People are polluted and whales are too. Sperm whales throughout the Pacific carry evidence of exposure to polycyclic aromatic hydrocarbons (PAHs), which occur in oil, coal, and tar deposits, and are produced as byproducts of fuel burning. Some of them are carcinogenic, and high levels of PAHs are found in meat cooked at high temperatures (such as grilling or barbecuing), as well as in smoked fish.
Whales also reveal exposure to DDT, which is banned in most Western countries, but still used to kill mosquitoes throughout much of the world. During 1999–2001, researchers biopsied skin and blubber from 234 male and female sperm whales in five locations (NOTE: Subscribers can still listen to this show) across the Pacific Ocean and analyzed them for the expression of an enzyme that metabolizes certain aromatic hydrocarbons--the more CYP1A1 is expressed, the more likely the animal has been exposed to those compounds.
The whale tissues from were also were analyzed for DDT. Exposure to these substances was highest in whales from the Galapagos Islands, second highest in those from the Gulf of California, and lowest in those from waters farthest from the continents. Sperm whales may be important sentinels of ocean health: Since they are so long-lived (up to 70 years), their skin carries evidence of the history of ocean (and Earth) pollution.
Showing posts with label DDT. Show all posts
Showing posts with label DDT. Show all posts
Saturday, December 11, 2010
Whales are Polluted
People are polluted and whales are too. Sperm whales throughout the Pacific carry evidence of exposure to polycyclic aromatic hydrocarbons (PAHs), which occur in oil, coal, and tar deposits, and are produced as byproducts of fuel burning. Some of them are carcinogenic, and high levels of PAHs are found in meat cooked at high temperatures (such as grilling or barbecuing), as well as in smoked fish.
Whales also reveal exposure to DDT, which is banned in most Western countries, but still used to kill mosquitoes throughout much of the world. During 1999–2001, researchers biopsied skin and blubber from 234 male and female sperm whales in five locations (NOTE: Subscribers can still listen to this show) across the Pacific Ocean and analyzed them for the expression of an enzyme that metabolizes certain aromatic hydrocarbons--the more CYP1A1 is expressed, the more likely the animal has been exposed to those compounds.
The whale tissues from were also were analyzed for DDT. Exposure to these substances was highest in whales from the Galapagos Islands, second highest in those from the Gulf of California, and lowest in those from waters farthest from the continents. Sperm whales may be important sentinels of ocean health: Since they are so long-lived (up to 70 years), their skin carries evidence of the history of ocean (and Earth) pollution.
Whales also reveal exposure to DDT, which is banned in most Western countries, but still used to kill mosquitoes throughout much of the world. During 1999–2001, researchers biopsied skin and blubber from 234 male and female sperm whales in five locations (NOTE: Subscribers can still listen to this show) across the Pacific Ocean and analyzed them for the expression of an enzyme that metabolizes certain aromatic hydrocarbons--the more CYP1A1 is expressed, the more likely the animal has been exposed to those compounds.
The whale tissues from were also were analyzed for DDT. Exposure to these substances was highest in whales from the Galapagos Islands, second highest in those from the Gulf of California, and lowest in those from waters farthest from the continents. Sperm whales may be important sentinels of ocean health: Since they are so long-lived (up to 70 years), their skin carries evidence of the history of ocean (and Earth) pollution.
Wednesday, November 17, 2010
New Hurdle for California Condors May Be DDT From Years Ago
BIG SUR, Calif. — Four years ago, in a musky, leaf-lined cavity halfway up a 200-foot redwood tree here, two California condors made the region’s first known nesting attempt in more than a century.
Joe Burnett, a senior wildlife biologist with the Ventana Wildlife Society and the lead biologist for the Central California condor recovery program, who had been monitoring the condor pair, was delighted with this promising development in the continuing effort to save the nation’s largest bird from extinction. When this first breeding attempt proved unsuccessful, Mr. Burnett attributed it to the young birds’ inexperience. But when he climbed the giant tree to examine the abandoned nest, he was stunned at what he uncovered: the first evidence of a potentially significant new hurdle for the condor program.
