Iturria: El Correo

«elegir entre el gas y el agua»

'Fracking ez' cifra en 2.119 los pozos necesarios para sacar gas

La plataforma alertó en las Juntas Generales del riesgo de contaminación de este sistema

18.04.12 - 02:22 -

MARTA PECIÑA | VITORIA.

Hacen falta 2.119 pozos para sacar el gas del subsuelo alavés a través del sistema 'fracking', según explicó ayer Mikel Otero, portavoz de la plataforma contra este sistema de extracción, en su comparecencia en las Juntas Generales de Álava. La cifra se obtiene de las reservas estimadas en territorio alavés, de 180.000 millones de metros cúbicos. Los argumentos que desgranó Otero pretendían demostrar que el Gobierno vasco se ha convertido en principal impulsor del proyecto, pero que en él, sólo se tienen en cuenta las variables económicas y técnicas en cuanto a su rentabilidad, mientras que las medioambientales han quedado apartadas. Puso como ejemplo, que «los nueve permisos que se tramitan en Álava afectan al 90% del territorio».

 

El portavoz de 'Fracking ez Araba' explicó, asimismo, que este sistema exigirá millones de metros cúbicos de agua, «que quedará contaminada en el subsuelo alavés». Este material corre el riesgo de «afectar a los 55 pozos abiertos para otras actividades» y apostó por «elegir entre el gas y el agua».

Otero asumió que las actuaciones realizadas hasta ahora son reversibles, «pero no cuando se empiece a fracturar», e insistió en los riegos de esta actividad. Se remitió a los estudios realizados en Estados Unidos, donde la técnica lleva implantada ya varios años. Recordó los accidentes que se producen por desbordamiento de las balsas que contienen lo materiales contaminantes, la filtración de gas a los pozos ya existentes, los problemas de sellado y alertó de que «durante el primer año se obtiene el máximo rendimiento, pero luego la tasa productividad baja entre un 60 y un 80%, así que la vida útil de un pozo viene a ser de siete años y para seguir extrayendo el gas, hay que construir uno nuevo». Cada pozo ocupa una superficie de unas dos hectáreas en el terreno.

Otero recordó que la extracción del gas alavés no debería ser una cuestión económica, sino de «apuesta por otro modelo energético». Puso como ejemplo los casos de Francia o Bulgaria donde «han prohibido está técnica» o el de Dinamarca «donde también hay gas de este tipo, pero han decidido que en 2050 toda su energía procederá de fuentes renovables».

Por otra parte, los grupos municipales del PNV y Bildu mostraron su malestar con los ponentes elegidos para las jornadas sobre fracking organizadas la próxima semana por el Gobierno vasco, la Diputación y el Ayuntamiento.

Clues to Species Decline Buried in Pile of Bird Excrement

Iturria: Sciencemag

by Helen Fields on 17 April 2012, 7:01 PM |

 

Hidden treasure. Chimney swifts (bottom left) roosted in this chimney until it was capped in 1992; researchers dug out their poop and studied the hard remains of insects they'd eaten (top right).

