Salmon Fishery on the Rocks

  • The Chinook salmon was initially introduced to the Great Lakes in the 1870s. Michigan, New York and Wisconsin reintroduced the Chinook salmon to the Great Lakes in 1966. (Photo courtesy of USFWS)

There’s a decision looming for Lake Huron that would have been unthinkable 10 years ago. The state must decide whether it should keep putting chinook salmon in the lake. The fish has been the driving force behind sport fishing in the Great Lakes. But the salmon’s future in the Upper Lakes is now questionable. Peter Payette reports:


It’s hard to overstate how drastically salmon transformed the Great Lakes after they were introduced more than 40 years ago.


Ed Retherford is a charter boat captain on Lake Huron.
He says in the old days on a weekend in Rockport he’d see cars with boat trailers backed up for a mile or two waiting to launch.
But that’s all gone now.


“You’d be lucky, except maybe for the brown trout festival, you’d be lucky to see twenty boats there on a weekend. It just decimated that area. You can imagine the economics involved.”


Chinook or king salmon practically disappeared from Lake Huron about seven years ago. Most of the charter boats are gone now because the kinds of fish that remain are just not as exciting to catch as salmon.


State officials figure little towns like Rockport lose upwards of a million dollars in tourism business every year without the fishery.

More about Chinook salmon from the DNR

A related Environment Report story

Ten Threats to the Great Lakes

Transcript

The salmon’s demise followed the disappearance of its favorite food, little fish called alewives. Scientists say there were too many salmon eating the alewives and problems lower down on the food chain caused by invasive mussels.


State fisheries biologist Jim Johnson says salmon would rather starve than eat something besides an alewife.


“So at first, the salmon went through a period of just being starved out. They didn’t have enough to eat. They wouldn’t switch to eating round gobies and they died of malnutrition.”


The changes in Lake Huron since have been significant.


Neither salmon nor alewives are native to the lake. And with them out of the way, native fish like walleye have come back.


The state continues to stock one and a half million Chinook salmon in Lake Huron every year.


But Jim Johnson says the walleye eat most of them. He says Lake Huron can’t support a big salmon fishery any more.


“It’s just not realistic. The lake doesn’t offer that and there’s nothing the DNR can do to change that.”


The question now is whether to stock any chinook salmon in Huron at all. Giving up on the most popular sport fish in the Great Lakes is hard to swallow but most people see the writing on the wall. So even if stocking continues, it will likely be a fraction of what it once was.


On the other side of the state, there are now worrying signs that the same fate might be in store for Lake Michigan.


There are lots of salmon in Lake Michigan today.


But charter boat captain Denny Grinold says something went wrong last fall. He says the big salmon, the four-year old fish that come up into the rivers to spawn in August, never showed up.


“You keep looking for ‘em. You keep looking for ‘em. You go out and you fish the patterns that you’ve fished in the past. Those large Chinook should be there and they just weren’t there.”


The warm water and lots of windy days last year might account for the missing fish. But research provides no comfort for the future.


The DNR has created a system of red flags to evaluate the conditions for salmon in Lake Michigan. These are based on things like how much food is available, the weight of the fish and how many are being caught.


Twenty of the 30 flags have been triggered.


The manager of Lake Michigan for the Department of Natural Resources, Jim Dexter, says the lake is not a happy place.


“The lake is very perturbed. It’s certainly not a stable, quality ecosystem. I mean it’s working right now. It’s producing a fishery. People are happy but it’s tenuous.”


There’s not much the state can do to change anything.


If the experience of Lake Huron is any guide, it’s the presence of those little feeder fish, alewives, that is critical.


At the moment, there are believed to be fewer alewives in Lake Michigan than at any time on record.


For the Environment Report, I’m Peter Payette.

Fixing a Broken Ecosystem

  • Steve Dahl is a commercial fisher on the North Shore of Lake Superior. When he's fishing for herring, Dahl pulls his gill net up and passes it across his boat, plucking herring from the mesh. (Photo by Stephanie Hemphill)

For decades, exotic species have been invading the Great Lakes and mixing up the ecosystem. A few years ago the constant changes led to the collapse of the food web in Lake Huron. That event has gotten people interested in restoring native fish with the hope that they’ll be more stable, but as Peter Payette reports, not everyone wants the food web in the Great Lakes to look exactly like it did a century ago.
The Herring Replacements: the Beloved Alewife
Say it together now… “Coregonus artedi”
More from the Wisconsin Sea Grant

Transcript

Once upon a time, every Great lake was stuffed with lake herring. Trout would feast on them and so would people all over the Midwest, sometimes smoking or pickling the white flaky meat. Herring can grow more than two feet long. Every year commercial fishing nets would haul tens of millions of pounds of herring out of the lakes.