“The eggshell fragments we found appeared abnormally thin,” Mr. Burnett said. “They were so thin that we had to run tests to confirm that it was a condor egg.” The fragments reminded him of the thin-shelled eggs from birds like brown pelicans and peregrine falcons, which had been devastated by DDT but are now on the rebound.
The discovery raised a disturbing question: could DDT — the deadly pesticide that has been banned in the United States since 1972 — produce condor reproductive problems nearly four decades later?
To find out, the Ventana Wildlife Society, which manages the Central California condor releases, has collected as many subsequent wild-laid eggs as possible. The handful of Big Sur breeding pairs lay a single egg once every other year. Ventana biologists brave the region’s trackless terrain to exchange a wild-laid egg with one from the zoo-based captive-breeding program. The unsuspecting condor pair then hatches the substitute egg as if it is their own.
In addition, Ventana biologists began to look for possible sources of DDT. Condors are carrion eaters, and in recent years the Big Sur birds have turned to what was historically a major food source: marine mammals. Mr. Burnett now suspects that animals like California sea lions may present a hidden danger to condors. Even today, sea lion blubber contains high levels of DDE, a toxic metabolic breakdown product of DDT.
Ventana biologists have been comparing the thickness of the eggshells recovered from the Big Sur birds with those produced by the Southern California condor flock that lives many miles from the coast. The Southern California birds do not feed on marine mammals, and their eggs are normal. Mr. Burnett says that preliminary results from Ventana’s study suggest that the Big Sur eggs are “substantially thinner” than those from the inland birds, and that early indicators point to DDT as the principal cause of the thinning.
Although no known source of DDT exists near Big Sur, a large DDT hot spot in the marine sediments off the Southern California coast called the Palos Verdes Shelf has attracted Mr. Burnett’s attention because it is near a breeding ground for California sea lions that eat the area’s fish. The sea lions then migrate up the coast. Hundreds of these sea lions use a rocky beach near Big Sur as a stopping point on the trip north. In recent years, this sea lion “haul-out” has become a favorite feeding spot for the Big Sur condors.
The DDT that pollutes the Palos Verdes Shelf originated half a century ago with the Montrose Chemical Corporation. At the time, Montrose was the world’s largest producer of what was once hailed as a “miracle pesticide.” According to Carmen White, the Environmental Protection Agency’s remedial project manager for the site, in the 1950s and ’60s Montrose discharged its untreated DDT waste directly into the Los Angeles County Sanitation District’s sewer system. An estimated 1,700 tons of DDT settled onto the seabed, where it continues to contaminate Pacific Coast waters. The E.P.A. has declared the area a Superfund site, and Ms. White is coordinating a plan to cover the most contaminated parts with a cap of sand and silt in 2012.
According to David Witting, a fishery biologist for the National Oceanic and Atmospheric Administration, diet determines how DDT affects various species. By 1971, when local officials forced Montrose to stop its discharge, Dr. Witting said brown pelicans and other surface-feeding birds had been hit hard. The pelicans were feeding on small, DDT-contaminated fish that picked up the pesticide as it drifted to the surface near the sewer outfall.
Once Montrose stopped discharging DDT into the sewer, that contamination source disappeared. “Brown pelicans rebounded fairly quickly after the dumping stopped,” Dr. Witting said.
James Haas, the environmental contaminants program coordinator for the Pacific Southwest region of the United States Fish and Wildlife Service, noted that other birds in the region that feed higher on the food chain, like bald eagles, continue to suffer from DDT-induced eggshell thinning.
Concerns about condors and DDT have prompted the Fish and Wildlife Service to initiate a new one-year project to study how marine mammals might be carrying Montrose DDT up the California coast. The main investigator, Myra Finkelstein at the University of California, Santa Cruz, is also leading a four-year study to investigate risk factors and management strategies to ensure the condor’s long-term sustainability. This includes not only DDT but also poisoning that comes from ingesting lead-bullet fragments found in hunter-shot game. Lead poisoning was a major factor in the bird’s brush with extinction and remains the primary danger today to released condors.
