Tag: food chain

Ten Threats: Dead Zones in the Lakes

  • These fishermen at Port Clinton, Ohio, are a few miles away from the dead zone that develops in Lake Erie every summer... so far, most fish can swim away from the dead zone. But the dead zone is affecting the things that live at the bottom of the lake. (Photo by Lester Graham)

One of the Ten Threats to the Great Lakes is nonpoint source pollution. That’s pollution that
doesn’t come from the end of a pipe. It’s oil washed off parking lots by storms, or pesticides and
fertilizers washed from farm fields. Nonpoint source pollution might be part of the reason why
some shallow areas in the Great Lakes are afflicted by so-called dead zones every summer.

Transcript

In another report on the Ten Threats to the Great Lakes series, reporter Lester Graham looks at a
growing problem that has scientists baffled:


One of the Ten Threats to the Great Lakes is nonpoint source pollution. That’s pollution that
doesn’t come from the end of a pipe. It’s oil washed off parking lots by storms, or pesticides and
fertilizers washed from farm fields. Nonpoint source pollution might be part of the reason why
some shallow areas in the Great Lakes are afflicted by so-called dead zones every summer.


Dead zones are places where there’s little or no oxygen. A dead zone develops in Lake Erie
almost every summer. It was once thought that the problem was mostly solved. But, it’s become
worse in recent years.


(sound of moorings creaking)


The Environmental Protection Agency’s research ship, the Lake Guardian, is tied up at a dock at
the Port of Cleveland. Nathan Hawley and his crew are loading gear, getting ready for a five day
cruise to check some equipment that measures a dead zone along the central basin of Lake Erie.


“What I have out here is a series of bottom-resting moorings that are collecting time series data of
currents and water temperature and periodically we have to come out here and clean them off and
we take that opportunity to dump the data as well.”


Hawley is gathering the data for scientists at several universities and the National Oceanic and
Atmospheric Administration’s Great Lakes Environmental Research Lab. The information helps
them measure the behavior of the dead zone that occurs nearly every year in Lake Erie…


“What we’re trying to do this year is get a more comprehensive picture of how big this low-oxygen zone is and how it changes with time over the year.”


One of the scientists who’ll be pouring over the data is Brian Eadie. He’s a senior scientist with
NOAA’s Great Lakes Environmental Research Lab. He says Lake Erie’s dead zone is a place
where most life can’t survive…


“We’re talking about near the bottom where all or most of the oxygen has been consumed so
there’s nothing for animals to breathe down there, fish or smaller animals.”


Lester Graham: “So, those things that can swim out of the way, do and those that can’t…”


Brian Eadie: “Die.”


The dead zone has been around since at least the 1930’s. It got really bad when there was a huge
increase in the amount of nutrients entering the lake. Some of the nutrients came from sewage,
some from farm fertilizers and some from detergents. The nutrients, chiefly phosphorous, fed an
explosion in algae growth. The algae died, dropped to the bottom of the lake and rotted. That
process robbed the bottom of oxygen. Meanwhile, as spring and summer warmed the surface of
Lake Erie, a thermal barrier was created that trapped the oxygen-depleted water on the bottom.


After clean water laws were passed, sewage treatment plants were built, phosphorous was banned
from most detergents, and better methods to remove phosphorous from industrial applications
were put in place.


Phosphorous was reduced to a third of what it had been. But Brian Eadie says since then
something has changed.


“The concentration of nutrients in the central basin the last few years has actually been going up.
We don’t understand why that’s happening.”


Eadie says there are some theories. Wastewater from sewage plants might be meeting pollution
restrictions, but as cities and suburbs grow, there’s just a lot more of it getting discharged. More
volume means more phosphorous.


It could be that tributaries that are watersheds for farmland are seeing increased phosphorous. Or
it could be that the invasive species, zebra mussel, has dramatically altered the ecology of the
lakes. More nutrients might be getting trapped at the bottom, feeding bacteria that use up oxygen
instead of the nutrients getting taken up into the food chain.


Whatever is happening, environmentalists are hopeful that the scientists figure it out soon.


Andy Buchsbaum heads up the Great Lakes office of the National Wildlife Federation. He says
the dead zone in the bottom of the lake affects the entire lake’s productivity.


