Mystery of Bizarre Bird Deformities May Be Solved
For two decades, bird experts in Alaska have been puzzled by the twisted beaks of chickadees and other backyard birds. Now they worry the disorder is spreading.
ANCHORAGE, ALASKA Scientists working with sophisticated DNA sequencing technology think they may have solved a 20-year-old mystery of what has caused thousands of Alaska’s wild birds to be afflicted with deformed, twisted beaks.
The findings suggest that a newly discovered virus – poecivirus – may be the culprit behind the bizarre beak deformities in chickadees, crows, and other birds. Birds with the defective beaks, which sometimes cross like warped chopsticks, starve to death or die early.
The virus may endanger the health of bird populations around the world, particularly sensitive endangered species, says Colleen Handel, a research wildlife biologist with the U.S. Geological Survey in Anchorage.
Already the deformities seem to be spreading: Bird watchers in the Pacific Northwest, Great Britain, India, and South America have been reporting growing numbers of birds with deformed beaks, including 24 species in North America and 36 in the United Kingdom.
If the virus is causing these twisted beaks – a condition called avian keratin disorder – it raises many questions. Why is the pathogen emerging now? Why is it spreading? Is it newly evolved? Is there something in the environment that is fueling it?
Biologists at the USGS in Anchorage first observed these deformities among black-capped chickadees in the late 1990s. Since then, the researchers, now assisted by California molecular scientists, have been trying to find the cause. They’re not quite there yet. The scientists cautiously say in their new study that they’ve detected “a strong, statistically significant correlation between poecivirus infection and avian keratin disorder and black-capped chickadees.”
Screening of 19 chickadees with twisted beaks revealed that 100 percent were infected with the virus, while only two of nine chickadees without the deformity had the virus. Why those two birds were infected but did not have twisted beaks is unknown, but it’s possible that they had only recently been infected so the abnormal beak growth was not yet detectable. Two northwestern crows and two red-breasted nuthatches with twisted beaks also had the virus.
“It’s really exciting that we found this new virus, and it looks like it really could be the cause. But we haven’t yet proven that it is the cause of the disease,” says University of California, San Francisco, disease ecologist Maxine Zylberberg. She discovered the virus and its relationship with avian keratin disorder using next-generation genome sequencing while working with a team at the California Academy of Sciences.
To prove the new virus is causing avian keratin disorder—rather than just coincidentally found in the deformed birds—the researchers will test more samples and more species. The USGS plans to design experiments exposing healthy birds to the virus to see if they develop beak deformities.
No evidence of other causes, such as chemical pollutants and diet deficiencies, has emerged.
Normally beak defects are detected in less than 1 percent of wild birds. But between 1999 and 2008, Alaska researchers found twisted beaks in 6.5 percent of more than 2,000 black-capped chickadees captured around Anchorage and the Matanuska Valley. For northwestern crows at six Alaska sites in 2007 and 2008, the deformities were found in 17 percent, the “highest rate of gross deformity every documented in a wild bird population,” according to the U.S. Geological Survey.
In most cases, the upper beak extends over the lower beak, sometimes growing twice as long, curving down and interfering with eating, preening, and nest building.
Chickadees, the size of a small avocado, stay year-round in Alaska, so they need all of their life skills to survive harsh winters. The handicapped birds can starve or freeze when they can't groom their feathers.
Suspecting that a virus is the cause opens up new worries of a pandemic among birds, and of how to mount an effective response to outbreaks. There is no known treatment.
“We want to know the mode of transmission. The birds most commonly with beak deformities seem to be social animals. Chickadees come to bird feeders. Crows congregate along coastlines. It’s a lot like human sanitation. Wash your hands! We have to let people know to keep bird feeders clean,” says Handel. In 1998 Handel was the first to recognize, collect data, and finally, with colleague Caroline Van Hemert, name the disorder.
X-rays of the deformities showed something odd: The accelerated growth occurred not in the bone beak but in the keratin, the thick fibrous protein layer that covers the bone. That layer, called the rhamphotheca, is adapted for food foraging, and contains sensory organs that detect prey.
Now that the new virus has been identified, birds around the world can be tested for it. A side benefit of the sequencing research has been the development of an easy, inexpensive swab test for the virus that eliminates the necessity of killing the birds.
In the fall the Falcon Research Group in Bow, Wash., founded by raptor biologist Bud Anderson, will collect swabs from red-tailed hawks suffering from elongated, mangled beaks. Anderson noticed deformed red-tails on the Samish Flats in Skagit County, Washington, in the late 1990s, at about the same time Handel started collecting sightings in south-central Alaska.
“We want people to look for abnormal clusters of birds with beak deformities,” says Handel, “just like the Centers for Disease Control and Prevention looks for abnormal clusters of disease in humans.”
At her own bird feeders, Handel, who has lived in Alaska for 40 years, echoed sentiments of other fans of the black-and-white chickadees.
“We feel that all of these birds are part of our families," she says. "They come to our back yards. We see them. We feed them. We consider them our birds. It’s a gut-wrenching experience when we see these small birds with gross beak deformities. They’re handicapped in everything they do. We want to remedy the situation."
Source : National Geographic
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Vanishing Act: Why Insects Are Declining and Why It Matters
Insect populations are declining dramatically in many parts of the world, recent studies show. Researchers say various factors, from monoculture farming to habitat loss, are to blame for the plight of insects, which are essential to agriculture and ecosystems.
Every spring since 1989, entomologists have set up tents in the meadows and woodlands of the Orbroicher Bruch nature reserve and 87 other areas in the western German state of North Rhine-Westphalia. The tents act as insect traps and enable the scientists to calculate how many bugs live in an area over a full summer period. Recently, researchers presented the results of their work to parliamentarians from the German Bundestag, and the findings were alarming: The average biomass of insects caught between May and October has steadily decreased from 1.6 kilograms (3.5 pounds) per trap in 1989 to just 300 grams (10.6 ounces) in 2014.
"The decline is dramatic and depressing and it affects all kinds of insects, including butterflies, wild bees, and hoverflies," says Martin Sorg, an entomologist from the Krefeld Entomological Association involved in running the monitoring project.
Another recent study has added to this concern. Scientists from the Technical University of Munich and the Senckenberg Natural History Museum in Frankfurt have determined that in a nature reserve near the Bavarian city of Regensburg, the number of recorded butterfly and Burnet moth species has declined from 117 in 1840 to 71 in 2013. "Our study reveals, through one detailed example, that even official protection status can't really prevent dramatic species loss," says Thomas Schmitt, director of the Senckenberg Entomological Institute.
Declines in insect populations are hardly limited to Germany. A 2014 studyin Science documented a steep drop in insect and invertebrate populations worldwide. By combining data from the few comprehensive studies that exist, lead author Rodolfo Dirzo, an ecologist at Stanford University, developed a global index for invertebrate abundance that showed a 45 percent decline over the last four decades. Dirzo points out that out of 3,623 terrestrial invertebrate species on the International Union for Conservation of Nature [IUCN] Red List, 42 percent are classified as threatened with extinction.
"Although invertebrates are the least well-evaluated faunal groups within the IUCN database, the available information suggests a dire situation in many parts of the world," says Dirzo.
Scientists have described 1 million species of insects so far, and estimate at least 4 million are still unrecorded.
A major survey of threats to insect life by the Zoological Society of London, published in 2012, concluded that many insect populations worldwide are in severe decline, limiting food supplies for larger animals and affecting ecosystem services like pollination. In Europe and the United States, researchers have documented declines in wild and managed bee populations of 30 to 40 percent and more due to so-called colony collapse disorder. Other insect species, such as the monarch butterfly, also have experienced sharp declines.
Jürgen Deckert, insect custodian at the Berlin Natural History Museum, says he is worried that "the decline in insect populations is gradual and that there's a risk we will only really take notice once it is too late."
Scientists cite many factors in the fall-off of the world’s insect populations, but chief among them are the ubiquitous use of pesticides, the spread of monoculture crops such as corn and soybeans, urbanization, and habitat destruction.
A significant drop in insect populations could have far-reaching consequences for the natural world and for humans, who depend on bees and other invertebrates to pollinate crops. A study by Canadian biologists, published in 2010, suggests that North American bird species that depend on aerial insects for feeding themselves and their offspring have suffered much more pronounced declines in recent years than other perching birds that largely feed on seeds. The analysis is based on data from the North American Breeding Bird Survey. The decline in birds that feed on flying insects appears to be significantly stronger than in perching birds in general, according to co-author Silke Nebel, now with the Upper Thames River Conservation Authority in Ontario.
Scientists have described 1 million species of insects so far, and estimate that at least 4 million species worldwide are still unrecorded. For people living in areas with ample wilderness and a plethora of biting mosquitoes that carry malaria and other diseases, a decline in insect populations might seem like an outlandish concern. But in areas with intensive industrialized agriculture, the drop in insect populations is worrying.
Dirzo, Science (2014)
According to global monitoring data for 452 species, there has been a 45 percent decline in invertebrate populations over the past 40 years.
So far, only the decline of honeybee populations has received widespread public attention, in large measure because of their vital role in pollinating food crops. The rest of the insect world has been widely ignored. Often insects are perceived as a nuisance or merely as potential pests. But while certain insect species, such as the European corn borer, undoubtedly cause enormous damage in agriculture, scientists emphasize the ecological importance of diverse and abundant insect populations.
In Britain, an alliance of 22 publicly funded environmental research institutions has compiled a list of ecosystem services delivered by insects: "Over three-quarters of wild flowering plant species in temperate regions need pollination by animals like insects to develop their fruits and seeds fully," the group says. The researchers emphasize that pollinating insects improve or stabilize the yield of three-quarters of all crop types globally — one-third of global crop production by volume.
Germany's Federal Agency for Nature Conservation stresses that insects are a major food source not only for birds, but also for bats and amphibians. Another important role is played by specialized insects such as long-legged flies, dance flies, dagger flies, and balloon flies, which prey upon pest species.
Deckert of the Berlin Natural History Museum has compiled a long list of factors that contribute to insect loss. One factor — the widespread overuse of nitrogen fertilizer — enables a few plant species such as corn to thrive, while the majority of plant species that live in symbiotic relationships with highly specialized insects dwindle.
In large parts of Europe, the U.S., and South America, monocultures cover vast areas of the landscape, creating "biological deserts" devoid of hedges or ponds where insects could reproduce. Attempts to make the European Union’s agricultural system more environmentally friendly have largely failed in recent years.
Of particular concern is the widespread use of pesticides and their impact on non-target species. Many conservationists view a special class of pesticides called neonicotinoids — used over many years in Europe until a partial ban in 2013 — as the prime suspect for insect losses. The European Food Safety Authority is currently reviewing the ban. Other pesticides are widely used worldwide.
“There are many indications that what we see is the result of a widespread poisoning of our landscape,” says Leif Miller, director general of the German chapter of BirdLife International.
A recent increase in insect monitoring efforts stems from the rise of ‘citizen science’ projects.
Yet even environmental campaigners like Miller admit that the root causes and the full dimension of the problem aren't yet fully understood. “I suspect it is a multiplicity of factors, most likely with habitat destruction, deforestation, fragmentation, urbanization, and agricultural conversion being the leading factors,” says Stanford ecologist Dirzo.
To understand the problem better, scientists are now urging increased monitoring efforts. Given the importance of insects for agriculture and biodiversity, one might assume that in rich countries like Germany, insect populations are being closely studied. But this is not the case. "For the 30,000 insect species in Central Europe, only a few specialists exist, and they often carry out monitoring as a side job," says Deckert.
In-depth monitoring only exists in select regions or for specific species. In Germany, only 37 insect species are closely tracked, according to the Federal Agency for Nature Conservation — a mere 0.12 percent of all species.
A recent increase of monitoring efforts stems from the rise of “citizen science” projects, where lay people with an interest in the outdoors are trained to collect data. One such project is a butterfly monitoring program run in association with Butterfly Conservation Europe. Each year, thousands of volunteers comb through the landscape to compile lists of butterflies they encounter.
Globally, however, comprehensive data for long-term comparisons does not exist. “Unfortunately, information on invertebrates in general, including insects, is very limited, restricted to a few groups and a few localities,” says Dirzo.
That's why Wolfgang Wägele, director of the Zoological Research Museum in Bonn, is now calling for a large-scale monitoring effort. Wägele and his team have developed a plan for an automated biodiversity surveillance system, which would photograph, videotape, capture, or audio-record animal and insect species and perform automatic analysis of species richness and abundance. "We have weather stations all over the country, so let's add a dense network of biodiversity stations so we can measure automatically how much life there is in our landscapes," says Wägele
He plans to use automated identification techniques, either through artificial intelligence image analysis or genetic fingerprinting, or by matching acoustic recordings with data collections. For example, if grasshoppers make their characteristic sounds near the station, the species will be identified and the number of insects recorded. If an aerial insect lands in a trap, its genome will be compared to a database.
For larger insects like butterflies, scientists can use photographic image analysis to come up with a precise identification.
“Such a system could collect, identify, and record species data 24/7 and gather data we desperately need to assess the decline of insects,” says Wägele.
Recently, a pilot installation for the system already discovered a new mosquito species, now called Ctenosciara alexanderkoenigi, in the museum’s park. The nationwide monitoring scheme is currently under funding review by Germany’s Federal Research Ministry.
Many biologists support more intensive monitoring efforts, but point out that in Europe there’s already enough knowledge about insect decline to start addressing root causes — mainly in agricultural policy. According to conservation organizations like BirdLife International, new attempts are necessary to "green" EU agricultural policy in a substantial way by creating incentives for enriching landscapes with hedgerows, reducing fertilizer and pesticide use, and better rewarding organic agriculture. Previous efforts to do so have largely failed.
“The key question is whether governments view biodiversity as an add-on or as something that is of existential importance for our future,” says Deckert.
Source : Yale360
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Scientists say that ‘nature,’ untouched by humans, is now almost entirely gone
Implicit in much, if not all, modern environmental sentiment is the idea that the natural world has been despoiled by humans — and if we could just leave it alone, things would get better.
But new research suggests that in reality, humans have been altering the natural world for millennia, long before the 15th century dawn of the Age of Discovery, when European societies mastered long-distance ocean navigation and began to spread their cultures, animals and diseases to new continents.
The result of these changes, accumulating over time, has been “the creation of extensively altered, highly cosmopolitan species assemblages on all landmasses,” the authors write in a study published Monday in the Proceedings of the National Academy of Sciences. “‘Pristine’ landscapes simply do not exist and, in most cases, have not existed for millennia.”
Conservationists often have the goal of “let’s get back to that natural environment with humans out of the picture,” said Melinda Zeder, one of the study’s authors and an anthropologist with the National Museum of Natural History at the Smithsonian Institution. “And that’s a chimera; that’s a false hope. It’s too late for that.”
“People have been modifying their environments for tens of thousands of years,” added Jon Erlandson, an archeologist, professor and director of the University of Oregon Museum of Natural and Cultural History, and another of the study’s co-authors. “Humans have literally impacted everything from mammoths to microbes. Most people have no idea how heavily we’ve altered things — and for how long.”
Erlandson said that it’s tempting to think that people thousands of years ago weren’t smart or technologically sophisticated, but that’s not necessarily the case.
“The story we’re putting together is that for many, many thousands of years, people have basically been like us,” he said. “They were ingenious in developing new technologies and modifying their local environments.”
But as humans have evolved and proliferated, that innovation — and the subsequent effect on the environment — has sped up.
“When anatomically modern humans appear about 200,000 years ago, there’s what I think is a continual acceleration of technological change,” he said.
As humans spread across the globe, he said, they invented things such as the bow and arrow, fishing spears, ceramics and agricultural advancements that made life easier but also impacted the environment.
Based on a large synthesis of archaeological, fossil and ancient DNA data, the researchers conclude that humans started dramatically changing the world’s natural ecosystems well before 12,000 years ago. By that time, the species had emerged from Africa and colonized much of the globe. And already, mega-scale human impacts on the landscape and the creatures living on it included changing the regime of burning on lands from Africa to New Guinea, as early humans exploited fire for purposes of agriculture and hunting.
And that’s only one type of change already afoot. By between 20,000 and 23,000 years ago, the study notes, one of the earliest human introductions of a species from one region to another had already occurred — when the northern common cuscus, a marsupial, was spread from New Guinea to Indonesia and other locations.
Also between 50,000 and 10,000 years ago, the researchers report, humans drove at least some extinctions of large megafauna in Australia, Tasmania and other locations. Whether our ancient ancestors are responsible for over-hunting and killing off these great beasts — and causing ecological upheaval through their extinction — has often been a contentious topic, but the paper comes down behind the idea that at least some of this is probably due to human incursions. “A lot of the megafaunic extinctions are probably not human related, but others are,” Zeder said.
And still, this was only the beginning — merely what we could do to the Earth as hunter-gatherers. But as humanity entered the Holocene period, known for its mild climate, some 11,700 years ago, we learned to build societies dependent on agriculture — a development that only increased our footprint on the landscape.
At this point, the study explains, handpicked farm and human-friendly animal and plant species were favored, cultivated and spread. Meanwhile, the clearing of forested land for agriculture and the mass planting of certain types of staple foods, such as rice, actually changed the greenhouse gas composition of the atmosphere between 4,000 and 1,000 years ago (although nothing like what happened after the industrial revolution — but wait, we’re getting there).
Prime among humans’ favored animals were ruminants — cows, sheep, goats. Their original domestication, the study says, occurred near the start of the Holocene in the Near East, but soon they’d been transported all over the place. Ditto for chickens (which originated in East Asia).
Farming had sweeping implications for nature across large stretches of land. But perhaps the most special havoc was wreaked on evolutionarily unique island ecosystems once seafaring societies, such as the Polynesians, found ways to reach them. They didn’t just bring along animals that would aid in agriculture — they accidentally also brought along pests.
“Pacific rats and black rats (Rattus rattus) were widely introduced to global islands as accidental stowaways on boats beginning in the Middle Holocene, as were housemice (Musmusculus), various commensal shrews and lizards, and numerous insects and land snails,” the authors note.
And the pace just increased from there, as human societies and their transportation and trade systems became more and more advanced. The gist is that while we are radically impacting nature and landscapes in the present, this is just a stepwise development upon what we have been doing for thousands of years.
“Today isn’t a radical right turn, and that all of a sudden we’re having these impacts, which is sometimes the attitude, but it is part of the progression of this continuing ramping up of scope and impact that today is taken to ridiculous levels,” Zeder said.
“The amazing array of cross-disciplinary work in archaeology and paleoecology described in this wide-ranging paper is revealing the surprisingly large extent of early human transformations of this planet,” said William Ruddiman, a University of Virginia researcher who studies paleoclimatology but was not involved in the work, in commenting on the paper. “Yet very few scientists in other disciplines are aware of this emerging story, especially fields that emphasize physics and chemistry. This emerging evidence confirms large early agricultural effects on landscapes and on greenhouse-gas emissions.”
Granted, human greenhouse gas emissions from the burning of fossil fuels still only show up much later in the story. While deforestation and agriculture changed the greenhouse gas composition of the atmosphere beginning thousands of years ago, it’s still just a murmur compared to the sharp spike in atmospheric carbon dioxide concentrations from 280 parts per million prior to the Industrial Revolution to over 400 parts per million today.
To show just how extensive the modern impact has become, consider that now, even the one continent where nobody lives except for occasional teams of scientists — Antarctica — also shows a clear human impact. Lead pollution, carried by the air, reached the seventh continent before its first explorer, Roald Amundsen, did in 1911, recent research suggests.
The new research feeds heavily into a very big debate right now in the sciences and beyond. The question is whether we are in a new geologic epoch, the “Anthropocene,” characterized by widespread and geologically detectable human impact on the planet — and if so, when that period started.
Many researchers believe the alteration of the atmosphere through major infusions of industrial greenhouse gases marks the start of the Anthropocene, placing that era’s beginning within the last few hundred years. But the current researchers disagree. “The assertion that preindustrial societies had only local and transitory environmental impacts is mistaken and reflects lack of familiarity with a growing body of archaeological data,” they write.
Even more provocatively, the researchers argue not only that humans have been pervasively changing nature for about as long as there have been humans, but that it isn’t always bad. In many cases, ancient humans also hit on innovative and sustainable ways of managing soils and landscapes, they say. And in any case, human management of ecosystems is inevitable.
“These findings suggest that we need to move away from a conservation paradigm of protecting the earth from change to a design paradigm of positively and proactively shaping the types of changes that are taking place,” said Oxford’s Nicole Boivin, the study’s lead author. “This sounds scary, and it sounds very self-serving. But the reality is that there are 7 billion people living on an already heavily altered planet. It is a pipe dream to think that we can go back to some sort of pristine past.”
Indeed, Erlandson said that while human impacts have only accelerated, the research has given him an optimism that humans will find a way to deal with climate change, in part because societies have risen to almost every quandary that has come before.
“There’s a story of ingenuity built into this deeper time perspective,” he said. “Humans have over and over again met challenges in different parts of the world, and they’ve found ways to meet those challenges. Every generation has its challenges. But we have found ways to solve them.”
“No matter how bad we screw things up,” he added, “if we can find the collective will, we can overcome them.”
Source : Washington Post
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Saving Amphibians: The Quest To Protect Threatened Species
The decline of the world’s amphibians continues, with causes ranging from fungal diseases to warmer and drier climates. Now, researchers are looking at ways to intervene with triage measures that could help save the most vulnerable populations.
In the mountains of western Washington, Oregon, and northern California, the Cascades frog lives most of its life cycle buried beneath deep, wet snow. When summer rolls around, though, it emerges into alpine wetlands to mate and emit its signature call, which sounds a lot like a person chuckling.
The habitat of these chuckling frogs, though, and other amphibians, is being squeezed by what researchers call a climate vise. Receding glaciers here left the mountains pockmarked with thousands of lakes and ponds, some the size of a car and some acres in size. Originally fishless, 19th and 20th century managers introduced fish to 95 percent of the lakes, carrying them in on horseback or dropping them from airplanes.
It seemed like a good idea at the time. But the invasive trout have hammered the frog and salamander populations: They not only gobble up the tadpoles and juveniles, they limit the production of invertebrates, essential amphibian food. Amphibians can often escape the fish-filled ponds for nearby fishless wetlands, but as temperatures warm and snowpack shrinks, these survival outlets are waning and disappearing.
The solution? Fishing with a vengeance. After modeling which wetlands are most likely to disappear in the coming years, researchers and managers are going into the lakes with gill nets and pisicides — fish poison — to take out the troublesome trout. It seems to be working. In Washington's North Cascades National Park, fish removal in nine lakes saw the return of long-toed salamanders and tailed frogs, though the Cascades frog hasn't bounced back as a result of these measures yet.
The decline of the world's amphibians is ramping up — a third of amphibian species are threatened with extinction worldwide, with 160 species having already disappeared.
There is no smoking gun in the declines – instead scientists call it a "smoking arsenal."
And while the causes of the decline — from fungal diseases to a warmer and drier world — are complex and the dynamics poorly understood, the kind of intervention taking place in the Cascade Mountains is something that scientists increasingly believe they have to do.
In 2013, a paper in PLOS ONE shocked amphibian researchers and conservationists with its finding that amphibians across North America were rapidly disappearing at a rate of more than 3 percent each year. "It's a pretty fast decline," said Michael Adams, a biologist with the U.S. Geological Survey’s Amphibian Research and Monitoring Initiative, one of the study’s authors. "Even species that the IUCN [International Union for Conservation of Nature] said were doing OK were disappearing."
In a paper that will be published later this month in Scientific Reports – Nature, researchers found similar alarming declines at dozens of national parks, wildlife refuges, and other sites throughout North America. Another significant finding in the same paper is that there is no smoking gun in the declines — instead scientists call it a "smoking arsenal."
"It's different things in different places in different years," says Evan Grant, a wildlife biologist with the USGS and one of the authors of the paper. The four main factors are climate warming and drought, disease, declining habitat, and pesticides. "We found that population trends are local — they are responding to local factors so that a coordinated global solution to any one of these threats is unlikely to solve the decline. It's really working locally trying to figure out what's most important in a location and come up with novel solutions."
Biologists are seeing bizarre scenes, "extreme drying events," said Maureen Ryan, an ecologist and conservation biologist at Conservation Science Partners, who led much of the work with the Cascades frog. One biologist saw the results of a mortality event in Olympic National Park with adult Cascades frogs. "In most summers they stay moist, but the whole landscape was so dry [the biologist] was finding encrusted, dried-up adults, which is really weird," said Ryan. "They are only 100 or 150 meters from a pond, but basically it's so hot and dry they didn't move and their habitat dried up."
An urgent search is on around the world for adaptations to stem the precipitous decline. Some scientists have shifted their primary focus from research to conservation. "Where we are now is we know they are happening, we know it’s complex, we know we don't have a full grip on all of the drivers," said Ryan, "but we are going to do what we can to shift the pace of declines."