Because of the lead poisoning problem, in 2008 California enacted legislation requiring hunters in condor country to use ammunition without lead.
Despite lead poisoning and the emerging DDT challenge, Mr. Burnett remains optimistic. He is hopeful that taking steps like capping the DDT-contaminated Montrose marine sediments as well as continuing research will provide solutions. He notes that in 1982 the population of California condors had been reduced to 22 birds. Although problems remain, bringing back the condor has been a conservation success story. There are now 380 California condors in the world, with about half of these titans of the sky flying free in the Western United States.
“There is a light at the end of the tunnel,” Mr. Burnett said. “We just don’t know how far out that light is.”
By JOHN MOIR
http://www.nytimes.com/2010/11/16/science/16condors.html?_r=2
Joe Burnett, a senior wildlife biologist with the Ventana Wildlife Society and the lead biologist for the Central California condor recovery program, who had been monitoring the condor pair, was delighted with this promising development in the continuing effort to save the nation’s largest bird from extinction. When this first breeding attempt proved unsuccessful, Mr. Burnett attributed it to the young birds’ inexperience. But when he climbed the giant tree to examine the abandoned nest, he was stunned at what he uncovered: the first evidence of a potentially significant new hurdle for the condor program.
“The eggshell fragments we found appeared abnormally thin,” Mr. Burnett said. “They were so thin that we had to run tests to confirm that it was a condor egg.” The fragments reminded him of the thin-shelled eggs from birds like brown pelicans and peregrine falcons, which had been devastated by DDT but are now on the rebound.
The discovery raised a disturbing question: could DDT — the deadly pesticide that has been banned in the United States since 1972 — produce condor reproductive problems nearly four decades later?
To find out, the Ventana Wildlife Society, which manages the Central California condor releases, has collected as many subsequent wild-laid eggs as possible. The handful of Big Sur breeding pairs lay a single egg once every other year. Ventana biologists brave the region’s trackless terrain to exchange a wild-laid egg with one from the zoo-based captive-breeding program. The unsuspecting condor pair then hatches the substitute egg as if it is their own.
In addition, Ventana biologists began to look for possible sources of DDT. Condors are carrion eaters, and in recent years the Big Sur birds have turned to what was historically a major food source: marine mammals. Mr. Burnett now suspects that animals like California sea lions may present a hidden danger to condors. Even today, sea lion blubber contains high levels of DDE, a toxic metabolic breakdown product of DDT.
Ventana biologists have been comparing the thickness of the eggshells recovered from the Big Sur birds with those produced by the Southern California condor flock that lives many miles from the coast. The Southern California birds do not feed on marine mammals, and their eggs are normal. Mr. Burnett says that preliminary results from Ventana’s study suggest that the Big Sur eggs are “substantially thinner” than those from the inland birds, and that early indicators point to DDT as the principal cause of the thinning.
Although no known source of DDT exists near Big Sur, a large DDT hot spot in the marine sediments off the Southern California coast called the Palos Verdes Shelf has attracted Mr. Burnett’s attention because it is near a breeding ground for California sea lions that eat the area’s fish. The sea lions then migrate up the coast. Hundreds of these sea lions use a rocky beach near Big Sur as a stopping point on the trip north. In recent years, this sea lion “haul-out” has become a favorite feeding spot for the Big Sur condors.
The DDT that pollutes the Palos Verdes Shelf originated half a century ago with the Montrose Chemical Corporation. At the time, Montrose was the world’s largest producer of what was once hailed as a “miracle pesticide.” According to Carmen White, the Environmental Protection Agency’s remedial project manager for the site, in the 1950s and ’60s Montrose discharged its untreated DDT waste directly into the Los Angeles County Sanitation District’s sewer system. An estimated 1,700 tons of DDT settled onto the seabed, where it continues to contaminate Pacific Coast waters. The E.P.A. has declared the area a Superfund site, and Ms. White is coordinating a plan to cover the most contaminated parts with a cap of sand and silt in 2012.
