Bases de données TCHERNOBYL
Dossier "Le paradis ou non pour les animaux?"
"Dépression scientifique" à Tchernobyl?!
ADIT, mars 2009

    Twenty years after the Chernobyl meltdown in Ukraine, radiation is still hammering the region's insect, spider, and bird populations.
     At least that's what Reuters and the BBC reported last week based on a paper published in the journal Biology Letters by ecologists Timothy Mousseau of the University of South Carolina and Anders Møller of the University of Paris-Sud. For the past 10 years, the duo has been running transects through the region counting wildlife and measuring radiation levels with dosimeters.
     "We wanted to ask the question: Are there more or fewer animals in the contaminated areas," Moller told Reuters. "Clearly there were fewer."
     But at least one scientist formerly associated with the team is questioning the new research. Sergey Gaschak, a researcher at the Chernobyl Center in Ukraine, told the BBC that he drew "opposite conclusions" from the same data the group collected on birds. This might seem like little more than blunt criticism, but I knew that Møller's research ethics had previously been called into question.
     In 2003, the Danish Committee on Scientific Dishonesty ruled that Møller had fabricated data in a 1998 paper on oak leaves while he was still based in Denmark. A subsequent investigation by the national research agency in France, where Møller currently lives, proved inconclusive. But while doing research for a 2007 profile of Møller that I was writing for The Scientist magazine, I interviewed many researchers who claimed that Møller's fabrications extended to the bird studies for which he is best known. At the time, Møller told me that his publication rate had declined substantially since the misconduct charges were made public, but a quick look at his publication record shows the prolific ecologist cranked out nearly 30 studies in 2008.
     To find out more, I asked Gaschak to clarify his critique of the Chernobyl bird study in which he was directly involved. He says the research was flawed from the get-go, starting with the study design. The reason: researchers selected study sites that varied in radiation levels, but they failed to control for important differences in habitat vegetation, which would affect bird distributions.
     Gaschak notes that he collected the raw bird data in the Red Forest, the highly contaminated region that surrounds the power plant, but when he saw Møller's analysis before publication it contained "quite unexpected results." He also doubts that the team could have obtained the volume of data they have based on the time they spent in Chernobyl.
     Gaschak, however, was unwilling to specify precisely which numbers he felt were most suspect because he had already "wasted a lot of time on Møller & Mousseau." He did say that he once questioned Mousseau about Møller's methods but didn't get any straight answers. Instead, he says, Mousseau was "irritated" by his queries and eventually he and Moller "avoided any contact" with him.
     "They have an idea to show by any means that radiation has exclusively negative effects,"Gaschak says, "That's it. Truth is not their target."
     Mousseau denies Gaschak's charges, claiming that Gaschak's interpretation has been colored by his own self-interest.
     "Sergey has been struggling for the last 20 years to maintain gainful employment," Mousseau says, noting that Gaschak is determined to preserve the Chernobyl zone in the Ukraine as a wildlife refuge where he can continue to work. Mousseau says he has no concerns about the reliability of the data Møller collected or of their analysis "I walk with him," he says, "We do these transects together." He praised Gaschak as a naturalist but questioned his analytical experience, noting that he had not previously published a paper on the topic. He calls Gaschak's claim "hearsay" and says that "giving it that much weight does the whole scientific enterprise a disservice."
     Unfortunately, Gaschak says, the current sorry state of science funding in former Soviet countries, has not afforded him the opportunity to try to replicate – or prove wrong – Møller's work. "That is why [there are] so few publications about wildlife in the contaminated areas," he says. The lack of funding, he maintains, has allowed one voice to dominate the public conversation.
Chernobyl animals worse affected than thought: study

An elk stands in a forest in the 30 km (18 miles) exclusion zone around the Chernobyl nuclear reactor near the village of Babchin some 370 km (217 miles) southeast of Minsk February 1, 2008.

Bison walk in the 30 km (18 miles) exclusion zone around the Chernobyl nuclear reactor near the village of Babchin some 370 km (217 miles) southeast of Minsk February 3, 2009.

