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Ocean acidification leaving fish in the dark: study

Increasing carbon dioxide in the world’s oceans could hamper fishes' eyesight, slowing their reaction times and leaving them…

Now you see me… Ocean acidification is making things blurry for fish. Flickr/Mr. T in DC

Increasing carbon dioxide in the world’s oceans could hamper fishes' eyesight, slowing their reaction times and leaving them vulnerable to predators or unable to hunt, new research has shown.

Experts say it adds to the existing evidence that ocean acidification will be bad for marine ecosystems and possibly fisheries.

Ocean acidification is one of the effects of increasing atmospheric carbon dioxide by burning fossil fuels, which is also increasing global temperatures.

CO2, when absorbed by seawater, is converted to carbonic acid. Since the industrial revolution, ocean pH has decreased by 0.1, corresponding to a 30% increase in ocean acidity.

Previous studies have confirmed that acidification can have a wide variety of impacts on ocean life, including damaging shells and corals and interfering with fishes' sense of smell, with the polar regions particularly vulnerable. Acidification is also known to effect neurotransmitters in fish brains.

The new study, in the Journal of Experimental Biology, shows that increasing CO2 has a direct impact on fish eyes.

The researchers measured the impact of acidification on fish eyes by subjecting damselfish to different amounts of dissolved CO2 and lights flickering at different speeds.

All animals, including humans, can see lights flickering — up to a point. Above a certain speed, flickering lights appear constant. The speed at which flickering light becomes constant varies among species.

The researchers found that at high levels of CO2 fish had trouble resolving high-speed flashes.

Weng-Sun Chung, PhD candidate at University of Queensland and an author on the study, said that although there was no direct evidence that fish have slower reaction times with more CO2, the study suggested such effects are likely.

Many fish are dependent on quick reaction times to hunt for food, or escape form predators. If fish are unable to see fast-moving predators or prey, they would be unable to react. Instead, the fish would just see a blur.

Fish that could better cope with higher CO2 would have an advantage over fish with slower reaction times, which could disrupt ecosystems, Chung said.

Winners and losers

Professor Ivan Nagelkerken, an ocean acidification researcher at University of Adelaide, said the study adds to the picture of ocean acidification and its impact on marine life.

“There are a very wide range of impacts of acidification. Most are related to the different senses that fish use.”

“We know ocean acidification has a negative effect on the auditory capabilities of fish, and that it interrupts their olfactory capabilities, for example failing to smell optimal habitat and predators. Research has also shown that it effects visual perception.”

Professor Nagelkerken said research also shows competition between species may be altered.

“Some fish may get bolder and more aggressive thanks to ocean acidification, and other fishes not. So if you put two species together you will see a shift in aggressiveness and dominance.”

Wider ranging impacts might include changes to marine fisheries, and a decline in biodiversity “in favour of more generalist species that can cope with more variable environments”.

But Professor Nagelkerken warned it was too early to predict winners and losers.

“We’re very far from understanding all of it because there are so many different ecosystems and species.”

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62 Comments sorted by

  1. Michael Shand

    Software Tester

    Great Article, it will be interesting to see which fish come out on top but I fear there will only be loosers as a result of this acidifcation

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    1. Michael Shand

      Software Tester

      In reply to Felix MacNeill

      Yay, Jelly fish!! apparently Crustaceans as well, blue crabs, American lobsters, and a large prawn defied expectations and grew heavier shells as CO2 levels rose - not more meat though

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    2. Felix MacNeill

      Environmental Manager

      In reply to Michael Shand

      Does anyone know any good jellyfish recipes? i suspect we may need them before too man ymore generations...

      I look to Jamie Oliver on this question! how about 'Jamie's Next Century: a hundred and one ways with jellyfish and cockroaches'

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    3. Michael Shand

      Software Tester

      In reply to Felix MacNeill

      LOl, maybe jellyfish shots? I'm no scientist but I am pretty sure jellyfish are just bad thoughts that have solidfied

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    4. Felix MacNeill

      Environmental Manager

      In reply to Michael Shand

      Hey, I wonder what jellyfish and vodka would do when mixed? Either way, after a few you probably wouldn't care...

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    1. In reply to Toby James

      Comment removed by moderator.

    2. In reply to Toby James

      Comment removed by moderator.

