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.

Related Links

How the West Was Warned

  • Wen Baldwin, a volunteer with the National Park service, pulls a non-stick teflon frying pan out of Lake Mead, the reservoir of Hoover Dam. Quagga mussels smothered the pan in a matter of weeks. (Photo by Shawn Allee)

A tiny aquatic pest called the
quagga mussel is invading lakes
and streams across the country.
It’s even clogging up pipes in
some big-city water systems, dams,
and power plants. When environmental
disaster strikes, sometimes people
scratch their heads and ask: how
could this happen? Shawn Allee reports, in the case of
one quagga mussel invasion, people
got plenty of warning:

Transcript

A tiny aquatic pest called the
quagga mussel is invading lakes
and streams across the country.
It’s even clogging up pipes in
some big-city water systems, dams,
and power plants. When environmental
disaster strikes, sometimes people
scratch their heads and ask: how
could this happen? Shawn Allee reports, in the case of
one quagga mussel invasion, people
got plenty of warning:

n 2007, biologists declared that quagga mussels had infested infested Lake Mead just outside
Las Vegas.

But years before that, park staff and volunteers like Wen Baldwin told folks how to avoid the
problem.

Baldwin says some people helped – most people told him to just drop it.

“Oh, it won’t happen to us. That’s the American theory – fire, cancer, whatever. Oh, it
won’t happen to me.”

But it did happen, and here’s how it went down.

Baldwin went to this conference out East where biologists explained how quaggas clog pipes at
water treatment centers and power plants.

“There was a presentation about them and I realized, hey, they could get in here and they
could cost me money, you money, everybody money. They could raise havoc as they have in
the Great Lakes.”

Baldwin got worried.

Quagga mussles hitchhike on boats, and Lake Mead is a boating hot spot.

Baldwin warned people – wash down your boat before you put it in the lake!

“I put on a lot of programs trying to get people on board. Just didn’t work that well.”

Now, quagga mussels are making a mess of Lake Mead – and Web Baldwin can show how.

Baldwin tests how well quagga stick to different material.

We’re on this dock one morning, and he pulls a rope out of the water.

The rope’s covered with shells that look like fingernail-sized clams.

Allee: “I reckon you have to be pretty careful with your hands, there.”

Baldwin: “Boy, they’ll cut you to ribbons. I go home looking like my hands went through a
meat grinder.”

At the end of the rope – he’s tied a skillet.

Baldwin: “They’ll stick to teflon.”

Allee: “They’ll stick to teflon. Your eggs won’t stick to teflon all that well, but quagga
mussels will.”

Baldwin: “They will. And anywhere they attach the glue they use will hasten the
deterioration of the surface they attach to.”

A quagga-coated teflon pan is a shocker – but what does a quagga invasion mean?

Well, for one, if you dock your boat at Lake Mead – you’ve gotta scrape it all the time.

Swimmers wear shoes to protect their feet from quagga-coated rocks.

And quagga are getting costly.

Zegers: “We’ve been monitoring water quality in the lake pretty extensively.”

Roefer: “These are the six locations we collect samples at.”

I’m with Ron Zegers and Peggy Roefer. They’re with the Southern Nevada Water System. It
provides water to Las Vegas and other cities.

They walk me through slides divers took near water intake pipes – deep in Lake Mead.

Roefer: “And this is where our intake is, on Saddle Island. This is actually the inside of the
rock structure you can see the quaggas on the inside of that. Quagga mussels were
approximately two inches thick.”

Zegers and Roefer say they’re trying plenty of things to keep quagga out of the water supply.

The first is the old stand-by: chlorine.

But too much chlorine can make people sick.

Zegers: “More of those disenfection byproducts form, which puts us closer to our
regulatory compliance issues, so we also have to be concerned about that also.”

Roefer: “You know we’re watching the alternative control strategies, the bio-bullets and
pseudo-flourence and those kinds of things.”

Allee: “Sounds like an arms race.”

Roefer: “Yeah, who can get there first. The annual for this is one to four million dollars.”

Allee: “One to four million dollars. You know, you could clean a lot of water if you didn’t
have to deal with these critters.”

Zegers: “That’s correct. Now it’s just an anticipated expenditure that certainly wasn’t
budgeted for when they first appeared, and now it’s just gonna be a way of life.”

And it could become a a way of life for more lakes if we don’t stop quaggas from spreading
around.

For The Environment Report, I’m Shawn Allee.

