Friday, December 28, 2012

Can the oyster industry survive ocean acidification?

 

 

     For four frustrating months in 2007, Mark Wiegardt and his wife, Sue Cudd, witnessed something unsettling at their Oregon oyster hatchery: tank bottoms littered with dead baby oysters.

     Usually, the larvae are grown until they're three weeks old and a quarter of a millimeter in size — 10 million bunched together are roughly the size of a tennis ball.

     Then they are shipped to 50-some growers in the U.S., Canada and Mexico. But that summer, the oysters died before they were ready to ship. Whiskey Creek Shellfish Hatchery struggled to fill a third of its orders.

     "You have good and bad weeks, but this was a blanket kill on everything we tried to do," recalls Wiegardt. "We thought we were going out of business because we couldn't make the larvae grow."


     It turned out that "corrosive" seawater, which makes it harder for young oysters to build shells, was largely to blame. Like the atmosphere, the world's seas are burdened by our fossil fuel use and deforestation.

      The ocean has sponged up a quarter of the carbon dioxide humans have produced since the Industrial Revolution, steadily lowering its pH.

     Today's seas are 30 percent more acidic than their pre-industrial ancestors. By the turn of the century, scientists anticipate they will be 150 percent more so — a trend that led National Oceanic and Atmospheric Administration (NOAA) chief Jane Lubchenco to call ocean acidification climate change's "equally evil twin."

     See here for the full story: http://www.hcn.org/issues/44.21/can-the-oyster-industry-survive-ocean-acidification/article_view?b_start:int=0

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