Chemicals in the water are mixing up fish's gender (Photo courtesy of US Fish and Wildlife Service)
Scientists already know estrogen from things like ‘The Pill’ is getting into the water and causing reproductive problems for fish. Male fish are picking up female attributes. Some males are even growing eggs. Now a study finds there are other chemicals getting into water that might be messing with fish gender even more. Rebecca Williams reports:
Transcript
Scientists already know estrogen from things like ‘The Pill’ is getting into the water and causing reproductive problems for fish. Male fish are picking up female attributes. Some males are even growing eggs. Now a study finds there are other chemicals getting into water that might be messing with fish gender even more. Rebecca Williams reports:
This study’s found a group of chemicals that block the male hormone testosterone is getting into rivers.
Charles Tyler is the lead author of the paper in the journal Environmental Health Perspectives.
He says they don’t know exactly where these chemicals are coming from, but some medicines and pesticides can block testosterone. So, add that to the estrogen…
“And so it’s very likely they’re going to have interactive and additive effects, if you like, to induce a double whammy on the poor fish.”
Tyler says they don’t know if what’s happening in fish is also happening in people.
Human male fertility has been declining. But there might be other chemicals contributing to the problem.
And besides, there’s a difference. Fish can’t get away from these testosterone blocking chemicals or the estrogen in the water – they live and swim in them. So Tyler says they’re getting a much higher dose.
The timber rattlesnake has been wiped out in several states in the East and Northeast and is not doing well in the Midwest. (Photo by David Larson, Saint Louis Zoo)
Scientists are worried that
snakes living in sprawling areas could be affected.
In one region, researchers have implanted dozens of
snakes with radio transmitters. Julie Bierach reports, it’s part of an effort to prevent a
decline in the snake population and educate people
that they can live with them:
Transcript
Scientists are worried that
snakes living in sprawling areas could be affected.
In one region, researchers have implanted dozens of
snakes with radio transmitters. Julie Bierach reports, it’s part of an effort to prevent a
decline in the snake population and educate people
that they can live with them:
Wayne Drda loves snakes:
“I think they’re really neat animals.”
In this wilderness area, Drda and his team are studying the basic movement patterns and habitat use of
Timber rattlesnakes and Osage copperheads:
“A lot of the wildlife areas, are being surrounded by subdivisions and homes, and some are
completely surrounded. And so the animals tend to wander out of the wildlife areas into
backyards and many of them don’t survive that.”
The timber rattlesnake already has been wiped out in several states in the East and Northeast. And the
timber rattler is not doing very well in many states in the Midwest. Drda says snakes in general get a
bad rap. A lot of people don’t like them, so otherwise peaceful people can turn into what he calls “nature
vigilantes,” and they kill snakes on sight:
“Well, I guess the most common way is with a shovel. That’s always the common joke, the
shovel. (Laughs)”
Drda wants to prevent that from happening as often in his area. He’s the field manager for the Pitviper
Research Project at Washington University’s Tyson Research Center near the suburbs of St. Louis,
Missouri. He’s trying to help suburbanites understand that the Timber rattler is a much less aggressive
species of rattlesnakes.
Drda and his team have implanted 26 snakes with the radio transmitters, and track them daily using a
GPS system. Ryan Turnquist is one of the students tracking the snakes:
“And basically we use that to map it on an area photo and determine how far the snake moved,
where the snake moved, what kind of habitat they used, home range size.”
On this day, they’ve already tracked 8 snakes. And now, they’re on their way to find another. Turnquist
turns on the GPS system. And we begin to plow through the woods. Each snake has been named and assigned its own frequency on the transmitter.
The 4-foot-long male rattlesnake we’re tracking has been named Aron.
As we get closer, the signal gets stronger. Turnquist leads the way pointing the big steel antenna in
several directions. And then, we see him. Aron is lying in the sun, half coiled, near a log . He blends in
with the pile of leaves that surround him. He doesn’t rattle, but instead is still, hoping we don’t see him.