Efforts to slow the decline are hamstrung by a lack of good data on the maddeningly complex ecosystems where amphibians live and problems they face. Wetlands of all types — fens, bogs, lakes, and potholes, among others — are some of the most biodiversity-rich environments on earth. Half have disappeared in the last 150 years, and climate change and human development are altering those that remain. But knowing where to act depends largely on modeling what will happen in coming decades.
Much of the focus then is on finding better tools. "People have always said that wetlands are too complicated to model," said Ryan. "We're trying to change that." Ryan and her colleagues are using a combination of approaches to better understand and map wetlands in the Pacific Northwest, their hydrology, and what is happening to them. The researchers plan to export those techniques to other parts of the world.
Meghan Halabisky, a PhD student at the University of Washington, uses a combination of new and old imaging techniques that give a much more accurate picture of the landscape than past approaches. The new data, she says, is a revelation. "Compared to other ecosystem types, wetlands are very poorly mapped," she said. "The national wetland inventory, the best map that we have, underestimated the wetlands by 50 percent of what I found. A lot of the habitat wasn't picked up. "
For imaging at Mount Rainier National Park, the most helpful technology was LIDAR, which is an aerial laser scan of the topography. "It creates a 3D model of the landscape, and allows me to find water that might be obstructed by steep topography or trees,” Halabisky said. “With aerial imagery, it's hard to see wetlands because there are too many shadows. But LIDAR is a way to get past the shadows that obscure the wetlands."
Better data means creating better models about future scenarios. That, in turn, allows biologists to decide which habitat is most important and most at risk, and then to design conservation strategies.
Mountain lakes in national parks or a national forest are fairly simple systems without a lot of human impact, which makes them fairly straightforward to study and manage. Outside of reserves, though, where the landscape and hydrology have been greatly altered, issues are often far more complicated.
The same researchers are now creating a similar model of the eastern Columbia Plateau, the dry region of eastern Washington and Oregon. There are many more sunny days here than on the Pacific Coast, which means they can use Landsat imagery that goes back to 1984. Because Landsat provides a visual record of the land for more than 30 years, it gives the history of these features, and much more of a story about their trajectory and trends.
For instance, in areas that were wetlands in 1984 and have been drying out over the last 30 years, you can look at the surrounding activity and tell what might be causing it. "What is the driver?" said Halabisky. "Is groundwater being pumped out? Is it a climate variable? Is it the surrounding land use?" An irrigation pivot sprinkler might have been installed, for example. "With a historical record you can begin to ask these questions."
Meanwhile a wide range of conservation measures are being developed and used. In some places where the "hydro-period" is shortening as drought frequency increases — amphibians need about a hundred days to complete their life cycle
Amphibians are being successfully treated in captivity with antifungals after a disease outbreak.
— managers are lining ponds with plastic to stem water loss, or taking out trees to increase stream flow, or promoting certain kinds of forest growth for shading or to increase relative humidity.
In the U.K., researchers from a group called Pond Conservation have created the Million Ponds Project as an adaptation strategy for freshwater species, including amphibians. The plan is to double the number of ponds on the landscape.
Disease is one of the great problems in the decline. The science, though, is often incomplete and confounding, and response currently is limited to emergency room measures. The chytrid fungus has killed amphibians around the globe in alarming numbers, and researchers are concerned that Bsal, a virulent fungus killing salamanders in Europe, could emerge here. People are successfully treating amphibians in captivity with anti-fungals, prophylactically or after an outbreak. Treating infections in the wild is a different matter. Scientists recently reported the first successful eradication of chytrid in the wild – an effort to keep Majorcan midwife toads, which despite their name are frogs and live on the Spanish Island of Majorca, from disappearing. Researchers bathed thousands of tadpoles in antifungal solution and used disinfectant in their pools to kill the chytrid fungus there.
Others are plucking frogs out of harms way. "Folks across Panama are picking up frogs and putting them in shipping containers and raising them and waiting until the disease is passed," Grant said. "People are also thinking about microevolution and genetic resistance to disease." That means figuring out how best to use populations of yellow-legged frogs in the Sierras, for example, that for some reason are resistant to the chytrid fungus that has devastated other populations of that species.
But the scenario is complicated by research that shows that disease dynamics are in part related to climate change. Warmer water temperatures may stress amphibians and reduce their resistance, or habitat changes may affect their recovery. "Amphibians have the ability to manage and clear infections," says Adams. "We've seen that with chytrid fungus, and it’s important.
They select a microhabitat with temperature gradients that are unsuitable to the fungus, and if they get in an extreme enough environment, the infection goes away. These things have thermal tolerances." At the same time, warmer temperatures seem to help some species clear infections, and scientists in Europe are experimenting with heating the water amphibians live in, or the spaces where they are kept in captivity, to heal Bsal infections.
A lot of amphibian conservation then is about best guesses, tradeoffs, and apportioning limited funding based on woefully incomplete information. Carter Johnson at South Dakota State University has studied the numerous prairie potholes — estimated at 8 million — that exist across 270,000 square miles in the Dakotas and Canada. Conservationists have bought land with potholes in western South Dakota because native grasslands around them are intact, providing habitat for amphibians, ducks, and other species. That area, though, is warmer and could change faster than other parts of the pothole region. "So the question is: Where do you put your money?” he said. “If the West isn't going to be favorable anymore, it's going to be too dry, then don't put all of your conservation money there, put it in the East where the climate is going to be more favorable. But the land values are higher there and so easement costs are higher and restoration costs are higher."
As ecologist Ryan noted, "It's a very complex problem."
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Two widely used pesticides likely to harm 97% of endangered species in US
Malathion and chlorpyrifos are each likely to harm most of the 1,782 mammals, birds, fish, reptiles and plants listed under the Endangered Species Act
Almost all of the 1,700 most endangered plants and animals in the US are likely to be harmed by two widely used pesticides, an alarming new Environmental Protection Agency (EPA) analysis has found.
Malathion, an insecticide registered for use in the US since 1956, is likely to cause harm to 97% of the 1,782 mammals, birds, fish, reptiles and plants listed under the Endangered Species Act. Malathion is commonly used to treat fruit, vegetables and plants for pests, as well as on pets to remove ticks.
A separate pesticide, chlorpyrifos, is also a severe risk to 97% of America’s most threatened flora and fauna. Chlorpyrifos, which smells a little like rotten eggs, is regularly deployed to exterminate termites, mosquitoes and roundworms.
A third pesticide, diazinon, often used on cockroaches and ants, threatens 79% of endangered species. The EPA study is the first of its kind to look at whether common pesticides harm US wildlife.
The risk posed by malathion and chlorpyrifos is so widespread across the US that the few species considered not at risk are mainly those already classified as extinct, the EPA study found. In March last year, the World Health Organization said that malathion and diazinon are “probably carcinogenic to humans”.
Lori Ann Burd, environmental health director at the Center for Biological Diversity, said: “For the first time in history, we finally have data showing just how catastrophically bad these pesticides are for endangered species – from birds and frogs to fish and plants.
“These dangerous pesticides have been used without proper analysis for decades, and now’s the time to take this new information and create commonsense measures to protect plants, animals and people from these chemicals.”
Environmental groups and some farmers have been pushing the federal government to better explain the impact of pesticides upon wildlife and humans. There have been calls to ban seven organophosphate pesticides – used on corn, cotton, watermelon and wheat – due to evidence that they can cause cognitive problems in children and thousands of deaths among bird species.
In January, the EPA acknowledged that imidacloprid, one of the world’s most commonly used pesticides, can be harmful to honeybees, the most important pollinators of crops. Jonathan Lundgren, a senior entomologist, has accused federal agencies of suppressing negative research into the effects of pesticides. Federal officials have rejected the claims.
“The EPA has allowed chemical companies to register more than 16,000 pesticides without properly considering their impacts. That has to stop,” Burd said. “These evaluations are a huge step forward for the EPA. Now that we know the magnitude of danger these pesticides pose, it’s clear we need to take action.”
The EPA was contacted for comment on further action as a result of the studies.
Source : The Guardian
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Pharmaceutical Pollution and Personal Care Products: Silent Killers
Pollution as a result of pharmaceutical production and personal care products (PPCPs), falls under a category of health hazards that are deemed “silent killers.” While attention is often given to loud and vivacious complications such as cancer, “silent killers” like pharmaceutical pollution and water contamination often fly under the radar. However, the lack of attention given to these issues does not, in any way, halt their determination to sit silently among us.
Medication or personal care products--including cosmetics, sunscreen, and menstrual care products--act as pollutants, thus threatening fundamental components of life such as food and water supply. The issue of pharmaceutical pollution can be found in terrestrial and aquatic environments throughout the world; these pollutants can accumulate in the environment, commonly as antibiotics, supplements, personal care products, or steroids, causing havoc to the balance of nature with their toxic metabolites. According to the Environmental News Network in 2013, about 28.66 tons of pharmaceutical pollution enters the environment from disposal down the drain and another 29 tons are disposed in landfills solely in North America. In addition to these methods, pollutants are introduced to the environment through human and animal excretion, agricultural use, manufacturing waste, and disposal of expired medicine. Despite the existence of drug take back programs and guidelines for safe disposal that attempt to mediate the issue of improper disposal of medicine, lack of both publicity and abundance of these programs halts any progress.
A large amount of pharmaceutical pollution also comes from pharmaceutical companies. Unfortunately, when creating new drugs, these companies are more concerned with efficacy than the potential environmental impacts of the drug. An environmentally detrimental new technology is the introduction of pharmacokinetic parameters into antibiotic drugs that modify the chemical structure of drugs to increase the drugs longevity in the body. However, this also has the undesired effect of increasing the drugs’ ability to bioaccumulate in the environment.
This matter is only worsened by the intrinsic nature of pharmaceuticals and personal care products. Because pharmaceutical and personal care products dissolve easily and have high temperatures of evaporation, they are introduced and absorbed readily into the environment by these methods. As reported by the US Geological Survey in 2002, detectable amounts of antibiotics, hormones, and a variety of nonprescription drugs were in 80 percent of the waterways sampled. Although the long term effects of these trace amounts of pollutants on humans has yet to be determined, there are several concerning phenomena that are attributed to PPCPs bioaccumulation.
In 2010, Amy Pruden, an assistant professor of civil and environmental engineering at Virginia Tech, determined that PPCPs pollution could be a catalyst for antibiotic resistance for which she was given a National Science Foundation (NSF) Faculty Early Career Development (CAREER) award. Almost all antibiotics drugs pass through the body without being metabolized or absorbed. In most cases, only 10% of common antibiotic drugs are absorbed and utilized by the body, with the other 90% being introduced into the environment through human excretion. This form of pharmaceutical pollution is cited to be a major cause of antibiotic resistance and the creation of “superbugs.” Not only does this cause treatment with antibiotics to be ineffective in some individuals, it also leads to the creation of bacteria, and thus, bacterial infections that cannot be cured. In addition to this, the impact of PPCPs pollution is manifesting in populations of fish and frogs found in waterways throughout the United States. After conducting a study of fish populations of 164 randomly selected waterways in the United States, the Environmental Protection Agency found that there was indeed trace amounts of pharmaceuticals in fish tissue. This proves that these substances are persisting in these aquatic environments and can be passed onto humans through fish consumption. However, a particularly concerning result of PPCPs pollution is that both fish and frog development have been observably altered. The EPA has reported unequal male to female ratio as well as organisms with male and female parts in fish populations around areas in the Potomac. Controlled by very specific hormones, development in frogs is highly susceptible to environmental factors. Due to this fact, when exposed to these pollutants, metamorphosis in frogs has been shown to be dramatically delayed.
While there is no dispute that there is pollution from pharmaceutical and personal care products, the lack of the discovery of long term effects on humans has fostered indifference on the subject. However, the true concern with PPCPs is its potential to create a snowball effect where a small concern can build upon itself to create a situation with disastrous consequences.
If the creation of antibiotic resistance and the negative effects on the development of aquatic organisms is not enough of a source for concern, the potential health hazards of the accumulation and persistence of these substances in the environment should be enough to make someone think twice before flushing their medication down the toilet.
Source : University of Berkley-California
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Why Are These Male Fish Growing Eggs?Fish in wildlife refuges are feminized, probably by hormone-skewing pollution. What does this portend for the health of all creatures—and people?
SWANTON, Vermont—Silver maples, lanky and bare, stand on the frozen flood plain at the Missisquoi National Wildlife Refuge. Two sets of tracks—fox and mouse—weave across the snowy surface of the river, which is home to bass, muskrats, and beavers. In the fall, more than 20,000 migrating ducks will converge here, and in the summer, one of the refuge’s rarest species, spiny softshell turtles, will bask and forage on its gravelly beaches and sandbars.
Sixty miles south of Montreal, near the U.S.-Canada border, Missisquoi National Wildlife Refuge is one of the most productive and pristine wetland ecosystems in the Northeast. Yet even here, scientists have found an abundance of fish with bizarre abnormalities that suggest exposure to hormone-disrupting water pollution.
Scientists from the U.S. Fish and Wildlife Service and the U.S. Geological Survey studied fish in 19 national wildlife refuges in the U.S. Northeast, including Missisquoi. Their conclusion: An astonishing 60 to 100 percent of all the male smallmouth bass they examined had female egg cells growing in their testes.
Scientists call this condition intersex, and while its exact causes are unknown, it’s been linked to manmade, environmental chemicals that mimic or block sex hormones.
Over the past decade, feminized male fish have been discovered in 37 species in lakes and rivers throughout North America, Europe, and other parts of the world. Experts say the new discovery in protected wildlife refuges is worrisome because it suggests that pollution may be even more pervasive than previously thought.
“There are no truly untouched areas. I think the take away here is that everything we do, everything we use or put on the land, ends up in the water at some point,” says Luke Iwanowicz, a U.S. Geological Survey fish researcher based in West Virginia who led the wildlife refuge study.
What scientists don’t know is what these feminized fish portend for the health of these species, for the environment, and perhaps for humans, too.
“When fish are getting intersex, it’s probably a good indication that something is wrong in the environment,” says Vicki Blazer, a researcher at the U.S. Geological Survey’s National Fish Health Research Laboratory in West Virginia.
Female Eggs in Male Testes
Intersex males don’t look outwardly different than normal males. In fact, federal scientists uncovered the condition by accident in the Chesapeake Bay watershed in 2003. They were conducting a post-mortem examination to determine the causes of a smallmouth bass die-off when they found male fish with female egg cells in their testes. In a follow-up study, they found these intersex conditions in more than three-quarters of male smallmouth bass caught in parts of the Shenandoah and Potomac Rivers in Virginia and West Virginia.
Gender in fish isn’t always straightforward. Some species of fish—including clown fish, grouper, and gobies—are hermaphrodites, meaning they naturally have both male and female sex organs. They are born with the ability to change their gender—it’s a special adaptation that some species have evolved to improve their chances at reproducing.
Intersex is different. It happens in species of fish that aren’t hermaphroditic, and it doesn’t help reproduction. In severe cases, it can make fish sterile.
“Intersex definitely is not normal,” says Don Tillitt, a U.S. Geological Survey toxicologist. The presence of female eggs in male testes indicates some kind of hormonal confusion. Scientists call this phenomenon endocrine disruption.
Mounting evidence suggests that intersex in fish may be the result of exposure to contaminants that encompass a wide range of natural and synthetic chemicals, including pharmaceuticals, pesticides, and personal care products. Some chemicals of concern include estrogens from birth control pills, the plasticizer bisphenol A, and the herbicide atrazine. These chemicals can mimic and in some cases interrupt a body’s normal hormonal processes.
Worldwide, intersex conditions caused by hormonal disruption have occurred in an array of aquatic animals, including alligators, turtles, and frogs.
In the Chesapeake Bay watershed, researchers found the most evidence of intersex fish in areas with a lot of agriculture and wastewater effluent, and large human populations. Hormonally active chemicals have been shown to flow into rivers and lakes through discharge from wastewater treatment plants and runoff from roads, yards, and farm fields.
“We knew this was going on in the Chesapeake watershed, but we didn’t expect to see issues like this in protected natural areas with far less development,” Iwanowicz says.
A Symptom of Polluted Water
When Iwanowicz and his colleagues examined bass—both largemouth and smallmouth—on wildlife refuges from Virginia to Maine, their goal was to assess potential water quality threats from endocrine-disrupting chemicals. Bass—especially smallmouth bass—serve as indicator species for scientists, meaning they are particularly sensitive to pollutants in the environment.
“One of the roles of the national wildlife refuges is to preserve natural ecosystems, so it’s a management issue for us,” says Ken Sturm, Missisquoi’s refuge manager. “Water is the blood of this ecosystem. Intersex in fish may be a symptom of larger problems with water quality that we’re just beginning to understand.”
Some of the refuges sampled, such as John Heinz at Tinicum in Philadelphia and Great Swamp in New Jersey, are close to major East Coast urban centers. Others, including Moosehorn National Wildlife Refuge in Maine and Missisquoi, are more remote—surrounded by forests, farm fields, and small towns.
The researchers found intersex smallmouth bass everywhere they looked. About 85 percent of the males collected in the refuges were intersex. At least some males at every site had female egg cells. It was less prevalent in largemouth bass—about 27 percent.
Surprisingly, the phenomenon wasn’t nearly as widespread in previous testing at eight U.S. river basins, including the Mississippi, Rio Grande, and Columbia Rivers. In that research, 33 percent of male smallmouth bass were feminized.
Why are there so many intersex fish on the refuges? No one knows.. For most of the refuges, there are no identifiable sources—no sewage treatment plant or industrial facility, for example—putting out pollutants that could explain the phenomenon.
“It’s really pretty staggering to be seeing these percentages in areas we would think of as pristine natural areas,” says Christopher Martyniuk, a fish biologist at the University of Florida who was not involved with the refuge study.
We like to think of the far wilds of northern Vermont or Maine as pristine, explains Iwanowicz, yet the newest study serves as a reality check.
Even protected places are influenced by their surroundings, adds Sturm, who has managed the Mississquoi refuge for five years. The Mississquoi River winds for 80 miles through the northern Green Mountains along the U.S.-Canada border before it pours into Lake Champlain. The area is rural, peppered with dairy farms, small towns, and vacation homes. The refuge is made up of narrow strips of land that stretch like a claw from the river mouth into the lake.
“Anything that goes into the water along the way water flows right through the refuge,” he says.
Too Much EstrogenEstrogen-like chemicals are the suspected culprits. A higher-than-expected level of estrogen activity was detected in water collected from 79 percent of the sites. However, no tests have occurred yet to identify specific chemicals.
An unusual signature in the blood of fish from the Missisquoi River also points toward environmental estrogens. Researchers found high levels of vitellogenin—a protein involved in producing egg yolk—in many smallmouth bass. In male fish, the gene that tells the body to produce vitellogenin is usually “turned off,” explains Iwanowicz. That gene only “switches on” in the presence of estrogen, a female sex hormone.
“When we find vitellogenin in the blood it’s a pretty clear indication that those male fish were exposed to extra estrogens of some kind,” says Iwanowicz.
One environmental estrogen is ethinyl estradiol—a chemical found in birth control pills. In laboratory studies, scientists have been able to induce intersex in some fish by exposing males to the compound.
Yet the answers in nature—where fish are exposed to a variety of chemicals and other stressors—are never as clear-cut as in the tightly controlled laboratory environment.
Other environmental factors might contribute to intersex in fish, including low levels of dissolved oxygen and warming water temperatures. Scientists don’t yet understand how some of these other factors may be influencing feminization, explains Tillitt.
Researchers are also probing the consequences of intersex for fish health.
Experiments with minnows suggest that exposure to environmental estrogens may cause problems for fish populations. Very severe levels of feminization—having a lot of egg cells in the testes—can impair sperm quality, impeding a fish’s ability to reproduce. But feminization is a continuum: Males with only a few eggs in their testes may have no trouble at all reproducing.
The intersex findings in bass at the refuges don’t appear to be linked to any population-scale reproductive problems for the popular sport fish.
Nevertheless, Sturm worries about what the findings mean for some of the refuge’s more vulnerable species, such as the spiny softshell turtle. About 200 of the leathery-skinned turtles reside in Lake Champlain, most of them clustering around the mouth of the river. They’re vulnerable to water pollution and other threats, including predation, boating, and fishing hooks. No other population of spiny softshell turtle exists in New England or Quebec, though it is found elsewhere in North America.
“Bass are a sentinel species, but it’s possible that other animals could be affected too,” says Sturm.
Reproductive impairment isn’t the only concern, says Blazer. In the Potomac and Susquehanna Rivers, she’s seen an increase in diseases, die offs, and infections in some fish species. Their immune systems are weak. These health problems seem to correlate with levels of intersex.
“It’s possible that the environmental chemicals inducing intersex may also be causing immune system problems,” she says.
Exposures to endocrine disrupting chemicals in drinking water, food, and household products have been linked to health problems in people too, including reduced fertility, developmental delays in children, and some cancers. But it’s too soon to say whether feminized fish are indicative of health effects for humans too.
“Knowing that environmental chemicals which disrupt endocrine function are out in the environment at concentrations above thresholds for effect should lead us to try to evaluate the risk in a more comprehensive fashion,” says Tillitt.
Along the Missisquoi
On the banks of the Missisquoi, frozen marsh grasses crunch underfoot. A downy woodpecker flits among the wayward branches of an uprooted tree. Muskrat lodges—small mounds made from bulrush and cattail—dot the landscape.
Winters are bleak here, but in a few months, the ice will thaw and the refuge once again will teem with wildlife. Established in 1943 as part of the Migratory Bird Conservation Act, the Missisquoi refuge occupies a prime spot on the Atlantic Flyway—one of North America’s major bird migration routes.
Two years ago, the refuge and the Missisquoi delta were designated a Wetland of International Importance under an international treaty that calls attention to globally important ecosystems. That puts the refuge on a list that includes renowned habitats such as the Florida Everglades and Africa’s Okavango Delta.
While seven miles of trail and other public activities occur at the refuge, much of the refuge’s 7,000 acres are off-limits to people. “Wildlife is our first priority. Humans come second,” says Sturm.
Yet the refuge—and the river itself—are not untouched. Vermont Route 78, a main thoroughfare connecting northern Vermont with New York State—bisects the refuge wetlands, causing wildlife deaths from roadkill. Just south of the refuge, an abandoned dam blocks sturgeon, walleye and other fish species from reaching important spawning grounds in Lake Champlain. In the summer, manure from farm fields upstream trickles into the river, causing smelly algae blooms in Missisquoi Bay.
“As stewards of an internationally important wetlands, we do what we can to protect it, but we don’t have ultimate control over its fate,” says Sturm. “Communities must come together to protect the entire watershed.”
Source : National Geographic
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Why Thousands of Dead Seabirds Are Washing Ashore in Alaska - One of the largest die-offs in Alaskan history has wildlife biologists puzzling over what’s to blame.
Many incidents "boil down to a common problem," says WaPo: "the animals' environments are changing, and they're struggling to keep up."
From seabirds to whales to antelopes to starfish, animal die-offs across the globe are raising alarm about the deadly impact of climate change on the world's ecosystems and their vulnerable inhabitants.
An estimated 8,000 black-and-white common murres were found dead on the beaches of Alaska's Prince William Sound over the weekend, joining thousands more that have washed up on beaches from California to the Gulf of Alaska over the past year. The seabirds, who appear to have died of starvation, "are indicators of what is happening in the marine ecosystem," the U.S. Fish and Wildlife Service (USFWS) wrote in a press release (pdf) on the matter.
While the USFWS notes that "seabird mortality events occur occasionally, especially after a hard winter, and causes are often difficult to determine," it also points out that the "current die-off, however, appears to be unusually large."
Meanwhile, the BBC reports that at least 45 pilot whales have died in the southern Indian state of Tamil Nadu, after more than 80 were stranded on the shore at Tuticorin. M. Ravi Kumar, the top government official in the port town, told the Associated Press that the whales began washing up on beaches on Monday evening, and that while 36 of the large mammals had been rescued and pushed back out to sea, they appeared disoriented and kept coming back.
These heart-wrenching stories add to a list of similar incidents—a massive starfish stranding on Australia's Moreton Island; the mysterious die-off of endangered antelopeslast spring in Central Asia, which killed more than half of the entire species in less than a month; drought in the Western U.S. transforming stretches of river into a "mass graveyard for baby salmon;" and historic coral bleaching events that degrade and erode the structure of living reefs.
A study published last year in the Proceedings of the National Academy of Sciences, in fact,showed that mass die-offs of birds, fish, and marine invertebrates are growing increasingly frequent and severe, hiking at a rate of approximately one major mortality event per year over the past seven decades.
"Incidents like these are often mysteries to be unraveled, with scientists sorting through various explanations—hunger, habitat loss, disease, disorientation—for the mass deaths," Sarah Kaplan wrote at the Washington Post on Wednesday. "But in a swath of recent cases, many of the die-offs boil down to a common problem: the animals' environments are changing, and they’re struggling to keep up."
In the case of the seabirds, for example, a possible explanation is that the birds' usual food supply—the schools of herring and other small fish typically found near the coast—has itself been decimated by warming oceans or this year's extreme El Nino weather pattern.