    3. Ben Marshall
      Ben Marshall is a Friend of The Conversation.

      Writer

      In reply to Michael Shand

      [cont.] Toby: No, I'm not.
      Michael: Yes you are.
      Toby: No, I'm not.
      Michael: Yes you are.
      Toby: Here, look. I've got a fact.
      Michael: That's not a fact, it's a factoid. A factoid is a fact that's had its legs and arms and eyes removed, and all the truthiness squeezed out of it. Here's a fact to compare. See how my fact is way bigger and healthier than your factoid.
      Toby: Okay, fine. Here's another fact. That's twice as many.
      Michael: Toby, that's the same factoid. You pretended to…

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    4. Michael Shand

      Software Tester

      In reply to Ben Marshall

      Pretty much summed it up, except for the best friends part at the end, I got no time to be friend those who are fundamentally dishonest

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    5. Ben Marshall
      Ben Marshall is a Friend of The Conversation.

      Writer

      In reply to Michael Shand

      I'm just chuffed I didn't get 'moderated'. :)
      Don't get me wrong, Michael, I feel your pain and anger at the BS 'debate'. I'm keen to get conversations going with moderate Conservatives so we can progress past the 'absolute crap' mindset and put our combined thinking toward bipartisan mitigation efforts.

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    6. Michael Shand

      Software Tester

      In reply to Ben Marshall

      This is why I am excited about Peter Cosgrove, he seems to fit that bill.

      Once the conservatives start to wake up they will realise that the solution to this problem is fundamentally conservative, it is market based mechanism such as internalising the current externality of CO2 by putting a price on it - after you do that, accurately reflect the cost of this externality in the market, he market will take care of the rest

      of course we also need to stop oil and gas subsidies - which again is a conservative position, governments should do what people cannot do for themselves and no more.

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    7. Ben Marshall
      Ben Marshall is a Friend of The Conversation.

      Writer

      In reply to Michael Shand

      Being a Leftie Republican, I'm 'meh' about Cosgrove - I want angry, conscience-driven GG's riding around in their carriages appalled at what they see out their window and complaining in loud expletives about it all, causing a ruckus and getting sacked.

      But, yes, re market-based approaches to mitigation, there's long been a conservative chorus of economists advocating such - as part of the mitigation mix. But, while Rupert still walks the Earth and this shower of Hard Right run the Coalition, we will not see any of it. sigh

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    8. Neville Mattick
      Neville Mattick is a Friend of The Conversation.

      Grazier: ALP Member at A 4th Generation Grazing Station

      In reply to George Allen

      Thanks George for your comments and the Authors' for this 'shock wave' about the future of the Ocean's and their inhabitants.

      Whilst I shouldn't use anecdotal references' it is hard not to; as a student of the landscape for fifty plus years in one location there has been great change which has marginalised the ability to grow food as we used to do so readily.

      I fear that whilst ever 'the market prevails' and the tea party is in control we will slide ever faster to the solution Nature has for us.

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    9. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to George Allen

      The new moderation standards are making a big difference - all the comments here are worth reading!

      George Allen is quite right - not only do we need a carbon tax, but "a much heavier carbon tax". Certainly Abbott won't do this. And Labor have shown no signs that they would either. Plus, as we are talking about the GBR, Labor are also in favour of exporting coal - which if it all went, would be enough to provide 25% of the carbon needed to take global warming up to 2 degrees. Oh, and Labor want new ports and lots of ships going through the GBR just like the Liberals.

      So if we can say Abbott won't do it, then it's also fair for me to say that The Greens will do it.

      Problem is almost no-one votes for them because most people who want action on climate change vote Labor and just wish Labor would do much much better.

      It's a pity that the idea of getting change by democracy - voting for the policy you want to see - is such a strange idea in Australia.

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  2. James Hill

    Industrial Designer

    Isn't it the decrease in ocean alkalinity that is the problem?
    Since the ocean is still alkaline, but less so now because of CO2, then all this emphasis on "acidification" is a bit misleading, since the pH of the ocean is not yet below pH 7.0?
    Yes, we all know how nasty and destructive "Acid" is, and it might be a good way to attract public attention to a real problem of decreasing alkalinity.
    But the ocean has not actually turned to acid yet, and ironically enough, dissolved CO2 acts as a buffer…

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    1. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to James Hill

      Acidification means making more acid, not just making an acid more acid.