According to David Witting, a fishery biologist for the National Oceanic and Atmospheric Administration, diet determines how DDT affects various species. By 1971, when local officials forced Montrose to stop its discharge, Dr. Witting said brown pelicans and other surface-feeding birds had been hit hard. The pelicans were feeding on small, DDT-contaminated fish that picked up the pesticide as it drifted to the surface near the sewer outfall.
Once Montrose stopped discharging DDT into the sewer, that contamination source disappeared. “Brown pelicans rebounded fairly quickly after the dumping stopped,” Dr. Witting said.
James Haas, the environmental contaminants program coordinator for the Pacific Southwest region of the United States Fish and Wildlife Service, noted that other birds in the region that feed higher on the food chain, like bald eagles, continue to suffer from DDT-induced eggshell thinning.
Concerns about condors and DDT have prompted the Fish and Wildlife Service to initiate a new one-year project to study how marine mammals might be carrying Montrose DDT up the California coast. The main investigator, Myra Finkelstein at the University of California, Santa Cruz, is also leading a four-year study to investigate risk factors and management strategies to ensure the condor’s long-term sustainability. This includes not only DDT but also poisoning that comes from ingesting lead-bullet fragments found in hunter-shot game. Lead poisoning was a major factor in the bird’s brush with extinction and remains the primary danger today to released condors.
Because of the lead poisoning problem, in 2008 California enacted legislation requiring hunters in condor country to use ammunition without lead.
Despite lead poisoning and the emerging DDT challenge, Mr. Burnett remains optimistic. He is hopeful that taking steps like capping the DDT-contaminated Montrose marine sediments as well as continuing research will provide solutions. He notes that in 1982 the population of California condors had been reduced to 22 birds. Although problems remain, bringing back the condor has been a conservation success story. There are now 380 California condors in the world, with about half of these titans of the sky flying free in the Western United States.
“There is a light at the end of the tunnel,” Mr. Burnett said. “We just don’t know how far out that light is.”
By JOHN MOIR
http://www.nytimes.com/2010/11/16/science/16condors.html?_r=2
New Hurdle for California Condors May Be DDT From Years Ago
BIG SUR, Calif. — Four years ago, in a musky, leaf-lined cavity halfway up a 200-foot redwood tree here, two California condors made the region’s first known nesting attempt in more than a century.
Joe Burnett, a senior wildlife biologist with the Ventana Wildlife Society and the lead biologist for the Central California condor recovery program, who had been monitoring the condor pair, was delighted with this promising development in the continuing effort to save the nation’s largest bird from extinction. When this first breeding attempt proved unsuccessful, Mr. Burnett attributed it to the young birds’ inexperience. But when he climbed the giant tree to examine the abandoned nest, he was stunned at what he uncovered: the first evidence of a potentially significant new hurdle for the condor program.
“The eggshell fragments we found appeared abnormally thin,” Mr. Burnett said. “They were so thin that we had to run tests to confirm that it was a condor egg.” The fragments reminded him of the thin-shelled eggs from birds like brown pelicans and peregrine falcons, which had been devastated by DDT but are now on the rebound.
The discovery raised a disturbing question: could DDT — the deadly pesticide that has been banned in the United States since 1972 — produce condor reproductive problems nearly four decades later?
To find out, the Ventana Wildlife Society, which manages the Central California condor releases, has collected as many subsequent wild-laid eggs as possible. The handful of Big Sur breeding pairs lay a single egg once every other year. Ventana biologists brave the region’s trackless terrain to exchange a wild-laid egg with one from the zoo-based captive-breeding program. The unsuspecting condor pair then hatches the substitute egg as if it is their own.
In addition, Ventana biologists began to look for possible sources of DDT. Condors are carrion eaters, and in recent years the Big Sur birds have turned to what was historically a major food source: marine mammals. Mr. Burnett now suspects that animals like California sea lions may present a hidden danger to condors. Even today, sea lion blubber contains high levels of DDE, a toxic metabolic breakdown product of DDT.