In the case of the saiga antelopes last year, the WaPo reports, researchers believe "an abnormally wet spring induced by climate change transformed some normally harmless pathogens that ordinarily live in the saigas' guts. The suddenly lethal pathogens swept through Kazakhstan's herds. Once sickened, the animals died in a matter of hours."
Citing the PNAS study, Kaplan concludes: "These die-offs matter not just because of the inherent value of the creatures involved...but because whole ecosystems may depend on that species to survive."
Source : Common Dreams
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Elephant loss could change landscape forever
The disappearance of elephants and other large land animals could have a devastating and permanent effect on plants and animals they live with, say researchers.
When they analyzed large animal, or megafauna, extinctions in the Americas since humans moved in about 15,000 years ago, they discovered long-lasting changes in the local landscape after the largest of the land animals—among them mammoths and mastodons—disappeared.
Recent studies point to the loss of mammoths, native horses, and other large animals in Alaska and the Yukon as the reason a productive mix of forest and grassland turned into unproductive tundra that dominates the region today.
Similarly, mammoth and mastodon extinctions in the Pacific Northwest and the northeastern United States seemed to have changed the vegetation and, in the western United States, decreased the diversity of small mammals, says study leader Anthony Barnosky, professor of integrative biology at the University of California, Berkeley.
“Ecological studies have shown that if you pull out a top predator or a key herbivore today, you get dramatic change in the ecosystem. Our study makes it clear that in the past, such changes have lasted for thousands of years. These extinctions really do permanently change the dynamics. You can’t go back.”
Yet not all extinctions left major changes in the ecosystem. Ground sloth and glyptodont extinctions in South America had no noticeable effect on the vegetation of Patagonia and the Pampas, for example.
“It’s not a simple story, where if you pull out a big beast you see major changes in the landscape,” Barnosky says. “It’s actually dependent on how big a beast you pull out, and also how that beast interacts with the plants and animals in the area, and what other plants and animals are there. It depends on what the animal does for a living.”
Large browsers like mammoths, mastodons, and today’s elephants, for example, eat small trees and shrubs and uproot or break down trees, as well as trample and churn the soil. Other large herbivores, such as bison and moose, also keep shrubs in check and change soil structure and nutrients as they feed, defecate, and urinate. As a result, such large-bodied plant eaters play a key role in keeping forests from overrunning grasslands, as the group found happened in North America.
Ecosystems changed forever
“You see the impact of defaunation today in Africa, where the removal of elephant populations has led to these shrubby, scraggly acacias filling the savanna landscape,” says coauthor Charles Marshall, professor of integrative biology and director of the University of California Museum of Paleontology. “Africa today, with its elephant populations, seems to fit the model of North America with its mammoths and mastodons.”
In the Pampas of Argentina, however, the disappearance of the South American mastodon had no observable effect on the flora and fauna, probably because the weather and rainfall are not conducive to forests.
Understanding these relationships can be important today in targeting conservation efforts, says postdoctoral fellow Emily Lindsey.
“This information could be useful to conservation biologists in pinpointing which types of ecosystems are likely to be affected by global climate change, and which would be most responsive to conservation and restoration efforts,” she says.
The current study, published in the Proceedings of the National Academy of Sciences, captures only the grossest environmental changes resulting from large-mammal extinctions, since not all ecosystem changes leave traces in the fossil record, Barnosky cautions.
“The fact that we saw the impact we saw is a pretty robust conclusion that these ecosystems were changed forever by the disappearance of these animals. Anytime you pull a big animal out of an ecosystem, there are some pretty huge effects, as demonstrated by ecologists today. But they might not be recognizable in the fossil record.”
The new research was sparked by other ecological studies on the impacts of adding or subtracting large mammals such as deer and elk from American landscapes, or removing wildebeest and elephants in Africa.
Scientists decided to look for traces of ecosystem change resulting from the loss of about three-quarters of all large land mammals that roamed North and South America after humans arrived from Siberia about 15,000 years ago. About 60 large mammals died out in North America about 12,000 years ago, probably due to a combination of hunting and changing climate. Mammoths and mastodons, as well as horses, elk, moose, and carnivores such as the saber tooth cat and the dire wolf, disappeared.
It took longer for South American species to go extinct, but the continent eventually lost about 99 species, including giant armadillos, saber-toothed cats, mastodon relatives called gomphotheres, and two entire orders of endemic South American ungulates, including the hippo-like Toxodonts in the order Notoungulata and the camel-like Macrauchenia in the order Litopterna.
What will the planet look like?
In three areas of North America—northwestern and northeastern America and Alaska/Yukon—fossils showed not only a change in plant communities with an increase in fire frequency, but also a decrease in diversity of small mammals. A study conducted by coauthor Elizabeth Hadly, a professor at Stanford University, for example, documented a decrease of small rodent diversity in California after these extinctions, allowing the most widespread “weedy” mouse species to dominate the landscape.
“The take-home message from western North America is that grazing and browsing by extinct megafauna such as proboscideans favored open-habitat mosaics,” Hadly says. “When these ecosystem engineers became extinct at the end of the Pleistocene, denser deciduous forests established. The loss of the mosaic Pleistocene habitats in western North America led to a decrease in the diversity of small mammals.”
“If we lose some of these big-bodied animals that are threatened with extinction today, we lose a lot more than those animals, we lose the entire ecosystems of which they are part,” Barnosky says. “We are moving into new territory in terms of what the planet will look like.”
Other coauthors of the study are from the University of Chile and California State University, Sacramento. The National Science Foundation funded the work.
Source : Futurity
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Climate change shrinking bees’ tongues, scientists say
Two species have adapted to feeding on shorter-tubed flowers since warmer summers have made deep-tube blooms less available, researchers believe.
Poor bees can’t catch a break.
Pesticides, pathogens and habitat loss have all decimated pollinator populations, with some North American bumblebee species declining up to 96 per cent in just a few decades.
Now, scientists say that climate change is causing some bees’ tongues to shrink.
A U.S.-Canadian research team found that deep-tubed flowers are blooming less often on the slopes of three Rocky Mountain ridges in Colorado, changes linked to increasingly warmer summers. As a result, two long-tongued species of alpine bumblebees that co-evolved to pollinate these plants have seen a 24-per-cent reduction in tongue length over the past 40 years.
The researchers believe the bumblebees have rapidly adapted to feeding on shorter-tubed flowers, transforming them from long-tongued specialist pollinators to short-tongued generalists over the course of a few dozen generations — potentially disrupting their alpine environment.
“The silver lining is that bees are adapting. That’s a good thing — they’re responding to these changes in selective pressure,” says Nicole Miller-Struttmann, an evolutionary ecologist at SUNY College at Old Westbury and a co-author on the paper, which was published Friday in the journal Science.
“The not-so-silver lining is the effect that this might have long term on the plants.”
The long-tubed flowering species the researchers examined live for many years, so the bees’ shift to shorter-tubed flowers hasn’t yet had an impact. But if the bees are visiting these species less often and spreading less of their pollen, the plants could decline, triggering further stresses on every other organism that relies on them.
“It’s sort of this cascading effect. At what point do things start falling apart? It will be really hard to predict what a seemingly small change like this will have on the larger community,” says Sheila Colla, a York University conservation biologist who specializes in North American bumblebees. Colla, who was not involved in the research, called the news “depressing, as most of the stuff that comes my way is.”
For the study, the researchers turned to a collection of alpine bumblebees gathered in the Rockies between 1966 and 1980 and stored at entomology museums. To measure their tongue lengths, Miller-Struttmann and her colleagues slowly rehydrated the specimens in a moist environment: To fold the tongues out to full length, they needed to make them flexible again. To compare the older bees with modern ones, the researchers spent successive field seasons on the same mountain peaks netting insects and measuring flower density.
One species of bumblebee, Bombus balteatus, saw their mean tongue length drop to six millimetres from eight millimetres in one mountain-range population. Another species,Bombus sylvicola, saw a drop to just under four millimetres from just over five millimetres.
Miller-Struttmann adds that while it’s good news the bees are adapting, it’s impossible to say how much more stress they can handle.
“Is that evolution fast enough in the long term? We don’t know yet.”
Source : The Star
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Evidence of Coal-Fly-Ash Toxic Chemical Geoengineering in the Troposphere: Consequences for Public Health
J. Marvin Herndon
The widespread, intentional and increasingly frequent chemical emplacement in the troposphere has gone unidentified and unremarked in the scientific literature for years. The author presents evidence that toxic coal combustion fly ash is the most likely aerosolized particulate sprayed by tanker-jets for geoengineering, weather-modification and climate-modification purposes and describes some of the multifold consequences on public health. Two methods are employed: (1) Comparison of 8 elements analyzed in rainwater, leached from aerosolized particulates, with corresponding elements leached into water from coal fly ash in published laboratory experiments, and (2) Comparison of 14 elements analyzed in dust collected outdoors on a high-efficiency particulate air (HEPA) filter with corresponding elements analyzed in un-leached coal fly ash material. The results show: (1) the assemblage of elements in rainwater and in the corresponding experimental leachate are essentially identical. At a 99% confidence interval, they have identical means (T-test) and identical variances (F-test); and (2) the assemblage of elements in the HEPA dust and in the corresponding average un-leached coal fly ash are likewise essentially identical. The consequences on public health are profound, including exposure to a variety of toxic heavy metals, radioactive elements, and neurologically-implicated chemically mobile aluminum released by body moisture in situ after inhalation or through transdermal induction.
Source : Int. J. Environ. Res. Public Health
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Pesticide alters personalities of helpful spiders
Jumping spiders are like natural pesticides, preying on insects that damage crops. But a common synthetic pesticide may disrupt this service by changing their personalities.
Nature provides free pest control, from bats and birds to snakes and spiders. These predators can help protect agricultural crops, but we often try to supplement their services with our own synthetic pesticides. And as a new study suggests, one common insecticide might affect pest-killing spiders' ability to do their job.
The chemical in question is Phosmet, a broad-spectrum insecticide that's used in fields and orchards across North America. It's highly toxic to a wide range of insects — including honeybees, unfortunately — but it was thought to be relatively safe for spiders. As the study's authors report, however, it can have an insidious effect on at least one key species ofjumping spider that normally protects crops.
"Bronze jumping spiders play an important role in orchards and fields, especially at the beginning of the agricultural season, by eating many of the pests like the oblique-banded leafroller, a moth that attacks young plants and fruit," lead author and North Dakota State University researcher Raphaël Royauté says in a statement.
"Farmers spray insecticides on the plants to get rid of these same pests, and it was thought that it had little significant effect on the spiders' behaviors. But we now know that this isn't the case."
Yes, spiders have personalities
Previous research has shown that spiders — like humans and many other animals — have distinct personalities, resulting in different decisions made by "bold" and "shy" individuals. This can affect their ability to catch prey or their interest in exploring new territories, both of which are key to their survival and their success in limiting pests.
"Most individuals have an individual signature in their behaviors, what scientists call 'personality types,'" Royauté says. "Some individuals are willing to take risks when predators are present, explore new territories faster, or capture prey more quickly."
Yet the effects of insecticides on spider personalities are poorly understood, he adds. "We know that drinking alcohol can make us act in weird ways, by removing some social inhibitions for example. So one of the primary questions of my research became: can insecticides cause similar personality shifts in individual spiders?"
To shed more light on this, the study's authors focused on how spiders behaved before and after sublethal doses of Phosmet. They found that, in general, the spiders' behavior grew less predictable, with individuals deviating from their personality types once they were exposed. This could be because some individual spiders are more sensitive to the insecticide than others, the researchers say.
Male and female spiders also showed different responses to the toxin. Males were able to continue capturing prey about as well as they had before, but their personality types seemed to fade away when exploring their environment. Females, on the other hand, showed a much stronger effect in their hunting behavior.
"Inactive females were quicker to capture prey in the absence of insecticide exposure, a tendency no longer expressed in the treated group," the researchers write in the journal Functional Ecology. "Males did not show evidence for such an activity-prey capture syndrome, even in the control group, but showed a decrease in correlation strength among all activity traits. Taken together, our results suggest that insecticide-exposed individuals showed a strong departure from their personality tendencies."
Our spider sense is tingling
Phosmet is mainly used on apple trees to control codling moths, according to a fact sheet by the Oregon State University Extension Service, but it's also used on various other crops to fight aphids, suckers, mites and fruit flies.
While Phosmet was the focus of this study, the researchers say the real lesson of their findings isn't about a single pesticide. It's about how we evaluate the safety of all pesticides for non-target wildlife, especially beneficial, pest-controlling predators. The spiders' personality shifts weren't evident when researchers averaged the behavior of a whole population, but they were significant on an individual level.
"By looking at the way that insecticides affect individual spider behaviors, rather than averaging out the effects on the spider population as a whole, as is traditionally done in scientific research, we are able to see some significant effects that we might have otherwise missed," says co-author and McGill University ecologist Chris Buddle.
"It means we can measure the effects of insecticides before any effects on the spider population as a whole are detected, and in this case, it's raising some red flags."
Source : Mother Nature Network
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Drugging the Environment
Humans have spiked ecosystems with a flood of active pharmaceuticals. The drugs are feminizing male fish, confusing birds, and worrying scientists.
In the fall of 2012, PhD student Hendrik Wolschke leaned over the side of a boat on the Elbe River in Northern Germany and lifted a stainless steel bucket from the water’s depths. Pulling it aboard, he set the sloshing bucket next to a pile of empty plastic bottles.
Once he’d filled them with the river water, Wolschke packed the bottles into coolers for transport southeast to the chemistry laboratory of his doctoral advisor, Klaus Kümmerer, at Leuphana University of Lüneburg. There, the bottles joined water samples collected from all around Germany: the North Sea, drainage streams from wastewater treatment plants, even drinking water straight from municipal taps.
Each sample was tested for the most widely prescribed antidiabetic drug in the world—metformin, which treats high blood sugar by suppressing glucose production in the liver. Humans do not metabolize the drug, so within 24 hours of being swallowed, metformin is excreted from the body essentially unchanged.
Because of its high prescription rate—the U.S. alone dispensed 76.9 million metformin prescriptions in 2014—it’s not surprising that the drug is abundant in the environment. Metformin was present in every water sample Kümmerer’s team tested, including tap water, at concentrations exceeding environmental safety levels proposed by an international Rhine River Basin agency by 50 percent. When publishing the results in 2014, Kümmerer and his coauthors concluded that the drug is likely “distributed over a large fraction of the world’s potable water sources and oceans.”1
That sounds melodramatic, but he may be right, and the problem is not limited to metformin. Rebecca Klaper and colleagues at the University of Wisconsin–Milwaukee recently measured concentrations of pharmaceuticals in Lake Michigan, where researchers had speculated that any drugs that were present would be highly dilute and not detectable. On the contrary, Klaper’s team found evidence of 32 pharmaceuticals and personal care products in the water and 30 in the lake’s sediment. Fourteen of these were measured at concentrations considered to be of medium or high risk to the ecosystem, based on data from the US Environmental Protection Agency (EPA) and other researchers.2 Metformin topped the list, at concentrations of concern even 3 kilometers off the shores of Milwaukee.
Ecologists have long recognized that pharmaceuticals, both unmetabolized drugs like metformin and others that break down into various metabolites, are polluting the environment, but researchers have traditionally focused on just two classes: antibiotics and endocrine-disrupting compounds such as the birth control hormone estradiol. Antibiotics in the environment promote antibiotic resistance in a range of bacterial species, and endocrine disruptors are known to affect development and reproduction in animals.
Metformin was not thought to have either of those effects on animals. But in lab experiments conducted earlier this year, Klaper’s team discovered that male minnows exposed to metformin at concentrations comparable to those of wastewater treatment plants produce proteins typically found only in female fish, develop feminized gonads, weigh less, and have fewer offspring.3 The antidiabetic is now one of a growing list of drugs that researchers are realizing pose major ecological problems.
“All [pharmaceuticals], by design, are meant to elicit a biological response,” says the US Geological Survey’sDana Kolpin, chief of the organization’s Emerging Contaminants Project. “We need to know what the environmental consequences are.”
What lies beneath
Pharmaceuticals are ubiquitous in wastewater, deposited primarily from human urine and feces. The active ingredients from leftover pills thrown in patients’ trash or even hospital waste also find their way to waterways, but the contribution of those sources pales in comparison to the share “from all of us,” says Kümmerer.
Sewage treatment plants remove some pharmaceuticals from water during basic filtering processes, says Klaper, but many pass through unhindered. Metformin, for example, is stable against common water treatments such as UV light irradiation. And at this point, it is prohibitively expensive to add technologies that can filter out these chemicals.
From sewage plants and landfills, drugs make their way into streams, rivers, lakes, seawater, and even into drinking water. Currently, however, the EPA does not regulate even a single human pharmaceutical in drinking water. An EPA list of pollutants that may make water unsafe, but are not regulated, includes eight hormones and one antibiotic. Metformin is not on the list. “Legislation is not protecting ecosystems at the moment,” says Kathryn Arnold, an ecologist at the University of York in the U.K., where there are also no regulations for pharmaceuticals in water.
Many ecologists believe that should change. Pharmaceutical use in the general population is growing, with sales expected to increase five percent annually for the next five years, so more and more drugs are likely to be entering the environment. Like so-called “legacy” pollutants that have been banned in many countries, including polychlorinated biphenyls (PCBs) and DDT, pharmaceuticals can persist for years, even decades. Pharmaceuticals are designed to maintain their strength and quality on the long route from manufacturer to pharmacy to medicine cabinet, and even sometimes inside the human body. That same stability, unfortunately, prevents many pharmaceuticals from degrading in the environment.
Researchers at Umeå University in Sweden measured concentrations of the widely marketed antianxiety drug oxazepam in sediment cores from the same lake bed deposited over three decades. Based on the sediment samples, they were able to identify the specific year that oxazepam first came on the market, and the amount of drug deposited in newer layers over the years correlated tightly with the numbers of prescriptions. Then, when the researchers measured concentrations in core samples extracted 30 years ago, they found that the older cores and more-recent samples had the same drug levels at the same time depths. Oxazepam hadn’t degraded at all over time, says study author Tomas Brodin, an ecologist at Umeå.
To make matters worse, pharmaceuticals are hard to detect and measure in the environment. Detection methods are improving, however. Early methods used by the US Geological Survey required one liter of water and could identify 15 to 20 compounds, while the latest method measures more than 100 drugs in just a 20-milliliter sample. But scouring for individual agents isn’t enough. Our modern environment contains a swirling mixture of pharmaceuticals, pesticides, industrial by-products, and a plethora of other chemicals. “What’s happening in reality is an exceedingly complex cocktail of compounds,” says Kolpin.
And within that chemical concoction, drugs interact with one another, with bacteria, and with basic environmental elements such as water. Chemical and biological reactions can result in a host of transformation products—new chemicals with new properties. Some bacteria break down metformin, for example, yielding a metabolite called guanylurea, which is also bioactive and stable in the environment. Similarly, the antidepressant enlafaxine (trade name Effexor) degrades into desvenlafaxine (Pristiq), another antidepressant. Such metabolites can sometimes be more toxic than their parent compounds.
“Degradation expands that universe of potential chemicals exponentially,” says Kolpin.
At high enough levels, pharmaceutical compounds can be lethal to wildlife. More often, however, drugs have subtle but significant effects on the behavior and development of organisms.
Of the drugs that scientists test for in the environment, an emerging class of interest is selective serotonin re-uptake inhibitors (SSRIs), commonly prescribed for depression and anxiety disorders. “These chemicals are psychotropic. In humans they affect cognition, mood, and behavior,” says Melanie Hedgespeth, a graduate student at Lund University in Sweden. “So if they’re out there, they have potential to also affect behavior in aquatic organisms.”
Last year, Hedgespeth analyzed the effects of a popular SSRI, sertraline (trade name Zoloft), which had previously been detected in water samples and fish tissue in the U.S., Canada, and elsewhere. She spiked tanks full of juvenile perch with three concentrations of sertraline: 120 nanograms per liter (a level detected in wastewater), 89 micrograms per liter, and 300 micrograms per liter. After just eight days of exposure, the fish started eating less, even at high prey densities and at the lowest environmental drug concentration, though the effect at that level was “marginal.”4Hedgespeth hypothesizes that the behavioral change is due to loss of appetite, a recorded side effect of the drug in humans. If such a decline in feeding occurs in the wild, it could impact the reproduction and life span of entire populations of fish, says Hedgespeth. “People tend to focus on mortality, but this could potentially impact fish in the longer term.”
Other research has shown how widespread the ecological effects of pharmaceutical pollutants can be. Every summer from 2001 to 2003, researchers in Canada poured a small amount of 17α-ethynylestradiol, the synthetic estrogen used in many birth control pills, into an experimental lake in northwestern Ontario. They then measured the effects of the hormone on a diversity of aquatic wildlife, including algae, microbes, zooplankton, minnows, trout, and other fish. Over the course of the experiment—the researchers collected data through 2005—the fathead minnow population in the lake nearly crashed due to reproductive failure. The lake trout and white suckers that relied on the minnows for food also suffered, declining in abundance due to lack of food. The minnow’s prey—zooplankton and insects—subsequently flourished.5
“Not only were there direct effects on one species, there were direct and indirect effects on multiple species at different trophic levels within the lake,” says Arnold, who edited the special issue of Philosophical Transactions of the Royal Society B in 2014 on pharmaceuticals in the environment that included the study. “It’s clear there are lots of knock-on effects that are difficult to predict with standard ecological risk assessments.”
Pharmaceuticals can also accumulate as they work their way up the food chain, exposing predators to higher levels than those found in the environment. Brodin and colleagues at Umeå found that while oxazepam had no effect on damselfly behavior, it did accumulate in the insects. And when perch ate oxazepam-riddled damselfly nymphs, the fish retained an average of 46 percent of the drug from the insects. The more damselflies they ate, the more the drug accumulated in the fish.6 In a separate experiment, the normally shy perch that hunt in schools became considerably bolder after exposure to oxazepam, eating more quickly and leaving their schools more often.7 “It was a drastic behavioral modification,” says Brodin.
It may be that the drug reduced the perch’s tendency to seek safety in numbers from predation, Brodin speculates. “Perhaps they perceived their environment as less risky.” Interestingly, when no predators were around, the effect was positive for the fish, making them more efficient hunters. But testing such effects in the wild is a difficult thing to do, Brodin notes. While it is easy to measure whether a chemical is deadly to a species, there is rarely an easy way to tell if it is promoting survival, which can also cause significant changes in an ecosystem.
While most studies on the effects of environmental pharmaceuticals have focused on aquatic species, terrestrial organisms such as birds, worms, and insects can also be exposed to the drugs when they feed on sewage, on fields fertilized with human or animal waste, or on the flesh of livestock treated with drugs. In the late 1990s, for example, tens of millions of vultures began dropping dead around India and Pakistan. First, scientists assumed it was an infectious agent, then an environmental toxin. It was neither. In 2004, they pinpointed the cause: an anti-inflammatory drug named diclofenac. The birds had suffered acute kidney failure after ingesting diclofenac from the carcasses of livestock that had been given the drug to treat lameness and fever.8“Vultures in that region were exceedingly sensitive to diclofenac,” says Kolpin. “That’s a classic example of unintended consequences.”
India, Nepal, and Pakistan banned veterinary use of diclofenac, but in 2013, Spain, home to 95 percent of Europe’s vultures, authorized the sale of the drug for use in animals. Wildlife groups immediately called for a full veterinary ban on the drug, and the European Commission asked the European Medicines Agency (EMA) to conduct a review of the risk of the drug. In December 2014, the EMA concluded that vultures and other carrion-eating birds were at risk from diclofenac, but the European Commission has not yet made a final decision on whether it will outlaw the drug.
Meanwhile, many more terrestrial species are at risk from countless other pharmaceuticals polluting the environment. Some 10 to 30 percent of the antidepressant fluoxetine (trade name Prozac) is excreted unchanged by humans, and, like many other pharmaceuticals, fluoxetine is environmentally stable. The University of York’s Arnold estimated the concentration that would accumulate in earthworms living in sewage, and then how much of the drug would make it into a bird’s system if half its diet consisted of such worms. Adjusting for body mass, the total amount was equivalent to roughly 5 percent of a human dose of fluoxetine.9
Knowing that fluoxetine can cause reduced libido and decreased appetite in human patients, Arnold feared birds might suffer similar effects. “That could have big implications on survival,” she notes. Daily for four months, she and her team fed wild-caught starlings wax worms injected with low doses of fluoxetine. Sure enough, the birds that ingested the drug ate less and at all the wrong times: they snacked throughout the day rather than consuming large meals at sunrise and sunset, the optimal mealtimes for wintering birds.9“If you have a harsh winter, [and] you have an animal not feeding heavily at the start and end of the day, they’re likely to starve,” says Arnold.
With more and more examples of the effects of pharmaceuticals on wildlife, researchers are growing increasingly worried about potential effects of such pollutants on humans. “Human health is the million-dollar question,” says Kolpin. “All our environmental research, while maybe not a direct link to human health, certainly suggests that, as we start seeing things that affect aquatic and terrestrial organisms, we should be concerned about human health as well.”