“If you’re removing the oxygen there, for whatever reason, for any period of time, you’ve
completely thrown that whole system out of balance. It’s all out of whack. It could mean
irreversible and devastating change to the entire ecosystem.”


And Buchsbaum says the central basin of Lake Erie is not the only place where we’re seeing this
low-oxygen problem…


“What makes the dead zone in Lake Erie even more alarming is that we’re seeing similar dead
zones appearing in Saginaw Bay which is on Lake Huron and Green Bay in Lake Michigan.
There, too, scientists don’t know what’s causing the problem. But, they’re already seeing
potentially catastrophic effects on aquatic life there.”


State and federal agencies and several universities are looking at the Lake Erie dead zone to try to
figure out what’s going on there. Once they do… then the battle likely will be getting
government to do what’s necessary to fix the problem.


For the GLRC, this is Lester Graham.

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Revisiting an International Water Agreement

The United States and Canada are updating a 30 year-old regional water quality agreement. The governments are launching 14 public hearings in both countries to gather ideas. We have more from the Great Lakes Radio Consortium’s Rick Pluta:

Transcript

The United States and Canada are updating a 30 year-old regional water quality
agreement. The governments are launching 14 public hearings in both countries to
gather ideas. We have more from the Great Lakes Radio Consortium’s Rick Pluta:


The Great Lakes Water Quality Agreement was initially designed to rid the Great Lakes
of chemicals. In the 1970’s, it resulted in the ban of phosphorus in detergents and other
consumer products. The ban is widely credited with starting to clean up the lakes.


Dennis Schornack is the U.S. chair of the International Joint Commission. He says a lot
of new problems have emerged since the agreement was last updated in 1987.


“Looking to the future, the threats that we have today have changed, one especially
important threat is invasive species. Foreign species have disrupted the food chain in the
Great Lakes.”


Schornack says other issues that need to be addressed include water runoff from streets
and farms that contain pesticides and other chemicals, and lakefront development.


The U.S. and Canada hope to complete an update of the Great Lakes protection
agreement in 2006.


For the GLRC, I’m Rick Pluta.

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Ten Threats: Predicting New Invaders

  • Some say it's only a matter of time before the Asian Carp enters the Great Lakes. (Photo courtesy of the USFWS)

More than 160 kinds of foreign creatures are in the Great Lakes right now, and every few months, a new one finds its way into the Lakes. Those invasive species are considered the number one problem by the experts we surveyed. The outsiders crowd out native species and disrupt the natural food chain, and it’s likely more will be coming. Zach Peterson reports scientists are putting a lot of time and effort into figuring out which new foreign creatures might next invade the Great Lakes:

Transcript

There are new problems for the Great Lakes on the horizon. The Great Lakes Radio Consortium’s Lester Graham is our guide in a series that explains that new invasive species are one of the Ten
Threats to the Great Lakes:


More than 160 kinds of foreign creatures are in the Great Lakes right now, and every few months, a new one finds its way into the Lakes. Those invasive species are considered the number one problem by the experts we surveyed. The outsiders crowd out native species and disrupt the natural food chain, and it’s likely more will be coming. Zach Peterson reports scientists are putting a lot of time and effort into figuring out which new foreign creatures might next invade the Great Lakes:


(Sound of boat motor)


Jim Barta is a charter boat captain just above Lake Erie on the Detroit River. He says over the last decade, zebra mussels and other foreign species have altered the habitat of the walleye he fishes for.


Water that once had a brownish hue is now clear. That’s because Zebra mussels have eaten the algae and plankton that used to cloud the water, and that means Barta’s boat is no longer invisible to the fish he aims to hook.


“You could catch the fish a little closer to the boat because they weren’t as spooked by the boat. They weren’t as afraid of what was taking place.”


So Barta had to rethink his tactics. He now casts his lines out further, and he’s changed lures to continue catching walleye.


But there are other problems the zebra mussel is causing. Eating all the plankton means it’s stealing food at the bottom of the food chain. And, that affects how many fish survive and how much the surviving fish are able to grow.


Anthony Ricciardi is trying to help Barta, and other people who rely on a stable Great Lakes ecosystem. He’s an “invasion biologist” at McGill University in Montreal.