Related Links

Tiny Pest Threatens the Las Vegas Lights

  • Hoover Dam's backside stretches more than 700 feet from top to bottom, but the dam's seeing trouble from the tiny aquatic zebra mussel. (Photo by Shawn Allee)

Hoover Dam generates some of the power that lights Las Vegas all night long. But there’s something
that’s making that job a bit more difficult. Shawn Allee found out, it’s a tiny aquatic pest:

Transcript

Hoover Dam generates some of the power that lights Las Vegas all night long. But there’s something
that’s making that job a bit more difficult. Shawn Allee found out, it’s a tiny aquatic pest:

The usual tour of Hoover Dam starts at the visitor’s center – way at the top.

Robert Walsh works with the federal agency that runs Hoover.

He says, go ahead – look over the edge.

Allee: “OK. That’s creepy. Seriously, that’s creepy.”

Walsh: “It’s spooky. Are you afraid of heights?”

Allee: “No, they don’t bother me at all.”

The dam stretches down 700 feet, and it holds an enormous reservoir – Lake Mead.

This tour is awesome, but Walsh says there’s another tour, too.

It’s, um, NOT so awesome.

It’s all about the trouble the tiny quagga mussel is causing Hoover and other nearby dams.

To get that tour, Walsh takes me to Leonard Willet.

Allee: “Where are we right now?”

Willet: “It’s kind of a work station where all the quagga mussel control activities take place
for Hoover Dam.”

Allee: “It’s quagga mussel central for this area?”

Willet: “Exactly.”

Willet first heard quagga mussels were growing in the nearby Lake Mead reservoir in 2007.

He called an expert for advice.

“First thing out of her mouth was, ‘I’m sorry to hear that.’ I knew it was a lot more serious.
And I asked her what we’re in for.”

Willet learned quickly enough – quagga mussels attach to nearly anything underwater.

He shows me a sandal that was in water – and is smothered in them.

They’re like clams the size of your pinky fingernail.

“We went from zero to THAT in seven months.”

And that’s the problem.

Hoover Dam uses water from Lake Mead to spin generators.

The water moves around in pipes – and quagga mussels can attach to them – just like on that sandal.

Allee: “What does that mean in a real practical sense?”

Willet: “Our intake towers would close off. Once you start closing off, you can’t spin the
generators. That’s just kind of the big view of it.”

Zero power generation.

That’s the worst-case scenario. It hasn’t happened – but it’s a fight to prevent it.

“Now, we’re going to go down to the third floor, which is the generator floor.”

The generators are inside broad metal cylinders.

Big water pipes turn the generators. Smaller ones cool them off.

“Well, we circulate cold water from those pipes. If those start to plug up with mussels, then
you can’t keep a generator cool, if those … it shuts down due to overheating.”

Right now, it takes a lot of scraping to keep everything clear.

All this effort’s adding up – Willet says he’ll spend 2 million dollars soon on new equipment.

Even with that, Willet is still a bit jittery about some pipes outside, at the very bottom of the dam.

“The one that’s probably the scariest of all is, we have a fireline that runs around here.
Mussels love it. Then, your firelines, when they’re needed, are plugged with mussels. So
that’s another area you have to really be careful of, safety-wise.”

This didn’t have to happen.

Quagga mussels invaded eastern rivers and the Great Lakes first.

Experts figure the mussels hitched a ride West on someone’s fishing boat.

Apparently – someone didn’t clean their boat properly – and mussels dropped into Lake Mead.

Allee: “When they built this amazing structure during the Depression, do you think they had
any idea that something like this could ever happen?”

Willet: “I think there was a lot of disagreement among professionals that a little mussel the
size of your finger nail could impact a large hydro facility, but we’re quickly learning a bunch
of them can impact water and power delivery.”

Willet says if boaters aren’t careful – they’ll spread quagga mussels to the Pacific Northwest, where
there’re lots of dams and hydro power plants.

After all, if it can happen at mighty Hoover Dam – it could happen anywhere.

For The Environment Report, I’m Shawn Allee.

Related Links

A Silver Bullet for Zebra Mussels?

  • Zebra mussels were discovered 20 years ago, and have since spread across the country (Photo courtesy of the US Fish and Wildlife Service)

Researchers say they’ve found something
that will kill invasive zebra and quagga mussels.
The mussels got into the US in the ballast of
foreign ships. Since then they’ve spread throughout
the country. Rebecca Williams reports:

Transcript

Researchers say they’ve found something
that will kill invasive zebra and quagga mussels.
The mussels got into the US in the ballast of
foreign ships. Since then they’ve spread throughout
the country. Rebecca Williams reports:

So, let’s say you have a nasty pest, an invasive species. Then someone says, we can get rid of that
pest and it looks like there’s no environmental downside.