“Benign by design”
Papers on the ecological impact of drugs have examined only a handful of the estimated 4,000 pharmaceuticals used around the globe in medicine and agriculture. Some scientists argue that we should spend less time identifying individual drugs in the environment and more time trying to prevent them from reaching it in the first place. “We have to think about preventative measures, not wait until the negative effects play out,” says Kümmerer.
One option is to outfit wastewater treatment plants with equipment to remove pharmaceuticals. In Sweden, for example, Brodin and colleagues are rebuilding an entire wastewater plant to incorporate ozonation, a process that can remove some pharmaceuticals from water by bubbling ozone gas through it. The team of researchers will then monitor local streams to see how the plant upgrades affect organisms in the surrounding ecosystem.
Technologies such as ozonation and nanofiltration are expensive, however, and no one method has been shown to remove all bioactive agents. Therefore, some researchers advocate measures to prevent pharmaceuticals from ever entering the water system, namely by designing drugs that quickly degrade in the environment—“benign by design,” as Kümmerer calls it. After giving a talk at a German cancer research center, Kümmerer was approached by scientists who had made a derivative of the anticancer drug ifosfamide. In the hopes of increasing absorption of the drug in the gut and reducing side effects in patients, the chemists replaced the part of the molecule known to keep the drug stable with a sugar. The chemists realized that the replacement might also make the drug more biodegradable in the environment, and they asked Kümmerer to test it.
He found that the derivative, glufosfamide, was biodegradable and still as potent an anticancer agent as the original.10 Glufosfamide is currently in a Phase 3 clinical trial for metastatic pancreatic cancer.
Pharmaceutical companies can and should use such “green” chemical techniques to design drugs that biodegrade quickly in the environment, says Paul Anastas, director of the Center for Green Chemistry and Green Engineering at Yale University. “For not just pharmaceutical chemists, but for all chemists, whenever we know things are going into the environment, we have an obligation to make sure they are as least toxic as possible.”
There is nothing inherently difficult about doing so, Anastas adds. “It’s all about just controlling properties to get the function you want. That is simply another design challenge.” And it shouldn’t be hard to convince companies to manufacture drugs to be greener, he says. “Nobody purposely designs a substance to be toxic in humans or the environment. There is just a lack of awareness of what’s possible.”
But until drugs are truly environmentally friendly, research into their distribution and effects carries on, says Kolpin. “Over the next five years, we’re going to have a much better understanding of the bad actors out there.”
INFOGRAPHIC - THE FLOW OF PHARMACEUTICALS
Source : The Scientist, author Megan Scudellari is a freelance science writer in Boston, Massachusetts.
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Study backs up theory that warming, pollution combine to hurt Alaska's wood frogs
Alaska’s hardy wood frogs, like other amphibians around North America, have been plagued by a mysterious disorder that is deforming and killing them off.
In various spots in Southcentral and eastern Interior Alaska, clusters of frogs are emerging from ponds with misshapen or missing limbs, abnormal eyes or other physical oddities. Now, laboratory evidence is backing up some theories about the cause.
A study by researchers from Alaska Pacific University, the U.S. Fish and Wildlife Service and the University of California, Davis, found that in warmer water that contains minute traces of copper, dragonfly larvae attack wood frog tadpoles more quickly and frequently.
The study, published in the journal Ecosphere, supports two hypotheses about wood frog deformities in Alaska: one concerning warmer water temperatures that are hastening predation by tadpole-biting dragonfly larvae and the other concerning chemical contamination.
The laboratory study used water that was warmed up to 71.6 degrees Fahrenheit -- a temperature consistent with the warming that is happening in the wild and with what is forecast for the future, said co-author Mari Reeves, a U.S. Fish and Wildlife Service ecologist who has devoted several years to studying Alaska’s wood frogs.
What she, lead author Tess Hayden of APU and other scientists found was that, in a controlled laboratory setting, dragonfly larvae attack wood frog tadpoles 30 minutes earlier and three times as often in warmer, copper-tainted water than in clear and cooler water, which was down to 62.6 degrees.
Attacks by dragonfly larvae have been hypothesized to cause limb amputations for the frogs that grow from the tadpoles; warmer waters are believed to be encouraging a proliferation of dragonflies and their larvae. But chemical contamination is also believed to be a contributing factor.
In the laboratory study, tadpoles in the clean water spent more time swimming around in deeper areas; those in the water with copper spent more time being stationary near the surface, making them more vulnerable to attack, Reeves said.
Her hypothesis about that particular behavior is that copper, even in the minute amounts used in the study, interferes with frogs’ ability to get oxygen -- just as copper contamination is known to interfere with the functioning of fish gills and the ability of fish to get oxygen.
The level of copper in the water used in the laboratory study -- 1.85 parts per billion -- was minute, Reeves said, considering that 1 part per billion is like “one sheet of toilet paper in a roll of toilet paper that stretches from New York to London.”
And it was less than half the 4 parts per billion copper level found in Anchorage ponds and wetlands that are used to treat road drainage, she said.
The copper is believed to be coming from tiny particles that wear off on car brake pads. Because of the known risks to wildlife from copper, some states are considering bans on the use of copper in brake pads, Reeves said.
The laboratory findings come as part of a national program launched in 2000 to examine die-offs and deformities of amphibians, some of which are threatened with extinction.
A 10-year national study by the U.S. Fish and Wildlife Service, with results published in 2013 in the journal PLOS ONE, found hotspots for wood frog deformities in Alaska’s Kenai National Wildlife Refuge and Tetlin National Wildlife Refuge, along with hotspots for amphibian deformities in certain areas of the Lower 48.
That broad study built on earlier work, including a 2008 study led by Reeves which found that in Kenai and Tetlin National Refuge sites near roads, there was an especially high concentration of frog deformities -- up to 20 percent.
The new laboratory study is considered a follow-up to previous work, Reeves said. “This is kind of the tail end of those studies,” she said.
While deformities have been well-documented on the Kenai Peninsula, the area of trouble for wood frogs extends into Anchorage, Reeves said.
Though Anchorage wood frogs have not been studied as closely as those in the Kenai Refuge, it appears that urban development brings further stress to the amphibians as their territory becomes fragmented by pavement, she said.
“They need wetlands habitat and upland habitat and need to get between the two,” she said.
Source : Alaska Dispatch News
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Water toxins blamed for hundreds of turtle deaths
Hundreds of small turtles have washed up dead on the eastern end of Long Island in the last month, a die-off scientists blame on waterborne toxins that have reached unprecedented levels for reasons that aren’t entirely clear.
Necropsies on some of the more than 200 diamondback terrapins found on the island’s North Fork point to saxitoxin, a biotoxin produced in algae blooms that has been found in the water at 10 times the normal level. The poison collects in shellfish, which are eaten by the turtles in brackish bays and estuaries, quickly causing paralysis and death.
“We’re seeing bodies washing up in perfect condition. This has never happened before. It’s an alarming thing,” said Karen Testa, executive director of Turtle Rescue of the Hamptons, whose volunteers have collected dozens of dead turtles and sent them to state officials for analysis.
She says all signs point to saxitoxin. “There’s no other explanation for what’s causing the die-off of these poor animals,” she said.
Christopher Gobler, a professor at Stony Brook University’s School of Marine and Atmospheric Sciences who has studied algae blooms off Long Island for more than 20 years, said saxitoxin is normally detected in the region’s waters, but he has never seen saxitonin this high and never seen it cause such a wildlife die-off.
Red algae blooms produce the saxitoxin, which state officials have called a “dangerous neurotoxin” that can damage or impair nerve tissue. Shellfish filter the toxic algae cells from the water and when other creatures chomp down on the shellfish, they can become paralyzed.
Saxitoxin can also cause paralytic shellfish poisoning in humans, which typically results in numbness and tightening in the face and a loss of coordination. In most cases, patients make a full recovery in a few days, but rare cases have resulted in death.
Suffolk County has never had a reported case of illness or death related to saxitoxin, Assistant Deputy County Executive Justin Meyers said. But he said there is a “long-term potential threat to public health” if the saxitoxin levels continue to rise.
Meyers said county and state officials had advised people not to consume shellfish from the area and enacted a shellfishing ban for three creeks and bays. The county health department also advised against swimming in discolored water.
“This is a serious threat to public health,” said Adrienne Esposito, executive director of the Citizen’s Campaign for the Environment. “When you have a saxitoxin that can kill humans, you need to address the cause.”
Gobler and Esposito both believe the increase in saxitoxin levels may be related to nitrogen in the water caused by leaking septic tanks and sewage that makes its way into bays, though there appears to be no explanation for why the levels are now higher than ever before.
Meyers said the county has a plan to reduce nitrogen pollution, including acquiring $400 million in state and federal grants to improve wastewater infrastructure. The county also is trying to convert 360,000 homes from cesspools to municipal sewers
Source : Daily Record
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Starfish suffer mysterious and gruesome demise along west coast
The cause of the most deadly sea star epidemic in recorded history remains unclear, but experts believe it may be a poorly understood ‘wasting’ disease
It is a gruesome death. First the legs shrivel up, followed by lesions. Then the legs inch away and finally detach. The victim continues to deteriorate until it is nothing but a plot of sticky goo.
This is the thoroughly unpleasant way by which scores of sea stars, also known as starfish, have perished along the North American west coast in the most deadly epidemic to hit the iconic echinoderms in recorded history.
From southern Alaska down to Baja California, sea stars have been dying in droves. The culprit, it is suspected, is a little-understood “wasting” disease known as “sea star-associated densovirus”, or SSaDV.
“It is unprecedented,” says Richard Ambrose, a marine biologist at UCLA. “It’s a really extensive decline of a really important component of rocky tidal and subtidal communities along the whole west coast. It’s pretty serious.”
While this is not the first time sea stars have been hit by a mass wasting event –similar die-offs occurred in the 70s and late 90s, and their cause remains unknown – it is by far the most destructive, extensive and perplexing. First observed in Washington state in June 2013, the disease has gradually spread up and down the coast.
No one knows what exactly is behind the sea star’s suffering. A multi-authoredstudy published in the Proceeding of the National Academy of Sciences pins a densovirus as the most likely cause of the wasting but no one is certain why the virus, which has been in the aquatic ecosystem for years, is affecting sea stars today.
“The densovirus is a good candidate for the immediate cause but there has to be some other explanation for why we’re having an outbreak now. Nobody really understands why that is,” says Ambrose.
Part of its perplexity is the disease’s trajectory. It will hit one area, while leaving others around it safe, only to show up months later in the areas previously spared. This is in contrast to past wasting events which have been generally uniform across a region.
Peter Raimondi, a marine biologist at University of California, Santa Cruz, and co-author of the PNAS study, helps run an online observation log that plots the scope of the wasting. The observation log, which has a database of photos from scientists and concerned citizens alike, has been instrumental in monitoring the disease and will be crucial in ultimately determining the underlying causes.
“It is by far the best study in marine disease ever,” says Raimondi. “We are almost in real time being able to detect where the outbreak is and what species are being affected.”
Until the primary cause is known however, scientists have no way of combatting the disease.
So who, or what, are the suspects? The most obvious is warmer water temperatures. This has triggered sea star wasting events in the past. However the areas in the pacific northwest where the current wasting was initially observed are home to frigid waters.
A second guess is pollution, but this too is unconvincing, as the disease is found in both clean and dirty areas.
Some have cited radiation from the 2011 Fukushima Daiichi nuclear disaster in Japan as a possible cause, but there is no evidence that supports this.
Sea stars, a predator of mussels, clams and snails, are a vital component of the aquatic ecosystem. Their absence will undoubtedly have environmental repercussions. But due to the sheer scope of this die-off, it’s impossible to predict exactly what will happen in the ecosystem.
“A lot of people think nothing might occur and a lot of people think a lot’s going to occur,” says Raimondi. For now, there’s nothing to do but collect data and wait.
But there is hope on the horizon. Baby sea stars, about the size of the a thumb nail, have been sighted in several disease-hit areas along the coast. Raimondi’s log has added a page to collect observations of the infant stars.
The hope is that they have developed a resistance to the disease. Scientists are holding their breaths: the the babies will need to survive long enough to become reproductive if they are to make any difference and raise population levels.
If not, Pacific Coast sea stars are in for even rougher seas ahead.
Source : The Guardian
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Exposure to metformin, a first-line treatment for type-2 diabetes, feminizes male minnows and impacts fertility at levels common in wastewater effluent.
By Brian Bienkowski
Environmental Health News
Male minnows exposed to a widely used diabetes drug ubiquitous in wastewater effluent had feminized reproductive parts and were smaller and less fertile, according to a new study.
It is the first study to examine the drug metformin’s impact on fish endocrine systems and suggests that non-hormone pharmaceuticals pervasive in wastewater may cause reproductive and development problems in exposed fish.
Metformin is largely used to combat insulin resistance associated with type-2 diabetes, which accounts for about 90 percent of all diagnosed U.S. adult diabetes cases.
Researchers from the University of Wisconsin-Milwaukee exposed young fathead minnows to water containing levels of metformin commonly found in wastewater effluent. Eighty-four percent of 31 metformin-exposed male fish exhibited feminized reproductive organs.
“Normally in females you see eggs developed in ova, in males, you see a different structure – producing tiny sperm instead of an egg structure,” said Rebecca Klaper, an associate professor at the University of Wisconsin-Milwaukee and senior author of the study. “We saw development of larger egg structures within the [male’s] testis.”
A couple of non-exposed males had very minor feminization, but signs of egg development were nothing compared to what happened in the exposed fish, Klaper said. In addition to the feminization, exposed male minnows weighed less and had significantly less babies when they reproduced, suggesting that the feminization may impact their ability to reproduce properly.
Pharmaceutical chemicals are ubiquitous in wastewater effluent. Researchers estimate that, by mass, metformin is among the most common pharmaceutical in wastewater.
More than nine percent of the U.S. population has diabetes, according to the Centers for Disease Control and Prevention. The agency estimates that from 1980 to 2011, cases of diagnosed diabetes almost tripled.
Increased illnesses means more drugs. Pharmaceutical drugs get into our wastewater when people flush their medication or, more commonly, when they excrete them. Metformin, unlike many pharmaceutical drugs, is not metabolized by the human body, and gets excreted unchanged.
Metformin’s “really been hitting people’s radar more of late,” said Dana Kolpin, a U.S. Geological Survey research hydrologist based in Iowa and project chief of the agency’s emerging contaminants project. Kolpin said as water testing methods have gotten more sophisticated, metformin seems to be one of the most frequently detected. “It’s persistent and mobile,” he said.
Scientists have expressed concern that birth control and other hormone mimicking drugs in water could impact fish populations and cause feminization. Last year U.S. Geological Survey researchers reported intersex fish in Pennsylvania’s Susquehanna, Delaware and Ohio river basins, suggesting that estrogenic chemicals were to blame.
However, metformin is not an estrogenic or hormone-mimicking drug. Rather it is designed to improve insulin sensitivity. It appears a “nontraditional endocrine disrupting chemical,” Klaper and her University of Wisconsin-Milwaukee colleague, Nicholas Niemuth, wrote in the study published in the journal Chemosphere.
While researchers are not totally clear how the drug disrupts fish hormones, metformin has been shown to alter the activity of certain enzymes that are involved in hormone pathways.
“We know from some vertebrate studies that insulin and metabolism in an organism is tied into reproduction,” Klaper said. “But how metformin would cause a difference in actual egg production is something we don’t know but is very interesting. Now we’re trying to figure out why.”
Klaper previously found that metformin caused some signs of endocrine disruption when she exposed adult fish to the drug for 28 days. However, no intersex tissue was found, suggesting that exposure during development might be the major concern.
It’s not clear if all fish would react to metformin exposure as the fathead minnows did, Kolpin said. Klaper said the development of male and female fish is not entirely the same across species. She said they would continue testing fathead minnows and also look at zebrafish to see if they exhibit similar impacts.
Kolpin said some waterways also have been shown to have a metformin transformation compound, called guanylurea, which is formed when metformin comes in contact with bacteria such as in sewage.
“It’ll be worth finding out if its transformation product also has these bioactive properties,” Kolpin said.
The U.S. Environmental Protection Agency’s latest drinking water contaminant candidate list — water pollutants not subject to regulations yet but that might render water unsafe — includes several pharmaceuticals that act on hormones. Metformin is not on the list, published in February.
Klaper and Niemuth wrote that metformin would probably not show up as an endocrine disruptor under the current testing used by the U.S. EPA Agency, which relies on the binding of chemicals to hormone receptors. Structurally, metformin doesn’t resemble hormones. The results, they argue, suggest the EPA should broaden its testing.
“Given its environmental persistence and presence worldwide, this compound merits further research on its potential environmental impacts as well as its impacts on vertebrate development more generally and should be added to the list of potential EDCs [endocrine disrupting chemicals],” Klaper and Niemuth wrote.
Source : Environmental Health News
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Mercury Pollution Threat to Arctic Bird
Mercury pollution has risen nearly 50-fold in the feathers of a breed of Arctic bird over the past 130 years, say scientists.
Analysis of museum specimens shows high mercury levels in the endangered ivory gull.
It could have implications for the bird's ability to reproduce and raise chicks, says a Canadian team.
Mercury levels are going up in other Arctic birds, fish and mammals, due to atmospheric pollution, they report.
Biologists at the University of Saskatchewan, Canada, say the ivory gull (Pagophila eburnea) acts like a "mercury barometer", sounding alarm bells for contamination of Arctic animals with mercury pollution.
"We're concerned because the mercury's going up but their diet hasn't changed over the 130 years we've studied," lead researcher, Dr Alex Bond, told BBC News.
"This is a genuine increase - it's gone up 45 times, which is twice the average for an animal species in the Arctic."
Mercury in the atmosphere comes from natural sources such as volcanoes, as well as human activities like coal burning. Air currents can transport mercury to the Arctic from mid-latitudes in just a few days.
"A reduction in atmospheric mercury would be key - this is probably where much of it is coming from - and that would come by burning less coal," said Dr Bond.
Feather cluesThe researchers analysed museum feather samples of the ivory gull from the Canadian Arctic and western Greenland from 1877 to 2007.
They found the bird had been exposed to mercury for decades, from scavenging on the carcasses of whales, seals and other mammals killed by predators such as polar bears.
The gull is endangered in Canada, where numbers have declined by 80% since the 1980s.
Elsewhere, it is classified as near-threatened by the International Union for Conservation of Nature.
Rises in mercury levels could be due in part to this decline, as well as factors such as hunting and changes in the sea ice, the researchers reported in the journal, Proceedings of the Royal Society of London B- Biological Sciences.
Source : BBC News
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Monoculture and Loss of Biodiversity: Effects on Human Health
Robert Rountree, MD
Biodiversity, or biologic diversity, refers to the variety of life on Earth, including genetic diversity, species diversity, and diversity of ecosystems and habitats. Recently, scientists have shown interest in biodiversity in relation to health, as well as the relationship between diversity in general and health. Exploring or spending time in nature allows us to encounter numerous wild species.This connection between nature and biodiversity and health can be very healing; however, over the course of many wilderness hikes and scuba dives on coral reefs around the globe, I have seen a dramatic reduction in all types of wildlife over the last 30 years. This reduction in the number of species—a decline in biodiversity—parallels what the published research is showing, that there has been a huge drop-off in a wide range of wildlife all over the planet.
Many biologic scientists are calling this the sixth great extinction event.1,2 Recently, Eric Chivian, MD, and Aaron Bernstein, MD, of Harvard Medical School, Boston, Massachusetts, published a book entitled Sustaining Life: How Human Health Depends on Biodiversity.1 Drs. Chivian and Bernstein explain that the fifth most recent extinction was 65 million years ago when the dinosaurs became extinct. In this sixth extinction, we can expect a loss of ~ 40% of the world’s amphibian species and numerous mammals, as well as many species of insects and a wide variety of plants.
This loss will impact us in many ways. For example, we need bees to pollinate our food crops. More than a third of the foods we eat are pollinated by bees. When sufficient numbers of bees die, crops need to be pollinated by hand, a situation that is already occurring in parts of southwest China. Bats consume massive quantities of night-flying insects. Rapid declines in bat populations has resulted in an increase in insects that consume crops, which forces farmers to accelerate their use of insecticides. The yearly loss in square miles of the rainforest is another example of one part of this crisis concerning biodiversity. Rainforests have been called “the lungs of the planet,” because they consume carbon dioxide and generate copious amounts of oxygen. However, it has been estimated that we are losing 137 plant, animal, and insect species every single day as a result of rainforest deforestation. The loss of plant and animal species from the rainforests will obviously have a big impact on the way we eat and live. Although the loss of biodiversity is a topic of discussion in biologic circles, it is something that is almost never talked about in the medical community, despite the potential profound impact it can have on our health. This article explores biodiversity, as part of diversity in general, and the impacts on our health and well-being.
Reasons for the Loss in Biodiversity
There are many different reasons postulated to explain the increasing loss of biodiversity on our planet. While some of those reasons may be known, such as the loss of habitat, others are not as clear. The removal of trees is just one example of a loss of habitat. Brazil is one example of where this is happening on a large scale. In the Brazilian Amazon, a massive number of trees are being removed to make room for cattle and/or soybean fields. In Indonesia, the rainforests are being cleared rapidly to make room for palm-oil plantations. The loss of all these trees is having a huge impact on biodiversity, mainly with respect to a resulting loss of birds, primates, insects and native plants.3
Global climate and other environmental changes are also having an impact in other ways. For example, in coral reefs, large numbers of fish and other marine species are dying because the oceans are getting warmer and more polluted, along with other destructive human practices, such as harvesting fish by dynamiting the reefs.4 We know that a small change in water temperature, by as little as half a degree, can result in the death of coral.
Effects on Human Health In the case of bees, some scientists believe that the increasing use of pesticides, such as neonicotinoids, are at least partially responsible for the bees’ reduction in numbers.5 These pesticides weaken the immune systems of the bees, which makes them more susceptible to Varroa destructor mites and other harmful parasites. The result is sudden, large die-offs in entire colonies, a phenomenon known as Colony Collapse Disorder.
Amphibians comprise another example of a group of animals that we know are declining at alarming rates.6 These animals are known as indicator species, because they parallel a decline in both vertebrates and invertebrates.2,7 We know that all of these impacts—deforestation, human destruction of reefs, pesticides, pollution, increasing water temperature, and others—work together in a vicious cycle. How does all this affect our health? One example is the potential loss of medicines from the rainforest. In the book by Drs. Chivian and Bernstein, an example is given of a frog whose reproduction involves laying eggs and then swallowing them.1 The egg develops in the stomach of the frog so that, when the tadpole develops, it is released from the egg and vomited up by the frog. Scientists realized that the egg must be releasing some kind of chemical that blocks stomach acid. This had the potential to be of major benefit to people with gastric ulcers and other stomach problems. However, by the time scientists became interested in studying the mechanism, that particular species of frog became extinct.
Relationship Between the Loss of Biodiversity and Health
Although the loss in biodiversity can have numerous causes, in the end, it does not matter how the habitat is being changed. Just the fact that it is actually happening means we are losing animal and plant species and, with them, a loss of potential therapeutic options. Environmental changes can include urbanization, coastal reef damage, loss of freshwater and wetland habitats, deforestation, and land degradation. These changes can result in, or occur along with, the loss of species. Environmental changes can result in direct health impacts to populations, such as flooding, heat waves, water shortages, and exposure to pollutants. However, these changes can also result in more personal health impacts, such as an increase in the risk of infectious disease or reduced food growth caused by a decrease in arable farm land, resulting in malnutrition and impoverishment. There is also a potential for depletion in natural medicines. We know that there are numerous plants in the rainforest that potentially are of pharmaceutical benefit; however, many of these plant species are threatened because of activities such as logging.8
Relationship Between Biodiversity Loss and Increased Infectious Disease
Risk Scientists are researching the potential for loss of diversity to increase zoonotic diseases.9–12 Zoonoses are infectious diseases of animals that can be transmitted to humans. This association between changes in habitat and an increase in zoonoses has been examined in several studies. One prominent example is a study published in Nature, in 2010, entitled “Impacts of Biodiversity on Emergence and Transmission of Infectious Diseases.”12 This study examined twelve separate zoonotic diseases systematically. The researchers determined that each disease became more prevalent when biodiversity was lost. Some particularly disturbing examples of this phenomenon include West Nile and Lyme disease, both of which can have devastating effects on human hosts. In communities where destruction of woodlands has resulted in low bird biodiversity, the birds that remain, such as robins, crows, and blue jays, make particularly good hosts for the West Nile virus. This means that there are more birds that can be carriers for the virus, creating a larger reservoir for mosquitoes to become infected by the virus and pass it on to humans (i.e., the human infection rate rises).