Ricciardi looks for evidence that can predict the next non-native species that might make it’s way into the Great Lakes. He says species that have spread throughout waterways in Europe and Asia are prime candidates to become Great Lakes invaders.


“If the organism has shown itself to be invasive elsewhere, it has the ability to adapt to new habitats, to rapidly increase in small numbers, to dominate ecosystems, or to change them in certain ways that change the rules of exsistence for everything else, and thus can cause a disruption.”


Ricciardi says most aquatic invasive species are transported to North America in the ballast tanks of ocean freighters. Freighters use ballast water to help balance their loads. Some of the foreign species hitchhike in the ballast water or in the sediment in the bottom of the ballasts.


Ships coming from overseas release those foreign species unintentionally when they pump out ballast water in Great Lakes ports. Ricciardi says one of the potential invaders that might pose the next big threat to the Great Lakes is the “killer shrimp.” Like the Zebra Mussel, it’s a native of the Black Sea.


“And it’s earned the name killer shrimp because it attacks invertebrates, all kinds of invertebrates, including some that are bigger than it is. And it takes bites out of them and kills them, but doesn’t necessarily eat them. So, it’s not immediately satiated. It actually feeds in a buffet style: it’ll sample invertebrates, and so it can leave a lot of carcasses around it.”


Ballasts on cargo ships aren’t the only way foreign species can get into the Lakes. Right now, scientists are watching as a giant Asian Carp makes its way toward Lake Michigan. It’s a voracious eater and it grows to a hundred pounds or more.


This non-native fish was introduced into the Mississippi River, when flooding allowed the carp to escape from fish farms in the South. A manmade canal near Chicago connects the Mississippi River system to the Great Lakes.


If it gets past an electric barrier in the canal, it could invade. Many scientists believe it’s just a matter of time. Another invasive, the sea lamprey, also got into the Great Lakes through a manmade canal.


But, researchers don’t usually know when or where an invader will show up. David Reid is a researcher for the Great Lakes Environmental Research Laboratory in Ann Arbor. He says they can’t predict the effect an invader will have when it arrives in its new ecosystem.


“That’s the problem. We don’t know when the next zebra mussel’s going to come in. We don’t know when the next sea lamprey type of organism is going to come in. Generally, if you look at the invasion history of the Great Lakes, you’re seeing about one new organism being reported probably about once every eight months.”


Knowing what the next invader might be could help biologists, fisheries experts, and fishermen know what to do to limit its spread. Invasional biologists hope that their work will help develop the most effective measures to limit harm to the Great Lakes.


For the GLRC, I’m Zach Peterson.

Related Links

Environmental Superheroes

  • Super Rachel confronts Chemical Man before they duel. (Photo courtesy of the Shakespeare in the Schools Program at the University of Pittsburgh)

Drama is a unique way to connect children with their textbooks. That’s why a play on the achievements of Rachel Carson might be coming to a classroom near you. The Great Lakes Radio Consortium’s Lisa Ann Pinkerton reports on how the life of one prominent environmentalist is teaching students about
science:

Transcript

Drama is a unique way to connect children with their textbooks.
That’s why a play on the achievements of Rachel Carson might be coming to
classroom near you. The Great Lake Radio Consortium’s Lisa Ann Pinkerton
reports on how the life of one prominent environmentalist is teaching
students about science:


The office of Professor Buck Favorini is in a tall gothic tower. It was the inspiration for Gotham City in the first Batman movie. Inside his tower at the University of Pittsburgh, Professor Favorini has his own superhero story. His children’s play, Rachel Carson Saves the Day, is a science lesson in the language of children.


“We have used the sort of idiom of superheroes in the play, because it’s a way of teaching kids about science that they can understand simply by looking keenly at the world around them.”


Favorini says if Rachel Carson hadn’t been smart, bold, and risky, pesticides like DDT might still be in wide use. Some people honored her for her book Silent Spring. Others saw her as a reckless, unpredictable scientist threatening their chemical superhero.


“People made some of the worst chemicals in the world launched a very expensive campaign to undermine Rachel Carson’s scientific abilities partly based on the fact that she was a woman.”


Perched on a hill, overlooking another part of Pittsburgh, is Spring Hill Elementary.


LOUDSPEAKER: “Third, fourth, and fifth grade teachers, we’ll call you to the
assembly as soon as the staff sets up in the auditorium. Thanks.”


