Author: Celeste Headlee

Biologists Help Prehistoric Fish Make a Comeback

  • Sturgeon like this adult used to be common in the Great Lakes. Today biologists are trying to restore populations of the ancient fish. (Photo courtesy of the USFWS)

Biologists with the U.S. Geological Survey are trying to bring Lake Sturgeon back to the Detroit River. The giant fish once spawned in the riverbed every spring before moving on to Lake Erie… now, the sturgeon are rapidly disappearing. The Great Lakes Radio Consortium’s Celeste Headlee reports:

Transcript

Biologists with the U.S. Geological Survey are trying to bring Lake Sturgeon
back to the Detroit River. The giant fish once spawned in the riverbed every spring before
moving on to Lake Erie. Now, the sturgeon are rapidly disappearing. The Great Lakes Radio Consortium’s Celeste Headlee reports:


Sturgeon are the largest fish in the Great Lakes. The grayish brown creatures can grow up to
seven feet long, and weigh more than 200 pounds. Sturgeon have been on Earth for 100 million
years – 40 million years before the dinosaurs – and they have remained essentially
unchanged in all that time. Instead of scales, the fish have an almost leathery skin and five rows
of bony plates running along their torpedo-shaped bodies.


Fish biologist Bruce Manny says sturgeon were once abundant in the Great Lakes. Back in 1880,
in one month’s time, fishermen pulled four thousand of them from the Detroit River.


“They tore holes in their nets when they were fishing for other fish that they cared about. So
when they found a sturgeon in their nets, they would kill them, bring them to the shore, pile them
up on shore, dry them out and use them for fuel in the steamships. Burn them up.”


People didn’t eat a lot of sturgeon, but the creatures were caught and killed while fisherman
angled for more valuable fish. Scientists estimate that over-fishing has caused sturgeon
populations in all of the Great Lakes to dwindle to less than one percent of their
former number. The state of Michigan closed the Detroit River to all sturgeon fishing years ago.
Bruce Manny says he decided to check on the sturgeon and see if the fish population had started
to recover.


Manny assembled a team of biologists from the U.S. Geological Survey. They started trapping
and then tracking sturgeon with electronic transmitters. Manny says he was surprised when his
team caught only 86 fish over course of four years. Manny says he realized the sturgeon
were in serious trouble and he obtained grants to investigate further. USGS scientists followed
the tagged fish for two years, and their patience was eventually rewarded. Manny found the first
known spawning site ever documented in Detroit River in modern times.


“We were excited all right. Eureka moment. I mean, this is like a very, very great coincidence
that we were able to find these spawning ready males, and they were able to find a female. When
there are only 86 fish caught in four years out here, there aren’t that many around. So to find
somebody to spawn with, so to speak, is a real challenge, I would say.”


The area where the sturgeon mated lies close to a sewer discharge pipe. There are limp, brown
grasses bordering grey, mucky water. Manny sent divers down and discovered the fish had
actually produced fertilized eggs. Manny says this was a major step forward for his project.


Sturgeon are pretty picky about their nesting sites. They need a fast moving current and several
layers of rock where the eggs rest safely. The problem is a lot of the gravel has been mined out of
the Detroit River for use in construction.


Another problem is the sturgeons’ longevity. Fish biologist Ron Bruch is in Wisconsin. He
oversees sturgeon populations in Wisconsin’s Winnebago River system. He says female
sturgeons live more than 100 years and they don’t spawn until they are at least 20 years old.


“Their life history works well for a long-lived species, but it doesn’t work well for a species that’s
exploited heavily. So, sturgeon can only tolerate very low exploitation rates, and when the
exploitation is high the populations collapse.”


Wisconsin was the first state in the U.S. to create a sturgeon management program, more than
100 years ago, and the fish are abundant there.


Bruch says that’s why many other states have come to him for advice on how to strengthen their
sturgeon populations. He helped build the first man-made Lake Sturgeon spawning site and he
thinks a program started in Michigan has a good chance to succeed.


Bruce Manny plans to build three sites, using limestone, coal cinders and gravel. He’ll monitor
them closely to determine which kind of rock the fish prefer. Manny says he doesn’t mind
spending so much time with sturgeon. He says he admires the fish, and imagines that
each of them has a distinct personality.