Another example is Lyme disease. The spirochete bacteria (Borrelia burgdorferi) that causes Lyme disease is readily carried by white-footed mice (Peromyscus leucopus), which have poor immune systems that are not good at fighting off the bacteria. These mice are also poor groomers, resulting in ticks remaining on the mice for long periods of time. This makes it easier for the ticks to become infected with the spirochetes, which the ticks can pass on to humans during a blood meal. Other species, such as squirrels, are better at removing ticks from themselves and are less likely to infect—or be infected by—the ticks. When a forest is decimated, the predators that eat the white-footed mice, such as wolves and owls, are lost, as are the competitors of the mice. This has caused a fivefold increase in these mice in eastern U.S. forests—areas where Lyme disease is endemic. Also of interest, is the back story behind how the human immunodeficiency virus (HIV) made the jump from animals to humans. Some scientists believe that the epidemic resulted from humans increasing the amount of bush meat consumed because of a lack of usual food resources. This activity enabled human exposure to the virus in the chimpanzees. Similarly, Ebola virus is a zoonotic infection carried by fruit bats in the African forest. When those forests are cut down, the fruit bats are more likely to come in contact with people. One of those fruit bats was thought to be the vector of the West African Ebola epidemic that started with a single infected toddler in a small town in Guinea and subsequently spread to thousands of people in countries throughout the region with devastating effects. Normally, the “dilution effect,” of a healthier habitat, would result in a diminished ability for the bacteria, spirochetes, or viruses to find a competent host because the ideal reservoir (such as white-footed mice) has been diluted by competing species.
Current evidence suggests that preserving intact ecosystems and their endemic biodiversity should generally reduce the prevalence of infectious diseases. Relationship Between the Loss of Plant Species and Negative Health Effects It has been speculated that there are ~ 350,000–400,000 known plant species on the planet. Approximately 45% of these, or ~ 200,000 species, are potentially edible. However, only ~ 50,000 plant species are actually used as foods or in foods as spices, and, of these, only 15 crop plants are cultivated to provide 90% of the world’s food energy intake. These include rice, wheat, and corn,13 the major food crops that most humans commonly eat. Considering the massive number of potential plant and fungal food species, only a tiny fraction of the total is found on shelves in a typical grocery store. Generally, these are hardy plants that have been able to travel from where they were grown to the local grocery store—sometimes halfway across the world. This means that many heirloom crops with unique properties and flavors are not widely available for consumption. These unique crops are going extinct because of neglect. Recently, a study cited by the Global Crop Diversity Trust suggested that up to 95% of some fruit and vegetable varieties in the United States have become extinct over the past 100 years.14
The trend in our society is to move away from biodiversity and toward monoculture, which is the focus on growth of single crops, typically in huge farms run by large multinational corporations. In fact, the Center for Food Safety states that only a small number of corporations control more than half of the global commercial seed market.15 These corporations include Monsanto, with more than a quarter of the proprietary seed market, followed by DuPont, Syngenta, Bayer, Dow, and BASF.
Role of Genetically Modified Organism Crops in Biodiversity Decline
The two most common forms of genetic modification in large-scale production include insertion of a gene that confers resistance to certain herbicides, or a gene that produces a crystal toxin (Bacillus thuringiensis toxin) that protects the plant from certain insects. By genetically modifying a plant to be resistant to an herbicide such as glyphosate (Roundup®), the company is then able to sell the seed together with the herbicide, thus increasing the sales of both products. Studies by the U.S. Geologic Survey and other researchers have found that the use of glyphosate has become so ubiquitous that it commonly contaminates water supplies, the air, and produce.16–18 Consequently, laboratory studies have found glyphosate in the urine of individuals all over Europe, even though genetically modified organisms (GMOs) are banned in that part of the world.19 One of the economic advantages of GMO crops is that the plants have a resulting genetic signature that can be identified by laboratory testing, thus allowing the manufacturer to determine if a farmer is using that company’s seeds. This allows the seller to charge the farmer much higher prices for what the seeds would normally cost in the marketplace. If a farmer’s fields become inadvertently contaminated with the patented strain of seed, then the manufacturer has the right to sue the farmer for patent infringement—a scenario that has occurred many times with farmers in the United States and Canada. Companies who own the patents on GMO seeds have expressly and contractually forbidden all independent research on these seeds. This means that all the published research on these seeds only comes from “approved” sources.
This type of monoculture is a major contrast to the age-old practice in which farmers save their seeds at the end of the harvest and replant them the following year. Take the example of maize (Zea mays), also known as corn in many Englishspeaking countries. Maize represents a major cultural heritage for Mexico, where it has been cultivated for > 8000 years as a result of breeding teosinte (Zea spp.), a wild grass. There are now thousands of varieties of corn grown in Mexico, many of which are tied to specific indigenous groups and religious ceremonies. Because of genetic drift, all of these thousands of strains could potentially disappear forever, only to be replaced by a few monocultures of GMO maize. Fortunately, in 2013, the Mexican government banned planting of GMO maize, although it remains to be seen how long this ban will last. One of the selling points for GMO crops is that they will solve the current hunger crisis by helping to produce enough food to feed the world. However, according to the U.S. Department of Agriculture and other scientists, there are no good data indicating that genetic modification of plants increases crop yields.20 Furthermore, most of the GMO crops grown in the United States are used for animal feed and for production of highly processed foods, which does nothing to address poor nutrition related to poverty. In addition, the issue of super weeds is increasingly becoming problematic because increasing numbers of weeds are developing resistance to glyphosate, requiring ever-increasing amounts of herbicide.21
Placing so much emphasis on the narrow focus of genetically altered herbicide-resistant crops results in a lack of discussion about long-term sustainable approaches, such as integrated weed management.21 Rather, the increase in superweeds resistant to existing herbicides has led to development of GMO plants that are tolerant of additional herbicides, such as 2,4-D (2,4-dichlorophenoxyacetic acid), a component of Agent Orange, which has long been implicated in a wide range of health problems. Recently, despite protests from a large number of health organizations, the U.S. Environmental Protection Agency approved a request to sell Enlist Duo,™ a product made by Dow Chemicals, which consists of GMO seeds tolerant of a product known as Roundup and of 2,4-D.22 Likewise, Monsanto has created a product called Roundup Xtend,™ which combines glyphosate with dicamba (3,6-dichloro-2-methoxybenzoic acid), an organochlorine herbicide. This never-ending spiral of engineering crops tolerant of increasingly powerful (and toxic) combinations of pesticides can be likened to the Greek myth of the multiheaded serpentine Lernaean Hydra: Every time one tries to cut off a head of the Hydra, two more appear. In many ways, this scenario is identical to what has happened with antibiotics and bacteria. Widespread overuse of antibiotics has led to the rise of resistant “superbugs.” In response, we have created ever more potent antibiotics, only to find that bacteria quickly mutate to outsmart the drugs and become resistant to everything used to defeat the bacteria. The antibioticresistant genes are then transferred to bacteriophages, which spread these genes rapidly through the planetary microbiome. Although the marketing materials issued by companies that develop these crops state that they will increase self-sufficiency and security, and conserve biodiversity, these findings were not supported by the report from The Center for Health and the Global Environment at the Harvard School of Public Health.23 The report stated that GMO foods may actually damage biodiversity by promoting greater use of pesticides associated with GMO crops. These pesticides are toxic to some species and will introduce exotic genes and organisms into the environment, which will become woven into the DNA of wild and traditionally cultivated plants. All of this will add up to GMO crops taking over existing varieties of plants. In addition, the cost of planting these crops is much more expensive, which puts a serious strain on farmers’ budgets. A recent study suggests that, if farmers simply diversified their crop rotations—such as including a small grain crop, for example, oats, along with the corn/soy rotation and offseason cover crops—weeds were suppressed even while using less fertilizer and herbicides.24
Relationships Among Biodiversity in Soil, Biodiversity in the Gut, and Health Soil has often been called the “skin of the earth.” Because of urbanization, there is an increasing issue worldwide with the loss of arable land or fertile soils used for growing crops and other plants. The biodiversity and the overall quality of the world’s soils have been affected profoundly. Soils contain tens of thousands of bacterial taxa, as well as millions of fungal hyphae, mites, nematodes, earthworms, and arthropods.25 Soils are regularly being sprayed with herbicides, pesticides, and fumigants. A fumigant essentially destroys all living material in the soil and sterilizes it. Once the natural microbial diversity of the soil has been destroyed in such a manner, it can never be replaced. Daphne Miller, MD, a family doctor who practices in San Francisco, California, recently wrote a book on this topic.26 In her book, she discusses the relationship between a healthy patient and a healthy farm, and the critical role of the soil in the healthy farm. By losing the diversity of microbes in the soil, crop growth is being affected negatively.25 Dr. Miller aptly points out the many parallels among microbial and nutritional diversity in the soil, in animals, and in humans. These issues are also addressed in Symphony of the Soil, 27 a powerful documentary directed by Deborah Koons Garcia. Simply put, these are all different components of the same biologic system. Gut microbial diversity is much higher in some hunter– gatherer societies, such as the Hadza tribe in Tanzania. This has been investigated by The Human Food Project, a study investigating microbial diversity of feces using DNA analysis.28 Ongoing research in the Human Genome Project is attempting to determine what specific dietary components and lifestyle factors contribute to increased microbial diversity and richness in our intestines. Many scientists are suggesting that the loss of diversity of soil microbes is overlapping with what is happening in our gut microbiomes. Martin Blaser, MD—former chair of the Department of Medicine at New York University (NYU) Langone Medical Center, and current director of the NYU Human Microbiome Program—recently wrote a book entitled Missing Microbes: How the Overuse of Antibiotics is Fueling Our Modern Plagues.29 The premise of Dr. Blaser’s book is that we are experiencing a loss of diversity of our gut bacteria and that this is increasing our risk of developing chronic diseases.30 Some of the diseases associated with decreased diversity of the gut microbiome include obesity, type 1 diabetes, allergies, inflammatory bowel disease, and asthma.29,31 This also relates to the “hygiene hypothesis,” which I have discussed in a previous column.32 This hypothesis suggests that a lack of exposure to “bugs” has been implicated in allergies and autoimmune diseases.33 Dr. Blaser suggests that one possible reason for this is the overuse of antibiotics. Being born by cesarean section, living in excessively sterile environments, consuming diets low in fiber, and aging also play roles in the decrease of microbial diversity. Although use of prebiotics, probiotics, or fecal microbiota transplants are potential options for restoring microbial diversity in the intestines of people with chronic health problems, a better approach for the general public is to prevent this loss in the first place. We need to stop the indiscriminate use of so many antibiotics, pesticides, and herbicides. By losing the diversity of microbes in the soil, crop growth is being affected negatively. Remember there is a complete parallel between what is happening in nature and on the farm with the soil, and what is happening in the human gut, with respect to a loss of microbial diversity. Adding compost to the soil, or using purified fecal samples for transplants, are basically dealing with the issue of unhealthy soil and an unhealthy gut in the same way—by adding back the microbial diversity that has been lost.
Parallels Among Biodiversity Loss, Global Business Diversity Loss, and Health Interestingly, we are not just experiencing a loss of biodiversity in nature. There is also a declining diversity within health care, which seems to be moving toward a one-size-fits-all approach to disease. In particular, the loss of diversity within the pharmaceutical industry is also impacting our patients’ health and their wallets. Just comparing the Physician’s Desk Reference of today34 with one from ~ 10 years ago reveals that many of the common, inexpensive drugs that were extant for years are suddenly no longer available, only to be replaced by extremely expensive alternatives. For example, mebendazole—which was approved by the U.S. Food and Drug Administration (FDA) in 1974, and has long been a standard, effective, inexpensive, and safe treatment for helminths and other intestinal parasites—is no longer being manufactured and is now unavailable in the United States. In some cases, the only viable alternative is albendazole, which, despite being on the market since 1982, has an average wholesale price of ~ $6.00 per daily dose. This dire situation was discussed in some detail in a recent, disturbing editorial in The New England Journal of Medicine entitled “High-Cost Generic Drugs—Implications for Patients and Policymakers.”35 Other new drugs have come on the market that are not necessarily more effective but are a lot more expensive. In fact, some agents are so expensive that insurance companies are unwilling to pay for them unless the insured person is very ill. An example of this is Harvoni® (a combination of sofosbuvir and ledipasvir), used for treating hepatitis C. It is a highly effective drug with minimal side-effects. Unfortunately, most of the people who could benefit cannot afford its unreasonably high cost of $85,000–95,000 for a course of treatment. Colchicine is another example. Colchicine is an herbal medicine—derived from the autumn crocus plant (Colchicum autumnale)—that has been prescribed for more than 3000 years for flares and prevention of gout.36 However, a few years ago the FDA suddenly realized that this medicine had never been officially “approved.” The FDA demanded clinical trials before the drug could continue to be sold. Given this was a generic drug, there was little profit motive for the companies that were selling it to spend the millions of dollars necessary for a human study. Instead, Sun Pharma (originally URL Pharma) became a new player in that market by conducting a single clinical trial of 1 week’s duration. Based on the positive results of that trial, the FDA allowed only Sun Pharma to sell colchicine—all the other manufacturers were forced to stop making the drug. Consequently, the cost skyrocketed from $0.10 per pill to $4.85 per pill, although there was no significant difference in the “new” medication, compared to what had already been on the market for many years. This means that elderly patients with gout who are dependent on colchicine are now facing a serious financial crisis if they want to keep taking the drug. This situation does not benefit anyone other than the company that makes the profit. It is based on a system of greed, rather than one that is genuinely trying to help people. I see a direct parallel between pharmaceutical companies that are charging extraordinary amounts of money for their new drugs (some of which are not new at all) with the agricultural companies that manufacture patented seeds for GMO crops. These seeds provide no unique benefit to consumers, and it is unclear if these crops genuinely provide any benefit to farmers. However, it is very clear that GMO crops provide significant financial benefits for their manufacturers. Although the FDA states that it aims to ensure that no one is getting hurt, there was very little evidence that people were being harmed by contaminated or “unapproved” colchicine products. In contrast, there is clear financial harm to people who will go bankrupt because of the increased health care costs of the most expensive versions of drugs they have replaced for inexpensive—but effective—generics these patients have been taking for years.
Conclusion In the last few years, there seems to be no end to the bad news about animals and plants that are on the verge of extinction. Every day we hear the sad story of yet another species that is rapidly in decline or at risk of disappearing, including polar bears, sea stars, sea turtles, wild salmon, Atlantic cod, orca whales, coral reefs, frogs, salamanders, bats, honeybees, Monarch butterflies, or gray wolves. Each situation is distressing in and of itself, but when this phenomenon is viewed as a whole, the staggering immensity of it all should be a major source of alarm and a call to action. Unfortunately, a large number of influential politicians are all too willing to dismiss the overwhelming amount of firm scientific evidence showing that we are entering the sixth extinction event. These politicians believe that we should continue moving along the identical path at full speed: extracting as many resources as we can from the planet without any regard for long-term consequences. The Endangered Species Act (ESA) is arguably one of the most powerful pieces of environmental legislation ever to be introduced by the U.S. Congress. Unfortunately, a number of politicians currently in power have vowed to dismantle the act because it gets in the way of cutting down forests, damming rivers, or drilling for oil, gas, and minerals. These extraction industries may provide us with short-term financial gains, but, in the long run, we risk depleting the ecosystem and the diversity of plant and animal species necessary for our survival. It will be a different world without frogs and honeybees. In my opinion, the ESA is a critical legal bulwark against forces that seriously threaten the survival of the human species. As a concerned health care provider, I believe that we should uphold that legislation at all costs. One way to do this is to select several environmental organizations, such as the Center for Biological Diversity or the Natural Resources Defense Council, and support them with generous donations.
I would like to end this discussion on a positive note by suggesting some options for increasing biodiversity in our lives. The first is to increase the diversity of foods we eat. We can do this by regularly going to farmer’s markets and trying new and interesting foods, such as different varieties of tomatoes and zucchini, as well as other unique fruits and vegetables. Although this costs a little more, I believe the price is worth it, given that increased consumer demand will encourage the production of heirloom plants, and that will support the growth of small farms. We can also encourage our patients to increase the variety of foods they eat, based on the U.S. Healthy Foods Diversity Index.37 Eating organic, locally grown food (especially food we have grown ourselves) is another way to support biodiversity. Most GMO products are used to make highly processed foods. Eating fresh, minimally processed foods is the best way to avoid supporting the GMO industry. At the same time, we should avoid the use of foods containing palm oil from unsustainable plantations. Much of the deforestation that occurs in Indonesia involves replacing the forest with palm tree plantations. Boycotting oil from these plantations will let the large food companies know that this practice is unacceptable. Minimizing the use of plastics and synthetic personal care products is another way to support planetary diversity. In addition, we need to find a way to encourage the use of botanical medicines for self-care and for clinical purposes. Botanical medicine represents the opposite of monoculture, and provides a major opportunity for increasing diversity and truly personalized medicine. James A. Duke, PhD—a world-renowned researcher and author in the field of botanical medicines—has pointed out that, unlike synthetic medications, our bodies have interacted with the phytochemicals in plants for millennia. There remains a huge potential for us to find new beneficial phytochemicals in wild plants, but only if we can keep the rainforests intact long enough for us to explore what is out there. There is a lot of traditional wisdom about the healing properties of plants that we could learn from indigenous peoples before that knowledge is lost forever. It is not too late to start, but, given that we are already in an era of a major biologic extinction event, there is clearly a great urgency to the task at hand.
Source : Journal Alternative and Complementary Medicine
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Michigan’s bald eagles full of flame retardants.
What does your old couch have to do with the health of the nation’s most iconic bird? More than you think.
Michigan’s bald eagles are among the most contaminated birds on the planet when it comes to phased-out flame retardant chemicals in their livers, according to new research.
The study, published last month in the Journal of Great Lakes Research, found that the top predators in the Great Lakes are highly exposed to banned flame retardants, still widespread in the environment.
Michigan’s population of bald eagles is stable, but the compounds have been linked in other birds to impaired reproduction, weird behavior and development, and hormone disruption.
“While the sensitivity of eagles to PBDEs has yet to be determined, there is a possibility that the exposures reported here may be associated with sub-clinical effects,” Nil Basu, an associate professor at McGill University who led study while at the University of Michigan, said in an email.
More than four decades ago, companies started putting polybrominated diphenyl ethers, PBDEs, into furniture cushions, electronics and clothing in an effort to slow the spread of flames if they catch fire.
The chemicals quickly built up in people and the environment. Starting in the early 2000s, phase-outs began. PBDEs have been found in air, dirt and people in virtually every corner of the globe, including the Great Lakes region.
The compounds can leach out of products they were used in and stay in the environment for a long time. It’s most likely the eagles are exposed through eating contaminated fish. But the chemicals also can enter landfills, latch onto dust and be inhaled, or be licked off the feathers, Basu said.
The chemicals "are everywhere,” Basu said. “They build up in the food chains so that top predators – such as bald eagles – accumulate high levels.”
Flame retardants have been found in birds all over the world – from the United States to China.
The researchers tested the liver tissues of 33 dead bald eagles collected from 2009 to 2011 by the Michigan Department of Natural Resources. They tested for four common types of PBDEs; all but two of the birds had all four compounds in their liver.
PBDE concentrations were "among the highest found in liver tissues of any wildlife,” the authors wrote, with one eagle measuring 1,538 parts per billion PBDEs in its liver. Americans have some of the highest levels of PBDEs in their bodies worldwide, with studies of U.S. breast milk finding median PBDE concentrations of about 30 ppb, though the types of PBDEs vary.
Tom Cooley, a wildlife pathologist with Michigan’s Department of Natural Resources, is in charge of figuring out why animals die in Michigan. In bald eagles it’s often things such as electrocutions, getting hit by cars, or lead poisoning, he said. The state does not usually test wildlife for flame retardants.
The four major PBDE compounds found in the bald eagles were from the flame retardant sold commercially as penta-PBDE mixture, used in plastics, wire insulation, cars and some textiles.
In 2009, penta, along with another common mixture octa, were added to a United Nations' Stockholm Convention as persistent pollutants to be phased out by countries around the world.
But, just as its chemical predecessors, PBDEs are “very persistent” once they get into the environment, said Marta Venier, an assistant scientist with Indiana University.
“We can expect to see PBDEs in wildlife for a long time,” she said. In the current study, the researchers also found PBDEs in the liver tissue of all 35 dead river otters that were collected throughout Wisconsin from 2009 to 2010.
Bald eagles nest statewide in Michigan, Cooley said. The state’s birds – just like the rest of the nation – were on the brink of extinction in the 1950s and early 1960s, mostly due to chemicals such as PCBs and DDT in pesticides.
In the late 1960s researchers recognized the problem and chemical bans and species protection spurred a comeback.
Michigan’s population is strong and has been going up, Cooley said. “We have about 750 active nests throughout the state,” he said.
Research on PBDEs suggests the compounds might harm highly exposed birds.
There is “great concern” about the exposure because eagles are not only exposed to flame retardants but “hundreds of other potentially toxic chemicals,” Basu said. “We know very little of how contaminants interact to affect health,” he said.
Much of the research on what PBDE exposure might mean to birds has been done on captive kestrels. Canadian researchers have found that exposure to the compounds as an embryo caused development and reproduction problems in male birds.
Chemicals do not impact all bird species in the same way so it is unclear how, if at all, the compounds impact Michigan’s bald eagles.
“If there were health problems, it would be kind of under the radar and we wouldn’t necessarily notice in the [dead] birds we got in here,” Cooley said.
The bald eagles might have more flame retardants in them than recent research indicates. “They focused on a small range of PBDEs,” Venier said, adding that there are many other mixtures outside of the four the group studied.
Basu said that banned PBDEs should eventually decrease in the eagles but, he cautioned, “it can take years or decades for this to occur.”
In addition, there are now replacement flame retardants, too, with unknown but potentially worrisome environmental health risks.
“The market of flame retardants is a bit like a whack-a-mole game,” Venier said. “One gets phased out and another one is introduced keeping properties similar to the one it replaced.
“It goes on and on.”
Source : Environmental Health News
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Common bird species such as sparrow and skylark facing decline in Europe
Some rarer birds have grown in number over last 30 years due to conservation efforts while some well known species have fallen
Bird populations across Europe have decreased by over 420 million in the past 30 years, according to a study that brings together the results of scientific surveys in 25 countries While some rarer species have seen an increase in numbers due to concerted conservation efforts, more common species across Europe are facing a steep decline.
Some of the birds that have suffered the most alarming declines are the most well known species including the house sparrow which has fallen in number by 147m or 62%, the starling (53%) and skylark (46%).
The study looked at 144 species across Europe between 1980 and 2009. Dividing the species up into four groups, from extremely rare to most common, analysts found that a small number of common species declined by over 350 million –over 80% of the total population decline of birds in that time period overall. Rarer birds, in contrast, increased by over 21,000 in the same time period.
The results indicate that efforts at conserving rarer species seem to be having an impact but may be too narrow an approach, possibly at the expense of more common species.
“The focus up to this point has very much been on conserving rare species,” says the lead author, Richard Inger, from the University of Exeter. “That’s what it should be, in many ways, but the issue there is that if you’re not careful, you can spend all of your conservation dollars on just protecting the rare things. You can take your eye off the ball, if you will.”
Birds which increased over the course of the study include the blackcap (up 114%), common chiffchaff (up 76%) and wren (56%).
The issue is complicated by the fact that conserving rare bird species is relatively easy in comparison to more widespread efforts required to conserve common ones. “If the species is very localised, there may be very strong conservation measures,” says Graham Madge, a spokesman for the Royal Society for the Preservation of Birds, which collaborated on the study. “Whereas for a species like the skylark, which will occur in most countries across Europe, it’s much harder to bring in a rescue measure because it requires the rollout of broad, landscape-scale conservation measures.”
The most commonly cited reason for this vast decline in bird species is agricultural intensification which has squeezed out areas that birds need for feeding and nesting.
But Inger emphasises that this can’t be seen as the only problem. “People have tended to concentrate on farmland, but some of these species that don’t use farmland habitats at all are also declining. It’s a sign of wider scale environmental issues, such as increases in urbanisation, and the only way we’re going to protect these widespread species is a more holistic approach to how we manage the environment in general.”
Nevertheless, Madge and Inger agree that wildlife-friendly farming schemes like the UK’s will be necessary to focus conservation efforts beyond token rarer species. But the repercussions extend beyond just bird biodiversity, as birds play vital roles in ecosystem processes such as decomposition, pest control, pollination, and seed dispersal. Since common species exist in higher numbers, they play a bigger role in maintaining the ecosystem as well.
“This was a bit of a wake-up call really,” says Inger. “We knew we were going to see a big decline in bird populations, but to see how big that number really was and how focused the declines were on this small number of common species was really very surprising.”
Source : The Guardian
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Drugs flushed into the environment could be cause of wildlife decline
New studies show antidepressants causing starlings to feed less and contraceptive drugs reducing fish populations in lakes
Potent pharmaceuticals flushed into the environment via human and animal sewage could be a hidden cause of the global wildlife crisis, according to new research. The scientists warn that worldwide use of the drugs, which are designed to be biologically active at low concentrations, is rising rapidly but that too little is currently known about their effect on the natural world. Studies of the effect of pharmaceutical contamination on wildlife are rare but new work published on Monday reveals that an anti-depressant reduces feeding in starlings and that a contraceptive drug slashes fish populations in lakes.
