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Can we keep discussions about ocean acidification honest?

Lisa Suatoni

Posted January 12, 2012

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In his article, ‘Taking Fears of Acid Oceans with a Grain of Salt’, Matt Ridley recycles the standard arsenal of invalid climate ‘skeptic’ arguments and tactics, but applies them to ocean acidification, the lesser known global impact from rising atmospheric CO2 concentrations. 

The result is an exercise in obfuscation.  As a scientist working on these issues for the past five years, I was struck by several gaping holes (and inaccuracies) in his piece – taking liberty to manipulate facts in order to misrepresent them.

For instance, he plays unproductive semantic games, arguing that because ocean pH is not predicted to fall below the ‘neutral point’ of 7.0, the term ‘ocean acidification’ is a misnomer.  This ignores the fact that scientists refer to a drop in pH as ‘acidification’, regardless of where you are on the scale.  The term is simply used to describe the direction of change. pH_scale.jpg

He also makes the same (tired) mistake as those who confuse ‘weather’ for ‘climate’ when he equates short-term natural variation in pH with that of long-term change in the average pH of the world’s oceans.  These are not equivalent.  That’s like saying there is a drought because it’s been a dry week, even if rainfall is above average for the year.

Contrary to Ridley’s arguments, scientists can measure and differentiate between these two types of variation—and organisms do not experience short-term and long-term variations in the same manner.  That is why the sugar maple in my backyard survived today’s 20 degree F fluctuation in air temperature – but the Connecticut population is unlikely to successfully compete with oaks and survive the predicted 4-6 degree F rise in average regional temperature over the next century.

Ridley goes on to raise irrelevant facts by discussing pH and freshwater as a comparison to ocean acidification – but there is no relationship here.  While the natural variation of pH in fresh systems is high, it has no bearing on the oceans, or the survival marine organisms.

Worst of all, Ridley flatly misstates research conclusions when he claims that “laboratory experiments find that more marine creatures thrive than suffer when carbon dioxide lowers the pH level to 7.8.” The opposite is true and you can see for yourself:

Hendriks et al., 2010

Kroeker et al., 2010

Gattuso J.P., et al., 2011.

Ridley is correct in pointing out that not all marine organisms will suffer from an increase in ocean acidity. Some, in fact, will likely thrive (e.g., seagrasses).  However, he omits the conclusions from the studies he alludes to.  In regions with naturally occurring higher levels of acidity, resulting from volcanic venting of CO2, researchers have found substantial losses in marine biodiversity at the same pH levels that are predicted at the end of this century. Specifically there was a 30% decline in overall species richness in Italy (Hall-Spencer et al., 2008) and a 39% decline in hard coral species richness in the Indo Pacific (Fabricius et al., 2011). 

If these naturally more acidic sites portend the future of marine ecosystems, does a 30% loss in species diversity constitute a catastrophe for the world’s oceans?  It does for people who have come to rely on the affected organisms for income or food. 

There are local economies in the United States – and around the world - that rely disproportionately on species that show vulnerabilities to ocean acidification.  For example, New Bedford, Massachusetts, which has ranked highest among U.S. ports for values of seafood landings over the past decade, gets 77% of its total landings revenues from sea scallops ($306 million in 2010) (NOAA, 2011).  In laboratory experiments, a close relative, the Atlantic bay scallop demonstrates a drop in larval survivorship and impaired shell development as ocean acidity increases (Talmage and Gobler, 2010). And in the Pacific Northwest, oyster hatcheries are already seeing the impact to larval oysters – leaving owners worried about their livelihoods. This alone is cause for concern. 

Taking ocean acidification ‘with a grain of salt’ would be a mistake.  At the very least, experts and the U.S. government should identify economically vulnerable ‘hot spots’ and begin to monitor the chemical and biological changes that are occurring off our coasts. 

 Literature Cited:

Fabricius K. E., Langdon C., Uthicke S., Humphrey C., Noonan S., De’ath G., Okazaki R., Muehllehner N., Glas M. S. & Lough J. M., 2011. Losers and winners in coral reefs acclimatized to elevated carbon dioxide concentrations. Nature Climate change 1:165-169.

Gattuso J.-P., Bijma J., Gehlen M., Riebesell U. & Turley C., 2011. Ocean acidification: knowns, unknowns and perspectives. In: Gattuso J.-P. & Hansson L. (Eds.), Ocean acidification, pp. 291-311. Oxford: Oxford University Press.

Hall-Spencer J. M., Rodolfo-Metalpa R., Martin S., Ransome E., Fine M., Turner S. M., Rowley S. J., Tedesco D. & Buia M.-C., 2008. Volcanic carbon dioxide vents show ecosystem effects of ocean acidification. Nature 454:96-99.

Hendriks IE, Duarte CM, Alvarez M (2010) Vulnerability of marine biodiversity to ocean acidification: A meta-analysis. Estuar Coast Shelf Science 86: 157–164.

Kroeker KJ, Micheli F, Gambi MC, Martz TR (2011) Divergent ecosystem responses within a benthic marine community to ocean acidification. P. Natl. Acad. Sci. USA: doi/10.1073/pnas.1107789108.

NOAA, 2011.  Fisheries of the United States:  2010.  National Marine Fisheries Service/Office of Science and Technology

Talmage, S. C. and Gobler, C. J.  Effects of past, present, and future ocean carbon dioxide concentrations on the growth and survival of larval shellfish.  P. Natl. Acad. Sci.

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Christopher S. JohnsonJan 12 2012 09:49 PM

Thank you for this rebuttal. The Wall Street Journal has now moved it's environmental lies and misinformation from the editorial page to the news area. Unacceptable.

klemJan 13 2012 10:18 AM

I don't know but it seems that ACC and ocean acidification fears are going the way of the dodo.

Perhaps its time you looked for other work.

MikeJan 13 2012 11:01 AM

klem, did you know that the shellfish industries on both coasts and Alaska are suffering already? Clammers in Maine find that larvae are just dissolving when seeded into "dead mud". Some have taken to crushing up clam shells and spreading them on the mud to help buffer pH, which that seems to make it viable again.

Oyster hatcheries have figured out that they need to keep sea water out, again apparently due to pH problems.

Jellyfish, on the other hand, seem to be less affected by acidification. They may even be able to take advantage of vacated niches as other species recede. That lets them grow in both number and size. Maybe you heard about the Japanese fishing boat that was sunk by a giant jelly? They really like warmer waters, and the ocean temperatures have hit record highs in recent years. So jellyfish are on the rise--4 nuclear plants around the world found their intakes clogged and had to shut down this year (Japan, Scotland, Israel and Florida).

I'm most worried about the plankton, which have declined 40% since 1950.

Matt RidleyJan 14 2012 04:23 PM

Far from "recycling the standard arsenal of invalid arguments", my column focuses on the results of a brand new, peer-reviewed paper from the Scripps Institute. So I shall not be taking any lessons from you about keeping this debate honest.

Christopher S. JohnsonJan 15 2012 02:57 PM

Can anyone confirm that this was the WSJ journalist, Matt Ridley, commenting here? If it was, surely he would have cited the Scripps paper that supported all of his claims. That must be some paper. Revolutionary.

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