Guest Essay by Kip Hansen

 

There are many ways that today’s researchers can have their work misrepresented in the press, often in embarrassing ways.  The most common origin of these embarrassing gaffs is the university or institutional Press Office or as it is called in some organizations, the Office of Public Affairs.

The latest absurd misquotation by a Press Office has been sent out to the world to be echoed again and again in the popular press by the Press Office of University of Exeter, Devon, South West England, United Kingdom.   Screen shot of their latest entry in the contest for the Least Accurate Headline:

There have been many fine blog posts, here and elsewhere, about the nonsense and non-science being promulgated about Ocean Acidification — or the slight  lowering of surface ocean water pH caused by the rise of atmospheric CO₂ concentrations.  There is quite a bit of concern in oceanic biology departments that this lowered pH will affect the nervous systems, breeding and growth of aquatic species.  There are some experiments that seem to show changes in fish behaviors under higher CO₂/lowered pH conditions.

Remember that almost all early work on Ocean Acidification and its potential effects has be carefully re-evaluated in light of the 2015 work of Christopher Cornwall and Catriona Hurd: “Experimental design in ocean acidification research: problems and solutions”.  [ See my essays on the topic:   Ocean Acidification: Trying to Get the Science Right and Dr. Christopher Cornwall Responds to “Ocean Acidification: Trying to Get the Science Right” ] More recent studies are getting better and follow more rigorous experimental designs.

The Headline:

“Acidic oceans cause fish to lose their sense of smell”

The Press Office of Exeter doubles down with a [mis]quote from lead author Dr. Cosima Porteus

“Our study is the first to examine the impact of rising carbon dioxide in the ocean on the olfactory system of fish. First we compared the behaviour of juvenile sea bass at CO2 levels typical of today’s ocean conditions, and those predicted for the end of the century. Sea bass in acidic waters swam less and were less likely to respond when they encountered the smell of a predator. These fish were also more likely to “freeze” indicating anxiety.

Well, I bet they would too — if only it were actually possible that the ocean, or oceans as stated, could or would ever become acidic.  Alas, it is physically impossible (maybe only extremely highly improbable —  the Earth could be struck by a solid giant CO₂ meteor or comet) that the Earth’s oceans will ever become acidic.  Currently the average pH of the oceans (if such a averaged metric makes any physical sense, which I doubt) is generally considered to be about 8.0.   More recent measurements have found that the open ocean pH can range from 8.2 to 8.0 (some say the open ocean pH is between 8.01 and 8.08) — in shallow tide pools or reef structures, sea water pH can range daily and seasonally from 8.4 to 7.8.   The European Project on Ocean Acidification (EPOCA) projects that free ocean pH will be as low as 7.8 by 2100, based on IPCC CO₂ projections.

For now, however, as we see by our little chart intended for middle school children, Sea Water is listed at pH 8.0, well on the basic side of neutral — and on the basic side it will remain, even if humans were to burn every last bit of coal and oil on the planet.

Now, it is obvious to everyone that the research did not involve testing sea bass juveniles in “acidic waters”.   The experiment involved controls in water with a pH of 8.1 (more basic than human blood, less basic than baking soda in water) and for the “treatment group” (higher CO2/lower pH) sea water with a pH of 7.8 (still more basic then human blood).  This range is shown in the illustration, on the left, yellow-highlighted in a red box.  Both the control and treatment pH are well in the basic (not acidic) range.

I am always interested in the journalism aspects of cases like these.  I wonder how the educated Press Officers at the University of Exeter could write such a misleading (actually false) headline.   I assume that to be employed in the university’s Press Office, staff would have to had graduated at least middle school, in which basic chemistry principles, like pH, are taught (at least here in the US).

I wrote and asked the authors of the paper — (quoting from my email, leaving out the pleasantries):

“I read the Exeter press release on your study “Near-future CO2 levels impair the olfactory system of a marine fish”  found here:  https://www.exeter.ac.uk/news/featurednews/title_672112_en.html in which you are quoted saying:

“Sea bass in acidic waters swam less and were less likely to respond when they encountered the smell of a predator.”

Have they quoted you accurately?

As we know, the ocean are not likely to become “acidic” anytime soon — if ever — and your study did not involve acidic sea water.  (Control pH 8.1 — Elevated CO2 pH 7.8 as I understand the Supplemental Information).”

