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Oysters Threatened by Ocean Acidification

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Oysters Threatened by Ocean Acidification

In my last blog, I celebrated emerging efforts to restore native Olympia oysters in San Francisco Bay for their value in mitigating coastal erosion, improving water quality, and other benefits.

But not long after my post went public, scientists from the University of California Davis presented new research showing that Olympia oysters may be facing a challenge that a site-scale restoration project may not be equipped to manage: ocean acidification.

Ocean acidification is often lumped together with climate change, but it has, in fact, no connection with global temperatures at all. What acidification and climate change have in common is that they are both caused by excess CO2 in the atmosphere.

Acidification occurs when CO2 dissolves in seawater and forms carbonic acid, causing a drop in the ocean’s pH levels and a corresponding increase in acidity. Over the last 250 years, average acidity has increased by about 30 percent. Some estimates suggest that – under a business-as-usual scenario in which carbon pollution continues unchecked – the average acidity of the surface ocean could increase by 100 to 150 percent by the end of this century.

What do these changes to ocean chemistry mean for marine life?  When carbonic acid levels are high, carbonate ion levels get low, making it difficult for many marine organisms to build their calcium carbonate shells, skeletons, or other hard parts.

Most commercial shellfish use calcium carbonate to build their shells, and UC Davis researchers showed that Olympia oysters are smaller after being exposed, as larvae, to a high carbon-dioxide environment.  This finding could spell disaster for oyster aquaculture, which generates more than $100 million in gross sales annually on the West Coast alone, contributing around $273 million overall to the region’s economy. It could also be a serious obstacle for shellfish restoration projects like the San Francisco Bay effort.

Featured photo by: Flickr user The Cozy Shack (A plate of oysters at San Francisco’s Ferry Building. Used under a Creative Commons license.)

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Read more: Environment, Green, Make a Difference, Nature, Nature & Wildlife, News & Issues, , , , , , ,

By Sarah G. Newkirk, The Nature Conservancy

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10:29AM PDT on Apr 20, 2013

thanks for sharing

3:57PM PDT on Mar 14, 2013

and hot dogs,
and sausage,
and pepperoni,
and white clam chowder eating
sea-food vegetarian!!

3:51AM PDT on Mar 13, 2013

No1 should eat these ! GO VEGAN !

11:11AM PDT on Mar 12, 2013

I'm with Katherine W.-no surprise here! We will everything in our way

10:01AM PDT on Mar 12, 2013

Well knock me over with a feather............I'm shocked to learn this......NOT! Yet another endangered species because of us humans.

7:47AM PDT on Mar 12, 2013

Seems a shame to show that picture with the article. It gives the impression that people are only concerned because it is affecting the food supply. We are destroying the oceans and all the life in it and we should stop because of the suffering we are causing. I know that is not the most productive approach to take with most of the population. People really only care about things that affect themselves. You do what you have to do and employ whatever tactics will work to bring about change. I guess the reason I found the picture so upsetting is because my son has pet mussels in his fresh-water aquarium. He works so hard to keep them alive and healthy. I just couldn't imagine eating a creature like that. We need to plant more trees to help clean the air so that all this CO2 doesn't settle in the oceans as well as reducing emissions.

6:34AM PDT on Mar 12, 2013

we need to find methods of maximising water recycling in industries and on the site disposal of waste of all kinds(including re-use) and reduction if not elimination of chemicals in agriculture replacing these with biodegradable environment friendly material all of which is within the realm of feasibility.
If only we have the will!

4:23AM PDT on Mar 12, 2013

thanks for the info

5:58PM PDT on Mar 10, 2013


12:39PM PDT on Mar 10, 2013


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Disclaimer: The views expressed above are solely those of the author and may not reflect those of
Care2, Inc., its employees or advertisers.

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