Wayne Drda has been studying snakes for 40 years. He knows what Aron is up to:
“This snake is probably in the most conspicuous situation you can find him in, except being out in
the road. He’s not going to give away his position by doing anything until he feels like he’s
really threatened. I mean he knows we’re here, but he’s probably not going to rattle.”
That happens a lot more often than you expect. Drda says they’ve already tracked some snakes that
have made their way to backyards of homes in the area. And the homeowners don’t even know it:
“We’ve been trackin’ this one snake, her name is Hortence. She’s basically been in somebody’s
backyard now for three weeks I guess.”
So far, the team has learned that the male timber rattlers have a larger home range. They breed in late
summer, or early fall, and they never breed with females from the same den where the males hibernate.
Jeff Ettling is with the St. Louis Zoo. He’s conducting a DNA analysis to determine which areas need to
be kept open so the snakes can travel back and forth without running into someone with a shovel:
“If we can get enough samples within a given area, we should be able to tell what the relatedness is
and which males are moving between dens. That’s what we’re hoping to find out. I mean, we have a good
idea by tracking them where they go. But which females are they breeding with from different
dens we really don’t have any idea right now.”
The research team is finding new scientific information about the snakes. But, they say the ultimate
goal is to explain to the people who live in the area that you can live with the rattlesnakes. They don’t
have to kill them. Drda wants people who find a timber rattler in their backyard to call a herpetologist,
instead of running for the shovel.
New research indicates that polluted run-off might be causing reproduction problems for ocean fish by making more males than females. The GLRC’s Lester Graham reports:
Transcript
New research indicates that polluted run-off might be causing
reproduction problems for ocean fish by making more males than
females. The GLRC’s Lester Graham reports:
Rivers dump much of the pollution and agricultural runoff they carry into
the oceans. That often causes a dead zone… an area where the oxygen is
depleted. New research being published in the journal, Environmental
Science & Technology, indicates low levels of oxygen can cause sex
changes in embryonic fish. That’s leading to an overabundance of
males.
The lead researcher, Rudolf Wu at the City University of Hong Kong
finds since there are a lot more males… it’s less likely the males fish will
find females to reproduce. That means there might not be enough new
fish to maintain sustainable populations.
Some dead zones develop naturally, but scientific evidence suggests that
often dead zones are caused by fertilizers used on farmland crops
running off into rivers and finally into the oceans.
New testing has found some of the most common cosmetic and beauty products contain chemicals linked to birth defects. The Great Lakes Radio Consortium’s Lester Graham has more:
Transcript
New testing found some of the most common cosmetic and beauty products contain chemicals linked to birth defects. The Great Lakes Radio Consortium’s Lester Graham has more:
Three environmental groups hired a major national laboratory to test 72 name-brand off-the-shelf beauty products for chemicals called phthalates. Of the 72, 52 of them contained phthalates. Jane Houlihan is with Environmental Working Group and one of the authors of the report on the testing…
“What this means for women is as they use cosmetics, they’re likely getting exposed to phthalates and it’s a potential concern for a baby in the womb, a male baby, since many of these chemicals are really strongly linked in animal studies to birth defects of the male
reproductive system.”
There is not yet a direct link between phthalates in cosmetics and reproductive birth defects in humans. The environmental groups found products on the market that don’t use the chemicals. So, they’re calling for elimination of the use of phthalates in beauty products.
For the Great Lakes Radio Consortium, this is Lester Graham.
Are sperm counts on the decline? Federal researchers hope they can find out. The government is about to launch the largest project ever to find out if something’s gone wrong with male reproductive health. The study will follow a recent report from the California Department of Health Services that startled the scientific community. The study found a significant drop in sperm count and raised questions about whether environmental chemicals are the culprit. The Great Lakes Radio Consortium’s Julie Edelson Halpert has more:
Chemicals in the water are mixing up fish's gender (Photo courtesy of US Fish and Wildlife Service)