Fisheries biologist Mark Ebener says herring, or cisco, would lay so many eggs in the fall it was a food source for other fish. Ebener says it still is in Superior.

“You go into parts of Lake Superior in December and the whitefish are just gorged on cisco eggs.”

But herring largely disappeared from the lakes in the middle of the last century for a variety of reasons including overfishing. Biologists like Mark Ebener thinks restoring the fish should be a top priority. He’s with Chippewa Ottawa Resource Authority.  It’s a tribal fishing agency based in Sault Ste. Marie. Some Michigan tribes have commercial fishing rights on the Great Lakes that date back to treaties signed in the 19th century. They’d like the states to be more aggressive about restoring native species. Ebener says if we want a stable ecosystem in the lakes, herring are crucial. 

 
“It was the prey species. So if you want to restore the connectivity of the lakes and the historic predator-prey dynamics, why would you ignore herring”

 While nobody would admit to ignoring the fish, figuring out exactly what happened to lake herring has not been a priority, but that’s changing.

Grand Traverse Bay is the only place herring are still known to breed in Lake Michigan. State fisheries biologists have been coming to this breeding ground near Elk Rapids for three years. The Department of Natural Resources and Environment wants to know why this remnant population doesn’t expand. Randy Claramont is the team leader. He says the primary suspect is an invasive fish that eats new born herring. They just picked one up in the net.

“There’s our predator. There’s a rainbow smelt. Right in where the cisco are, we also got an adult rainbow smelt.”

It’s not likely that a large scale effort to restore herring as the main prey fish in Lake Michigan would have universal support. That’s because the state is also responsible for managing the lake’s popular salmon fishery. Salmon are not native to the Great Lakes but are generally considered to be the most exciting sport fish to catch. Lots of anglers come up north to do this, so politically speaking, the salmon has clout.

 Jim Dexter, the Lake Michigan basin coordinator for the Michigan DNRE, doesn’t think salmon like to eat herring.

 “One thing that’s important to remember is that if you have a huge herring population,  I don’t think you’ll be able to maintain the type of salmon sport fishery that we currently have.”

But it’s a different story in Lake Huron where the salmon disappeared in 2004. That was after the food web, dominated by exotic species, crashed. The upheaval has sparked interest in rebuilding a more stable ecosystem, and that’s why the Michigan Steelhead and Salmon Fishermen’s Association actively supports efforts to reestablish the herring in Huron. The state planted 40,000 herring there last year. Managers of the project think they’ll need to plant a million fish a year for a number of years to reestablish the species in the lake. That would cost millions of dollars.

For the Environment Report, I’m Peter Payette.

Replumbing Chicago to Keep Carp Out

  • These fish get big. They eat a lot, and if they get into the Great Lakes, people worry they'll swallow up the food web. (Photo by the USFWS)

You might recall that Michigan got a kind of asian carp scare a few weeks back. Biologists found one asian carp near Chicago, past an electric barrier that was supposed to keep them away from Lake Michigan. They worry if carp make it to the Great Lakes and rivers in Michigan, they could crowd out native fish. Congress worries the barrier might not be enough and it wants a more permanent solution. Shawn Allee reports that won’t happen anytime soon.

“Eco-Sep” – The Corps of Engineers’ Study

Brush up on your Asian Carp Knowledge

More on the Electric Barriers

Transcript

Joel Brammeier’s with the Alliance for the Great Lakes, an advocacy group. When I meet him, I expect him to be completely freakin’ out, since just a few weeks ago biologists found one live Asian carp on the Great Lakes side of the electric carp barrier. That’s the, um, wrong side of the barrier, since we want Asian carp to stay on the other side, the side closer to the Mississippi. Anyway, Brammeier’s is either a good actor, or maybe he actually feels OK, since now other people, the right people, are freakin’ out, too. Those would be people in Congress.