Ventana biologists have been comparing the thickness of the eggshells recovered from the Big Sur birds with those produced by the Southern California condor flock that lives many miles from the coast. The Southern California birds do not feed on marine mammals, and their eggs are normal. Mr. Burnett says that preliminary results from Ventana’s study suggest that the Big Sur eggs are “substantially thinner” than those from the inland birds, and that early indicators point to DDT as the principal cause of the thinning.
Although no known source of DDT exists near Big Sur, a large DDT hot spot in the marine sediments off the Southern California coast called the Palos Verdes Shelf has attracted Mr. Burnett’s attention because it is near a breeding ground for California sea lions that eat the area’s fish. The sea lions then migrate up the coast. Hundreds of these sea lions use a rocky beach near Big Sur as a stopping point on the trip north. In recent years, this sea lion “haul-out” has become a favorite feeding spot for the Big Sur condors.
The DDT that pollutes the Palos Verdes Shelf originated half a century ago with the Montrose Chemical Corporation. At the time, Montrose was the world’s largest producer of what was once hailed as a “miracle pesticide.” According to Carmen White, the Environmental Protection Agency’s remedial project manager for the site, in the 1950s and ’60s Montrose discharged its untreated DDT waste directly into the Los Angeles County Sanitation District’s sewer system. An estimated 1,700 tons of DDT settled onto the seabed, where it continues to contaminate Pacific Coast waters. The E.P.A. has declared the area a Superfund site, and Ms. White is coordinating a plan to cover the most contaminated parts with a cap of sand and silt in 2012.
According to David Witting, a fishery biologist for the National Oceanic and Atmospheric Administration, diet determines how DDT affects various species. By 1971, when local officials forced Montrose to stop its discharge, Dr. Witting said brown pelicans and other surface-feeding birds had been hit hard. The pelicans were feeding on small, DDT-contaminated fish that picked up the pesticide as it drifted to the surface near the sewer outfall.
Once Montrose stopped discharging DDT into the sewer, that contamination source disappeared. “Brown pelicans rebounded fairly quickly after the dumping stopped,” Dr. Witting said.
James Haas, the environmental contaminants program coordinator for the Pacific Southwest region of the United States Fish and Wildlife Service, noted that other birds in the region that feed higher on the food chain, like bald eagles, continue to suffer from DDT-induced eggshell thinning.
Concerns about condors and DDT have prompted the Fish and Wildlife Service to initiate a new one-year project to study how marine mammals might be carrying Montrose DDT up the California coast. The main investigator, Myra Finkelstein at the University of California, Santa Cruz, is also leading a four-year study to investigate risk factors and management strategies to ensure the condor’s long-term sustainability. This includes not only DDT but also poisoning that comes from ingesting lead-bullet fragments found in hunter-shot game. Lead poisoning was a major factor in the bird’s brush with extinction and remains the primary danger today to released condors.
Because of the lead poisoning problem, in 2008 California enacted legislation requiring hunters in condor country to use ammunition without lead.
Despite lead poisoning and the emerging DDT challenge, Mr. Burnett remains optimistic. He is hopeful that taking steps like capping the DDT-contaminated Montrose marine sediments as well as continuing research will provide solutions. He notes that in 1982 the population of California condors had been reduced to 22 birds. Although problems remain, bringing back the condor has been a conservation success story. There are now 380 California condors in the world, with about half of these titans of the sky flying free in the Western United States.
“There is a light at the end of the tunnel,” Mr. Burnett said. “We just don’t know how far out that light is.”
By JOHN MOIR
http://www.nytimes.com/2010/11/16/science/16condors.html?_r=2
Joe Burnett, a senior wildlife biologist with the Ventana Wildlife Society and the lead biologist for the Central California condor recovery program, who had been monitoring the condor pair, was delighted with this promising development in the continuing effort to save the nation’s largest bird from extinction. When this first breeding attempt proved unsuccessful, Mr. Burnett attributed it to the young birds’ inexperience. But when he climbed the giant tree to examine the abandoned nest, he was stunned at what he uncovered: the first evidence of a potentially significant new hurdle for the condor program.
