Oceanographer Richard Feely says the shellfish industry is suffering in part because the more acidic seawater encourages the growth of a type of bacterium that kills oyster larvae.(Photo courtesy of the NOAA)
When carbon dioxide is released into the atmosphere, about a third of it absorbs into the ocean. That creates carbonic acid—the stuff in soda pop that gives it that zing.
That means seawater is becoming more acidic.
Scientists say this ocean acidification is starting to cause big problems for marine life. And Ann Dornfeld reports that could affect your dinner plans.
Transcript
When carbon dioxide is released into the atmosphere, about a third of it absorbs into the ocean. That creates carbonic acid—the stuff in soda pop that gives it that zing.
That means seawater is becoming more acidic.
Scientists say this ocean acidification is starting to cause big problems for marine life. And Ann Dornfeld reports that could affect your dinner plans.
Taylor Shellfish Farms has been growing oysters for more than a
century. And shucking them, one by one, by hand.
“An old profession. Y’know, they’ve tried for years to
find a way to mechanize it. There’s no way around it. Every oyster is
so unique in its size and shape.”
Bill Dewey is a spokesman for Taylor. The company is based in
Washington state. It’s one of the nation’s main producers of farmed
shellfish. Dewey says if you order oyster shooters in Chicago, or just
about anywhere else, there’s a good chance they came from Taylor.
But in the past couple of years, the company has had a hard time
producing juvenile oysters – called “seed.”
“Last year our oyster larvae production was off about 60
percent. This year it was off almost 80 percent. It’s a huge impact to
our company and to all the people that we sell seed to.”
Shellfish growers throughout the Pacific Northwest are having similar
problems with other kinds of oysters, and mussels, too. They suspect a
lot of it has to do with ocean acidification.
Richard Feely is a chemical oceanographer with the National Oceanic
and Atmospheric Administration. He says when the pH of seawater drops
too low, it can hurt marine life.
“What we know for sure is that those organisms that
produce calcium carbonate shells such as lobsters, and clams and
oysters, and coral skeletons, they generally tend to decrease their
rate of formation of their skeletons.”
Feely says it looks like acidified waters are affecting oysters
because their larvae build shells with a type of calcium carbonate,
called aragonite, which dissolves more easily in corrosive water.
The more acidic seawater also encourages the growth of a type of
bacterium that kills oyster larvae.
Feely says the changes in the ocean’s pH are becoming serious. He
recently co-published a study on the results of a 2006 research cruise
between Hawaii and Alaska. It was identical to a trip the researchers
took in 1991. They found that in just 15 years, the ocean had become
five to six percent more acidic as a result of man-made CO2.
“If you think about it, a change of 5% in 15 years is a
fairly dramatic change. and it’s certainly humbling to see that in my
lifetime I can actually measure these changes on a global scale. These
are very significant changes.”
A couple years ago, Feely gave a talk at a conference of shellfish
growers. He explained the impact ocean acidification could have on
their industry. Bill Dewey with Taylor Shellfish Farms was there.
“All these growers were walking around with all these
really long faces, just very depressed. I mean it was a very eye-opening presentation and something that’s definitely had growers
paying attention since, that this could be a very fundamental problem
that we’re going to be facing for a long time to come.”
Dewey calls shellfish growers the “canary in the coalmine” for ocean
acidification.
Scientists say if humans don’t slow our release of CO2 into the
atmosphere, shellfish may move from restaurant menus into history
books.
For The Environment Report, I’m Ann Dornfeld.