      Given The Conversation's new policy of deleting obvious trolls, if your questions are genuine I'd advise against accusing scientist of unjustified alarming of the population. The effects of the change in pH due to climate change are alarming, and the article here is yet one more bit of concerning news.

      If later post prove you a troll I will have wasted my time as my post will also be deleted. So I'll not say more now.

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    2. James Hill

      Industrial Designer

      In reply to Michael Wilbur-Ham (MWH)

      Just the sort of reply I 'd expect from someone who has obviously never subjected himself to the discipline of Chemistry.
      Am I accurate?
      Now is the ocean actually acid, as in having been acidified, as in acidification?
      On the other hand, if all the sea creatures under threat rely upon alkaline conditions, then the more accurate "de-alkalinisation" imparts more scientific meaning than this media friendly vision of creatures gasping in an ocean with the acidity of Coca Cola.
      The problem, Michael…

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    3. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to James Hill

      The "alarming vision of animals frothing away in a acid soup" is all made up by you. Would you like to provide some references to prove that this is what most scientists and environmentalists say?

      Wikipedia says "Ocean acidification is the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.[2] An estimated 30–40% of the carbon dioxide released by humans into the atmosphere dissolves into oceans, rivers and lakes.[3][4] To maintain…

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    4. In reply to James Hill

      Comment removed by moderator.

    5. James Hill

      Industrial Designer

      In reply to Michael Wilbur-Ham (MWH)

      Is this your preferred tactic, then Michael; attach such a confected stench to comments you dislike in the hope that the moderator will clear both your stench and the original "offending" post?
      Perhaps the moderator will not fall for such Machiavellian manipulation.
      Now are you back in the debate or not?
      Wake me up when the ocean has a pH below 7.0 then it will be acid then it will have been acidified, in the mean time it will, just as alarmingly, just as destructively be less alkaline, but still…

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    6. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to James Hill

      James... I'll have to remind you that changes to acidity/alkalinity in the ocean so far have had a major impact on the shell widths of minute organisms at the start of the food chain. If we keep going, we could end up with not much left. It's happened before due to CO2, a major extinction that is. I don't feel the need to be anything other than alarmist, principally because of massive amounts of unreleased carbon which we really are not so far taking into account. Pedantic -. Look at E. and think about the numbers Andrew Glikson has outlined. Even if he was wrong by 20%, they're horrendous.
      http://www.parliament.act.gov.au/__data/assets/pdf_file/0008/372266/09_Glikson.pdf

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    7. Chris O'Neill

      Retired Way Before 70

      In reply to James Hill

      James would probably complain that reducing ferric ions to ferrous ions should be called "de-oxidization" of ferric ions.

      I think he should go back and ask for a refund on his Chemistry 101 fees.

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    8. James Hill

      Industrial Designer

      In reply to Alice Kelly

      Please do fall fall into the trap Alice of assuming that I deny the effects of carbonic acid.
      An acid solution has a a pH below 7.0.
      An alkaline solution has a pH above 7.0.
      Putting acid into a neutral solution will "acidify" it.
      Putting acid into an alkaline solution will make it less alkaline.
      The ocean is alkaline and has been made less alkaline by human created CO2.
      Don't fall into the trap of thinking that a less alkaline ocean is not a problem. As you say, and so do the authors of the…

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    9. In reply to James Hill

      Comment removed by moderator.

    10. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to James Hill

      Is this rant really about just a terminology difference?

      I look forward to the moderators getting around to my reporting of the earlier posts to see what, if any, deletions happen.

      My view is that James Hill is just wasting our time.

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    11. Alice Kelly
      Alice Kelly is a Friend of The Conversation.

      sole parent

      In reply to James Hill

      Well I'm glad you got that off your chest James, it just isn't the point of the article. Did you read section E? because I fail to see how anyone in their right mind would not embrace "alarmism" as a natural consequence. The impacts seen now will increase, and unreleased carbon is a time bomb.

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    12. Chris O'Neill

      Retired Way Before 70

      In reply to James Hill

      By the way James, did you get a refund for not being taught "de-alkalinisation" or "de-oxidization" in Chemistry 101?