“With thousands of pharmaceuticals in use globally, they have the potential to have potent effects on wildlife and ecosystems,” said Kathryn Arnold, at the University of York, who edited a special issue of the journal Philosophical Transactions of the Royal Society B. ”Given the many benefits of pharmaceuticals, there is a need for science to deliver better estimates of the environmental risks they pose.”
She said: “Given that populations of many species living in human-altered landscapes are declining for reasons that cannot be fully explained, we believe that it is time to explore emerging challenges,” such as pharmaceutical pollution.
Research published in September revealed half of the planet’s wild animals had been wiped out in the last 40 years. In freshwater habitats, where drug residues are most commonly found, the research found 75% of fish and amphibians had been lost.
A few dramatic examples of wildlife harmed by drug contamination have been discovered previously, including male fish being feminised by the synthetic hormones used in birth-control pills and vultures in India being virtually wiped out by an anti-inflammatory drug given to the cattle on whose carcasses they feed. Inter-sex frogs have also recently been found in urban ponds contaminated with wastewater.
But because the pharmaceuticals are not designed to kill – unlike pesticides – the damage caused to wildlife can be more subtle.
In one of the new studies, Tom Bean at the University of York and colleagues, showed that the common antidepressant fluoxetine, at the low levels expected in the environment, led starlings to feed less often during the key foraging times of sunrise and sunset. “Importantly, fluoxetine is not the only pharmaceutical, or indeed the only antidepressant, to be detected in the environment,” he said. “Mixtures of pharmaceuticals could potentially be more potent.”
Another new study, led by Karen Kidd at the University of New Brunswick, showed synthetic oestrogen used in the birth control pill not only wiped out fathead minnows in lakes used for experiments in Ontario, but also seriously disrupted the whole ecosystem. The lakes’ top predator – trout – declined by 23-42%, due to the loss of the minnow and other prey, while insects increased as they were no longer being eaten by the minnows.
Amphibians are suffering the hardest in the global biodiversity decline and Cecilia Berg, at Uppsala University, and colleagues reported that a number of hormonally active pharmaceuticals harm reproduction in amphibians at concentrations that occur in natural waters.
The most environmentally dangerous drugs are identified in a paper by Anette Küster and Nicole Adler, both at Germany’s Federal Environment Agency. “For human medicinal products, hormones, antibiotics, [painkillers], antidepressants and [anti-cancer drugs] indicated an environmental risk,” they said. For veterinary drugs, hormones, antibiotics and parasiticides were highlighted.
Pharmaceuticals can contaminate the environment through discharges from drug factories, as well as through sewage. Professor Joakim Larsson, at the University of Gothenburg, found that drug levels in effluents can even exceed those found in the blood of people taking medication.
Larsson cited antibiotic pollution coming from factories in China, India, Pakistan, Korea, Denmark, Norway and Croatia. “Although pollution from manufacturing is less widespread, discharges that promote the development of drug-resistant microorganisms can still have global consequences.” He also documented antidepressant pollution from factories in Switzerland, Israel and Spain and “narcotic opioid” pollution in the US.
The use of pharmaceuticals is rising with increases in the human population and the livestock it keeps. Environmental exposure is also rising as sewage is increasingly used to irrigate or fertilise farmland. In the US, for example, about 4m tonnes of dry sewage biosolids are applied to land each year.
Sally Gaw, at the University of Canterbury, and colleagues warned that even less is known about the effect of pharmaceutical pollution in the oceans. “This is a critical knowledge gap given the significant increase in coastal human populations around the globe and the growth of coastal megacities, together with the increasing importance of coastal [fisheries] around the world.”
Source : The Guardian
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Toxic gulls: Quebec's contaminated bird colony offers clues about flame retardants
By Brian Bienkowski
DESLAURIERS ISLAND, Quebec – There are no homes, few trees and no real reason for any human to visit this 45-acre hunk of clay and dirt. Gulls run this island, their screaming audible for miles, their guano covering every square foot.
“There are about 100,000 of them,” says Jonathan Verreault. “And they’re pretty loud.”
An avian toxicologist, Verreault has ventured to this island in the St. Lawrence River about two miles off the tip of Montreal dozens of times over the past four years.
From afar it seems inconsequential, a barren landscape crumbling around its edges after decades of battering from high water and giant ships. Yet it is a focal point of research exploring the health effects of widely used chemicals that have contaminated animals, people and the environment around the globe.
The gulls that inhabit Deslauriers Island every summer are the most contaminated colony in Canada when it comes to flame retardants, including one compound that has accumulated in their eggs at concentrations up to 44 times higher than elsewhere.
Although several of these flame retardants were banned a decade ago, they are still showing up in gulls, kestrels and other winged creatures from the Great Lakes to China, prompting scientists to examine where they are lingering, what hidden health effects they are having on birds and what this all might mean for humans.
Research on Deslauriers and in Canadian laboratories indicates that flame retardants are altering birds’ thyroid hormones, reducing their clutch sizes, damaging their eggs, changing their behavior, shifting their gender ratio toward males and weakening their bones.
“Unfortunately for birds they’re the sentinels,” said U.S. National Institute of Environmental Health Sciences Director Linda Birnbaum, a toxicologist who specializes in the health effects of environmental contaminants.
“If we ignore what we see in birds we ignore real risk.”
Shrieking chemical monitors
The Jacques-Cartier Bridge is packed with honking cars and aggressive bicyclists trying to squeeze into Montreal. But on this late-spring morning, Verreault, an associate professor at the Université du Québec à Montréal, is headed west, toward a different kind of chaos.
About 5 percent of the world’s ring-billed gulls – about 48,000 pairs – inhabit Deslauriers Island. Their namesake comes from the black ring around the tip of their yellow bill. Orange rings circle their intense yellow eyes, a sharp contrast against their white body and drab gray wings.
The gulls, which winter mostly in the Great Lakes region and the Southeastern United States, arrive on the island around March to have babies and, like the tourists in nearby Old Montreal, enjoy the local urban dining options.
Verreault is greeted at a makeshift boat launch by Francis St-Pierre, a wildlife technician in charge of getting people to the island and back in one piece.
“You should’ve been here yesterday. Yesterday it was like summer,” St-Pierre says, tossing out winter coat-sized life preservers. “It’s rough out there today … Wind out of the north.”
The St. Lawrence River bounces the boat around as St-Pierre zigzags through the choppy current. Deslauriers takes shape in the distance. They hear the island before they reach it – a piercing cacophony of gulls swirling over the island and water.
Some gulls sit on crumbling nests of green and brown speckled eggs about the size of a chicken’s, biting each other whenever one gets too close. Others scurry around, occasionally taking flight. They all shriek maniacally, seemingly annoyed by the humans prying around their business.
“They don’t really attack or anything,” Verreault says, as he greets his team of graduate students and steps carefully so as not to step on any eggs. Chloé Desjardins, a graduate student of Verreault’s, smiles and pulls up a poncho sleeve to expose a fresh purple bruise from a snapping gull.
Using the gulls as chemical monitors for the region, Verreault and his team have been coming here during the late spring and early summer since 2010. A human presence in Montreal helps this colony – where there are people, there’s food. Flame retardants from furniture and electronics have permeated a landfill on the mainland where the gulls feed, the small fish they pluck out of the St. Lawrence River and a Montreal sewage treatment plant where they congregate.
“If something’s not in ring-billed gulls, it’s likely not in other species,” Verreault says.
Verreault has put in his time doing the dirty work and is now mostly an observer at Deslauriers. Four graduate students speak in clipped French to one another and weave around masses of gulls. They carry a remote control from a toy car and a metal case with wires protruding. Anthony Francois and his bird poop-covered colleagues set the trap – thin fishing line circling a bird nest connected to a battery and a trigger – and walk away with their remote to wait for a gull to plop back down on its eggs.
“We have about an 80 percent success rate in catching them,” Verreault says, proud of the homemade contraption. The numbers are on the scientists’ side today. The gull ambles back to its nest and is soon caught up in the line.
They capture, draw blood and then kill some gulls from the island every spring before the babies hatch. In a makeshift laboratory sheltered from the gulls by tall reeds, the students kill the bird using a horse castrator then use miniature razor blades to slice up the thyroid glands, liver and brains, storing all of the organs in nitrogen to bring back to the lab later that evening to test for contaminants.
All the gulls they test contain traces of flame retardants. Since the 1970s companies have added these chemicals, called polybrominated diphenyl ethers or PBDEs, to furniture cushions, electronics and clothing in an effort to slow the spread of flames if they catch fire.
The chemicals quickly built up in people and the environment. The world took notice in 2000 when Swedish researchers found that PBDEs were doubling in women’s breast milk every five years.
Over the next decade, regulations aimed at curbing PBDE use culminated in 2009 when two common mixtures, penta and octa, were added to a United Nations treaty, the Stockholm Convention, as persistent pollutants to be phased out by 152 countries.
"If something's not in ring-billed gulls, it's likely not in other species." –Jonathan Verreault, Université du Québec à MontréalFlame retardants stay in the environment for a long time and accumulate in wildlife tissues by moving up food chains. For birds, the original worry was for species that ate a lot of contaminated fish, such as the Great Lakes’ herring gulls.
However, researchers a decade ago found flame retardants in Sweden’s peregrine falcons, a land-based bird of prey. It was quite a shock because most experts thought PBDEs would act like the infamous industrial chemicals called PCBs, and accumulate mostly in fish, not in land creatures, said Cynthia de Wit, a Stockholm University professor who studied the falcons.
“We found them in cow tissues and such and I started thinking, what other animals in the terrestrial environment could end up with high levels?” de Wit said. “Everyone thinks of eagles and falcons because of DDT. And then wow, we found it.”
Dosing captive kestrels
Examining wild birds, however, wasn’t enough to figure out whether the chemicals were harming them.
By dosing captive kestrels – North America’s fierce little falcon – with levels found in wild birds, Kim Fernie and her colleagues have spent more than a decade pumping out evidence that flame retardants could be damaging kestrels' health and reducing their populations.
“We can’t do cause and effect studies with wild birds,” said Fernie, a research scientist with Environment Canada. “Birds are exposed to so many different types of stressors and to a whole slew of chemicals.”
Most of their findings have shown changes to kestrels’ reproduction. Exposure to PBDEs as an embryo caused enlarged testicles and decreased testosterone for male birds. When male kestrels ate a diet containing a newer flame retardant, called TBECH, before mating, 47 percent of the nests had at least one failed egg, compared with 23 percent of the non-exposed males. The exposed kestrels had about half as many male offspring.
During egg hatching in the laboratory, exposed kestrels had lower nest temperatures, which are critical for baby birds to develop properly. And when the birds were fed PBDE amounts found in wild birds, higher levels of the chemicals meant smaller eggs with thinner shells and delayed egg laying.
It seemed to span generations, as male kestrels that were exposed to PBDEs through their mothers grew up and couldn’t reproduce as well – 43 percent of their female pairs failed to lay eggs, and the males made fewer mating calls. Work with other birds corroborated such generational impacts, as zebra finches exposed to PBDEs while still in their eggs grew up to have smaller clutch sizes. Their baby birds also were born smaller than those of unexposed birds.
Then there’s the weird behavior.
When male kestrels dosed with PBDEs had their nestlings “they entered the nestbox less often and retrieved food less often” than non-exposed birds, Fernie said. The females made fewer mating calls and ate less. In unpublished research, male kestrels’ aggression levels were two times higher during courtship and incubation if they had been exposed to TBECH, Fernie reported at a toxicology conference.
“Anytime you see interference with reproduction or development, especially in captive populations like this, it should be a big red flag,” said Michael Fry, an environmental contaminant specialist with the U.S. Fish and Wildlife Service.
American kestrels declined about 1.5 percent a year between 1966 and 2010, according to the Cornell Lab of Ornithology. But it’s complicated when trying to pin a population decline on a specific contaminant, Fry said. Kestrels also struggle with habitat loss and other chemicals.
"Anytime you see interference with reproduction or development, especially in captive populations like this, it should be a big red flag." –Michael Fry, U.S. Fish and Wildlife ServiceJust because chemicals harm one bird species doesn’t mean it harms others, said Rob Letcher, a research scientist with Environment Canada. Nevertheless, PBDEs seem to affect thyroid hormones in glaucous and herring gulls.
And some initial evidence at Deslauriers suggests the flame retardants might mess with ring-billed gulls’ hormones, too. Gulls with high levels of flame retardants, especially the PBDE mixture called deca, are more likely to have altered thyroid hormones and lower bone mineral density, Verreault said. Thyroid hormones have been varied – both high and low – in Deslauriers’ ring-billed gulls with a lot of flame retardants, especially deca, in their blood.
While moseying around the island, Verreault picks up a handful of gull eggs from a scrappy little nest of sticks, grass and moss. Unlike other birds, gulls won’t abandon eggs if humans touch them. The colony’s population is strong but it has declined over the past few years. Verreault worries that if chemicals are messing with different hormones, bones and proteins it could mean trouble for the gulls.
“It’s all very subtle,” he said. “But all of this can add up to lower the health of the bird.”
What’s happening in captive kestrels and observed in wild gulls should be a warning, said Birnbaum of the National Institute of Environmental Health Sciences. She said there is “clear evidence” from studies of birds and other animals that PBDEs interfere with the endocrine system.
“Nature’s inherently conservative – the endocrine system was basically conserved throughout the vertebrate kingdom. When we see impacts on behavior in birds, nesting, impacts on survival, and behavior … the question becomes, why would we expect this would not be relevant to us?” Birnbaum said.
In human observations and rodent studies, PBDEs have been linked to reproductive problems, hampered brain development and reduced attention, motor skills, coordination and IQ.
“Whether it’s a bird or a person, thyroid hormones are critical to brain development, and some of these flame retardants impact the conversion of testosterone to estrogen,” Birnbaum said. “The developing brain needs this estrogen.”
“They don’t eat furniture”
While Francois draws blood from a hooded gull, Verreault pokes at the ground nearby. He picks up a small pile of puke-splattered plastic – the same type of stuff he found in the gastrointestinal tracts of some gulls in his lab last year. He holds up part of a plastic bag and points out small plastic pellets on the ground.
“Ring billed gulls regurgitate non-digestibles like plastic bags, pellets,” Verreault says. “However, the birds can still absorb some of the contaminants from them before their system throws it up.”
The Deslauriers gulls are essentially a terrestrial bird and what Verreault calls an “opportunistic eater,” which leaves them with a plethora of contaminants. “We do not have access to a non-contaminated ring-billed gull,” Verreault says. “This is the real problem. We just don’t have a reference.”
"Whether it's a bird or a person, thyroid hormones are critical to brain development, and some of these flame retardants impact the conversion of testosterone to estrogen. The developing brain needs this estrogen." –Linda Birnbaum, U.S. National Institute of Environmental Health SciencesOne compound stands out in the colony: a PBDE called deca that’s most often used in televisions and computers.
North American manufacturers of deca stopped making the chemical last year, and it is banned in Europe. It is currently under evaluation for international phaseout under the Stockholm Convention.
The penta and octa mixtures are declining for the most part across the globe since they were banned, de Wit said. “Penta going down is proof, if you do stop using something, it will improve the situation,” she said.
For deca, however, the trends are still upward. Part of the problem is that “these compounds were not used in transient products,” said Robert Hale, a chemist and professor at the William & Mary Virginia Institute of Marine Science. “With deca we’re talking furniture, electronics. We keep these things a long time, and then, when we’re done with them, there will still be releases.”
Birds’ chemical loads are largely dependent on where they sit in the food chain, Letcher said. Traditionally scientists have assumed most of birds’ exposure comes from fish. But “all of these species eat from different parts of the ecosystem,” Fernie said.
Verreault does find some fish in the Deslauriers’ gulls – the processed kind found in supermarket fish sticks. When he checked out the insides of some gulls last year he found French fries, meat, rice, corn, soybeans, worms, bugs and plastic.
"These compounds were not used in transient products. With deca we're talking furniture, electronics. We keep these things a long time, and then, when we're done with them, there will still be releases." –Robert Hale, William & Mary Institute of Marine ScienceThey have a human-like signature of pollutants in their tissues. “Essentially it’s a human with feathers,” he said.
He suspects it’s not what they’re dining on that’s leaving them with loads of flame retardants but where – at the landfills and wastewater treatment plants. “They don’t eat furniture,” he says.
Flame retardants end up in landfills when people trash furniture, TVs, carpet padding and electronics, said Heather Stapleton, a Duke University associate professor of environmental sciences and policy who specializes in flame retardants. Deslauriers Island is about 18 miles from Lachenaie dump, North America’s third largest landfill, which handles about one-third percent of Montreal-area garbage, with hills of trash up to 130 feet high.
“When these things sit in the landfills they start breaking down and leaching into the landfill,” Stapleton said. “Wildlife, birds feeding in the areas can pick them up through food.”
Flame retardants also latch onto dust particles in the air, she said. The birds can inhale them or they can get stuck on their feathers so when they preen, they gulp down chemicals.
Sewage is another concern as Deslauriers Island is right in the path of the treated wastewater released in the St. Lawrence River by the Jean-R. Marcotte treatment plant, the largest in North America. PBDE concentrations doubled over the past two decades in nearby Lake St. Pierre, most likely due to Montreal’s wastewater.
The loads in landfills and sewage treatment plants “are coming from our homes,” Stapleton said.
Deca, in particular, is a different beast from PCBs and other contaminants that end up in fish, Hale said. “It’s in computers and fabric coatings, we have much more intimate exposure potential, it’s in our homes and offices,” he said.
Finding the deca mixture in the ring-billed gulls has international significance because it proves that the chemical can build up in animals and people, said Joe DiGangi, senior science and technical advisor for the International POPs Elimination Network, which advocates for safe chemical policies.
“During recent Stockholm discussions at the screening phase, industry kept pushing back and saying [deca] is too big of a molecule to bioaccumulate, which is what they’ve said for years,” DiGangi said.
“And everyone would hold up scientific papers of birds.”
Verreault will probably only take one more trip to Deslauriers this summer. He will bring his children, including his 5-year-old son, who will have to be closely monitored because he tries to “add to the genetic diversity” by moving eggs from nests.
But now the hard part begins. Francois, Desjardins and others will run tests on the body parts and blood to check for PBDEs and their replacement chemicals, which also are starting to show up in the ring-billed gulls as well as in people and creatures around the world.
It’s a cat-and-mouse game: Just as researchers start to understand what a chemical might do to people or wildlife, a bunch more hit the market.
“The flame retardant story is especially illustrative of regrettable chemical substitutions,” DiGangi said. “Industry has been playing this game since the 1970s, substituting one bad chemical for another.”
Source : Environmental Health News
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Loss of night: Artificial light disrupts sex hormones of birds
High on bluffs overlooking the Pacific, Dominik Mosur was strolling along at 2 a.m. searching for owls. Darkness enveloped the Presidio, a historic military encampment turned national park, as Mosur made his way through cypress-scented fog. Alert in the mist as he cut through a forest, Mosur listened for the hoot of the great horned owl. Instead, he heard the singing of a bird that should have been asleep in its nest until dawn. The Nuttall’s white crowned sparrow was throbbing away with its distinctive zu-zee trill.
To this day, Mosur wonders whether the bright street lamps, 50 feet from the songbird’s territory, caused its odd nocturnal behavior, which usually is limited to moonlit nights along this part of the coast.
Mosur puzzled over the toll that the nighttime singing was taking on the songbird: Would it have the energy in the morning to defend its territory, attract a mate and raise its young?
Around the world, scientists seeking to answer that question have gathered mounting evidence that city lights are altering the basic physiology of urban birds, suppressing their estrogen and testosterone and changing their singing, mating and feeding behaviors. One lab experiment showed that male blackbirds did not develop reproductive organs during the second year of exposure to continuous light at night.
Streetlights, shopping centers, stadiums and houses turn night into day, a phenomenon that scientists call “loss of night.”
“Birds are particularly sensitive to light and different chemical interventions. If you see these deleterious effects in the birds, you’re likely to see them in humans in short-order. The smart thing to do is to pay attention to avian life,” said Vincent Cassone, whose University of Kentucky lab examines neuroendocrine systems of birds and mammals.
People can suffer an array of health problems when they work night shifts that alter their circadian, or daily, cycles governed by a biological clock. In the wild, light pollution causes hatchling sea turtles to lose their way from beach to the ocean, and disorients Monarch butterflies searching for migration routes. In field experiments, Atlantic salmon swim at odd times, and frogs stop mating under skies glowing from stadium lights at football games. Millions of birds die from collisions with brightly lit communication towers, and migratory flocks are confused by signals gone awry.
"Birds are particularly sensitive to light and different chemical interventions. If you see these deleterious effects in the birds, you're likely to see them in humans in short-order." - Vincent Cassone, University of KentuckyMore recently, researchers have documented an earlier dawn chorus, which influences mate selection, feeding and interplay among species. At a deeper, molecular level, the changes in birds’ hormones raise questions about their reproductive fitness and the potential for ecological and evolutionary consequences.
“Under light at night, something gets broken and you see a dampening of their hormonal system,” said University of Memphis biology professor Stephan Schoech, who found hormone changes in western scrub-jays.
Birds' intricate clocks
The yearlong cycle of light is the most important environmental cue for birds because it synchronizes their seasonal changes in physiology and behavior. Because artificial light upsets hormone levels and signals, it could disrupt their intricate clocks evolved to help them cope with their complex environments.
“Birds can tell time in their brains. They know what time of day it is, what tomorrow is going to be like. They know where they are in the world using solar information. They can track the sun. They hear the sound of ocean breakers and wind over mountains. Birds see in the ultraviolet range. They are phenomenally attuned to time and space to the point of approaching science fiction. You don’t need science fiction,” Shoech said.
Birds have light receptors in their retinas and in their pineal glands, as well as in other parts of their brains. The pineal gland secretes the hormone melatonin at night, which guides their biological clocks controlling body function, growth and behavior. In birds, melatonin appears essential to encode and store information about time.
Like humans, birds are diurnal, mostly evolved to a cycle of daytime activity and nighttime sleep. Birds synchronize their internal clocks with light to time their daily and seasonal foraging, communication, reproduction and migration. Birds depend on sounds they hear, and adjust their behavior to the rhythm of night and day. The timing of the first calls at sunrise – the dawn chorus or daybreak song – is based on changing light intensities. The end of foraging is based on darkening twilight.
Some birds appear to benefit from artificial night light. Male blue tits exposed to streetlights on the edge of a forest awaken earlier and are twice as successful in attracting females than birds in the inner forest. In light, females start laying eggs earlier. Shorebirds can increase foraging time under urban illumination.
But researchers caution that premature dawn calls may disrupt age-old signals for choosing mates, and expanded feeding may draw wading birds to degraded areas or to danger from predators.
"[Birds] are phenomenally attuned to time and space to the point of approaching science fiction. You don't need science fiction."-Stephan Schoech, University of Memphis“We don’t know if being active at night comes with energetic costs,” said biologist Davide Dominoni, who conducted research at the Max Planck Institute for Ornithology in Munich before moving on to the University of Glasgow.
Little is known about how the increase in length of day for the birds affects their fitness, reproductive success or survival.
“There might be a physiological or biomedical cost. With humans, we are starting to realize that disrupting body clocks can really come with serious health consequences linked to immune function, metabolism, cancer, obesity and diabetes. These types of things are relatively unexplored in wild animals," Dominoni said.
Astronomers were the first to caution about the harm that comes from sky glow, since it blocked views of faint celestial objects. Then came NASA photos of Earth from space: First the image of the Blue Marble, showing a small finite planet, then decades later, the Black Marble, showing the night sky invaded with artificial lights.
Two-thirds of the world, and 99 percent of the United States’ lower 48 and the European Union, live under conditions of light pollution. City lights can outshine natural night sky by 4.8 times, according to European scientists. In Vienna and Plymouth, England, the natural cycles of moon brightness are close to extinct.
In 2001, scientists reported that one-fifth of the world population, and more than two-thirds of the U.S. population, can’t see the Milky Way with the naked eye
“You can see how artificial light is spreading over the world, as much as a 20 percent increase a year in some geographic regions,” said Reinhard Klenke, a biologist at the Helmholtz Centre for Environmental Research in Leipzig, Germany.
Testosterone, estrogen altered
Seventy-five miles away from the Presidio, in Davis, Calif., researchers tiptoed in the low bushes trapping and netting western scrub-jays. Schoech has been studying Florida scrub-jays for more than 20 years. At this point he was investigating why the jays living in Florida suburbs were laying eggs two to four weeks earlier than jays in native wildlands.
"You can see how artificial light is spreading over the world, as much as a 20 percent increase a year in some geographic regions." - Reinhard Klenke, Helmholtz Centre for Environmental ResearchSchoech and his post-doctoral student, Eli Bridge, recruited energetic University of California students to help capture two dozen wild scrub-jays in Davis. Packing them carefully in modified pet carriers, they trucked the jays back to the Tennessee lab to serve as surrogates for the Florida scrub-jays, which are a protected species.