“It kinda sounds like snake oil. But it’s true.”

That’s Dan Molloy with the New York State Museum lab. He’s come up with a
way to kill zebra and quagga mussels.

Molloy says a strain of common bacteria is toxic to zebra and quagga
mussels. And, even if the bacteria are dead, they can still kill the
mussels.

“You know maybe horror stories of people applying biocontrol agents. And it
had effects they didn’t anticipate. We’re applying dead cells. And they’re
just as effective live or dead.”

It’s great news for power plants, because the mussels clog up intake
pipes.

But it’s not clear if the bacteria can kill mussels in open water.

For The Environment Report, I’m Rebecca Williams.

Related Links

Big Ships Required to Flush

  • A ship discharging its ballast water (Photo courtesy of the US Geological Survey)

Ships should be bringing in fewer unwanted
pests into the Great Lakes. Both Canada and the
U-S are now requiring ships to flush out their
ballast water tanks before entering the lakes.
Tracy Samilton reports:

Transcript

Ships should be bringing in fewer unwanted pests into the Great
Lakes. Both Canada and the U.S. are now requiring ships to flush out their
ballast water tanks before entering the lakes. Tracy Samilton reports:

Ships need to take on ballast water to keep them stable. When they pump in
water from freshwater foreign ports, they also suck up pests.

Since 2006,
Canada has required ships to flush their tanks with salty ocean water
before entering the Great Lakes. The U.S. adopted the requirement at the
start of this year.

Collister Johnson is with the U.S. side of the St.
Lawrence Seaway, which connects the Atlantic Ocean to the Great
Lakes. He says the rule will eliminate almost 99% of freshwater
pests in ballast tanks.

“If they’re exposed to salt water, especially full strength sea water, they
are effectively killed.”

Samilton: “Why didn’t we do this before?”

Johnson: (laughs) “I don’t know.”

It won’t completely eliminate the problem because some aquatic pests can
still survive in the sediment in the bottom of ballast tanks.

For The Environment Report I’m Tracy Samilton.

Related Links

Zebra Mussels 20 Years Later

  • (Photo courtesy of the US Fish and Wildlife Service)

The invasive zebra mussel has disrupted food chains and
caused billions of dollars in damage across the country. This
year marks the twentieth anniversary of the discovery of zebra
mussels. Mark Brush reports:

Transcript

The invasive zebra mussel has disrupted food chains and
caused billions of dollars in damage across the country. This
year marks the twentieth anniversary of the discovery of zebra
mussels. Mark Brush reports:

The invasive mussels first arrived here in the ballast water of foreign ships. The mussels
are really good at filtering food out of the water column – such as algae and zooplankton –
food that would eventually go to fish.

David Jude is a research scientist at the University of Michigan. He says, 20 years later,
researchers are still fighting a perception that zebra mussels are good for the
environment. That’s because the mussels do make the water clearer.

“Well if you get clear water that means that some of the algae and some of the
zooplankton that are in that water, that are part of the food chain, that are fueling our fish are going to be destroyed, degraded and
damaged.”

The Great Lakes have been hit hard by the invasive zebra mussels – and by their close
cousins – known as quagga mussels. Jude says in many places popular sport fish such as
salmon and yellow perch are having a tough time finding enough food to survive.

For The Environment Report, I’m Mark Brush.

Related Links

Freshwater Mussels Not Happy-As-Clams

Researchers have been finding trace amounts of pharmaceuticals in rivers and lakes. Now, a new report suggests that the presence of Prozac in water bodies might be endangering freshwater mussels. Celeste Headlee has details:

Transcript

A new report suggests that the presence of Prozac in natural water systems can increase
the risk of extinction for freshwater mussels. Celeste Headlee has details:


Many freshwater mussel species are already highly endangered. Experts say about 70
percent of the 300 known species of mussel in North America are extinct, endangered or
declining. Authors of the new study say even trace amounts of anti-depressants like
Prozac are dangerous to mussels because they interfere with reproduction.


Prozac and other prescription medications are flushed into sewer systems and then
released into rivers and streams. Researchers placed female mussels carrying larvae into
tanks with various concentrations of Prozac. Within two days, all of the mussels had
prematurely released their larvae, which then died.


The authors of the study say new wastewater treatment procedures might have to be
developed to filter out prescription and over-the-counter drugs before they reach
waterways.


For the Environment Report, I’m Celeste Headlee.

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.