Credit: Chris Grooms/Queen's University; (bird, left inset) Bruce Di Labio

In 2009, while searching for ways to help endangered birds, research technician Chris Grooms heard that a chimney on his university campus used to host a migratory species known as the chimney swift. When he investigated, he found a pile of bird excrement 2 meters deep. The poop lay at the bottom of a five-story-high chimney and had been deposited over 48 years by the birds, which had roosted there until the top was capped in 1992. Now, Grooms and his colleagues have dug into that pile of guano, revealing new clues about why the chimney swift and other species like it have begun to disappear.
Grooms volunteers for an environmental group in Ontario, Canada, that's trying to conserve local wildlife. He also works in a lab at Queen's University in Kingston that studies sediments in lakes. As dirt and dead things sink to the bottom of these bodies of water, they preserve a record of environmental conditions. Grooms wondered if the same thing had happened with his pile of bird poop. He brought the idea to the head of the lab, ecologist John Smol. Smol was intrigued: "It could be 2 meters of bird poop, or it could be a pretty important story."
The researchers entered the chimney through a little door near the bottom that was only big enough to crawl through. Behind the door was the wall of poop. It took 2 days to dig out enough of the crumbly, dark-gray, dry excrement so that the researchers could stand up. After 20 years, the poop had lost its smell, but the researchers wore respirators just in case some pathogen was hanging around.
With the help of radioisotopes produced by nuclear bomb tests, which linger in sediments and can be used for dating, the researchers worked out that the deposit built up between 1944 and 1992. A team at the University of Ottawa measured levels of DDE, a chemical that comes from the pesticide DDT, to see if DDT affected what insects the birds were eating. Another set of samples went off to Joseph Nocera, a conservation biologist at the Ontario Ministry of Natural Resources in Peterborough, who sorted out insect remains. Most were beetles; the next most common remains were from the Hemiptera, an order known as "true bugs" that includes stink bugs and cicadas.
As DDE increased through the lower layers of the deposit, beetles showed up less often in the birds' diets and true bugs became more common, the researchers report online today in the Proceedings of the Royal Society B. This result agrees with other reports that DDT is hard on beetles, while true bugs can evolve resistance quickly. The change in diet may also help explain why chimney swifts have declined so precipitously, Nocera says.
Canadian surveys have found that the number of chimney swifts dropped 95% between 1968 and 2005. Some researchers have suggested that part of the reason is that chimneys like this one, swifts' preferred habitat, have been capped or redesigned, making it harder for birds to get in. But the new work suggests that the decline may be diet related. Beetles generally contain more calories than do true bugs. Swifts need a ton of energy—they spend a lot of time on the wing, looking for food. A change in their diet, like substituting less-nutritious true bugs, could have a big impact. DDT was banned in the 1970s, but the beetles never seem to have gotten back their original place in the food web, Nocera says.
Nocera thinks DDT and other pesticides may have effects far beyond their well-known impacts on the eggshells of large birds, such as taking away the foods that chimney swifts, barn swallows, flycatchers, and other insect-eating birds relied on. He says he doesn't know of any other studies that have looked at a pile of bird poop on the scale of decades—other studies have looked at older guano. There are probably many more archives like this in the chimney swift's range, he says, and this study shows that it's possible to get useful information out of them.
Çağan Şekercioğlu, a conservation ecologist at the University of Utah in Salt Lake City, agrees with the team's conclusions. Pesticides get more concentrated as they move up the food chain, which means they can be worse for insect-eating birds than for birds that eat fruit or nectar, he says. Still, Şekercioğlu says he would have liked to see more discussion of how the loss of nesting and roosting sites—like the chimney in this study—affected chimney swift populations. But "it's a very good historical data set," he says. "We don't have that opportunity for almost any other bird species. It's a brilliant idea and very well thought out, and the fact that they found this potential link to DDT is fascinating."

Counting Penguins From Space

Iturria: Sciencemag

by Erik Stokstad on 13 April 2012, 4:16 PM | 1 Comments

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Credit: (left) DigitalGlobe; (right) British Antarctic Survey

Counting penguins isn't as hard as it might sound. (Hey, hold still!) Someone snaps a photograph of a colony and then marks up the picture to make sure that they aren't missing or double counting anybody. What is hard is getting to remote places, especially Antarctica. So a new approach is to use satellite images, and today researchers report the results of the first such comprehensive study. Scientists have found twice as many emperor penguins (Aptenodytes forsteri) as previously thought to exist, roughly 595,000 (plus or minus 81,000). They also came across seven new colonies (one shown at left), bringing the total to 44. To get the new number of birds, they had to enhance the images with a technique called pansharpening, which allowed them to distinguish between shadows, guano, and actual penguins. "This is a leap forward but it doesn't change the conservation concern [about] emperor penguins and many other species," says penguin expert P. Dee Boersma of the University of Washington, Seattle. "Unfortunately with climate warming and variation, we are likely to be studying the decline of emperor penguins. Satellite mapping will allow scientists to determine where the decline are occurring and by how much."

Wildlife Thriving After Nuclear Disaster? Radiation from Chernobyl and Fukushima Nuclear Accidents Not as Harmful to Wildlife as Feared

Iturria: Science Daily

ScienceDaily (Apr. 11, 2012) — Radiation from the Chernobyl and Fukushima nuclear accidents may not have been as harmful to wildlife as previously thought.