The staff is actor Elena Block and stage manager Josh Futrell. They hustle to assemble silver pipes of scaffolding and hang two white screens.


“There are two DVD players that do these great images that do these scenes from science and pictures of Rachel Carson. Sort of become this floating back drop.”


While Block is on stage as Rachel Carson, Futrell controls the images, music, and the voice of “Little Rachel’s” Mother.


FICTIONAL MOTHER: “Alice in Wonderland is your breakfast companion again.”


FICTIONAL RACHEL: “Oh Mama, I love this book, and so does Candy when I read it to her.”


(Sound of barking)


The play begins with Rachel as a young girl. She grows up quickly to become a marine biologist with the U.S. Fish and Wildlife Service. Her scientific observations reveal chemicals like DDT are contaminating waterways and silently creeping up the food chain.


FICTIONAL RACHEL: “This is the bird. The bird that ate the clam, that ate the
plankton, that swam in the ocean, fed by the stream, that carried the
chemical Jack-”


CHILDREN: “Sprayed!”


(Sound of clock ticking)


FICTIONAL RACHEL: “I’m in the late afternoon of my life and I am so angry. The next book I right is going to make a lot of noise.”


(Sound of “Mighty Mouse” theme)


To write Silent Spring, the passionate scientist/writer rips away her dress
to reveal a green superhero suit. Quickly Super Rachel is attacked by a man who’s face is hidden behind a long
pointed gasmask.


(Sound of fighting)


The Chemical industry attacks Rachel for her ideas. Images of nature and chemical compounds flash on the screens behind them. Super Rachel uses cartwheels and karate chops to over power Chemical Man.


(Sound of hip hop battle)


CHEMICAL MAN: “The bugs are buggin’ me.”


FICTIONAL RACHEL: “The chemicals are killin’ me.”


CHEMICAL MAN: “We’re gonna hit ’em from the air.”


FICTIONAL RACHEL: “How can you not care?”


Super Rachel prevails and DDT is officially banned in 1972.


(Sound of applause)


After the play, it’s clear the students of Spring Hill Elementary were paying attention.


GIRL: “She was trying to think of better ways to kill the insects instead of just polluting them.”


BOY: “I think she thought it was really important about the environment, and I think that’s good, because most people don’t.”


Not everyone agrees with the conclusions of Rachel Carson’s book, Silent Spring. Some scientists say Carson misrepresented existing 1950’s data on bird reproduction, and others say the very threat of malaria in developing countries should trump possible environmental threats of DDT. Actress Elena Block thinks despite these criticisms, Rachel Carson’s story has much to offer children.


“If they can sort of come away the idea with the idea that you can exact change being yourself from the place that you’re from. I think that’s pretty good, don’t you?”


Rachel Carson Saves the Day starts its second year of touring this fall, and perhaps it’s fun, multimedia look at environmental protection will inspire America’s next generation of intrepid scientists.


For the GLRC, I’m Lisa Ann Pinkerton.

Related Links

Woman Gives Poisoned Birds Refuge

  • Not only are birds affected by Type E Botulism, but fish are also killed by it. (Photo by Lester Graham)

For several years now, a strain of botulism has been killing shorebirds along parts of Lake Erie, Lake Ontario and Lake Huron. Tens of thousands of birds have died on Lake Erie in the last several years. But there’s one place where some sick birds are taken to be nursed back to health. The Great Lakes Radio Consortium’s Lester Graham
reports:

Transcript

For several years now, a strain of botulism has been killing shorebirds along parts of Lake Erie, Lake Ontario and Lake Huron. Tens of thousands of birds have died on Lake Erie in the last several years. But, there’s one place where some sick birds are taken to be nursed back to health. The Great Lakes Radio Consortium’s Lester Graham reports:


(Sound of an engine)


We’re crawling along sand dunes in a three-wheeled cart. Ray Bierbower is taking me to Gull Point. It’s an area on a spit of land called Presque Isle that juts out into Lake Erie at Erie, Pennsylvania. This area is part of a state park that gets four million visitors every year. But here, except for birds, it’s deserted.


“A lot of the shorebirds come through here, migrating, and they want to leave it alone. It’s shut off to the public. Basically, there’s just a select few that are allowed out in this area and we’re one of the groups that are allowed.”


