunlit waters sinks or is actively transported to depths, further counteracting any surface “acidification’. Some organic matter sinks so rapidly, CO2  is trapped at depths for hundreds and thousands of years. The dynamics that carry carbon to ocean depths largely explains why the oceans hold 50 times more CO2  than the atmosphere.

To maintain marine food webs, it is essential that upwelling bring sunken nutrients back into the sunlight to enable photosynthesis. Upwelling also brings stored CO2  and low pH water to the surface. Wherever upwelling recycles nutrients and lowers surface pH, the greatest abundance and diversity of marine life is generated.

Jim Steele is director emeritus of the Sierra Nevada Field Campus, SFSU and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism.

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July 14, 2020 6:19 am

I grow oysters in floats under my deck in a creek just off the Chesapeake Bay from spats already complete with shells, so this is very interesting to me. The story on how they figured out what was happening would also be interesting.

Starting the year after the first batch of spat were put out, the rip rap along the shore began to sprout oysters evidently from larvae coming from my floats. Up until that point the rip rap only had an occasional shell. Nature at work. I will say the oysters grow rapidly. A lot of carbon taken in to produce the shell material.

Reply to  rbabcock
July 14, 2020 7:11 am

An oyster a day keeps the covid away.

Gary Pearse
Reply to  Scissor
July 14, 2020 7:34 am

Actually a half dozen oysters provides the Daily Value of Zn. So yeah!

mike macray
Reply to  Gary Pearse
July 16, 2020 1:04 am

Thank you Gary Pearse!

I have long known that oyster shells are 43% carbonate so do my bit to save the planet regularly with a half dozen Rockefellers and a glass of Sancerre… ..acquiring my daily dose of COVID-19 killing Zn++ in addition is most
Many thanks again.

Reply to  rbabcock
July 14, 2020 9:15 am

“A lot of carbon taken in to produce the shell material.”

Yes, and it’s the sequestration of CO2 as carbonate rock that contributes to the long term depletion of atmospheric CO2 that mankind is lucky enough to be in a position to mitigate, if only the green nut jobs would get out of the way so that life on this planet can be saved from extinction.

If mankind doesn’t replenish atmospheric CO2, the long term prognosis is for it to drop below the levels required to sustain life since the rate of carbon sequestration by biology is greater than the rate of CO2 replenishment from natural sources.

Reply to  co2isnotevil
July 14, 2020 2:46 pm

Actually the idea that humans are adding all of the increased CO2 to the atmosphere is an erroneous idea from the IPCC. We have only added about 15% of the increase so about 3% of whats in the atmosphere now. In my opinion all the increase is beneficial so humans have helped a little but not anything like enough to effect the climate if CO2 has any measurable effect. I also think it is important to stress this fact because the misconception that we are causing all the increase implies we can control CO2 by stopping use of fossil fuels and we cant.

Reply to  DMA
July 15, 2020 9:36 am


There’s no doubt that burning fossil fuels, making concrete, Aluminum and many other industrial processes contribute to atmospheric CO2 and are the primary contributors to the modern increase in the steady state CO2 concentrations. This is not something that can be rationally dismissed, but neither it it all dangerous to the environment or the biosphere and dismissing mankind’s significant contribution to atmospheric CO2 levels unnecessarily invites the denier epithet. Based on the amount of CO2 mankind has emitted, without the carbon cycle recycling it, CO2 concentrations would be far higher then what they actually are.

The reality is that the effect of incremental atmospheric CO2 concentrations on the climate has been greatly exaggerated, demonized and irresponsibly called ‘settled’ by the IPCC in order to fabricate fake support for a catastrophe that the laws of physics unambiguously precludes and that they otherwise require in order to justify their existence and agenda.

To be absolutely clear, any increase in atmospheric CO2 is benign relative to the climate and highly beneficial to the biosphere. The fact that the green blob claims to care so much about the biosphere yet denies the unambiguous benefits of CO2 is a clear indication of just how misguided they are and how disingenuous their politicized rhetoric is.