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New research by Professor Jim Smith, of the University of Portsmouth, and colleagues from the University of the West of England has cast doubt on earlier studies on the impact on birds of the catastrophic nuclear accident at Chernobyl in April 1986.
Their findings, published in the Royal Society journal Biology Letters, are likely to also apply to wildlife at Fukushima in Japan following its nuclear disaster in 2011 and represent an important step forward in clarifying the debate on the biological effects of radiation.
Professor Smith, an environmental physicist at the School of Earth and Environmental Sciences, said: "I wasn't really surprised by these findings -- there have been many high profile findings on the radiation damage to wildlife at Chernobyl but it's very difficult to see significant damage and we are not convinced by some of the claims.

Chernobyl atomic power station, after nuclear catastrophe. Radiation from the Chernobyl and Fukushima nuclear accidents may not have been as harmful to wildlife as previously thought. (Credit: © Hellen Sergeyeva / Fotolia)

"We can't rule out some effect on wildlife of the radiation, but wildlife populations in the exclusion zone around Chernobyl have recovered and are actually doing well and even better than before because the human population has been removed."
Until now, scientists had thought radiation had a dramatic effect on bird populations following the Chernobyl disaster because it had caused damage to birds' antioxidant defence mechanisms. But Professor Smith and colleagues have, for the first time, quantified this effect. Their study modelled the production of free radicals from radiation, concluding that the birds' antioxidant mechanisms could easily cope with radiation at density levels similar to those seen at Chernobyl and Fukushima.
Professor Smith said: "We showed that changes in anti-oxidant levels in birds in Chernobyl could not be explained by direct radiation damage. We would expect other wildlife to be similarly resistant to oxidative stress from radiation at these levels.
"Similarly, radiation levels at Fukushima would not be expected to cause oxidative stress to wildlife. We believe that it is likely that apparent damage to bird populations at Chernobyl is caused by differences in habitat, diet or ecosystem structure rather than radiation.
"It is well-known that immediately after the Chernobyl accident, extremely high radiation levels did damage organisms. But now, radiation levels at Chernobyl are hundreds of times lower and, while some studies have apparently seen long-term effects on animals, others have found no effect.
"Some Belarussian and Ukrainian scientists who live and work in the Chernobyl exclusion zone have reported big increases in wildlife populations since the accident, due to the removal of humans from the area."
Professor Smith has studied contamination at Chernobyl for more than 20 years and regularly visited the exclusion zone for his research. He is author of a major book about the incident, Chernobyl: Catastrophe and Consequences, and is a former member of the International Atomic Energy Agency Chernobyl forum.

Scientists Determined First-ever Census for Emperor Penguins

Iturria: National Science Foundation



Press Release 12-071
Scientists Determined First-ever Census for Emperor Penguins