We’re here to pick up some dead birds. A couple of years ago you might have found dozens of dead birds at a time. Today, only five seagulls. Well, parts of them: two heads and some rotting carcasses.


“We haven’t been out here for two weeks. So, this is not too bad considering before.”


If these birds are like hundreds of others tested, they died from botulism poisoning. Researchers are figuring out how the botulism got into the food chain. The theory is that massive beds of zebra mussels and quagga mussels – both invasive species brought into the Great Lakes in the ballast water of ocean going ships – are causing conditions that rob oxygen on the bottom of the Lakes.


That encourages botulism bacteria to flourish and give off toxins. The mussels aren’t hurt by them, but round gobies, another invasive species, eat the mussels. When they get sick, they become easy pickings for the birds. Then, the birds get sick.


Sometimes, Ray Bierbower and his fellow summer interns find a bird that’s sick, but not beyond saving. The state park doesn’t have the facilities to help the birds, so they take them to a wild bird rehabilitation center in town.


The center, called Wild Wings is looks like some of the other two story houses in this blue-collar neighborhood. But once you’re inside, there’s no doubt that you’re in the right place.


(Sound of birds)


A man is dropping off four tiny wrens from the nest. Their mother stopped coming to feed them and he figures a cat must have killed her.


Wild Wing’s director, Wendy Campbell, takes them in. She’s a whirlwind of activity as she flits from cage to cage. She makes sure birds have water. She gives some of them medicine. And now with the tiny wrens here she makes sure they don’t miss feeding time.


In the basement, chickens, crows, an owl, and some pigeons are separated by chicken wire walls. She checks on a couple of seagulls in one the pens. Campbell is helping them recover from botulism poisoning.


“What you do is provide them with supportive care. You want to keep the birds out of sunlight, because sunlight perpetuates botulism toxin. And by re-fluiding them, because they’re usually dehydrated. And a lot of times, too, we can use Phillips Milk of Magnesia because that binds with botulism toxin and draws it out of their system. And many of the birds recover.”


Campbell says after she’s sure they’re fully recovered, she’ll release these gulls back into the wild.


“There’s no danger of them spreading it, because I’ve asked the Wildlife Health Center to make sure that I could release these birds that have recovered from botulism that they weren’t now going to be carrying it. And he said absolutely not. It’s out of their system.”


Wendy Campbell is quick to add that it doesn’t mean that the gulls can’t contract the botulism toxin again. Campbell says if this were a natural phenomenom, she would let nature take its course. But it’s not; humans brought the zebra mussels and quagga mussels that are causing the problem in the Great Lakes.


“Over ninety percent of the time, it’s as a result of human activities. We don’t believe in interfering with nature. But when they get hurt because they get hit by a car or they get poisoned by lawn care chemicals, that’s not nature. And so, somebody has to help them, and that’s why I do this.”


Campbell says the authorities in her area are doing a good job of cleaning up the bird carcasses along the lake beaches. If they’re not picked up, flies lay eggs, maggots are infected by botulism, and other birds eat the maggots, causing the botulism problem to spread.


Campbell says of the one thousand birds brought into Wild Wings center each year, only a handful of them are sick from botulism. That’s because most of them die from it before they can be helped.


For the GLRC, this is Lester Graham.

Related Links

Type E Botulism Spreading

  • Type E Botulism is taking its toll on loons and other waterfowl in the Great Lakes region. (Photo courtesy of the National Park Service)

A relatively new disease that kills birds and fish continues to spread in the Great Lakes basin. Scientists want to understand how Type E botulism is transmitted before it becomes an epidemic. The Great Lakes Radio Consortium’s David Sommerstein reports:

Transcript

A relatively new disease that kills birds and fish continues to spread in the Great Lakes basin. Scientists want to understand how Type E Botulism is transmitted before it becomes an epidemic. The Great Lakes Radio Consortium’s David Sommerstein reports:


Type E Botulism has killed thousands of loons, mergansers, and other birds on Lakes Ontario and Erie since 1998. So when biologist Tom Langen heard two dead seagulls on the St. Lawrence River had it, he investigated. He took a 350-mile boat ride along the length of the river. He collected all the dead birds and fish he could find for testing.