“We’ve seen over the past few months, more energy devoted to predicting and preventing a crisis to the Great Lakes than I’ve ever seen in my life.”

Brammeier says Congress doubts that electric barriers, poisons, or other gadgets will keep the carp out of Lake Michigan for good, so there’s talk about the mack daddy of Asian carp prevention: hydrological separation. This just means cutting off canals that connect Lake Michigan to rivers that head west. That’d make it impossible for carp to swim to the Lake.

“I think what folks are realizing now is that the only way to achieve that is physical separation between the Great Lakes and the Mississippi River. That’s easy to say, but it’s incredably difficult to conceptualize how that happens.”

Brammeier says the good news is that back in 2007, Congress already asked the U.S. Army Corps of Engineers to figure all this out. The bad news is that the study’s moving too slow for Congress. The Army Corps was planning to finish its proposal in, say, five years. Tomorrow, a U.S. Senate committee will debate asking the Corps to speed things up. They want the study finished in less than two years.

“Twelve to eighteen months with the right people, the right funding and leadership strikes me as a generous amount of time to get the answers we need.  It’s simply a matter of prioritization.”

“To do that in 18 months in my and my team’s opinion is not a reasonable assumption.”

This is Dave Wethington. He’s in charge of the study for the Army Corps of Engineers. Wethington says the real issue isn’t whether the Corps can propose some way of separating Lake Michigan from rivers that head west. He says it can do that. It’s that that there’s a lot to consider.

“What kind of impacts could there be to commercial shipping, passenger boats, recreational boats. What kind of flood risk could there be, to the Chicago area specifically.”

None of this is enough for some Michigan congressmen. Representative Dave Camp is from the 4th district.

“The problem is that it’s taking far too long. This will speed that up. What we’re trying to bring is this sense of urgency to the problem that, frankly, the bureacrats don’t get.”

Camp admits even if he gets his study eighteen months from now, he’d still have a problem. Re-jiggering the water canals around Chicago won’t be cheap, and there’d probably be a fight over that, too. Still, he says he’d rather have that fight sooner rather than later. After all, we might still have time to stop the carp’s invasion, but we’re pressing our luck if we wait too long.

For The Environment Report, I’m Shawn Allee.

By the way, we still don’t know where that carp that was caught beyond the electric barrier came from.  Scientists are using DNA tests to figure out whether it just swam through the barrier or whether someone released it into the wild. Biologists say that happens from time to time.

That’s the Environment Report. I’m Rebecca Williams.

Decades Spent Battling the Sea Lamprey

  • John Stegmeier electro-shocking for lamprey in Sand Creek. Stegmeier is one of the many people who go out every year to find where lamprey are spawning. (Photo by Dustin Dwyer)

What has rows and rows of sharp teeth…. sucks blood and rings up a 20 million dollar tab?

This is the Environment Report. I’m Rebecca Williams.

If you were thinking shark… or maybe blockbuster vampire movie… nope! It’s actually the sea lamprey.

HOW DID THE SUCKER GET IN?

LAMPREY INFO

Transcript

It’s an invasive parasite found in every one of the Great Lakes.  It invaded the Lakes in the early 20th century, and no one’s been able to get rid of it.  It’s a fish with a round mouth like a suction cup.  It latches onto big fish like lake trout and salmon…. and gets fat drinking their blood.

Fishery managers in the U-S and Canada work to keep this parasite in check.  It costs them 20 million dollars a year.  Those are your tax dollars, by the way.

Marc Gaden is with the Great Lakes Fishery Commission.  It’s the commission’s job to protect the multi-billion dollar fishery.

Gaden says the lamprey control program has beaten back the lamprey’s population by 90 percent.  And he says for now, humans are winning.

“The threat from lampreys at the moment is like a coiled spring.  As long as you have your thumb on it you’re going to be okay.  But the moment you let up on that control they’re going to spring back pretty quickly out of control.”

Gaden says they’re using a combination of weapons against the parasite.  They include a targeted poison to kill lamprey larvae, traps and barriers and sterilizing male lampreys. 

He says we are probably stuck with the lamprey forever.  That means we’ll be continuing to spend millions of dollars… every single year.

 
(music sting)

This is the Environment Report. 

