Acid test: Study reveals both losers and winners of CO2-induced ocean acidification

December 1, 2009
The effect of different CO2 levels on an American lobster.

( -- As the world’s seawater becomes more acidic due to rising atmospheric carbon dioxide, some shelled marine creatures may actually become bigger and stronger, according to a new study.

The finding, based on research by University of North Carolina at Chapel Hill marine scientist Justin Ries, could have important implications for ocean food webs and the multi-billion dollar global market for shellfish and crustaceans.

Previous research has shown that - the term for falling pH levels in the Earth’s oceans as they absorb increasing amounts of carbon dioxide (CO2) from the atmosphere - is likely to slow the growth or even dissolve the shells of such creatures.

However, the new study, published in the December issue of the journal Geology, suggests that sediment-dwelling may exhibit a wider range of responses to CO2-induced acidification than previously thought: some may get weaker while others become stronger.

Researchers also found that creatures whose shells grew the most, such as crabs, tend to on those whose shells weakened the most, such as clams.

Such changes could have serious ramifications for and prey relationships that have evolved over hundreds of millions of years, said Ries, Ph.D., assistant professor of marine sciences in the UNC College of Arts and Sciences.

“There is no magic formula to predict how different species will respond, but one thing you can be sure of is that ecosystems as a whole will change because of these varied individual responses,” Ries said.

The effect of different CO2 levels on a blue crab.

Researchers grew 18 different species of economically and ecologically important marine calcifiers (creatures that make their shells out of calcium carbonate) at various levels of CO2 predicted to occur over the next several centuries. When CO2 combines with water, it produces carbonic acid, raising the overall amount of carbon in seawater but reducing the amount of the carbonate ion used by organisms in their calcification.

Seven species (crabs, lobsters, shrimp, red and green calcifying algae, limpets and temperate urchins) showed a positive response, meaning they calcified at a higher rate and increased in mass under elevated CO2. Ten types of organisms (including oysters, scallops, temperate corals and tube worms) had reduced calcification under elevated CO2, with several (hard and soft clams, conchs, periwinkles, whelks and tropical urchins) seeing their shells dissolve. One species (mussels) showed no response.

“Shelled marine organisms need carbonate ions to build their shells that protect them from the intense predation that defines everyday life on the shallow sea floor,” Ries said. “The organisms that responded positively to higher CO2 levels are apparently more adept at converting the elevated dissolved inorganic carbon in the seawater, which results from elevated atmospheric CO2, back into a form that they can use directly in their calcification. The others, however, appear to be less adept at manipulating dissolved inorganic carbon.”

Ries said the varied responses may reflect differences in organisms’ ability to regulate pH levels at their sites of calcification; their ability to generate a protective organic layer that limits their exposure to surrounding ; whether they use more soluble forms of in their shells; and their ability to utilize CO2 directly via photosynthesis.

The effect of different CO2 levels on a sea urchin.

Provided by University of North Carolina at Chapel Hill

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Display comments: newest first

1 / 5 (6) Dec 01, 2009
sounds like good news
biger crabs biger fish more food for humans
ofcoourse we aka al gore we dont want that
they want hunger sufering and genocide

chek update on global warming scam hoax
climate gate
3.7 / 5 (3) Dec 01, 2009
The pictures are at 400ppm and 2850ppm, both which are greater than current CO2 levels.
It is improbable that we can increase levels above 1000ppm.
Of course if the oceans warm up and releases CO2, the atmosphere levels will go up and the ocean levels will go down.
By the way these critters evolved at CO2 levels far higher than 2850ppm.
1 / 5 (6) Dec 01, 2009
Ok.... I agree, and if you look at my posts lately, very much that AGW is an absolute scam.

However, is there anything with ocean acidification or does the data belong with AGW climategate?
2 / 5 (1) Dec 01, 2009
Thanks tpb. It seems that there are a lot of studies like this paraded in the press - the harms of far more CO2 than we'll actually ever see IRL.
5 / 5 (3) Dec 01, 2009
Ok.... I agree, and if you look at my posts lately, very much that AGW is an absolute scam.

However, is there anything with ocean acidification or does the data belong with AGW climategate?

You and I obviously have an ongoing disagreement so I don't expect you to take my word for anything, but I'm not aware of any significant attack on the pH data. I'd like to think those measurements are so repeatable that no one's seriously going to argue them.

I've long heard from the AGW Denier crowd that the ocean will continue to act as a wonderful carbon sink, so they don't seem to disagree that the oceans absorb CO2. That absorption necessarily affects pH levels.

There's a ton of research on it, including about 40 recent studies cited in the wikipedia article. I encourage you to check it out.
1 / 5 (3) Dec 02, 2009
curious why my last post was ranked as 1 out of 5... all I did was ask for source documents, so I can research this myself and not rely on the media.

Could it be because I'm not a AGW believer?
not rated yet Dec 04, 2009
I guess I'll just repeat that this isn't football and it's not about competing teams.

My guess, though, is that some people rate you down so low because you go so far out of your way to accuse scientists of being a bunch of scammers. This time you engaged in the Fox News style attack "I'm not saying they're full of crap, but are they full of crap just like those AGW guys?".

If you really wanted to know, you would have asked where you could find the data or studies. I assumed you were being honest in your question and provided you with a starting point, but your reply was not one of thanks but another attempt to stir the pot, accusing people of persecuting you because you're an AGW denier.

Although I should also note that you and your friends rated me "1 out of 5" on every AGW-related post where I disagreed with you.
not rated yet Dec 04, 2009
you and your friends rated me "1 out of 5" on every AGW-related post where I disagreed with you

You never bother to argue against our logic or even our science, you just throw out the 1 as if that can make you correct. You've been rating AGW opponents 1 for as long as I've been on this forum, only recently (when the AGW castle began to crumble) have you started posting anything for your side.

PS I think a decent portion of the present day AGW deniers (many used to rate me 1 as off-handedly as you still do) on this site were at one time proponents or at least didn't know for sure, however they were able to be honest and objective and acknowledge openly the deeply flawed theory and it's even more deeply flawed legislation.

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