Schoech’s experiment was likely the first to study birds’ sex hormones in both females and males in response to realistic exposures mimicking suburban lights. He demonstrated that artificial light tended to inhibit reproductive hormone secretion, confirming limited findings by others. The reductions of sex hormones – estradiol and testosterone – occurred at different times in females and males, creating a mismatch in cues that synchronize biological rhythms.
“Light at night disrupted the extraordinarily strong correlation between testosterone and estradiol in jays of both sexes that existed under unlighted nocturnal conditions,” Schoech said.
In natural darkness of night, birds’ reproductive hormones rise as the winter turns to spring and days lengthen. This did not occur among the jays exposed to night light. Instead, “light at night interfered with endocrine responses to increased day length,” Schoech said. At the end of the experiment, it turned out that the earlier scrub-jay eggs in Florida's suburbs probably had more to do with abundance of food than artificial light. But their investigation led to the intriguing findings about hormones and night light.
In Beijing, scientists published findings this year similar to Schoech’s, concluding that urban tree sparrows exposed to artificial night light began to secrete a reproductive hormone earlier than rural tree sparrows. The urban birds’ estradiol and testosterone levels were lower than those of rural birds.
In addition, male blackbirds exposed in a laboratory to light at night developed testes faster during the first year. “During the second year, the reproductive system did not develop at all,” according to a report by Dominoni and colleagues published last year. They wrote that "our data suggest that an uncontrolled increase in the amount of artificial light at night could pose serious risks for the reproductive capacity of avian species thriving in urban areas."
Nevertheless, Cassone of University of Kentucky said “the rub is how these endocrine changes translate into reproductive fitness. We frankly don’t know. It’s too early. It’s a reasonable thing to say that it’s disturbing a natural process."
On San Francisco’s clear Indian summer nights of September and early October, Mosur, a local bird expert, sets his spotting scope at the moon, hoping to catch silhouettes of warblers, thrushes and sparrows.
"The rub is how these endocrine changes translate into reproductive fitness. We frankly don't know." - Vincent Cassone, University of Kentucky“That’s when birders hope to hear, if not glimpse, the nocturnal migration of songbirds passing over on the way south,” Mosur said.
Like any big city, San Francisco struggles with lights. The bright lights of the Giants’ baseball park attract ashy storm petrels from nests 30 miles away, on the Farallon Islands. Residents argue over whether putting up lights on a soccer field in Golden Gate Park will interfere with bird migrations.
“I’ve noticed the night sky looks a lot different when I’m standing on Twin Peaks in the city or on a ridge near Lake Hennessey 20 miles north of Napa. There’s a big difference what you see in the sky,” he said. “I’m sure the birds see the differences, too.”
Source : Environmental Health News
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Neonicotinoids linked to recent fall in farmland bird numbers Research demonstrates for the first time the knock-on effects to other species of class of insecticides known to harm bees
New research has identified the world’s most widely used insecticides as the key factor in the recent reduction in numbers of farmland birds.
The finding represents a significant escalation of the known dangers of the insecticides and follows an assessment in June that warned that pervasive pollution by these nerve agents was now threatening all food production.
The neonicotinoid insecticides are believed to seriously harm bees and other pollinating insects, and a two-year EU suspension on three of the poisons began at the end of 2013. But the suspected knock-on effects on other species had not been demonstrated until now.
Peer-reviewed research, published in the leading journal Nature this Wednesday, has revealed data from the Netherlands showing that bird populations fell most sharply in those areas where neonicotinoid pollution was highest. Starlings, tree sparrows and swallows were among the most affected.
At least 95% of neonicotinoids applied to crops ends up in the wider environment, killing the insects the birds rely on for food, particularly when raising chicks.
The researchers, led by Hans de Kroon, an ecologist at Radboud University, in the Netherlands, examined other possible reasons for the bird declines seen during the study period of 2003 to 2010, including intensification of farming. But high pollution by a neonicotinoid known as imidacloprid was by far the largest factor.
“It is very surprising and very disturbing,” de Kroon said. Water pollution levels of just 20 nanograms of neonicotinoid per litre led to a 30% fall in bird numbers over 10 years, but some water had contamination levels 50 times higher. “That is why it is so disturbing – there is an incredible amount of imidacloprid in the water,” he said. “And it is not likely these effects will be restricted to birds.”
De Kroon added: “All the other studies [on harm caused by neonicotinoids] build up from toxicology studies. But we approached this completely from the other end. We started with the bird population data and tried to explain the declines. Our study really makes the evidence complete that something is going on here. We can’t go on like this any more. It has to stop.”
David Goulson, a professor at the University of Sussex, who was not involved in the new studies, said the research was convincing and ruled out likely alternative causes of bird decline. “The simplest, most obvious, explanation is that highly toxic substances that kill insects lead to declines in things that eat insects.”
There was little reason to doubt that wildlife in the UK and other countries were not suffering similar harm, he said. “This work flags up the point that this isn’t just about bees, it is about everything. When hundreds or thousands of species or insect are being wiped out, it’s going to have impacts on bats, shrews, hedgehogs, you name it. It is pretty good evidence of wholesale damage to the environment.”
Goulson said that, unlike the Netherlands, the UK did not monitor neonicotinoid pollution and the EU ban would not remove the substances from the environment. “They are still being widely used, as the moratorium only applies to three neonicotinoids and some crops. There is still a lot of them going into the environment. The door is far from shut.”
A spokesman for Bayer CropScience, which makes the neonicotinoid that was examined in the study, disputed the findings. “It provides no substantiated evidence of the alleged indirect effects of imidacloprid on insectivorous birds. Bayer CropScience is working with the Dutch authorities and agricultural stakeholders to ensure the safe use of imidacloprid-containing crop protection products and to preserve the environment.”
He added: “Neonicotinoids have gone through an extensive risk assessment which has shown that they are safe to the environment when used responsibly according to the label instructions.”
But de Kroon said new research, including his own, was showing that neonicotinoids posed an even greater threat than had been anticipated and new regulations had to take this into account. In 2012, MPs warned regulators appeared to be “turning a blind eye” to the harm caused by neonicotinoids.
David Gibbons, head of the RSPB centre for conservation science, said: “This elegant and important study provides worrying evidence of negative impacts of neonicotinoid insecticides on birds. Monitoring of neonicotinoid pollution in UK soils and waterways is urgently required, as is research into the effects of these insecticides on wildlife.”
A Defra spokesperson said: “Pesticide use across Europe is tightly regulated to protect the environment and public health – [pesticides] are a safe, effective and economical means of managing crops. We continue to review evidence on neonicotinoids.”
Also on Wednesday, further research showing that neonicotinoids damage the natural ability of bees to collect food was published in the journal Functional Ecology. The work used tiny tags to track bees and found those exposed to the insecticide gathered less pollen.
“Exposure to this neonicotinoid seems to prevent bees from being able to learn essential skills,” said Nigel Raine, a professor at the University of Guelph, Canada. He said the regulatory tests, which only looked for short-term, lethal effects, were failing to prevent serious harm. “These tests should be conducted for extended periods to detect the effects of chronic exposure.”
Source The Guardian
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Bats being blindsided by disease
Detected in Illinois last year, fungus has killed millions of the winged creatures in U.S. and Canada
An African straw-colored bat ducked for cover underneath Sharon Peterson's dark cardigan sweater. Nearby an Egyptian fruit bat hung upside down from husband Daniel Peterson's shirt collar, looking like an ornate medallion.
The Petersons, who have been educating people — and dispelling myths — about bats for almost 20 years, were in Aurora recently speaking to a group of gardeners about the mysterious nocturnal creatures and their importance to nature.
"There are few animals so misunderstood and so unappreciated," Sharon Peterson said. She and her husband are licensed by the U.S. Department of Agriculture to keep and exhibit bats.
Some species of bats pollinate plants and reseed the rain forest. Others, including those in Illinois, eat garden and crop pests and lower the risk of West Nile virus by consuming thousands of mosquitoes a night.
But some bats in Illinois and elsewhere in North America face a struggle that could threaten their survival. A disease called white-nose syndrome has killed millions of hibernating bats in 25 states. The disease showed up in Illinois last year and most recently appeared in Wisconsin and Michigan.
White-nose syndrome, named for the white fungus that appears on the bat's nose, was first documented in New York in 2006. Now, according to the U.S. Fish and Wildlife Service, the cold-loving fungus has killed more than 5.7 million bats in the Northeast and Canada, and in some areas, 90 to 100 percent of the cave- and mine-hibernating bats have died.
Some of the affected species, like the little brown bat, the big brown bat and the northern long-eared bat, are common in Illinois and crucial for the control of insects including mosquitoes and agricultural pests. A few that are present in Illinois, like the gray bat and the Indiana bat, are on the endangered species list.
"Pest control services provided by insect-eating bats in the United States likely saves the U.S. agricultural industry several billion dollars a year," Joe Kath, endangered species manager for the Illinois Department of Natural Resources, said last year when the discouraging word got out that white-nose syndrome had spread to Illinois.
Kath called bats "among the most overlooked, economically important, nondomesticated animals in North America."
And while studies continue nationwide, there is no known way to prevent white-nose syndrome or to stop it.
"Right now it looks kind of pessimistic," said Ed Heske, a mammal ecologist with the Illinois Natural History Survey. "A lot of smart people are trying a lot of different approaches to figure this out, and most of them have come up with dead ends.
"We can only hope that some kind of natural resistance emerges from this, like West Nile that does not have the impact it once had," he said. "But bats won't come back like birds because they do not reproduce as fast."
Most bats have one to three pups a year.
Heske is on a team of scientists from state and federal agencies as well as the University of Illinois who recently completed three years of fieldwork in Illinois concerning white-nose syndrome, he said. Lab work continues.
They found no white-nose syndrome here in the winter of 2012, but in February 2013 they confirmed that white-nose syndrome had been found in LaSalle County and three other counties farther south — Hardin, Pope and Monroe. This year, Heske said, they found the fungus in nine of the 10 caves they are monitoring in those counties as well as Saline and Pike counties.
Heske cautions that the fungus could also be elsewhere in the state.
"Those are only the counties where we looked," he said. "We don't know about the caves we didn't go in and the counties we didn't visit."
The disease interrupts winter hibernation, causing bats to wake every three to four days as opposed to the normal 10 to 20 days, according to the Department of Natural Resources. The bats wake up dehydrated and hungry when there are no insects to eat, and the fungus damages connective tissues, muscles and skin.
Of the 47 species of bats in the U.S., more than half hibernate and are therefore at risk of white-nose syndrome. About half of the 13 species in Illinois migrate like birds and the other half stay here, hibernating primarily in caves and mines throughout southern Illinois, along the Mississippi River and in LaSalle County, according to Doug Dufford, program manager of wildlife disease and invasive wildlife for the Department of Natural Resources.
Stacy Iwanicki, naturalist at the state's Volo Bog natural area near Ingleside, about an hour northwest of Chicago, is eager to see how many little brown bats will roost this summer in Volo Bog's bat barn, a secluded old barn housing what some believe to be the state's largest colony of little brown bats.
"At one time we believe we had more than 2,000 bats roosting there," Iwanicki said. "I am very curious as to what will happen to those bats in coming years. What's disturbing is that we won't know until it happens."
Across Illinois, caves on state and federal property have been closed to public access to minimize foot traffic that may spread deadly fungus spores. But scientists know the disease is also passed bat to bat, that authorities have no control over privately owned mines and caves, and that even when the bats are gone, the fungus continues to grow in the cool, humid environment, Heske said.
The bats we typically see here on summer nights roost by day in compact cavities under tree bark, in abandoned houses, small bat houses and barns and under the eaves of buildings, where they can shut down and find protection from weather and natural predators including owls, hawks, skunks, raccoons and snakes, Dufford explained.
"At one time we believe we had more than 2,000 bats roosting there," Iwanicki said. "I am very curious as to what will happen to those bats in coming years. What's disturbing is that we won't know until it happens."
Across Illinois, caves on state and federal property have been closed to public access to minimize foot traffic that may spread deadly fungus spores. But scientists know the disease is also passed bat to bat, that authorities have no control over privately owned mines and caves, and that even when the bats are gone, the fungus continues to grow in the cool, humid environment, Heske said.
The bats we typically see here on summer nights roost by day in compact cavities under tree bark, in abandoned houses, small bat houses and barns and under the eaves of buildings, where they can shut down and find protection from weather and natural predators including owls, hawks, skunks, raccoons and snakes, Dufford explained.
Source : Chicago Tribune
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Plant-Based Insect Repellents Provide an Alternative to Synthetic Formulas
by Tyler Smith
By the end of 2012, the US Centers for Disease Control and Prevention (CDC) had reported nearly 250 West Nile virus-related deaths in the United States. With more than 5,300 reported cases in 2012 — the most in nearly a decade1 — health officials are urging individuals to take certain precautions to avoid being bitten by mosquitoes, which can carry the virus. In addition to ensuring properly fitting screens on windows and doors, wearing pants and long-sleeved clothing when outdoors, and avoiding pools of stagnant water where mosquitoes lay eggs, the CDC recommends using an insect repellent with an active ingredient registered by the Environmental Protection Agency (EPA).2
Of EPA-registered active ingredients, the most widely recognized and studied synthetic compound is DEET (N,N-Diethyl-3-methylbenzamide), an insect repellent developed by the US Department of Agriculture (USDA) in 1952 and approved for public use in the late 1950s.3 Extensive testing supports the use of DEET as an effective method of preventing mosquito and tick bites, but mild skin and eye reactions have been reported, as well as several cases of seizures in individuals who frequently used DEET. EPA requires all DEET-containing products to contain detailed instructions for safe use, which includes avoiding over-application of the repellent and washing any treated skin or clothing after use. According to the EPA’s 1998 reregistration eligibility decision, “DEET is not believed to be acutely toxic nor carcinogenic, significantly developmentally toxic nor mutagenic at the doses tested.” Further, the EPA concluded that the “available data do not support a direct link between exposure to DEET and reported seizure incidences (14 cases).”4
In recent years, however, much research has been conducted on plant-based alternatives to synthetic formulas, which may be preferable to consumers with chemical sensitivities or those who wish to avoid synthetics.
“[Plant-based insect repellents] may be more cosmetically appealing, more widely available or producible, including in tropical countries where the public health value of repellents is especially important,” said Scott P. Carroll, PhD, a scientist affiliated with the Department of Entomology at the University of California-Davis (email, September 25, 2012). “Plants are great biochemical synthesists, and we are well adapted to plants, so it’s obviously functionally prosperous for investigation.”
Appeal of Plant-Based Insect Repellents
Plants produce chemicals that act as natural deterrents to pests, and they have been used since ancient times to repel insects, most commonly by burning plant material.5 The established use of plants as insect repellents in part contributes to their acceptability among consumers.
“There are quite a few natural products (oils and single compounds) that demonstrate repellent efficacy,” said Ulrich R. Bernier, PhD, a research chemist in the Mosquito and Fly Research Unit at the USDA’s Center for Medical, Agricultural, and Veterinary Entomology (email, September 21, 2012). “One advantage of using a plant-based botanical is user acceptability. People tend to favor natural products over synthetics.”
Plant-based active ingredients also are thought by some to pose fewer risks to users. And since repellents are often applied directly to the skin, consumers tend to favor products without harsh chemical smells. Although, according to some experts, an effective active ingredient is the most important consideration when choosing an insect repellent, personal preference plays a role in repellent selection as well.
“There is a strong perception that natural actives are safer than synthetics,” said Sarah J. Moore, PhD, a lecturer in the Department of Disease Control at the London School of Hygiene and Tropical Medicine, and a co-author of a 2011 review of plant-based insect repellents published in Malaria Journal (email, September 21, 2012). “Plant-based odours are scents that people feel comfortable with as they are natural. My research on [multiple] continents (North and South America, South-east Asia and Africa) has highlighted this same perception.”
Perhaps more importantly, insect repellents derived from plants can be an inexpensive, sustainable method of preventing disease in high-risk regions of the world. “If plant-based repellents are ethically sourced and produced then they can bring trade [to] developing countries and are less damaging to the environment,” said Dr. Moore.
In 1996, the EPA began compiling annual lists of newly approved biopesticide active ingredients.6 Biopesticides are defined as “naturally occurring substances that control pests (biochemical pesticides), microorganisms that control pests (microbial pesticides), and pesticidal substances produced by plants containing added genetic material (plant-incorporated protectants) or PIPs.”7
However, before being marketed, the Federal Insecticide, Fungicide, and Rodenticide Act requires the EPA to conduct rigorous testing of the ingredient to ensure that it does not pose a risk to human health or the environment.7
The first year records were available, six ingredients were addressed, including a German cockroach pheromone and multiple bacteria-derived ingredients. In 2010, the most recent year for which records are available, the list included 17 approved active ingredients, almost three times as many as were first approved in 1996. Combined, the annual lists contain more than 100 approved biopesticide active ingredients; however, only a small fraction of this number are specifically plant-based insect repellents.
Hydrogenated Catmint (Catnip) Oil
In December 2008, the EPA approved hydrogenated catmint oil (Nepeta cataria, Lamiaceae), a species of the mint family. Catmint, or catnip as it is more commonly referred to*, is best known for its ability to produce behavioral changes when given to cats, which typically last only a few minutes. The chemical believed to be responsible for this intoxication-like behavior in cats is known as nepetalactone, a mild hallucinogen.8
“[Catmint oil] is in the pipeline for becoming available as a consumer product, and [has] better lasting properties than citronella,” said Dr. Carroll (email, October 1, 2012).
According to the American Mosquito Control Association (AMCA), “Catnip has been noted for years as possessing repellency against mosquitoes. However, only recently has its efficacy been demonstrated to the extent it could be registered by the EPA.”9
The EPA has registered four formulations of catmint oil, including liquids and lotions with various percentages of the active ingredient. Each of these products is currently made by DuPont and exhibit protection times between seven and 15 hours.10 AMCA points out that “A commercial version is not yet available, though. Catnip products currently available through internet suppliers do not possess an EPA registration that validates its efficacy.”9
In 2007, Spero et al. published the results of repellency activity of hydrogenated catmint oil against mosquitoes and black flies in the Journal of Medical Entomology. According to the authors, “Iridoid monoterpenoids such as nepetalactone have long been known to be repellent to some insect species.… The related compound dihydronepetalactone (DHN) is also an effective repellent of a number of biting insect species.”11
Although DHN comprises only a small percentage of the oils of N. cataria, the authors explained that it can be produced by a chemical process known as catalytic hydrogenation of the nepetalactones in the oil, hence the name “hydrogenated” catmint oil.11
Spero et al. reported that hydrogenated catmint oil (HCO) offered protection for more than four hours, with a 15% lotion providing protection of more than eight hours. They concluded that their results “indicate strongly that HCO in different topical formulations offers an effective alternative to existing natural and synthetic insect repellents.”11
In the following year, Polsomboon et al. examined two separate categories of behavioral responses of mosquitoes to catmint oil — contact irritancy and non-contact repellency — in a paper published in the Journal of the American Mosquito Control Association. Using two species of mosquitoes, the researches determined that “catnip oil has strong irritant and repellent actions on mosquito test populations as indicated by the comparatively low escape time.”12
In its fact sheet on HCO, the EPA cited that “no risks to human health will be expected from the use of Hydrogenated Catmint Oil based on its low toxicity and current use as a food ingredient by the general public without any reported adverse effects on human health.” Further, in the environmental risk section of the fact sheet, they concluded that “it is not likely to accumulate in drinking water,” nor is it “expected to occur or pose a threat to non-target organisms.”13
Repellents Derived from the Lemon Eucalyptus Tree
In April 2005, the CDC approved botanically based para-menthane-3,8-diol, or PMD, as an effective insect repellent.14 PMD, which is derived from leaves of the lemon eucalyptus tree (Corymbia citriodora, Myrtaceae), was discovered in the 1960s by researchers conducting chemical screenings for potential insect-repelling properties of plants used in Traditional Chinese Medicine. In fact, as plants are occasionally named in accordance with their traditional uses, the Chinese name for lemon eucalyptus, quwenling, translates roughly to “effective mosquito repeller.”15
Although there are multiple plant-based active ingredients registered with the EPA, researchers have reported that PMD is “the only plant-based repellent that has been advocated for use in disease endemic areas by the CDC, due to its proven clinical efficacy to prevent malaria and is considered to pose no risk to human health. [PMD] provides very high protection from a broad range of insect vectors over several hours.”5
PMD is not to be confused with what is frequently referred to as “oil of lemon eucalyptus.” In distilling the essential oil from leaves of the lemon eucalyptus tree, PMD is left over as a waste product.5 It is this waste product that has been shown to be effective in repelling mosquitoes, more so than the oil itself. Although insect repellent products containing oil of lemon eucalyptus are available, Dr. Moore cautions against using anything but CDC- and EPA-recommended active ingredients, such as PMD, in areas with disease risk.
Depending on the concentration, PMD formulas can last up to eight hours,15 and have been shown to be almost as effective as those containing DEET. In some cases, PMD has been shown to be more effective than DEET in repelling certain species of mosquitoes.
“[Some plant-based ingredients can] better repel certain vectors, as in the case of PMD’s evident superiority to DEET in repelling Anopheles malaria vectors,” said Dr. Carroll. In a 2006 study published in the Journal of the American Mosquito Control Association, of which Dr. Carroll was a co-author, he wrote that “PMD has shown unprecedented repellency and consistency for a botanical.”15
Similarly, Dr. Moore, who conducts field research around the world, has found that PMD is consistently effective. Although her research primarily concerns the prevention of malaria, the same mosquito-repelling properties will protect against other mosquito-borne diseases such as West Nile fever and encephalitis, dengue fever, and yellow fever.16
“I can attest to the fact that PMD repellents are highly effective from both my research where they demonstrate good efficacy and the research of others who all show a consistently good effect in preventing bites from disease-vector insects,” she said. “I have lived in Tanzania for the past 6 years in a highly malarious area where we use PMD every evening in conjunction with long clothing, and we screen our home and use an insecticide-treated bed net as recommended best practise. I have never had a negative skin reaction or a vector-borne disease. Malaria is a preventable disease and we have effective tools, both synthetic and natural, to combat it.”
Citronella-Based Insect Repellents
Although PMD is a widely studied natural insect repellent, the plant-based ingredient citronella is arguably more recognized as a mosquito repellent. Citronella oil has been shown to be less effective than DEET, but it still can be a useful tool for repelling mosquitoes in areas without disease risk.
“Citronella has found its way into many commercial preparations through its familiarity, rather than its efficacy,” said Dr. Moore. “Citronella-based repellents only protect from host-seeking mosquitoes for about 2 hours.”
Citronella was first registered by the EPA in 1948 and was originally used in perfumes for its pleasant scent.4 Today, citronella candles are ubiquitous in American backyards, although it also is used in creams, lotions, and sprays. According to the EPA, citronella is classified as a biopesticide and registered as an insect repellent or feeding depressant and also as an animal repellent. Oil of citronella comes from 2 species of aromatic grasses, Ceylon citronella (Cymbopogon nardus, Poaceae) and Java citronella (C. winterianus). Citronella is regarded as a highly safe repellent; in a 1997 reregistration memo, the EPA concluded that “based on available data, the use of currently registered products containing oil of citronella in accordance with their approved labeling will not pose unreasonable risks or adverse effects to humans or the environment.”17
Hydrogenated catmint oil, citronella, and PMD are just three of the hundreds of plants or plant-based ingredients that have been studied for their insect-repelling properties. In addition to hydrogenated catmint oil, citronella, PMD, and DEET, Health Canada — the governmental body responsible for national public health in Canada — has approved products containing soybean (Glycine max, Fabaceae) oil for mosquito-repelling purposes for up to 3.5 hours, although less research has been conducted on this particular ingredient. Other commonly-cited botanicals used to repel mosquitoes include species in the mint family (basil [Ocimum basilicum] and peppermint [Mentha x piperita]), 2-undecanone (an extract from tomato plants [Solanum lycopersicum, Solanaceae]), neem oil (Azadirachta indica, Meliaceae), lemongrass (Cymbopogon citratus, Poaceae), fennel (Foeniculum vulgare, Apiaceae), and rue (Ruta graveolens, Rutaceae).18-20
Issues Associated with Plant-Based Repellents
As a scientific term, volatility refers to a chemical’s tendency to evaporate. Bruised or damaged plants will release volatile odors into the environment, which can offer protection from pests at a distance.4 However, when these chemicals are formulated into insect repellents that are applied to the skin, volatility becomes a problem.
PMD is unique in that it has an especially low vapor pressure, which causes it to evaporate slower than other plant-based insect repellents. Citronella, however, upon initial application, is just as effective as DEET, but its high volatility quickly decreases its effectiveness.
“Some plant-based molecules are incredibly effective in the short term but quickly evaporate and for this reason they don’t last as long as the synthetic molecules,” explained Dr. Moore.