“The eggshell fragments we found appeared abnormally thin,” Mr. Burnett said. “They were so thin that we had to run tests to confirm that it was a condor egg.” The fragments reminded him of the thin-shelled eggs from birds like brown pelicans and peregrine falcons, which had been devastated by DDT but are now on the rebound.
The discovery raised a disturbing question: could DDT — the deadly pesticide that has been banned in the United States since 1972 — produce condor reproductive problems nearly four decades later?
To find out, the Ventana Wildlife Society, which manages the Central California condor releases, has collected as many subsequent wild-laid eggs as possible. The handful of Big Sur breeding pairs lay a single egg once every other year. Ventana biologists brave the region’s trackless terrain to exchange a wild-laid egg with one from the zoo-based captive-breeding program. The unsuspecting condor pair then hatches the substitute egg as if it is their own.
In addition, Ventana biologists began to look for possible sources of DDT. Condors are carrion eaters, and in recent years the Big Sur birds have turned to what was historically a major food source: marine mammals. Mr. Burnett now suspects that animals like California sea lions may present a hidden danger to condors. Even today, sea lion blubber contains high levels of DDE, a toxic metabolic breakdown product of DDT.
Ventana biologists have been comparing the thickness of the eggshells recovered from the Big Sur birds with those produced by the Southern California condor flock that lives many miles from the coast. The Southern California birds do not feed on marine mammals, and their eggs are normal. Mr. Burnett says that preliminary results from Ventana’s study suggest that the Big Sur eggs are “substantially thinner” than those from the inland birds, and that early indicators point to DDT as the principal cause of the thinning.
Although no known source of DDT exists near Big Sur, a large DDT hot spot in the marine sediments off the Southern California coast called the Palos Verdes Shelf has attracted Mr. Burnett’s attention because it is near a breeding ground for California sea lions that eat the area’s fish. The sea lions then migrate up the coast. Hundreds of these sea lions use a rocky beach near Big Sur as a stopping point on the trip north. In recent years, this sea lion “haul-out” has become a favorite feeding spot for the Big Sur condors.
The DDT that pollutes the Palos Verdes Shelf originated half a century ago with the Montrose Chemical Corporation. At the time, Montrose was the world’s largest producer of what was once hailed as a “miracle pesticide.” According to Carmen White, the Environmental Protection Agency’s remedial project manager for the site, in the 1950s and ’60s Montrose discharged its untreated DDT waste directly into the Los Angeles County Sanitation District’s sewer system. An estimated 1,700 tons of DDT settled onto the seabed, where it continues to contaminate Pacific Coast waters. The E.P.A. has declared the area a Superfund site, and Ms. White is coordinating a plan to cover the most contaminated parts with a cap of sand and silt in 2012.
According to David Witting, a fishery biologist for the National Oceanic and Atmospheric Administration, diet determines how DDT affects various species. By 1971, when local officials forced Montrose to stop its discharge, Dr. Witting said brown pelicans and other surface-feeding birds had been hit hard. The pelicans were feeding on small, DDT-contaminated fish that picked up the pesticide as it drifted to the surface near the sewer outfall.
Once Montrose stopped discharging DDT into the sewer, that contamination source disappeared. “Brown pelicans rebounded fairly quickly after the dumping stopped,” Dr. Witting said.
James Haas, the environmental contaminants program coordinator for the Pacific Southwest region of the United States Fish and Wildlife Service, noted that other birds in the region that feed higher on the food chain, like bald eagles, continue to suffer from DDT-induced eggshell thinning.
Concerns about condors and DDT have prompted the Fish and Wildlife Service to initiate a new one-year project to study how marine mammals might be carrying Montrose DDT up the California coast. The main investigator, Myra Finkelstein at the University of California, Santa Cruz, is also leading a four-year study to investigate risk factors and management strategies to ensure the condor’s long-term sustainability. This includes not only DDT but also poisoning that comes from ingesting lead-bullet fragments found in hunter-shot game. Lead poisoning was a major factor in the bird’s brush with extinction and remains the primary danger today to released condors.
