Acidification Of The World’s Oceans Affects More Than Just Shellfish

Strictly speaking, the ocean still has a pH of more than 7 the last time I saw. Acidification is lowering the pH, but not to where it is "sour", which would mean a pH of less than 7. But it still makes it harder for mollusks to build shells, and changes many other chemical processes that affect living organisms.

I can see why an article for the general public would not go into scientific details people might not understand or care about, but using the words "sour" and "pickling" is going too far, maybe. The point is the chemistry of the ocean is changing in a way that is harmful to things that live in it, due to the increase in CO2, which is due to human activity.

http://thinkprogress.org/climate/2013/11/14/2942311/ocean-acidification-marine-species/

By Joanna M. Foster on November 14, 2013

Hot and sour might be a delicious combination if you’re ordering soup in a Vietnamese restaurant, but when it comes to the world’s oceans, hot and sour is a deadly and destructive duo.

According to research just released by a panel of over 500 of the world’s leading experts on ocean acidification, increased levels of carbon dioxide in the atmosphere are acidifying the oceans at an “unprecedented rate, faster than at any time in the last 300 million years. Since the start of the industrial revolution, oceans have become 26% more acidic.

By 2100, ocean acidification is predicted to increase by 170 percent if current rates of greenhouse gas emissions continue. More acidic water will make the oceans unlivable for about 30 percent of ocean species. About one quarter of annual CO2 emissions from human activities currently end up in the ocean, or about 24 million tons of CO2 every day.

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Some of the species most at risk are mollusks like oysters and clams, and corals, but any species that needs a hard shell to survive may be affected. Oyster farmers in the Northwest are already seeing the impact. The global cost of the decline in mollusks could be $130 billion by 2100.

Coral reefs are already imperiled by warming oceans which cause coral bleaching. But ocean acidification alone is likely to cause reef building to cease by the end of the 21st century on the current CO2 emissions trajectory. All the fish that depend on corals for habitat will also be indirectly affected by ocean acidification.

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And there’s one more catch to keep in mind — as ocean acidity increases, the oceans’ capacity to absorb CO2 from the atmosphere decreases, which means that the enormous carbon sink that has helped to moderate the warming climate thus far will become less and less effective.


http://www.ocean-acidification.net/FAQacidity.html

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The oceans are not, in fact, acidic, but slightly basic.

Acidity is measured using the pH scale, where 7.0 is defined as neutral, with higher levels called "basic" and lower levels called "acidic".

Historical global mean seawater values are approximately 8.16 on this scale, making them slightly basic.

To put this in perspective, pure water has a pH of 7.0 (neutral), whereas household bleach has a pH of 12 (highly basic) and battery acid has a pH of zero (highly acidic).

However, even a small change in pH may lead to large changes in ocean chemistry and ecosystem functioning. Over the past 300 million years, global mean ocean pH values have probably never been more than 0.6 units lower than today (6). Ocean ecosystems have thus evolved over time in a very stable pH environment, and it is unknown if they can adapt to such large and rapid changes.