Al gray
July 14, 2020 6:52 am

The biggest and best freshwater mussels i ever saw were in a peaty stream in Glen Torridon . In 1975. Fully 6 inches long. Now geneticall i assume that these are a marine species that got stranded at the end of the last ice age. I also assume ambient pH around6.5-7.5. . They were in fine health

Ben Vorlich
Reply to  Al gray
July 14, 2020 11:45 am

Fresh water Mussels in Scotland have suffered greatly from illegal fishing, mainly searching for pearls. The were legally protected in the late 1990s, but policing rivers in the Highlands is not easy so the illegal fishing goes on pretty much unhindered.

July 14, 2020 7:01 am

So, Caldeira’s justification was that the far more accurate term, ‘ocean neutralization’ , doesn’t have the shock value the alarmists depend on in order to coerce people to buy into their science defying nonsense. At least he was honest …

Old Retired Guy
Reply to  co2isnotevil
July 14, 2020 8:18 am

Do you mean “honestly dishonest”, or “dishonestly honest”.

Reply to  Old Retired Guy
July 14, 2020 8:54 am

I meant honest about his ignobleness.

Reply to  co2isnotevil
July 14, 2020 11:37 am

Well I am surprised they did not come up with “debasing the sea”. Or maybe that was already reserved for the apparent diminution of Au in seawater caused by CC.

Tom in Florida
Reply to  co2isnotevil
July 14, 2020 3:08 pm

As I constantly point out, you don’t sell the steak you sell the sizzle. “Ocean Acidification” has lots of sizzle.

Gary Pearse
July 14, 2020 7:31 am

Another biological gem from you, Jim. Thank you. As first a field geologist mapping remote areas in northern Canada and Africa, and in later years mining exploration in both, plus SW US and Brazil, I considered that working in the natural, living environment a major joy in my profession.

Reading up on biology topics, though, was a mixed experience. Even in the late 50s and 60s it was hard to escape some of the activist cloud that had engulfed and skewed this most beautiful of sciences early. I hope there are more ecologists like you coming up. I’m firmly convinced that your matter of fact writings (as opposed to scoldings) are considerably more effective in inculcating a sense of responsible interaction with our fellow fauna and flora. Take care of yourself Jim and keep up the good work.

Rudiger Eichler
July 14, 2020 7:35 am

I found so many miss-spelled words so I changed my mind sharing the article.

Reply to  Rudiger Eichler
July 14, 2020 7:57 am

Since you’re so smart, why don’t you point out the mis-spellings so they can be corrected?
Or is feeling superior about all you can manage?

Reply to  Rudiger Eichler
July 15, 2020 3:39 pm

SpellCheck has reviewed this claim and rates it incorrect, mistaken, unfounded, contrary to fact, fallacious & fishy.
**–4 Rotten Oysters–**

Rud Istvan
July 14, 2020 7:39 am

I wrote up the details of this saga of the Whiskey Creek oyster hatchery on Netarts Bay, and how PMEL committed scientific misconduct concerning same that was echoed by the Seattle Times, in essay Shell Games in ebook Blowing Smoke. It was originally a guest post of same name over at Judiths around 2013-2014.

Curious George
Reply to  Rud Istvan
July 14, 2020 6:29 pm
A juicy bit: Seattle’s Center for Biological Diversity announced on 7/23/13 that it was suing the EPA for failing to curb CO2 emissions in order to halt Pacific acidification.

July 14, 2020 7:59 am

Why on Earth is Ocean “Acidification” still being discussed? Anyone with an understanding of Physical Chemistry can tell this is utter nonsense.

Reply to  Graemethecat
July 14, 2020 8:43 am

Really? How many people have an understanding of Physical Chemistry? No doubt higher in Asia and possibly parts of Europe, but here in the good old USA probably less than .5% and going down.

July 14, 2020 8:31 am
HD Hoese
July 14, 2020 10:37 am

In Louisiana, and elsewhere, oysters sometimes live in reduced sediments, called coon oysters, although I never saw an racoon open an oyster. There is something called shell legacy, how well and long they last in such sediments. If the carbonates in shells didn’t turnover, we would be up to our (place uncertain) in them. One of the craziest things about oysters is that there was once serious consideration about putting them on the endangered species list, maybe don’t show up on computer screens.