Because of the lead poisoning problem, in 2008 California enacted legislation requiring hunters in condor country to use ammunition without lead.
Despite lead poisoning and the emerging DDT challenge, Mr. Burnett remains optimistic. He is hopeful that taking steps like capping the DDT-contaminated Montrose marine sediments as well as continuing research will provide solutions. He notes that in 1982 the population of California condors had been reduced to 22 birds. Although problems remain, bringing back the condor has been a conservation success story. There are now 380 California condors in the world, with about half of these titans of the sky flying free in the Western United States.
“There is a light at the end of the tunnel,” Mr. Burnett said. “We just don’t know how far out that light is.”
By JOHN MOIR
http://www.nytimes.com/2010/11/16/science/16condors.html?_r=2
Thursday, May 27, 2010
An eagle expedition
Lilydale, Minn. — Every year, ecologists with climbing gear scramble to the tops of trees in Minnesota and Wisconsin to gather baby eagles from their nests. They're testing the eaglets for a variety of chemicals, including DDT, the one that nearly wiped out the eagle population decades ago.
By all accounts, the eagle population in this part of the world is doing very well. But the researchers are still finding plenty of chemicals in the blood of baby eagles. To find out more, we tagged along on one of those research expeditions.
National Park Service ecologist Bill Route and his crew are searching national park lands in Minnesota and Wisconsin, looking for eagle nests.
He points to a big old cottonwood tree, right at the edge of the Mississippi River in Lilydale Regional Park, across from Fort Snelling.
"It's that tree right there, kind of leaning over. It's hard to see, shrouded in all those leaves there," Route said.
Two budding biologists are using a cross-bow to shoot climbing ropes over a branch just above a nest.
"I think they have their first line fixed, so that means he's been successful at finding the right limb he wants to climb," Route says.
The climber hoists himself gracefully up the rope; then he disappears for awhile in the leaves.
The eagles in this popular park seem pretty calm about people. One soars in a wide circle above the nest, clucking mild disapproval at the intruders.
Spotting the eagle's nest"Some pairs squawk a lot and make a lot of noise, but they never dive-bomb onto the climbers," said Route. "Other parents will just go to a tree nearby and just sit there and sulk at us."
The climber found three chicks in the nest, and now each one is tucked into a bag hanging from his belt.
The climbers carry the captives to dry land, where a dozen or so birders and park officials have gathered to watch.
They weigh the birds while they're still in the bags. Then they set the youngsters down on small canvas tarps to band them.
They take measurements that suggest these creatures are roughly seven weeks old. They're about the size of a newborn human baby, and they're quite calm.
They pant a little in the heat, and glare at their handlers with steady dark eyes. Their feathers are a little scruffy, and one of them smells like dead fish.
"Now we're going to do the most important sample, the blood sample," said Route.
The researchers are looking for six types of contaminants -- lead and mercury, DDT and dioxin, and a couple of newer chemicals.
DDT, the pesticide that was banned in the U.S. in 1972, has been declining steadily over the last 25 years. But Bill Route says it's still found occasionally in eagles' blood. DDT is still used in many places, including South America.
"It may be the prey they're getting from South America -- maybe migratory birds that are coming up, and they have [DDT] in their systems, they're preying on them; they're getting it in their systems."
Route says the ban on lead pellets in shotguns has helped reduce lead poisoning, but eagles are still poisoned by lead from fishing tackle.
And then there are the new chemicals, like flame retardants. Route says in the first part of this decade, the flame retardant chemicals found in eagles' blood doubled. But recently Europe and some states have banned certain formulations, and those chemicals immediately began to decline.
"But there's 170 formulations of flame retardants, so it's pretty hard for us to keep up with," he said.
They're also checking for perfluorinated chemicals, like the stain-resistant and heat-resistant products once made by 3M. Traces of those products spiked in eagles five years ago, but they've been declining quickly since 3M stopped making them.
These new chemicals don't have the outright lethal effect that DDT had on eagle populations. But Bill Route says they may have subtle effects, especially because there's so many of them.
