Acidic Oceans Dissolving Shellfish Industry

  • 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.

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CO2 Eats at Ocean Creatures

  • Healthy Reef Systems May Be a Thing of The Past(Photo courtesy of Mikael Häggström)

Some scientists think we might be headed for a mass extinction event
in the oceans. When carbon dioxide gets released into the atmosphere,
a lot of that CO2 soaks into the oceans. That makes the water more
acidic. When the pH gets too low, it dissolves the skeletons of
animals like coral and mussels. Ann Dornfeld reports:

Transcript

** The story as originally broadcast incorrectly referred to the publication as “Natural Geoscience.” It should be “Nature Geoscience.”

Some scientists think we might be headed for a mass extinction event
in the oceans. When carbon dioxide gets released into the atmosphere,
a lot of that CO2 soaks into the oceans. That makes the water more
acidic. It can dissolve the skeletons of
animals like coral and mussels. Ann Dornfeld reports:

Fifty-five million years ago, a mass extinction happened when the
oceans became too acidic.

Richard Feely is a chemical oceanographer for the National Oceanic and
Atmospheric Administration. He says that today’s ocean acidification
is happening too quickly for many species to adjust.

“Over the last 200 years we’ve seen a 30-percent increase in acidity
of the oceans, and about six percent of that increase of acidity of
the oceans has been in the last 15 years.”

Researchers at the University of Bristol in England ran simulations of
the acidification processes 55 million years ago and today. They found
that acidification is happening ten times faster these days than it
did before the prehistoric mass extinction.

That could mean that if we don’t slow our release of CO2 into the
atmosphere, life in our oceans could crash within a century or two.
The study is published in the journal of Nature Geoscience.

For the Environment Report, I’m Ann Dornfeld.

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If You Can’t Beat ‘Em, Eat ‘Em

  • Every march, the Cownose Stingrays migrate into the Chesapeake Bay from the Atlantic. They come to give birth, mate, and eat. (Photo courtesy of NOAA)

We like seafood – a lot. Many
species are disappearing. That’s
causing a ripple effect that’s
changing the patterns of sea creatures.
In the Cheseapeake Bay, it’s an invasion
of stingrays. The cownose stingray
is eating oysters that are commercially
raised there. Some people say: if
you can’t beat them, eat them. Sabri
Ben-Achour has the story:

Transcript

We like seafood – a lot. Many
species are disappearing. That’s
causing a ripple effect that’s
changing the patterns of sea creatures.
In the Cheseapeake Bay, it’s an invasion
of stingrays. The cownose stingray
is eating oysters that are commercially
raised there. Some people say: if
you can’t beat them, eat them. Sabri
Ben-Achour has the story:

In a little boat just off shore of Virginia’s Cone River, AJ Erskine leans overboard. He is using 20-foot poles with gaping jaws full of long needle like teeth to scrape the bottom of the emerald colored river.

“These things are called hand tongs.”

Up comes a pile of oysters. They’re only about a year old.

“We don’t feel comfortable giving them more than one year of a chance.”

That’s because Erskine is worried about stingrays, specifically Cownose Rays. Every march, the winged sea creatures migrate into the bay from the Atlantic. They come to give birth, mate, and eat.

“What they do is flap their wings, put the oysters in a pile, and crunch the shells, and they go through a seed bed of oysters in a weekend.”

Erskine says it’s become a huge problem for oyster farmers.

The rays also damage the underwater environment. They uproot aquatic grasses, destroying nurseries for fish and blue crabs.

Some biologists believe there are more rays because a main predator – the shark – has been overfished out in the Atlantic. Tiger Sharks in this area have declined 99% over the past 30 years.

Other biologists say it’s that strict limits on fishing in the Chesapeake Bay have meant fewer rays caught accidentally in giant nets. Whatever the reason, oyster farmers are looking for a way to control the rays.

A hundred miles inland, in Richmond, Mead Amery thinks he has a solution.

“Depending on how you prepare it, it’s delicious.”

Avery is a seafood distributor. He and officials with the State of Virginia want you to try stingray.

“The texture is wonderful, it has a veal pork type of texture.”

It’s been a tough sell so far.

“People hear ray and think, ‘I don’t wanna eat that!’”

Marketers are trying hard though. They don’t call it Cownose Ray but rather Chesapeake Ray. They’re pushing the ray in restaurants from Virginia to Japan. And it may take off – after all, lobsters used to be considered insects of the sea and only the poor ate them. The popular Chilean Sea Bass used to be a nuisance by-catch.

But, while those cases offer hope for marketers, they carry warnings for environmentalists. Both Sea Bass and Maine lobsters were dangerously overfished because of their popularity. Bob fisher is a biologist with the Virginia Institute of Marine Science. He knows full well there are risks involved in going after stingrays.

“You remove a top predator like that from the food chain, we don’t know what the repercussions would be.”

He says stingrays are slow to mature and give birth to only one offspring at a time. And no one even knows how many there are. But Fisher is still very much open to the idea of harvesting the rays given the problems they seem to be causing for oyster growers.

“I look at things that are in our oceans as resources, it’s our responsibility to take care of our resources, but it’s also a resource that’s there that can be, and I believe should be, utilized for humans.”

Fisher is working with the Marine Products Board, and the Department of Agriculture to come up with a plan to strictly limit fishing of the ray to what’s sustainable.

So, if the whole thing is successful, you might find Chesapeake Ray on a plate near you.

For The Environment Report, I’m Sabri Ben-Achour.

Related Links

Money for Mussels

A million dollar fine will be used in restocking and studying
freshwater mussels. The Great Lakes Radio Consortium’s Lester Graham
reports:

Transcript

A million dollar fine will be used in restocking and studying freshwater
mussels. The Great Lakes Radio Consortium’s Lester Graham reports:


A Japanese-owned company called Tennessee Shell Company has paid the first
installment of the million dollar fine. The company pleaded guilty to
illegally harvesting freshwater mussels in Michigan, Ohio, Kentucky, and
West Virginia. The company places mussel shell material in oysters to grow
cultured pearls. Chuck Traxler is with the U.S. Fish and Wildlife Service. He
says the money from the fine won’t just go into the the agency’s general
account.


“The entire amount will be used for mussel research. This is unique
in that these funds are going to be used to help the species that was
damaged.”


Besides being over-harvested, native mussel populations have declined
because of poor water quality and because of invasive species such as the
zebra mussel.


For the Great Lakes Radio Consortium, this is Lester Graham.