According to Dr. Bernier, volatility is one of the challenges to formulating an effective and long-lasting botanical insect repellent. “One the greatest problems with naturally based repellents is the volatility of those oils or compounds within oils that contribute to the observed repellency,” he said. “There are a number of natural compound repellents on the market and some of these do repel for a short time.”
However, there are some ways to mitigate the effects of the high volatility of plant-based active ingredients. One option is to combine plant-based chemicals with larger molecules that evaporate more slowly. Vanillan, a relatively large molecular component of the vanilla bean (Vanilla spp., Orchidaceae), has been added with some success to botanical insect repellent formulas to reduce the formulas’ volatility.5 And in recent years, advances in nanotechnology have provided even more options to increase the duration of plant-based repellents. These techniques have been used in some citronella formulas. For example, “[e]ncapsulated citronella oil nanoemulsion [can be] prepared by high-pressure homogenization … to create stable droplets that increase the retention of the oil and slow down release.”5
To counteract the high volatility of some plant-based active ingredients, some mosquito repellents contain higher concentrations of these ingredients. And as with any dermatological applications of chemicals — plant-based or synthetic — there is some risk of a reaction.
“Some essential oils can cause skin irritation,” said Dr. Moore. “Read the label — if there are high concentrations of essential oils they are unlikely to be suitable for those with sensitive skin. If you have a reaction, immediately discontinue use and consult a physician if you have a dermatitis that does not resolve after a few days.”
As consumer interest in plant-based products grows, scientists will continue to study plants to learn more about their insect-repelling properties. Botanical formulas, when used properly, provide an alternative to synthetic repellents. Although plant-based insect repellents often are not as effective as DEET, in time, this may change.
“As technology improves so that formulations make essential oils and other plant based molecules remain on the skin for as long as DEET, then we will see more effective plant-based repellents that can be used to prevent disease. I am certainly keen to see this happen if it means that products can be made in a more environmentally sustainable way through fair trade,” said Dr. Moore. “It will hopefully help make repellents such as citronella and PMD more accessible to those living in disease endemic countries of the tropics because they often cannot afford to purchase repellents imported from outside. I am keen to see more manufacturers taking on this challenge.”
*Catnip is the Standardized Common Name (SCN) according to the American Herbal Products Association’s Herbs of Commerce, 2nd edition. Catmint is the Other Common Name (OCN).
1. Division of Vector-Borne Diseases: West Nile Virus. Centers for Disease Control website. Available at: www.cdc.gov/ncidod/dvbid/westnile/index.htm. Accessed January 7, 2013.
2. West Nile virus: What you need to know. Centers for Disease Control website. Available at: www.cdc.gov/ncidod/dvbid/westnile/wnv_factSheet.htm. Accessed September 26, 2012.
3. The insect repellent DEET. Environmental Protection Agency website. Available at: www.epa.gov/opp00001/factsheets/chemicals/deet.htm. Accessed September 25, 2012.
4. Reregistration eligibility decision (RED): DEET. Environmental Protection Agency website. Available at: www.epa.gov/oppsrrd1/REDs/0002red.pdf. Accessed September 28, 2012.
5. Maia MF, Moore SJ. Plant-based insect repellents: a review of their efficacy, development and testing. Malaria Journal. 2011;10(Suppl 1):S11. Available at: www.ncbi.nlm.nih.gov/pmc/articles/PMC3059459/. Accessed September 21, 2012.
6. New biopesticide active ingredients – 1996. EPA website. Available at: www.epa.gov/oppbppd1/biopesticides/product_lists/new_ai_1996.htm. Accessed April 16, 2013.
7. Regulating biopesticides. EPA website. Available at: www.epa.gov/pesticides/biopesticides/index.htm#factsheet. Accessed April 16, 2013.
8. What is catnip? Feline Advisory Bureau website. Available at: www.fabcats.org/behaviour/other/catnip.html. Accessed April 16, 2013.
9. Repellents. American Mosquito Control Association website. Available at: www.mosquito.org/repellents. Accessed April 19, 2016.
10. “Nepeta cataria” - Insect repellents: use and effectiveness. EPA website. Available at: http://cfpub.epa.gov/oppref/insect/search_results.cfm?Rangetime=&hidSelected=1&ProductName=&Ingredient=Catnip+Oil&Company=null&Registration=&Submit=Search. Accessed April 16, 2013.
11. Spero NC, Gonzalez YI, Scialdone MA, Hallahan DL. Repellency of hydrogenated catmint oil formulations to black flies and mosquitoes in the field. Journal of Medical Entomology. 2008;45(6):1080-1086.
12. Polsomboon S, Grieco JP, Achee NL et al. Behavioral responses of catnip (Nepeta cataria) by two species of mosquitoes, Aedes aegypti and Anopheles harrisoni, in Thailand. Journal of the Mosquito Control Association. 2008;24(4):513-519.
13. Hydrogenated catmint oil fact sheet. EPA website. Available at: www.epa.gov/oppbppd1/biopesticides/ingredients/factsheets/factsheet_004801.htm. Accessed April 19, 2013.
14. CDC adopts new repellent guidance for upcoming mosquito season [press release]. Atlanta, GA: Centers for Disease Control and Prevention; April 28, 2005. Available at: www.cdc.gov/media/pressrel/r050428.htm. Accessed September 21, 2012.
15. Carroll SP, Loye J. PMD, a registered botanical mosquito repellent with DEET-like efficacy. J Am Mosquito Contr. 2006;22(3):507-514. Available at: www.ncbi.nlm.nih.gov/pubmed/17067054. Accessed September 26, 2012.
16. Infectious disease information: mosquito-borne diseases. Centers for Disease Control and Prevention website. Available at: www.cdc.gov/ncidod/diseases/list_mosquitoborne.htm. Accessed September 27, 2012.
17. R.E.D. facts: oil of citronella. Environmental Protection Agency website. Available at: www.epa.gov/oppsrrd1/REDs/factsheets/3105fact.pdf. Accessed September 26, 2012.
18. Henson S. Re: Using herbal medicines to prevent and treat malaria. HerbClip. April 15, 2005 (No. 010253-278). Austin, TX: American Botanical Council. Botanical prevention and treatment of malaria - Part 1 by Yarnell E, Abascal K. Altern Complement Ther. 2004;206-210.
19. Bissinger BW, Apperson CS, Sonenshine DE, Watson DW, Roe RM. Efficacy of the new repellent BioUD® against three species of ixodid ticks. Exp Appl Acarol. 2009:48:239-250.
20. Polsomboon S, Grieco JP, Achee NL, et al. Behavioral responses of catnip (Nepeta cataria) by two species of mosquitoes, Aedes aegypti and Anopheles harrisoni, in Thailand. J Am Mosquito Contr. 2008:24(4):513-519.
Source : American Botanical Council
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Frogs’ immune systems weakened by chemicals, study finds
Frogs’ immune systems weakened by chemicals, study finds Young frogs exposed to flame retardants have weakened immune systems, which could leave them more susceptible to diseases that are ravaging amphibians worldwide. A new laboratory experiment is the first to link flame retardants to immune system problems in frogs, and adds to evidence that pollutants may contribute to global declines of their populations.
Young frogs exposed to flame retardants have weakened immune systems, which could leave them more susceptible to diseases that are ravaging amphibians worldwide.
A new laboratory experiment is the first to link flame retardants to immune system problems in frogs, and adds to evidence that pollutants may contribute to global declines of their populations.
Tadpoles of northern leopard frogs were exposed to polybrominated diphenyl ethers in their food from the time they could swim until they turned into frogs. Then scientists injected the young frogs with a foreign protein and found that they produced up to 92 percent fewer antibodies than non-exposed frogs.
“Making antibodies to get rid of pathogens is vital to frogs’ ability to fend off disease,” said Tawnya Cary, a postdoctoral scholar at the Institute for Biology Education at the University of Wisconsin, Madison, and lead author of the study.
Nearly one-third of the world’s amphibians – more than 1,800 species of frogs, toads, salamanders and newts – are threatened with extinction or already extinct. Chytrid fungus is to blame for devastating many populations, although other threats include habitat destruction, UV radiation and parasites.
One theory for the spread of the deadly fungus is that “pollutants alter immune function of the animals, and then they’re not able to fend off disease pathogens properly,” Cary said.
The period when tadpoles are turning into frogs – called metamorphosis – is a “very vulnerable time,” said Louise Rollins-Smith, an associate professor of pathology, microbiology and immunology at Vanderbilt University who did not participate in the study.
“Almost every organ reorganizes, including the immune system,” she said. “They have these little immune systems during metamorphosis, and they’re already having to deal with diseases and viruses. Not producing antibodies would be just one more handicap during this critical time.”
The researchers found reduced antibodies in the frogs at levels of flame retardants commonly found in the environment. It’s likely that such immune suppression would make the frogs more vulnerable to disease, but Cary said the researchers did not have funding to subject them to infectious agents to test that theory.
“Our findings demonstrate that environmentally realistic concentrations of PBDEs are able to alter immune function in frogs; however, further research is needed to determine how these alterations impact disease susceptibility,” the authors wrote in their study published in the journal Environmental Science & Technology.
However, the highest levels of the chemicals did not correspond with the biggest decrease in antibodies.
Frogs exposed as tadpoles to the most PBDEs – 634 nanograms per gram of food – produced 66 percent fewer antibodies than the non-exposed frogs. But those exposed to much lower concentrations – 1.1 and 71.4 nanograms – showed even more effects: declines of 89 and 92 percent. According to other animal research, hormone-disrupting contaminants can have more or different effects at low levels than at high levels.
Cary said it’s plausible that flame retardants interfere with the tadpoles’ hormones, which could cause their immune system to develop abnormally. PBDEs bind to a receptor in frogs that is responsible for triggering the immune system, according to previous research.
The same chemical mixture that suppressed antibodies in the new study’s frogs also has weakened immune systems of mice, mink and possibly people.
Frogs are exposed to flame retardants through dirt, plants and insects they feed upon.
PBDEs were used for decades in furniture cushion foam, plastics and electronics. The mixture that the researchers used was phased out in the United States 10 years ago, but the chemicals still enter the environment through long-lived products such as furniture, as well as from wastewater and sewage sludge, said Robert Hale, a professor of marine science at the Virginia Institute of Marine Science.
Northern leopard frogs are found in the northern and western United States and southern Canada. The species has experienced some population declines and habitat loss – especially in the West – but was denied endangered species protection in 2011. It remains a mystery why frog diseases have worsened, but some experts suspect contaminants and climate change. A lab study released last year found that frogs exposed to the herbicide atrazine early in life were more likely to die when faced with the chytrid fungus. However, other studies have not found that pesticides increase susceptibility to the fungus, said Carlos Davidson, a biologist and professor of environmental studies at San Francisco State University.
While it’s possible that “climate change has changed the playing field by altering temperatures that now favor the pathogen,” research hasn’t proved that, he said.
Amphibians are particularly vulnerable to environmental factors such as contaminants because they have thin, porous skins that absorb water.
“This study is definitely another piece to the puzzle of us trying to understand exactly how these toxics affect the development of frogs,” Rollins-Smith said.
Source : Environmental Health News
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Dolphins are dying all around Florida and scientists don't know how to stop it.
The die-offs of bottlenose dolphins are going on in three different places, and appear to be from more than one cause. Although dolphins are not an endangered species, the loss of so many all at once is clearly bad news, scientists say.
"This particular species has suffered a huge impact, all over the Southeast," said Blair Mase, a marine mammal specialist with the National Oceanic and Atmospheric Administration, which has classified each of the die-offs as an "unusual mortality event."
Greg Bossart, chief veterinary officer of the Georgia Aquarium, has studied dolphins for more than 30 years and said he can't recall another time when three separate "unusual mortality events" were going on at the same time involving a single species.
What makes so many deaths disturbing, he said, is that dolphins are regarded as "sentinels for ocean and human health," not unlike canaries in a coal mine.
The first sign of trouble came from the Gulf of Mexico. A month before the 2010 Deepwater Horizon oil spill began, dead dolphins began washing ashore along the Gulf Coast.
Then, as the oil spill continued through the summer, the number of dead and dying dolphins increased dramatically, and some began washing ashore on Florida Panhandle beaches as far east as Apalachicola. Some were premature newborns or stillborn dolphins.
A few were coated with oil, and some were suffering from a bacterial infection called Brucella, which scientists believe resulted from the oil suppressing the dolphins' immune system.
As of last Sunday, the total of dead dolphins along the gulf beaches had topped 1,000. The most recent one landed last week on the white sands near Panama City.
Then, beginning last year, dolphins began dying in droves over on Florida's east coast, in the Indian River Lagoon. So far 77 of the 600 that live in the lagoon have died, and only one sick one survived. The survivor, rescued in June and sent to SeaWorld for rehabilitation, was released back to the wild last week.
Hundreds of pelicans and manatees have died in the lagoon too. Scientists are still trying to figure out why, although they suspect it has something to do with the massive blooms of toxic algae that wiped out nearly half of the lagoon's sea grass beds.
The only clue on the dolphins appears to be that although they are emaciated, their stomachs were full of shrimp instead of their usual diet of sea trout, black drum and other fish.
Now comes the latest threat: a morbillivirus, similar to what causes measles in humans and distemper in dogs.
So far it has killed more than 750 dolphins all along the eastern seaboard. The die-off began in the waters off New York and slowly moved southward, shifting to Virginia, then North Carolina, with the numbers dropping in the North and rising in the South.
This month it showed up in a dead dolphin that washed ashore in Florida, near Jacksonville, Mase said. Two more dolphins that stranded themselves in Brevard County may have been victims as well. Tests are going on now to determine whether the virus killed them as well.
So far there is no sign that the morbillivirus has hit the already embattled Indian River Lagoon dolphins, but that's a possibility.
Dolphins along the Atlantic coast are migratory creatures, and when the infected ones surface to breathe, they spread the virus to other dolphins through droplets sprayed out of their blowholes, Bossart said. It can't be contracted by humans, although NOAA recommends against touching any dolphins found washed ashore.
This isn't the first time a morbillivirus has hit Florida's dolphin population. From June 1988 to May 1989, 742 dolphins — fewer than have died so far this year — died off the Atlantic coast from morbillivirus. Scientists estimated that during that epidemic, more than half the in-shore population of dolphins had been wiped out.
The 1980s dolphin die-off, the first to be attributed to morbillivirus, began the same way as this one. The first dead dolphins showed up around New York in the summer and then the epidemic made its way down the coast to Florida, persisting here until it ended at last the following spring.
Based on that pattern, Mase said, a lot more Florida dolphins are likely to die before the illness dissipates sometime next May.
"As the migratory population moves southward, you can expect the numbers in Florida to increase," Mase said.
There is no antiviral vaccine to give the dolphins to stop the die-off, just as there appears to be no way to halt the die-offs in Indian River Lagoon or along the Panhandle beaches. Scientists can only monitor what's happening and hope to discern the cause.
To Bossart, what's happening suggests that dolphins may be getting sick because the ocean around them is sick as well. Even before they began dying in droves, the dolphins in the Indian River Lagoon had high levels of mercury in their systems and quite a few were suffering from a fungal skin infection called lobomycosis.
"We've used the ocean as our toilet," he said, "and now it's starting to catch up with us."
Environmental Factors and Breast cancer
In addition to the traditionally acknowledged risk factors for breast cancer (age, reproductive history, genetic profile, alcohol intake, etc.), scientists are increasingly coming to understand that many chemicals commonly found in products we use daily may also be contributing to the very high incidence of breast cancer. We need to better understand the health effects of these environmental chemicals, especially so-called endocrine disrupting compounds (EDCs) in pesticides, plastics, many personal care products, etc. This knowledge may lead us to undertake actions that aim to prevent the disease.
Source : University of Texas, MD Anderson Cancer Centre
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The Dangers of Surveillance
Neil Richards, JD, privacy law expert and professor of law at Washington University in St. Louis.
From the Fourth Amendment to George Orwell’s Nineteen Eighty-Four, our law and literature are full of warnings about state scrutiny of our lives. These warnings are commonplace, but they are rarely very specific. Other than the vague threat of an Orwellian dystopia, as a society we don’t really know why surveillance is bad, and why we should be wary of it. To the extent the answer has something to do with “privacy,” we lack an understanding of what “privacy” means in this context, and why it matters. Developments in government and corporate practices, however, have made this problem more urgent. Although we have laws that protect us against government surveillance, secret government programs cannot be challenged until they are discovered. And even when they are, courts frequently dismiss challenges to such programs for lack of standing, under the theory that mere surveillance creates no tangible harms, as the Supreme Court did recently in the case of Clapper v. Amnesty International. We need a better account of the dangers of surveillance.
This article offers such an account. Drawing on law, history, literature, and the work of scholars in the emerging interdisciplinary field of “surveillance studies,” I explain what those harms are and why they matter. At the level of theory, I explain when surveillance is particularly dangerous, and when it is not. Surveillance is harmful because it can chill the exercise of our civil liberties, especially our intellectual privacy. It is also gives the watcher power over the watched, creating the the risk of a variety of other harms, such as discrimination, coercion, and the threat of selective enforcement, where critics of the government can be prosecuted or blackmailed for wrongdoing unrelated to the purpose of the surveillance.
At a practical level, I propose a set of four principles that should guide the future development of surveillance law, allowing for a more appropriate balance between the costs and benefits of government surveillance. First, we must recognize that surveillance transcends the public-private divide. Even if we are ultimately more concerned with government surveillance, any solution must grapple with the complex relationships between government and corporate watchers. Second, we must recognize that secret surveillance is illegitimate, and prohibit the creation of any domestic surveillance programs whose existence is secret. Third, we should recognize that total surveillance is illegitimate and reject the idea that it is acceptable for the government to record all Internet activity without authorization. Fourth, we must recognize that surveillance is harmful. Surveillance menaces intellectual privacy and increases the risk of blackmail, coercion, and discrimination; accordingly, we must recognize surveillance as a harm in constitutional standing doctrine.
Source : Social Science Research Network
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There is evidence that childhood exposure to lead causes permanent damage
CHILDHOOD exposure to environmental lead has been linked to mental, behavioural and physical deficits, and now the toxic lead dust has been connected to violent assault.
According to US researchers who compared statistics for six cities: Chicago, Indianapolis, Minneapolis, San Diego, Atlanta and New Orleans, rising levels of airborne lead dust lead to spikes in the rates of aggravated assault as exposed children grew up.
The findings, reported today in the journal Environment International, have implications for Australian mining communities, claims Mark Taylor, an environmental scientist at Macquarie University.
"There is an ongoing problem of environmental lead exposure from legacy mining and smelting, as well as contemporary production processes, especially in Port Pirie and Mt Isa," Professor Taylor said.
The new data comes from Howard Mielke, a specialist in environment and health with Tulane University in New Orleans, Louisiana, and epidemiologist Sammy Zahran, co-director of the Centre for Disaster and Risk Analysis at Colorado State University.
They point to a growing body of scientific evidence that childhood exposure to lead dust causes permanent damage to regions of the brain that govern mood regulation, executive control and judgment.
Professors Mielke and Zahrran found 90 per cent of the variation in aggravated assault across the US cities was explained by the amount of lead dust.
After controlling for other possible causes such as community and household income, education, policing effort, and incarceration rates, they found every 1 per cent increase in tonnage of environmental lead released 22 years earlier, raised the present rate of aggravated assault by 0.46 per cent.
National Australian data has not been collected, but statistics are telling.
According to Queensland Police Service statistics for 2006-2007, there were 2189 aggravated assaults per 100,000 of population in the mining and smelting town of Mt Isa, the highest in the state. In contrast, in Gladstone, where Australia's largest aluminium smelter operates, the figure was 427 per 100,000.
Mt Isa's assaults cannot be attributed to drunkenness as alcohol offences were nearly half that of Brisbane, with the second highest assault rate.
Likewise, in 2010 Broken Hill had 893.1 non-domestic violence related assaults per 100,000 of population. The rate for NSW was 550.8 and for Sydney, 488.4.
The drop in assaults in the US mirrors moves to phase out lead in petrol beginning in 1972 and ending with a nationwide ban in 1984. Australia phased out leaded petrol nationally on January 1, 2002.
Source : The Australian
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Biodiversity: Bat-killing disease now west of the Mississippi
SUMMIT COUNTY — With bat-killing white nose syndrome now documented in Missouri, conservation advocates say more action and more funding is needed to try and stop the spread of the disease, and the U.S. Fish and Wildlife Service last week announced seven grant awards worth $1.4 million for more research projects.
“Bats are crucial to our nation’s ecosystems and our economy,” said USFWS director Dan Ashe. “These grants provide critical support for the Service and our partners in addressing this unprecedented wildlife crisis.”
“Research will continue to be essential to the response to white-nose syndrome in North America,” said Dr. Jeremy Coleman, the Service’s national white nose syndrome coordinator. “We have made incredible progress in our understanding of the disease and how it affects bats, but we still have work to do. These projects will help further our understanding of white nose syndrome and the tools available to manage this devastating disease.”
Funded projects include detailed studies of Geomyces destructans, the fungus demonstrated to cause WNS, including how it interacts with bats and the environment; developing a better understanding of how white nose syndrome is transmitted; determining the mechanics of G. destructans infections in bats, including the susceptibility and resistance of bats to the infection; determining how persistent the fungus is in the environment; and identifying and developing non-chemical control options for treatment and prevention of spread of G. destructans.
White-nose syndrome has been confirmed in 19 states and four Canadian provinces at caves and mines where bats hibernate, and G. destructans has been detected on bats in one additional state. Winter hibernacula surveys are wrapping up, but the disease is expected to continue to spread in the future. The disease has already killed about 7 million bats throughout the eastern United States and Canada since it was first documented in upstate New York in 2006.
In Missouri, lab results confirmed that bats from two caves in Lincoln County, north of St. Louis, were infected with the fungus. The discovery is the first official report of the bat disease west of the Mississippi River. In 2010, the fungal pathogen was detected on asymptomatic bats in Missouri and Oklahoma.
“White-nose syndrome in Missouri is following the deadly pattern it has exhibited elsewhere,” said Mollie Matteson, a bat specialist with the Center for Biological Diversity, which has worked for years to raise funds for, and curb, the bat crisis. “First the fungus shows up on a few healthy bats. A couple of years later, the disease strikes. And if the pattern continues, we can expect that in another few years, the majority of Missouri’s hibernating bats will be dead.”
Bats provide vital services where they live. In Missouri, for example, it’s estimated that the state’s 775,000 gray bats eat more than 223 billion bugs each year.
Scientists estimate that, nationally, the loss of bats may cost farmers between $3.7 billion and $53 billion annually in crop losses and increased pesticide use, due to the disappearance of bats’ natural, freely provided pest control. Bats consume thousands of tons of insects every year.
Last month biologists confirmed white-nose syndrome for the first time in Alabama and Delaware, and National Park Service officials reported the bat disease for the first time in Acadia National Park in Maine and Great Smoky Mountain National Park in Tennessee and North Carolina. The disease has also been rapidly spreading this year to new locations in Kentucky, Ohio and Indiana, where it was documented for the first time last winter.
The bat epidemic is the worst wildlife-disease decline in U.S. history. Nine species of bat have been found with the fungus, and of these, six species have experienced mortality, several of them at rates approaching 100 percent. Biologists fear that several bat species, including the once-common little brown bat, may become extinct.
Scientists do not yet have an effective treatment; the only known way to contain the spread of white-nose is to reduce the risk of human transport of the fungus by closing caves to nonessential access and requiring decontamination procedures of those still entering caves.
Researchers believe the previously unknown fungus killing the bats was introduced to North America by cave visitors from Europe. There, the fungus has been discovered on bats in several countries, but it appears to do little to no harm to them.
Bats themselves can transmit the disease to each other and to new locations, but they are not capable of migrations greater than a few hundred miles. Fears of long-distance transport of fungus by people prompted limited cave closures on western federal lands following the discovery of the pathogen on asymptomatic bats in Missouri and western Oklahoma in 2010. However, western land managers have taken few precautionary measures against human spread since then.
In 2010 the Center filed a federal petition calling for the closure of bat caves on all federal lands in the lower 48 states as a precaution against the potential human spread of white-nose. Most federal lands in the eastern United States already have closure rules in place or require screening and decontamination of cave tourists, as is the case at Mammoth Cave National Park in Kentucky. But the majority of caves on western federal lands remain open, and decontamination procedures are not required.
“Now that white-nose syndrome is clearly at the doorstep of the West, there can be no more excuses for inaction on the part of western land mangers,” said Matteson. “This killer disease has shown over and over again that it moves in subtly at first, but before you know it there are dead bats all over the place.”
White-nose syndrome is now confirmed in 19 states and suspected in one; it is also confirmed in four Canadian provinces.
The loss of bug-eating bats may result in economic losses to American agriculture, as well as burgeoning populations of insects, no longer kept in check by bats. Scientists estimate that the loss of bats may cost farmers between $3.7 billion and $53 billion annually in crop losses and increased pesticide use, due to the disappearance of bats’ natural, freely provided pest control. Bats consume thousands of tons of insects every year.
BAT CRISIS: WHITE-NOSE SYNDROME - to read more click below
Source ; Summit County Citizens Voices
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