"So it could be these eagles or other animals -- or ourselves -- just aren't functioning quite the way we could be if it wasn't that we have a number of chemicals in our system affecting our neurology, affecting our endocrine system," said Route. "And I think there's lot of linkages that are tantalizing but not exactly smoking guns yet."
The population of eagles along the Mississippi River in the Twin Cities area is growing more than 10 percent each year. And that includes the three baby eagles returned to their nest after their adventure with the scientists.
By Stephanie Hemphill, Minnesota Public Radio
By all accounts, the eagle population in this part of the world is doing very well. But the researchers are still finding plenty of chemicals in the blood of baby eagles. To find out more, we tagged along on one of those research expeditions.
National Park Service ecologist Bill Route and his crew are searching national park lands in Minnesota and Wisconsin, looking for eagle nests.
He points to a big old cottonwood tree, right at the edge of the Mississippi River in Lilydale Regional Park, across from Fort Snelling.
"It's that tree right there, kind of leaning over. It's hard to see, shrouded in all those leaves there," Route said.
Two budding biologists are using a cross-bow to shoot climbing ropes over a branch just above a nest.
"I think they have their first line fixed, so that means he's been successful at finding the right limb he wants to climb," Route says.
The climber hoists himself gracefully up the rope; then he disappears for awhile in the leaves.
The eagles in this popular park seem pretty calm about people. One soars in a wide circle above the nest, clucking mild disapproval at the intruders.
Spotting the eagle's nest"Some pairs squawk a lot and make a lot of noise, but they never dive-bomb onto the climbers," said Route. "Other parents will just go to a tree nearby and just sit there and sulk at us."
The climber found three chicks in the nest, and now each one is tucked into a bag hanging from his belt.
The climbers carry the captives to dry land, where a dozen or so birders and park officials have gathered to watch.
They weigh the birds while they're still in the bags. Then they set the youngsters down on small canvas tarps to band them.
They take measurements that suggest these creatures are roughly seven weeks old. They're about the size of a newborn human baby, and they're quite calm.
They pant a little in the heat, and glare at their handlers with steady dark eyes. Their feathers are a little scruffy, and one of them smells like dead fish.
"Now we're going to do the most important sample, the blood sample," said Route.
The researchers are looking for six types of contaminants -- lead and mercury, DDT and dioxin, and a couple of newer chemicals.
DDT, the pesticide that was banned in the U.S. in 1972, has been declining steadily over the last 25 years. But Bill Route says it's still found occasionally in eagles' blood. DDT is still used in many places, including South America.
"It may be the prey they're getting from South America -- maybe migratory birds that are coming up, and they have [DDT] in their systems, they're preying on them; they're getting it in their systems."
Route says the ban on lead pellets in shotguns has helped reduce lead poisoning, but eagles are still poisoned by lead from fishing tackle.
And then there are the new chemicals, like flame retardants. Route says in the first part of this decade, the flame retardant chemicals found in eagles' blood doubled. But recently Europe and some states have banned certain formulations, and those chemicals immediately began to decline.
"But there's 170 formulations of flame retardants, so it's pretty hard for us to keep up with," he said.
They're also checking for perfluorinated chemicals, like the stain-resistant and heat-resistant products once made by 3M. Traces of those products spiked in eagles five years ago, but they've been declining quickly since 3M stopped making them.
These new chemicals don't have the outright lethal effect that DDT had on eagle populations. But Bill Route says they may have subtle effects, especially because there's so many of them.
"So it could be these eagles or other animals -- or ourselves -- just aren't functioning quite the way we could be if it wasn't that we have a number of chemicals in our system affecting our neurology, affecting our endocrine system," said Route. "And I think there's lot of linkages that are tantalizing but not exactly smoking guns yet."
The population of eagles along the Mississippi River in the Twin Cities area is growing more than 10 percent each year. And that includes the three baby eagles returned to their nest after their adventure with the scientists.
By Stephanie Hemphill, Minnesota Public Radio
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