“I wish they could talk to me and they do in some ways, because some of them have scars and
evidence of propeller hits which show that they’ve managed to take that sort of punishment and
survive it spite of it all. You know, they’re long-lived, they’re survivors, they’re
tough, and they’re successful.”


Ron Bruch it’ll be 100 years before fisherman will reel in these huge fish. He says many
generations of biologists will have come and gone before the sturgeon population is firmly
reestablished in the Great Lakes. And biologists, he says, will have to create a lot more
spawning sites like the ones in the Detroit River.


“In and of itself, it’s not going to restore all of Lake Erie or all the Great Lakes, but it’s a shining
example of what can be done in many areas around the Great Lakes to help produce Lake
Sturgeon spawning habitat and rehabilitate the Lake Sturgeon population.”


It’ll cost about half a million dollars to build the three fish nesting sites. Officials say they’ll be
ready in time for the sturgeon’s spawning season next May. If the project is successful in the
Detroit River, biologists hope to expand the program into other areas of the Great Lakes where
sturgeon were once abundant.


For the Great Lakes Radio Consortium, I’m Celeste Headlee.

Related Links

Study Ranks Pesticide Residues on Produce

A report from an environmental group says peaches, strawberries, nectarines, and apples are more likely to be contaminated by pesticides than other produce. As the Great Lakes Radio Consortium’s Celeste Headlee reports, the non-profit group says washing produce doesn’t eliminate pesticide residues:

Transcript

A report from an environmental group says peaches, strawberries, nectarines, and apples are more
likely to be contaminated by pesticides than other produce. As the Great Lakes Radio
Consortium’s Celeste Headlee reports, the non-profit group says washing produce doesn’ t
eliminate pesticide residues:


The Environmental Working Group tracked results from pesticide tests done by the U.S.
Agriculture Department and the Food and Drug Administration between 1997 and 2001. Those
tests track almost 200 pesticides on fruits and vegetables.


The EWG has issued a shopping guide with a list of the twelve most contaminated foods,
including bell peppers, celery, and potatoes. Also listed are the twelve safest foods, including
asparagus, avocados, and mangoes.


EWG President Ken Cook says he doesn’t want to discourage people from eating fresh produce.


“There is a way to look at the pesticide residues on these crops and make a decision about how
often you eat them or, when you have a chance, whether you can shop instead for organic choices
or select fruits and vegetables that have lower residue levels.”


The FDA says the consumption of pesticide residues is not dangerous, but Cook points out that
the government is constantly updating food regulations.


For the Great Lakes Radio Consortium, I’m Celeste Headlee.

Bush Chooses New Epa Administrator

President Bush has chosen Utah Governor Mike Leavitt as the new head of the Environmental Protection Agency. Some environmentalists say this nomination indicates that the Bush administration is no longer concerned about placating conservationists. The Great Lakes Radio Consortium’s Celeste Headlee reports:

Transcript

President Bush has chosen Utah Governor Mike Leavitt as the new head of the
Environmental
Protection Agency. Some environmentalists say this nomination indicates that the Bush
administration is no longer concerned about placating conservationists. The Great
Lakes Radio
Consortium’s Celeste Headlee reports:


If Leavitt is confirmed by the Senate, he will replace Christie Todd Whitman, who
resigned in
May.


Business leaders and Republicans describe Leavitt as a moderate and a consensus
builder.
Environmental groups, though, say Utah’s governor has a history of allowing
corporations to
pollute the state’s forests and waterways.


Scott Groene is the staff attorney for the Southern Utah Wilderness Alliance.


“He’s a smart man and he’ll be very careful not to blunder by telling the public
what he’s doing if
he’s actually rolling back environmental protections. That’s certainly what we’ve
seen here in
Utah, is that he’ll take some fairly extreme actions but then he’ll manage to claim
the middle
ground with his rhetoric.”


Leavitt says he wants to give states a larger role in environmental regulation. His
confirmation
hearings will be scheduled when the Senate returns to Washington in September.


For the Great Lakes Radio Consortium, I’m Celeste Headlee.

Virgin Shark Birth Sets Researchers in Motion

  • Biologists are looking at how a shark in a Great Lakes region aquarium gave "virgin birth" last year. Photo courtesy of Belle Isle Aquarium, Detroit.