The reply, from co-author Dr. Rod Wilson,  answering for Dr. Porteus who is on vacation, was as follows:

“Regarding the term “acidic” you are right that the oceans are unlikely to reach a pH lower than 7 by the end of the century, and so will not be strictly “acidic” within that time frame. However, due to rising CO2 levels the oceans are becoming more acidic (and therefore less alkaline, i.e. the pH value is dropping) than they have been in the past. So a more accurate quote would have been “Sea bass in more acidic waters swam less well….”, or you could instead say “Sea bass in water with higher CO2 swam less well…”. The important point is that the changes in CO2 and pH that are predicted to occur in our oceans during the rest of this century are found to cause surprisingly large effects on the behaviour, physiology and gene expression in fish. Furthermore, these effects are very often negative in terms of how we predict they might influence future populations.

A common problem when we write press releases is that those that use them often shorten the text without realising how this can alter the meaning, sometimes creating inaccuracies.

Dr. Wilson is a very understanding and patient man — I would have read the Press Office the riot act over such a silly error — it makes the researchers look bad in the eyes of the public and their colleagues.  And reflects very poorly on the University of Exeter — my high school newspaper would not have made such a elementary science error.

ADVICE TO RESEARCHERS:

Always require your personal pre-publication approval on all press releases issued by the institution about your work.

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About the study:

The actual study, “Near-future CO2 levels impair the olfactory system of a marine fish”,  is fairly interesting, until it veers off into the esoteric world of gene expression. I know so very little about “electrophysiology measurements, transcriptomics and γ-aminobutyric acid receptors”, there’s no sense me writing anything about that portion of the study, but will quote Dr. Wilson, co-author, on that later on.

The juvenile sea bass were placed in tanks with water either in the control conditions (pH 8.1 —  CO₂ 400 μ atm), or treatment conditions (pH 7.8 — CO2 1000 μ atm).  It is important to note that this is an acute (sudden) change, and not a slow acclimation.  After 2, 7 and 14 days, the fish are tested in a number of different ways to see if their responses– both physical and electrophysiological — to a variety of different “smells” (chemical cues mixed into control water or treatment water).  The results are detailed in the paper and supplemental materials.

Basically, for our purposes, it appears that juvenile sea bass have differing responses to water borne chemicals (we could call this “smells” or “odors”) under lowered pH (and higher CO₂).  Some of these differing responses could be considered detrimental to survival. Higher CO₂ exposed fish swim less and freeze (quit moving) more.  They seem to respond less readily to olfactory predator cues.  Given the experimental set-up shown in the illustration from the paper (above) ones is free to wonder if their responses are anything near those that would be found in the wild.

Of course, the rub is:  If the pH and CO₂ concentrations change in tiny increments over the next 80 to 100 years, will the same effects be seen or will the gene pool of sea bass adapt themselves to the changes, as apparently, they have adapted to past changes?

I’ll let Dr. Wilson have the last word.   Regarding these issues, Dr. Wilson gives us this:

“It is possible that the results may have been different if the juvenile sea bass had been hatched and raised in the elevated CO2 environment. However, various studies have shown similar findings in terms of disrupted behaviour even in fish that have been maintained in similar elevated CO2 levels over several generations. For this reason it seems very unlikely that the rate of change of CO2 in the water was the cause of the effects we saw rather than the effect of the CO2 itself. Secondly, we know that physiologically (in terms of blood chemistry) fish acclimate to elevated CO2 within 24 hours, and gene expression changes are usually complete within 2 to 7 days. So 14 days should be plenty of time for fish to reach anew steady state in terms of their behaviour and physiology. Of course, the rise in CO2 that is occurring in our atmosphere and oceans now is slow compared to any experiments we can carry out in the lab. So it is possible that the changes that occur over of many many generations (i.e. adaptation over the next 80 years or so) may be sufficient to overcome the negative effects that are so often observed in laboratory experiments. However, that is very difficult to know for sure, as we don’t have time to wait and see. That’s why short term experiments like these are a very useful starting point.”

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Author’s Comment Policy:

This essay is not about Ocean Acidification itself, but about poorly written and misleading  headlines and dodgy information contained in the Press Releases sent out by institutional Press Offices.

No researcher should ever allow the Press Office to mention his/her work or quote them without demanding the right of prior approval of the final copy of the press release.

I have yet to query a researcher on a press quote and have them respond “Yes, they have that quote right.”  It is always “That’s not exactly what I said.” and/or “That’s not really what I meant.”

When will they ever learn?

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Quick Links:

University of Exeter Press Release

Experimental design in ocean acidification research: problems and solutions

Ocean Acidification: Trying to Get the Science Right

Dr. Christopher Cornwall Responds to “Ocean Acidification….”

Acidic oceans cause fish to lose their sense of smell

EPOCA

Near-future CO2 levels impair the olfactory system of a marine fish

the paper and its supplemental materials

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