 
So we’ve been wrestling with the sea lamprey for decades… maybe you’re wondering who’s actually out there in the trenches?  Dustin Dwyer caught up with one of the lamprey hunters:

 
John Stegmeier stands in a shady stretch of Sand Creek near Grand Rapids, looking like a Ghostbuster. He’s wearing waterproof waders, and has a metal box strapped to his back, with wires and knobs sticking out.

I meet him in the middle of the stream, where he’s prowling for sea lamprey larvae. But he tells me to stay up on a log out of the water, because he’s packing a charge.

“That’s giving little pulses of electricity into the water. And then if one comes up, then we give them a fast pulse, and that would keep them from being able to swim and we’re able to scoop them up with our paddles here.”

 They go into a bucket alive, then they’re counted for a survey. These surveys help determine where the U.S. Fish and Wildlife service decides to dump a poison targeted specifically for sea lamprey.

Stegmeijer is one of just a dozen people on a survey team that’s responsible for testing every stream and river in the entire Lower Peninsula, plus the southern shores of Lake Erie.
On days like this one in the gentle stream of Sand Creek, he says, it’s a fun job.

“But there are days on little trout streams in beautiful woods and there are days in agricultural ditches next to dairy farms that might smell a little, and there’s some industrial ditches.”

In short, he has to go wherever the sea lamprey larvae go, and sometimes they go to some inconvenient places.

It’s all part of the battle to keep the sea lamprey in check, and Steigmeyer says it’s not exactly a losing battle.

“We’re kind of winning it, but it’s only a kind of win because we can’t get rid of them.”

What they can do is control them – keep the population low.
Stegmeier says if they weren’t doing this, sea lampreys could devastate the multibillion dollar fishing industry in the Great Lakes, but even with the treatments, every year, sea lampreys make it farther up Michigan’s rivers to spawn. And every year, there’s more area for his small team to cover, and more places that need chemical treatment – treatment that can get extremely expensive.
Still the battle must be fought.

For the Environment Report, I’m Dustin Dwyer in Grand Rapids.

  
You can take a look at a sea lamprey’s ugly little face… and see photos of what the lamprey does to fish at environment report dot org. 

I’m Rebecca Williams.

Oil Spill Worse by the Day

  • The gulf region is the world's largest producer of oysters and shrimp(Photo courtesy of the NOAA)

When an oil rig off the coast of Louisiana exploded last week, gulf coast officials knew they had a problem on their hands. But as Tanya Ott reports from Alabama, everyday they find it’s worse than they originally thought.

Transcript

When an oil rig off the coast of Louisiana exploded last week, gulf coast officials knew they had a problem on their hands. But as Tanya Ott reports from Alabama, everyday they find it’s worse than they originally thought.

It’s estimated more than 200-thousand gallons of oil are spewing out of the well each day. Cleaning up using chemicals causes problems because it might make it easier for marine animals to eat the oil. Burning the oil on the water is not great either. Casi Callaway is with the environmental group Mobile Baykeeper.

“The air quality impacts from it and therefore the health impacts from it are great – and frankly unknown.”

It’s not just an environmental crisis. It’s an economic crisis. This area is the world’s largest producer of oysters and shrimp. And the pristine gulf coast beaches fuel a tourism industry worth 20-billion dollars a year.

For the Environment Report, I’m Tanya Ott.

Related Links

The Great Blue Heron

  • An island in the Upper Mississippi, not far from downtown Minneapolis, is home to many Great Blue Herons.(Photo courtesy of Stephanie Hemphill)

Some people say robins are the first sign of spring. But there’s another bird that makes a dramatic entry in northern states. The Great Blue Heron soars in to make a nest… and guard it:

Transcript

Some people say robins are the first sign of spring. But there’s another bird that makes a dramatic entry in northern states. The Great Blue Heron soars in to make a nest… and guard it:

On an island in the Upper Mississippi River, a stand of cottonwood trees is silhouetted against a gray sky. The bare branches are festooned with big nests, made of twigs and branches. Next to the nests, like sentinels at the castle gate, stand Great Blue Herons. These birds are four feet tall. More than a hundred of them are claiming their domain in these trees, just upriver from downtown Minneapolis. When one takes off and glides away, its six-foot wing span dwarfs the ducks and songbirds sharing the island.