A female shark in an aquarium in the Great Lakes region has apparently given virgin birth. Four shark eggs hatched last year and three of those babies are now growing normally. As the Great Lakes Radio Consortium’s Celeste Headlee reports, it may be some time before the cause can be determined, but the event is still a surprise for biologists:

Transcript

A female shark in an aquarium in the Great Lakes region has apparently given virgin birth. Four
shark eggs hatched last year and three of those babies are now growing normally. As the Great
Lakes Radio Consortium’s Celeste Headlee reports, it may be some time before the cause can be
determined, but the event is still a surprise for biologists:

Biologists have a technical term for virgin birth. It’s called parthenogenesis. Doug Sweet is the
Curator of Fishes at the Belle Isle Aquarium in Detroit. He says parthenogenesis is common in
invertebrates and some amphibians.

“Most vertebrate animals, the females will produce eggs even if the male is not around. And it’s
just a matter of… it’s a chemical trick, basically, to get that egg to develop into an individual
without a sperm activating it.”

But parthenogenesis has been totally unheard of for sharks, until now. Last year, the Henry
Doorly Zoo in Omaha, Nebraska, announced they thought a Bonnethead shark there had
reproduced by parthenogenesis. The baby lived less than 12 hours, though, and genetic tests were
inconclusive.

But when Doug Sweet saw the press release from the Henry Doorly Zoo about a possible virgin
birth, he thought he’d try an experiment. Sweet decided to incubate the eggs of his two female
bamboo sharks. Four of the eggs developed. Sweet says the sharks were acquired by the
aquarium before they had reached sexual maturity, and they have never been exposed to a male.
He says the likely conclusion is that these sharks are reproducing by parthenogenesis.

Two other explanations, though highly unlikely, are that the shark has both testicular and ovarian
tissue, and fertilized its own eggs or that sharks are capable of storing sperm for years and even
passing it down to their offspring. Sweet has sent small clippings from the sharks’ fins to the
Henry Doorly Genetics Lab. Testing has already begun, but Sweet says it could take more than a
year to get the results. In the meantime, Sweet says the facts remain the same: a female shark
has given virgin birth. If it is parthenogenesis, he says, it will have important implications for
biologists around the world.

“Parthenogenesis just hasn’t been considered to happen in sharks; it’s never been recorded. It may
be happening all the time out there, so this is kind of breaking news in the shark world.”

The two adult bamboo sharks and the offspring are currently on exhibit at the Belle Isle
Aquarium in Detroit.

For the Great Lakes Radio Consortium, I’m Celeste Headlee.

Nation Failing in Radon Remediation?

A coalition of scientists is reporting that efforts to reduce radon levels in homes throughout the U.S. are largely failing. The Great Lakes Radio Consortium’s Celeste Headlee has more:

Transcript

A coalition of scientists is reporting that efforts to reduce radon levels in homes throughout the
U.S. are largely failing. The Great Lakes Radio Consortium’s Celeste Headlee has more:


Radon is a natural gas that emits low levels of radiation. Research has proven it can cause lung
cancer. Officials estimate 15 thousand lung cancer deaths can be traced back to radon each year
in the U.S. Congress passed the Indoor Radon Abatement Act in 1988, setting a national goal to
reduce radon in American homes to safe levels.


Peter Hendrick is the Executive Director of the American Association of Radon Scientists and
Technologists. He says the country’s radon program is ineffective, with dangerous levels of the
gas still present in ten million homes in the U.S.


“I believe that the reason behind that is because one particular agency, Housing and Urban
Development, has really not lived up to its responsibilities under the National Environmental
Protection Act to comply with EPA standards on radon.”


Hendrick is calling for the government to enforce existing laws and even create tax incentives for
compliance. Federal officials have not yet commented on Hendrick’s complaints.


For the Great Lakes Radio Consortium, I’m Celeste Headlee.

Rushing to Save Native Mussels

  • Michigan researchers are searching rivers and lakes for evidence of the native Purple Lilliput (pictured above). Photo by Doug Sweet.