Langen says the toxin is related to invasive species like the round goby and zebra mussels and passed up the food chain.


“The link seems to be somehow associated between mussels, the fish which feed on the mussels, and then the birds and fish that feed on the round gobies or feed on the mussels.”


Langen says stopping the spread of Type E Botulism is also important for people. Humans can get the disease if they eat birds or fish that are contaminated.


For the GLRC, I’m David Sommerstein.

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Mercury Rule’s Impact on Great Lakes Fish

The U.S. Environmental Protection Agency has a new rule to reduce mercury emissions from coal-burning power plants. But it might mean higher concentrations of mercury in fish in some inland lakes. The Great Lakes Radio Consortium’s Lester Graham reports:

Transcript

The U.S. Environmental Protections Agency has a new rule to reduce mercury
emissions from coal-burning power plants. But it might mean higher
concentrations of mercury in fish in some inland lakes. The Great Lakes
Radio Consortium’s Lester Graham reports:


The Bush administration’s EPA rule will use a cap and trade program to
reduce mercury. That means that overall mercury emissions will go down
over time, but some dirtier power plants can buy the rights to emit higher
levels of mercury. That could cause mercury hot spots. Higher levels of
mercury in nearby lakes would work up the food chain and concentrate
in fish. Mercury can cause neurological damage, especially to young
children. The toxin also can be passed on to fetuses.


Canadian studies last year already have shown higher levels of mercury in
people who regularly eat Great Lakes fish. The problem is expected to
become more severe in mercury hotspots.


Historically, walleye has had more mercury than some other types of fish in
the Great Lakes, but other large fish such trout and salmon, can also have
higher levels of mercury in their flesh.


For the GLRC, this is Lester Graham.

Related Links

Invasive Fish Rears Ugly Head in Great Lakes

  • With its ability to breathe out of water and wriggle its way over land during dry spells, the media has dubbed the northern snakehead "Frankenfish." Its appearance in Lake Michigan is scary to scientists. (Photo courtesy of USGS)

A few weeks ago, a Chicago fisherman caused a stir when he found a northern snakehead fish. The discovery set off a frantic search to find out if yet another invasive species is threatening the Great Lakes. The Great Lakes Radio Consortium’s Jenny Lawton has this report:

Transcript

A few weeks ago, a Chicago fisherman caused a stir when he found a northern snakehead fish. The find set off a frantic search to find out if yet another invasive species is threatening the Great Lakes. The Great Lakes Radio Consortium’s Jenny Lawton has this report:


Just before Halloween, the so-called Frankenfish reared its ugly head… filled with sharp teeth… in Chicago’s Burnham Harbor on Lake Michigan. And it’s still a mystery as to just how it got there.


Although the snakehead is arare item in some Asian cuisines, there’s a more common suspicion amongst local experts and hobbyists. That snakehead was probably a pet that outgrew its tank, and instead of the traditional farewell down the toilet, it was set free in Lake Michigan. Free to eat through the Lake’s food web.


Local pet store manager Edwin Cerna says that’s why he stopped selling the fish years before they were banned by U.S. Fish and Wildlife. He remembers one day, when he was adjusting a tank, he accidentally got in between a snakehead’s lunch and its mouth.


“He bit me in the hand… made me bleed. It hurts. It’s got a nice strong jaw and that’s why it’s so dangerous because it can kill big fish, literally cut them in half. It’s almost like a big old killer whale, like a miniature version of it.”


But why on earth would anybody buy a vicious fish that can grow up to three feet long in the first place? Jim Robinett is with the Shedd Aquarium in Chicago. He says he’s a fish geek.


“I gotta say, as a little fish, when you first buy them, they’re really attractive; they’re neat little animals, but they eat like crazy. They’re voracious.”


Robinett knows not to be fooled by the little guys because what happens next is the perfect plot for a B-horror movie. He says the snakehead fish grows quickly, eventually eating everything in its tank. If it doesn’t die from overgrowing that tank, its owner might be tempted to dump it into a nearby body of water where it will keep eating its way up the food chain. Robinett says that’s the fear in Lake Michigan.


“They could potentially start picking off small salmon and lake trout, which is native to these waters here, they’re not real discriminating, they’ve been known to take things as large as frogs, some small birds, even small mammals that happen to get in the way there close to shore. They’ll eat anything they get their mouth on.”