It’s hard to tell the males from the females because they’re the same blue and gray. Birder Sharon Stiteler is leading me on a tour of this rookery.

“The males arrive first, and they work out who’s going to take which nest. Where you see one bird standing up, that is most likely a male. He’s hanging out there because the other males who are still waiting to attract a female could come by and steal sticks out of his nest to make his nest look better.”

On some nests, you can see females already sitting on pale blue eggs the size of small mangoes. But Stiteler says herons are not always good parents.

“If the chick falls out of the nest and lands on the ground, that chick is toast: the parents will not continue feeding it. And oftentimes you’ll see turkey vultures hanging out at rookeries, and they’re waiting for the young to fall and starve, and then they’ll have a whole bunch of food.”

But at least on this island, there won’t be many predators like coyotes or foxes.

These birds were once threatened by humans. Their cousins the egrets were hunted for their beautiful white feathers, and both suffered disastrous population loss until the pesticide DDT was banned.

Now you can see them in streams and lakes all over. They breed in Canada and the upper midwest. They spend their winters wherever they can find food. Herons literally stalk their prey.

“They have a lot of patience, and they just stare at one spot for long time, and then they jab down and grab the fish. Their beak is shaped like a pair of super-sharp chopsticks. Sometimes they catch a huge fish and they have to juggle it around, especially if they have it perpendicular with their beak, they have to jostle it around, and the fish is wiggling, and eventually they get it just right so it’s straight in line with the bill, and you can watch this huge thing slide down that long slender neck.”

Sharon Stiteler is a part-time naturalist with the National Park Service, and she writes a blog called bird-chick-dot-com.

Today the herons are pretty quiet. But Stiteler has a Blackberry loaded with their sounds, including the prehistoric squawk they make when they’re startled.

And Stiteler says it can sound really strange when the young are clattering for food.

After the young are raised — at least the ones that survive — the herons will stay here on the river, until it freezes over and they can’t fish anymore. Stiteler says the birds decamp all at once.

“One day we have Great Blue Herons, and the next day they’re gone, and they migrate at night.”

They tuck back their long necks when they fly, forming an S-shape and hiding their true length.

Stiteler says the recovery of Great Blue Herons, along with pelicans, eagles, and other birds near the top of the food chain is a sign of a healthier ecosystem.

For The Environment Report, I’m Stephanie Hemphill.

Related Links

More Oceanic Garbage Patches Found

  • Marine researcher Marcus Eriksen says the plastic packaging that wraps nearly all consumer products is killing some marine animals.(Photo courtesy of the NOAA Marine Debris Program)

A giant field of plastic debris is floating in the middle of the northern Pacific Ocean. Now researchers are finding more of these garbage patches in other Oceans. Mark Brush has more:

Transcript

A giant field of plastic debris is floating in the middle of the northern Pacific Ocean. Now researchers are finding more of these garbage patches in other Oceans. Mark Brush has more:

Researchers say there are ocean currents that sort of swirl around like water in a toilet bowl. There called oceanic gyres.

The Algalita Marine Research Foundation was one of the groups that documented the problem in the North Pacific Ocean. This year they sailed to the gyres in the North Atlantic and in the Indian Ocean.

They found miles and miles of plastic fishing line, milk crates, spoons and forks, and bits of plastic bags.

Marcus Eriksen is with the group:

Eriksen: I challenge you to walk into Wal-Mart or a K-Mart and find a product that’s not made from plastic, packaged or labeled with plastic. And we’re finding more and more of this debris being lost onto the ground washing down rivers and streams out to sea.

Eriksen says the plastic is killing some marine animals. Fish, birds, turtles, and whales get tangled up in the mess – or they mistake it for food.

For The Environment Report, I’m Mark Brush.