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    13. James Hill

      Industrial Designer

      In reply to Chris O'Neill

      Chris, your example is hardly as fundamental to chemistry as acids and bases, now is it?
      More ludicrous than humorous.
      Now this adoption of the medieval mindset among supposed saviours of the environment is just putting Abbott and company out of a job.
      They all support the environment, but engaging accurately with the science themselves instead of merely accepting the pronouncements of experts, well it is just too hard?
      The medieval mindset does not allow of anyone reading the science texts for…

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    14. James Hill

      Industrial Designer

      In reply to James Hill

      That is more properly called "Noble Cause Corruption". Not noble corruption, corruption is never noble.

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    15. James Hill

      Industrial Designer

      In reply to Alice Kelly

      Yes, Cassandra, of the Trojan War, was an alarmist, for all the good it did her, or those she tried to warn.
      I suggest that "alarmism" is eagerly received by the Merchants of Doubt who simply reject it as "alarmism".
      Cassandra was ulitimately ineffective in avoiding the negative results she wished to avoid.
      If you still think that my posts decrease the magnitude of the problem, then look to your own inadequate understandings, Alice and stop insulting mine, with your facile lecturing.
      If you…

      Read more
    16. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to James Hill

      I reported this post too.

      I hope the moderators get around to this eventually because it is clear that James is just here to cause trouble.

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    17. Cory Zanoni

      Community Manager at The Conversation

      In reply to James Hill

      This is directed at the thread, not just James.

      I hesitant to delete a lot of the posts here as I feel they're a good example of how a relatively unprovocative subject can go completely off-rails because of tone, only to slide into personal attacks.

      In the future, I expect all posters to be respectful despite differing opinions and to avoid assuming the motivations of someone (author, poster or otherwise).

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    18. Chris O'Neill

      Retired Way Before 70

      In reply to James Hill

      "your example is hardly as fundamental to chemistry"

      Oh dear. So you don't think oxidation and reduction are fundamental to Chemistry????

      Riiiight.

      Here's a hint. Examples are given to demonstrate a principle.

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    19. Chris O'Neill

      Retired Way Before 70

      In reply to James Hill

      So you're happy to go along with calling the reduction of ions to a still-oxidized state "reduction" but when it comes to acidifying a solution to a a still-alkaline state we have to call it "de-alkalinisation"?

      Why does one case need a "de-" word and the other doesn't?

      Don't ever let anyone call you consistent.

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    20. James Hill

      Industrial Designer

      In reply to Chris O'Neill

      Yes, Chris it is rather inelegant, but the term "less alkaline" doesn't seem quite as scientific does it?
      It is still difficult to argue that a solution which is rendered less alkaline by the use of acid, in particular, has been "acidified".
      If the solution has been (by this use of the term) acidified, would a student be marked up or down for saying that the solution was, indeed, still alkaline?
      Acidified yet still alkaline; not confusing?
      One has to admit that the general use of the term "acidified" in the general debate is at the least very sloppy ,and not very informative of the whole process, with the inelegant "de-alkalinisation" being at least a more accurate description of what is actually happening.
      Thanks for mentioning consistency, Chris.

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    21. James Hill

      Industrial Designer

      In reply to Chris O'Neill

      Rather more obscure and difficult of understanding for those studying the subject, (as is being recommended for would be planet saviours who might wish to more than merely and uncritically mouth the pronouncements of others while at the same time decrying any dissenters?
      Very ethical.)
      By the way it may be easier to understand oxidation and reduction by focusing upon the transfer of electrons in the process, this tends to avoid the confusion inherent in relying upon empirical descriptions which in themselves carry no inherent meaning without further definition, and are thus by themselves, unlikely to contribute to further learning and understanding.
      Which further definitions you can supply, if you wish, for the edification of other readers who may be following your contributions to the debate?

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    22. Chris O'Neill

      Retired Way Before 70

      In reply to James Hill

      "It is still difficult to argue that a solution which is rendered less alkaline by the use of acid, in particular, has been "acidified""

      And by the same argument It is still difficult to argue that an ion which is rendered less oxidized by the use of a reducer, in particular, has been "reduced".

      "Acidified yet still alkaline; not confusing?"

