Sounds travel farther underwater as oceans become more acidic

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Sounds travel farther underwater as oceans become
more acidic
By Maggie Ahlrichs
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What is Ocean Acidification?

• The oceans dissolve about 1/3 of worldwide
  atmospheric CO2.
• The CO2 reacts with water to form carbonic acid
  (H2CO3).
• Carbonic acid in seawater reduces the calcium
  carbonate concentration.
• Ocean pH levels have fluctuated slightly
  throughout earths history, but acidification is
  occurring more rapidly than ever before.
• Scientists predict a drop in pH of about 0.4
  units and a decrease of 60 in calcium carbonate
  concentration by the end of this century.

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Past, present, and predicted oceanic pH levels
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(No Transcript)
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Impacts on Sound Travel Underwater

• As the water becomes more acidic, it absorbs less
  low- and mid- frequency sounds.
• It is calculated that sound is already traveling
  10 farther than it did a few hundred years ago.
• The Intergovernmental Panel on Climate Change
  (IPCC) predicts that the pH of seawater could
  decrease by 0.3 units by 2050, which would result
  in sound traveling up to 70 farther underwater.
• This will increase the amount of background noise
  and possibly affect the behavior of marine
  mammals.

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Other Impacts on Marine Organisms

• The surface oceans (where most life thrives) may
  lower in by 0.4 pH units by the end of this
  century, meaning that this seawater will be 150
  more acidic.
• The drop in calcium carbonate concentration
  creates difficulties for calcifying organisms
  (such as mollusks and coral reefs) to build
  shells and skeletons.
• Higher pH may result in acidosis, which is the
  buildup of carbonic acid in body fluids
• More pH sensitive creatures, such as cephalopods
  and larvae will likely see lower survival rates.
• Ocean ecosystems have evolved in a relatively
  stable pH environment, so it is unknown if they
  can adapt to such large and rapid changes.

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Coccolithophores grown under current oceanic
conditions
Coccolithophores grown under conditions expected
by the end of this century
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Sources

• http//www.sciencedaily.com/releases/2008/09/08092
  9144116.htm
• http//www.sciencedaily.com/releases/2008/05/08052
  1105251.htm
• http//www.geos.ed.ac.uk/ccs/Technical/Ocean/
• http//www.ocean-acidification.net/
• http//ioc3.unesco.org/oanet/FAQocs.html for
  information on possible methods of reducing rate
  of CO2 absorption