Related Links

Lake Huron’s Invasive Species

  • Filmmaker John Schmit says he wanted to make this film to show how even the smallest invader could mess up the delicate balance of life in the lake. (Photo courtesy of the NOAA GLERL)

You might call Lake Huron the forgotten Great Lake. There are no major cities on its shores. It doesn’t get the media attention the other four Great Lakes do. But its problems are just as bad or worse. Rebecca Williams reports a new documentary tells the story of Lake Huron’s struggle with dozens of alien invaders… and the biologists and fishermen who are trying to reclaim their lake:

Transcript

You might call Lake Huron the forgotten Great Lake. There are no major cities on its shores. It doesn’t get the media attention the other four Great Lakes do. But its problems are just as bad or worse. Rebecca Williams reports a new documentary tells the story of Lake Huron’s struggle with dozens of alien invaders… and the biologists and fishermen who are trying to reclaim their lake:

The documentary Lake Invaders is a cautionary tale about opening the door to strangers. It tells how Lake Huron was opened up to alien invasive species. The film paints fish biologists as the heroes rushing in.

“Seems like it always has to wait until it’s at a disaster level before you know, we can start fixing it… we’re constantly putting out these biological fires, running from fire to fire, to try to keep them under control. We have to find another way to approach this.”

More than 180 non-native species have gotten into the Lakes… and some of them have turned everything upside down. Long, slithering, blood-sucking parasites called sea lamprey were the first to get in. They slipped through a canal that connects the Atlantic Ocean and the Great Lakes. Lamprey killed off most of the big predator fish in the Lakes.

Then… came the alewife. Since the lamprey had taken out the top predators… there was nothing to eat the invading alewives. In the film… biologist Jeff Schaeffer explains how the small fish took over the lakes.

“At that time over 90% of the fish biomass of Lake Michigan and Lake Huron was probably dominated by the exotic alewife. One of my colleagues refers to the Great Lakes at that time as alewife soup.”

Suddenly… there was a major stinking mess. Each spring, hundreds of millions of dead alewives washed up on shore and rotted. Not the best thing for tourism.

Filmmaker John Schmit says he was surprised to learn what happened to the lakes next.

“The funny thing about the Great Lakes is there’s Pacific salmon in them.”

Schmit says biologists brought in millions of salmon from the Northwest to control the alewives. The crazy thing is… it worked. In the film we see how a 4 billion dollar sport fishing industry was born. And the native fish of Lake Huron were pretty much forgotten about.

The salmon fishery boomed for decades. Until the alewives crashed in 2003.

Fisher Doug Niergarth says then… the salmon started starving.

“Two years ago we saw some monster salmon heads that were sitting on little dwarfed bodies. And it was the ugliest thing and rather nasty. Just skinny and withered away. It was the nastiest thing you ever done seen.”

The fishing industry started slipping away. Marinas just scraped by. Tackle shops and motels closed. People finally realized there was something wrong with the lakes.

John Schmit says he wanted to make this film to show how even the smallest invader could mess up everything… both the delicate balance of life in the lake and the people who fish it and depend on money from tourism.

“Lake Huron has been the most impacted by the newest invaders. My personal concern, my investment in the Great Lakes and making this documentary is for people to be aware of the kind of damage invasive species can do to these huge lake systems.”

He says his film Lake Invaders is an example of what invasive creatures can do… not just to Lake Huron… but any ecosystem.

For The Environment Report, I’m Rebecca Williams.

Related Links

Putting Brakes on Brake Pad Material

  • A new Washington state law bans heavy metals in brakes and requires phasing out copper that's contributing to water pollution and harming fish. (Photo courtesy of the US Fish and Wildlife Service)

States are considering laws to phase out a material used in brake pads on cars and trucks. Lester Graham reports… it’s contributing to water pollution that’s affecting fish.

Transcript

States are considering laws to phase out a material used in brake pads on cars and trucks. Lester Graham reports… it’s contributing to water pollution that’s affecting fish.

There’s a fair amount of copper in brake pads. Every time you put on the brakes… some of brake pad and the copper in it is worn off. It ends up on the pavement and eventually is washed into a stream or lake. That’s been causing some concern in the state of Washington where too much copper is hurting the salmon. A new state law bans heavy metals in brakes and requires phasing out copper.
Curt Augustine is with the Alliance of Automobile Manufacturers. He says they worked with lawmakers and environmentalists to come up with the plan. Other states might adopt it.

“Bills have been introduced in California and Rhode Island and likely similar bills will end up in some of the Great Lakes and Chesapeake Bay states.”

The Washington law calls for brakes to contain no more than five percent copper by 2021 and then consider using even less in later years.

For The Environment Report, I’m Lester Graham.

Related Links

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