Most hobby fish don’t last long in Chicago’s cold water. But the northern snakehead is different. The snakehead is native to northern Asia, and the Lake Michigan Federation’s Cameron Davis says that makes the fish feel right at home around here.


“It’s a lot like us Midwesterners, it just kind of hunkers down and… that’s part of the problem with the snakehead is that it can live under very extreme conditions. Which means it’ll out compete those other fish, and that’s a tremendous problem.”


Snakeheads have another edge on other species. The fish guard their eggs, giving their young a better chance of reaching maturity. But perhaps the most peculiar thing about snakeheads is that they can breathe. In addition to its gills, they have an organ that works like a lung and allows it to breathe air. It’s able to live up to three days as it uses its fins to wriggle across land in search of another body of water.


But looking down into the murky waters at Burnham Harbor, Davis says we shouldn’t run screaming yet. It’s not exactly a horror film scenario.


“I don’t think that the snakehead is going to come and grab our children out of schools and eat them or anything like that. But it is a problem for those of us who like to fish for yellow perch and whitefish and some of the things that make the Great Lakes so fantatstic, could really be threatened by this fish getting into Lake Michigan.”


Other invasive species cause an estimated 137-billion dollars of losses and damages in U.S. waterways each year. Cameron Davis says simply banning the local sale of fish like snakeheads hasn’t been enough to keep the Great Lakes safe.


“We’ve got to stop imports of these kinds of fish into the United States. We can’t protect the Great Lakes unless we’re checking these things at the door when they come into the country. It’s that simple.”


Davis is pushing for the passage of the National Aquatic Invasive Species Act. The bill would allocate a total of 174-million dollars to develop new technology for identifying and eliminating the invaders if and when they arrive.


So far, local authorities ahven’t found another snakehead near the banks of Lake Michigan, but Cameron Davis says the initial find just proves how hard it is to regulate what comes into the country’s largest body of fresh water.


Standing on the dock at Burnham Harbor, Davis looks out over the dark waters and shakes his head.


“It’s just an indicator that we’re in a race against time right now. Let’s hope that if there are more than one out there, that they haven’t hooked up.”


If they have, he says, it could truly be the stuff horror movies are made of… at least, for the other fish in the Great Lakes.


For the Great Lakes Radio Consortium, I’m Jenny Lawton in Chicago.

Related Links

Doctors Publish Fish Buying Guide

Last month, the Federal Advisory Panel re-evaluated the food pyramid. The panel’s now saying Americans should increase the amount of fish they eat to two servings a week. But sorting through the various recommendations on how to avoid some contaminants in fish can be tricky. The Great Lakes Radio Consortium’s Lisa Ann Pinkerton reports on a group of doctors, who say their new guide will help clarify the concern about mercury in fish:

Transcript

Last month, the Federal Advisory Panel re-evaluated the food pyramid. The panel’s now
saying Americans should increase the amount of fish they eat to two servings a week.
But sorting through the various recommendations on how to avoid some contaminants in
fish can be tricky. The Great Lakes Radio Consortium’s Lisa Ann Pinkerton reports on a
group of doctors, who say their new guide will help clarify the concern about mercury in
fish:


Health officials continue to warn citizens about the dangers of mercury in fish. The EPA
indicates that eight percent of women of child-bearing age have elevated unsafe mercury
levels. Exposure early in life can damage the nervous system, leading to a variety of
learning disabilities.


Susan Marmagas is with the Physicians for Social Responsibility. She’s traveling the
country promoting a new wallet-sized guide to help consumers make informed choices.
She says the guide is stricter than federal guidelines.


“What we said is let’s make a very clear guide so that people can continue to eat fish as a
part of a healthy diet, but fish that are low in contaminants.”


Marmagas says the guide encourages the consumption of small fish, like tilapia and
halibut. These fish are at the bottom of the food chain, and therefore contain less
mercury.


For the Great Lakes Radio Consortium, I’m Lisa Ann Pinkerton.