High-resolution satellite images estimate emperor penguin numbers in Antarctica

Penguin census doubled previous estimates. Credit and Larger Version

April 13, 2012

View a video with Michelle LaRue of the University of Minnesota.
A new study using satellite mapping technology reveals there are twice as many emperor penguins in Antarctica than previously thought.
The results provide an important benchmark for monitoring the impact of environmental change on the population of this iconic bird, which breeds in remote areas that are very difficult to study because they often are inaccessible with temperatures as low as -58 degrees Fahrenheit.
Reporting this week in the journal PLoS ONE, an international team of scientists describe how they used Very High Resolution satellite images to estimate the number of penguins at each colony around the coastline of Antarctica.
Using a technique known as pan-sharpening to increase the resolution of the satellite imagery, the science teams were able to differentiate between birds, ice, shadow and penguin poo or guano. They then used ground counts and aerial photography to calibrate the analysis.
Lead author and geographer Peter Fretwell at British Antarctic Survey (BAS), which is funded by the U.K.'s Natural Environment Research Council, explains, "We are delighted to be able to locate and identify such a large number of emperor penguins. We counted 595,000 birds, which is almost double the previous estimates of 270,000-350,000 birds. This is the first comprehensive census of a species taken from space."
On the ice, emperor penguins with their black and white plumage stand out against the snow and colonies are clearly visible on satellite imagery. This allowed the team to analyze 44 emperor penguin colonies around the coast of Antarctica, and seven previously unknown colonies.
"The methods we used are an enormous step forward in Antarctic ecology because we can conduct research safely and efficiently with little environmental impact, and determine estimates of an entire penguin population, said co-author Michelle LaRue from the University of Minnesota and funded by the U.S. National Science Foundation (NSF).
"The implications of this study are far-reaching: we now have a cost-effective way to apply our methods to other poorly-understood species in the Antarctic, to strengthen on-going field research, and to provide accurate information for international conservation efforts."
NSF manages the U.S. Antarctic Program through which it coordinates all U.S. scientific research on the southernmost continent and aboard ships in the Southern Ocean as well as related logistics support.
Co-author and BAS biologist Phil Trathan noted, "Current research suggests that emperor penguin colonies will be seriously affected by climate change. An accurate continent-wide census that can be easily repeated on a regular basis will help us monitor more accurately the impacts of future change on this iconic species."
Scientists are concerned that in some regions of Antarctica, earlier spring warming is leading to loss of sea ice habitat for emperor penguins, making their northerly colonies more vulnerable to further climate change.
Trathan continued, "Whilst current research leads us to expect important declines in the number of emperor penguins over the next century, the effects of warming around Antarctica are regional and uneven. In the future, we anticipate that the more southerly colonies should remain, making these important sites for further research and protection."
This research is a collaboration between BAS, University of Minnesota/NSF, Scripps Institution of Oceanography and the Australian Antarctic Division.

-NSF-

Media Contacts Deborah Wing, NSF (703) 292-5344 dwing@nsf.gov

Program Contacts Alexandra Isern, NSF (703) 292-7581 aisern@nsf.gov


The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget is $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives over 50,000 competitive requests for funding, and makes about 11,000 new funding awards. NSF also awards nearly $420 million in professional and service contracts yearly.
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Asian 'phoenix' lived with the dinosaurs

Iturria: ABC Science

AFP

If it flew it may have had wingspan greater than that of the albatross (Source: Marj Kibby/Flickr)

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• Dinosaur-bird connection a thing of the past, Science Online, 25 May 2010
• Fossil sheds new light on 'dino-bird', Science Online, 12 May 2010
• Dinosaur bird was equipped to fly, Science Online, 06 Nov 2008

Palaeontologists have found the fossilised remains of a giant bird that lived in Central Asia more than 65 million years ago, a finding which challenges theories about the diversity of early birds.

The creature may have been taller than an ostrich if it had been flightless and, if it flew, had a greater wingspan than that of the albatross, according to a report in the journal Royal Society Biology Letters.
The scientists have named the bird Samrukia nessovi, after a mythological Kazakh phoenix known as the samruk, and after Lev Nessov, a celebrated Russian palaeontologist who died in 1995.
The estimate is based on a pair of mandibular rami, or the upright part of an L-shaped lower jawbone, that were found in Late Cretaceous sediment in Kyzylorda, southern Kazakhstan.
The bones measure 275 millimetres, indicating a skull that would have been a whopping 30 centimetres long.
What the bird ate and whether it flew are unclear because the evidence is so sketchy.
But if the two bones are a guide, the beast would have stood up to three metres high and weighed more than 50 kilograms if it had been flightless.
If it flew, the bird would have weighed at least 12 kilograms, with a wingspan of at least four metres.
The avian was "an undisputed giant," says the study.

Incomplete fossil record

Birds are believed to have evolved from tiny two-footed dinosaurs called theropods at the start of the Cretaceous era, around 150 million years ago.
The prevailing theory, based on usually-incomplete fossils, is that they remained extremely small for tens of millions of years.
Of more than 100 types of early birds that have come to light, only one - Gargantua philoinos, which lived around 70 million years ago - was large-bodied. The others were crow-sized or smaller.
And even the claim for G. Philoinos is under attack. Some scientists argue the fossil was really that of a pterosaur, or flying reptile, rather than a bird.