      Reduced yet still oxidized; not confusing?

      "Thanks for mentioning consistency"

      Pity you completely ignore it. If you wanted to show consistency you would have shown the consistency between acid/alkali terminology and oxidation/reduction terminology. The fact that you completely ignored the latter proves that you were not interested in consistency.

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    23. Chris O'Neill

      Retired Way Before 70

      In reply to James Hill

      "Rather more obscure and difficult of understanding for those studying the subject"

      I'm not surprised that you think reducing ferric ions to ferrous ions is "rather more obscure and difficult of understanding".

      Says a lot about you.

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    24. James Hill

      Industrial Designer

      In reply to Chris O'Neill

      Another two words, Chris, hoping that you will take the hint.
      Off topic.

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    25. Michael Wilbur-Ham (MWH)

      Writer (ex telecommunications engineer)

      In reply to Chris O'Neill

      I was disappointed that Cory didn't see James's posts as the obvious trolling and attempt to disrupt that I believe it to be.

      I'm getting back to real-life for now, so I'll leave it up to others to counter the trolls. And I suggest that rather than getting into long back and forths with the trolls that you do your best to get The Conversation to delete their posts.

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    26. Geoffrey Sherrington

      Surveyor

      In reply to Chris O'Neill

      Chris,
      Your analogy is not apt.
      Redox does not have a reference point in the way that pH has.
      Many people use pH 7 to distinguish acid from alkaline.
      There is no equivalent to generally class 'reduced' or 'oxidised'. Species are one or the other in respect of each other.
      Besides, almost every paper I've seen on oceanic pH uses a wrong definition.
      pH is calculated via activity, not concentration as usually stated, and in the high ionic strength environment of sea water, there is a significant difference.
      How much credibility should sceptics put towards papers that don't even get the most fundamental definition correct?
      Is that related to "denial"?

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    27. Doug Hutcheson

      Poet

      In reply to Chris O'Neill

      Chris, although entertaining, this thread has not yet used the obvious comparison, to explain the Ocean Acidification phenomenon:
      If water at 1°C receives enough energy to move it to 2°C, we can all agree it has warmed by one degree, even though we would also agree it is still cold.
      Equally, water at 99°C moving to 98°C has cooled by one degree, even though we would all agree it is still hot.
      Similarly, water that has moved 0.1pH toward the acid end of the spectrum can reasonably be said to have acidified, even though it is not yet at the pH we regard as acid.
      Since the beginning of the Industrial Revolution, the pH of surface ocean waters has fallen by 0.1 pH units. Since the pH scale, like the Richter scale, is logarithmic, this change represents approximately a 30 percent increase in acidity. http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F

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  3. John Doyle

    architect

    Sooner or later Nature will resolve this dilemma.
    We don't have to do anything. It's likely that by not doing anything we will just coast along while Nature works through the options. So let's just wait and see what happens. Will acidifying oceans cause fish stocks to collapse, or will we beat Nature to it? My guess is the second option will prevail.

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  4. Daniel Boon

    logged in via LinkedIn

    'fortunately' we humans have impacted greatly on their predator numbers (WA Government gets an award for that), so that is one less fear ...

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  5. Geoffrey Sherrington

    Surveyor

    If one calculates the amount of CO2 in known remaining fossil fuels and calculates the effect of a one-off dissolution in the oceans of the world, the overall pH might drop by about 0.4 pH units.
    That is for a stationary model.
    In a dynamic model where there is less instantaneous change of existing alkalinity, there is clearly absolutely no cause for alarm.
    So, why do we have alarm?

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    1. Doug Hutcheson

      Poet

      In reply to Geoffrey Sherrington

      Geoffrey, why do we have alarm? Perhaps this will be of interest:
      "Since the beginning of the Industrial Revolution, the pH of surface ocean waters has fallen by 0.1 pH units. Since the pH scale, like the Richter scale, is logarithmic, this change represents approximately a 30 percent increase in acidity. Future predictions indicate that the oceans will continue to absorb carbon dioxide and become even more acidic. Estimates of future carbon dioxide levels, based on business as usual emission scenarios, indicate that by the end of this century the surface waters of the ocean could be nearly 150 percent more acidic, resulting in a pH that the oceans haven’t experienced for more than 20 million years." http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F

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