In recent years, a great deal of attention has been focused on zebra mussels. They’re not native to the Great Lakes region and they’re pushing native mussels out of local lakes and streams. As the Great Lakes Radio Consortium’s Celeste Headlee reports, one scientist at a Detroit Aquarium has taken on the daunting task of trying to save a small, rare native mussel from disappearing in the state:

Transcript

In recent years, a great deal of attention has been focused on
zebra mussels. They’re not native to the Great Lakes region
and they’re pushing native mussels out of local lakes and streams.
As the Great Lakes Radio Consortium’s Celeste
Headlee reports, one scientist at a Detroit Aquarium has taken
on the daunting task of trying to save a small, rare native
mussel from disappearing in the state:


(ambient sound throughout – whenever Doug Sweet talks)


At a small pond near a highway, biologist Doug Sweet and his team put on waders and wet suits
and prepare to enter the sluggish brown water of Dawson’s Millpond Outlet in Pontiac. All
summer long, Sweet has made the trip from the Belle Isle Aquarium to this small pond looking
for a creature called the Purple Lilliput. These mussels, native to the Great Lakes area, have been
struggling to survive in Michigan, especially since the arrival of Zebra Mussels. Sweet’s made it
his mission to find out if there are any of these Lilliputs in Michigan still alive.


“I was very skeptical and didn’t know if we would find any live ones left because previous
surveyors were beginning to predict that they were gone. No one has found them for several
years.”


Zebra Mussels have been in the Clinton River for six or seven years. Zebras are very competitive
feeders. They strip the food out of the water before the native species can get it. Their presence
in domestic waters has had a catastrophic effect on many species. In fact, because of Zebra
Mussels and other factors like pollution, almost a third of North America’s freshwater mussels are
considered endangered or threatened with extinction.


Doug Sweet says Dawson’s Millpond Outlet is the last place to find Purple Lilliput mussels in
Michigan, and he’s afraid they will die out here, too.


“Looks like mostly all dead Purple Lilliputs. Yup.”


So far, Sweet and his team have found nine live Lilliputs. And that means there are probably
between 100 and 150 of them in that location. Though no one knows how long Purple Lilliputs
live, Sweet says other kinds of lilliput mussels live only about eight years.


“If the Purple Lilliputs are anything similar to that, then we’re running out of time because the
zebra mussels have been here for about six years now. And if they’re not reproducing, if there’s
too much competition, then we might be seeing the very last of the adult live Purple Lilliputs.”


When Sweet moved to the area, zebra mussels were starting to move into the Great Lakes region.
He’s a fish biologist, but he became so concerned about the plight of native mussels, he decided to
find out how they were faring. He contacted other biologists to ask what studies had been done.


Just a few years earlier, Oakland University Biology Professor Doug Hunter started looking for
the Purple Lilliput mussel in several lakes and streams around southeastern Michigan. During his
first few surveys, Hunter found more than 20 Lilliputs, but eventually he gave up hope and
assumed that the small creature was destined to die out in the state.


“Every year we went back after those first couple of fairly successful years, we got fewer and
fewer. The last time I went out there I think I got one or two. And I thought, “Well, this doesn’t
look good at all.” I wrote a report to the Wildlife Division in which I said, “I think this is an
imperiled population that may be on its way to local extinction.”


Doug Sweet picked up the research where Hunter left off and is now focusing his efforts on
trying to save the Purple Lilliput. Sweet says the number of lakes and streams in Michigan where
Zebra Mussels have taken hold is almost doubling every year. He says people should realize that
what they do with their boats affects an entire ecosystem.


“People are responsible for spreading the Zebra mussels all over the place. Everybody who has
Waverunners, boats, fishermen with bait buckets… they have to be conscientious that if they’re
fishing in one lake, you’ve got to clean your boat well before you transfer it to another lake or
stream.”


But even so, it may be too late for the Purple Lilliput. Sweet and his team snorkel through the
murky water, use glass bottom buckets, or dig their fingers into the black sediment, looking for
surviving buried mussels. Eventually, though, the hard work does pay off.


“A live one? Ooh, we think we have another live Purple Lilliput…
There we have it, another live one, ten, so this revises our population estimate right there, because
we found this in a quadrat excavation… This is excellent; it’s exciting. You know, who could say
that you’d get excited over a little critter like that.”


Later the same day, the team finds another live Purple Lilliput, a male, bringing the grand total up
to 11. Sweet hopes he can find a safe haven for the Lilliputs somewhere in southeastern
Michigan where the tiny population can slowly begin to recover. Doug Sweet is now finishing up
his fieldwork, and will soon begin studying his results for a report to the state.


For the Great Lakes Radio Consortium, I’m Celeste Headlee.