Related Links

Fish Diet Down in Diporeia Die-Off

  • This tiny crustacean is a favorite food item for Great Lakes fish. Scientists are trying to figure out why it's disappearing. (Photo courtesy of the Great Lakes Environmental Research Lab)

One of the basic building blocks of the Great Lakes food chain is disappearing. The bottom of the lakes used to be teeming with tiny crustaceans known as Diporeia. But their numbers are declining, and in wide stretches they’re just simply gone. Commercial fishers are beginning to see the effect on fish. The Great Lakes Radio Consortium’s Lester Graham has an update:

Transcript

One of the basic building blocks of the Great Lakes food chain is disappearing. The bottom of the lakes used to be teeming with tiny crustaceans known as Diporeia. But their numbers are declining, and in wide stretches they’re just simply gone. Commercial fishers are beginning to see the effect on fish. The Great Lakes Radio Consortium’s Lester Graham has an update:


Diporeia is a quarter-inch long shrimp-like creature that
lives in the sediment at the bottom of most of the Great
Lakes. Just about every fish at some time in its life
relies on diporeia for food. Those that don’t, eat the
fish that eat diporeia. Researchers used to find 10,000
of these animals in a square yard of sediment. Today the researchers are disturbed because they’re
taking up samples and finding only hundreds in a square yard and
sometimes finding none, not one.


But this isn’t simply scientific curiosity for
biologists. It has economic impact. Mark Gaden is with the
Great Lakes Fisheries Commission. He says this is
beginning to affect commercially harvested fish.


“There’s a very deep concern about the impact of
the loss of diporeia on the white fish diet.”


Gaden says the commercial fishers starting noticing that
the white fish looked different. Their body weight just
wasn’t what they were used to seeing.


Tom Spaulding is one of the partners in Gauthier &
Spaulding Fisheries in Michigan. They fish on Lake Huron.
He says white fish there aren’t getting enough to eat.


“Well, some of them definitely look skinny alright. And the other ones, they’re a longer fish, but
they just don’t have the body weight they should for a fish
that length. So, it’s got to be food-related, their
natural food, that diporeia shrimp. You see what I mean?”


And it’s not just the commercial fishers on Lake Huron.
It’s happening everywhere except Lake Superior. The Great
Lakes Fisheries Commission’s Mark Gaden says it’s got a lot
of fishers worried.


“Anytime, though, where you have something like
diporeia which is something that’s critical in the food web
and you see drastic, drastic declines in it and we’re not
quite sure why this is taking place, it’s cause for serious
concern.”


The commercial fishing industry is looking to the
researchers. The researchers have been working on this
problem for years. So, what’s causing it?


“Well, that’s what I’m struggling with. There’s
a lot of conflicting evidence.”


Tom Nalepa is a research biologist at the Great Lakes
Environmental Research Lab. He says it’s possible that the
invasive species the zebra mussel might be eating most of
the diporeia’s food.


“It lives on the bottom, but it needs that fresh
material that drops down right at the sediment surface.
And, this is exactly the same materials that zebra mussels
are filtering out. So, logically, it’s a food problem, but
the confusing thing about it is that the animals are not
showing any signs of starvation. They’re relatively
healthy, yet the population is dying off down to zero.”


The researchers continue to try to figure out exactly
what’s going on. But, if the zebra mussel is the culprit
in the die-off of the diporeia, the scientists say there’s
nothing that can be done about it. It’ll mean a huge
change in the natural balance of the Great Lakes. The
commercial fishers such as Tom Spaulding say they’re
hopeful that the white fish will find something else to eat.
They hope it’s just a matter of time. But, in the
Meanwhile, Spaulding says it’s not just white fish that are
being affected. It’s the fish that sport fishers like to
catch too.


“We’re seeing skinny lake trout out there.
We’re seeing other species too that are suffering because
the food chain, the food they’re after is low. But, it’s
not just a white fish problem in the Great Lakes right
now. And the finger seems to be pointing to the zebra
mussel, so, it’s a serious problem as far as changing the
whole ecosystem out there that we see.”


This might be only the latest economic damage caused by the
zebra mussel since it stowed away in a cargo ship in the
early 1980s. The mussel has cost industry because it clogs
intake pipes. It’s damaged the native mussel populations.
And the long-term damage to the environment of the Great
Lakes and the Mississippi River system where it’s also
spread is not yet clear.


One thing is clear – Any savings realized because of those cheap goods on that cargo ship,
can’t possibly offset the cost to the economy because of the zebra mussels that ship carried in its
ballast water.


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

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