Ron Long
July 14, 2020 10:52 am

Good posting, Jim, as always. The curious issue with me for “ocean acidification”, beside the false reference toward Ph moving toward neutral, is that bi-valve shells are closest to the chemical structure of aragonite, rather than calcite. Aragonite, although a calcium carbonate, does not fizz (give up CO2) under acid attack. As a bi-valve shell fossilizes it converts to calcite structure, and then fizzes under acid attack. So the whole issue of CO2 sequestration versus ocean Ph is complicated, and maybe calcium activity levels are also important.

July 14, 2020 3:14 pm

While not exactly about the topic in this excellent essay, the following relates to the subject matter. I would appreciate any reality related comments as to whether the referenced analysis makes sense or has some serious flaw(s).

The basics of the generally accepted view on atmospheric CO2 concentration is that sampling measurements show atmospheric CO2 concentration increasing over time. Based on the sample measurements, estimates of total quantity of the atmosphere, and estimates of total human emissions of CO2 (as a simplifying analogy, think: total # of molecules in the atmosphere and total number of CO2 molecules emitted), the consensus is that about 50% of human CO2 emissions end up in the atmosphere long term. Also the generally accepted view is that much of the other 50% ends up in the oceans. I know there are other hypothesis about atmospheric CO2 but I don’t care at the moment unless they explain something about my question.

Two essays by Chaamjamal
2019 update:

based on 124,813 measurements of ocean CO2 concentration from 1958 to 2014 made by Scripps Institution of Oceanography,
conclude that,
• analysis of the annual measured ocean CO2 concentration changes from 1958 to 2014,
• the measured CO2 concentration depth profile,
• and the measured total CO2 ocean concentration changes from 1958 to 2014
do not support the hypothesis that the ocean CO2 changes are due to human emissions.
It would, by the essay calculations, require about 14X 100% of the total human emissions to achieve the measured ocean concentration changes, thus the increased ocean CO2 concentration comes from some other source.

July 15, 2020 3:12 am

“Ocean acidification” is, in fact, not even a real thing. A general change in ocean pH is a projection of (bad) mathematical models. Oceans are actually basic (AKA alkaline) with an average pH = 8.2 ( note: pH below 7 is acid). pH of oceans varies a lot, by latitude, ocean depth, season, proximity to coasts, … Researchers measured falling pH (which they call “acidification”) in some places; but always where the pH began relatively high. That is: in those places where it was most likely to fall if measured over time. Researchers never showed ocean pH as a whole is becoming “acidified”, or is even falling. That would be impossible anyhow. We could burn all the fossil fuel in the world. Then dissolve all the CO2 it made into oceans – but oceans would still be basic. Because the vast majority of carbon in oceans is there as bicarbonate. The pH of oceans is due to a ratio of carbonate to bicarbonate maintained by the laws of chemistry. Carbonate is more basic but there’s less of it.

FYI: pH of 1M sodium bicarbonate = 8.2. Dissolving more CO2 makes more bicarbonate from carbonate – but the ratio of carbonate is maintained when limestone lining oceans dissolves to keep the ratio at about 1:10 carbonate to bicarbonate. This ratio is fixed by the chemistry of how salts behave in solution. It’s called an “equilibrium”. We can no more change the ratio than we can rewrite the laws of science (chemistry in this instance). Practically nothing we can do can upset this equilibrium to turn the oceans acidic. There’s just too few fossil fuel reserves and too much ocean.

Location of carbon in earth’s crust (gigatonnes):
20,000,000 – limestone
800 ——— CO2 in atmosphere
10000 —— fossil fuel
38000 —— oceans

It’s nearly all limestone. Much of it made from once available carbon which is now sequestered away as fossilized carbon-skeletons of microbes.

Patrick MJD
July 15, 2020 3:59 am

What acid oceans?

July 15, 2020 7:33 am

Jim, I have always appreciated your many posts and the balanced tone you use to make your points. Stay healthy and take care eh?

July 15, 2020 8:18 am

Interesting article. As Einstein noted, in science a single negative result carries more weight than 100 positive results.

July 17, 2020 1:47 pm

Relax folks. The open ocean is roughly 13 times less acidic than pure water. Given that the ocean basins are buffered by basaltic rock, the atmospheric CO2 concentration required to neutralize the ocean would have to be higher than the 6% level that would suffocate every breathing creature on the planet.

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