LONDON (Reuters) - Radiation has affected animals living near the site of Ukraine's Chernobyl nuclear disaster far more than was previously thought, a study showed Wednesday, challenging beliefs that local wildlife was on the rebound.
     The study showed that numbers of bumble-bees, butterflies, spiders, grasshoppers and other invertebrates were lower in contaminated sites than other areas because of high levels of radiation left over from the blast more than 20 years ago.
     The findings challenge earlier research that suggested animal populations were rebounding around the site of the Chernobyl explosion in Ukraine, which forced thousands to abandon their homes and evacuate the area.
     Estimates of the number of deaths directly related to the accident vary. The World Health Organization estimates the figure at 9,000 while the environmental group Greenpeace predicts an eventual death toll of 93,000.
     "We were amazed to see that there had been no studies on this subject," Anders Moller, a researcher at the National Center for Scientific Research in France, who led the study, said in telephone interview.
     "Ours was the first study to focus on the abundance of animal populations."
     Researchers said they had compared animal populations in radioactive areas with less contaminated plots and found that some were nearly completed depleted of animal life.
     "There are areas with an abundance of 100 animals per square meter," Moller said. "And then there are areas with less than one specimen per square meter on average; the same goes for all groups of species."
     The researchers also found that animals living near the Chernobyl reactor -- which was covered in a protective shell after it exploded in April 1986 -- had more deformities, including discoloration and stunted limbs, than normal.
     "Usually (deformed) animals get eaten quickly, as it's hard to escape if your wings are not the same length," Moller said. "In this case we found a high incidence of deformed animals."

     The findings challenge the view of Chernobyl as ecologically sound, despite the fact that Ukrainian officials have turned it into a nature reserve, with wolves, bison and bears.
     Earlier research into the area ignored the fact that animal populations had grown unimpeded in the absence of humans for many years after the blast, Moller said.
     "We wanted to ask the question: Are there more or fewer animals in the contaminated areas? Clearly there were fewer," said Moller, who has worked on Chernobyl since 1991.
     While researchers focused on the 30 kilometer radius around the Chernobyl reactor, the fallout from the explosion covered a vast swathe of Eastern Europe, including parts of Russia, Ukraine and Belarus.
     The findings probably apply to those areas as well, Moller said, adding that any decontamination effort was unlikely due to the extent of the fallout.
Chernobyl 'shows insect decline'

By Victoria Gill
Science reporter, BBC News

Chernobyl is largely human-free but still contaminated with radiation

Researchers in Chernobyl
The team counted insects and spider webs in the 'unique' exclusion zone

     Two decades after the explosion at the Chernobyl nuclear power plant, radiation is still causing a reduction in the numbers of insects and spiders.
     According to researchers working in the exclusion zone surrounding Chernobyl, there is a "strong signal of decline associated with the contamination".
     The team found that bumblebees, butterflies, grasshoppers, dragonflies and spiders were affected.
     They report their findings in the journal Biology Letters.
Professor Timothy Mousseau from the University of South Carolina, US, and Dr Anders Moller from the University of Paris-Sud worked together on the project.
     The two researchers previously published findings that low-level radiation in the area has a negative impact on bird populations.
     "We wanted to expand the range of our coverage to include insects, mammals and plants," said Professor Mousseau. "This study is the next in the series."

Ghost zone
     Professor Mousseau has been working for almost a decade in the exclusion zone. This is the contaminated area surrounding the plant that was evacuated after the explosion, that remains effectively free of modern human habitation.
     For this study they used what Mousseau described as "standard ecological techniques" - plotting "line transects" through selected areas, and counting the numbers of insects and spiders webs they found along that line.
     At the same time, the researchers carried hand-held GPS units and dosimeters to monitor radiation levels.
     "We took transects through contaminated areas in Chernobyl, contaminated land in Belarus, and in areas free of contamination.
     What we found was the same basic pattern throughout these areas - the numbers of organisms declined with increasing contamination."
     According to Professor Mousseau, this technique of counting organisms is "particularly sensitive" because it can account for the changing pattern of contamination across the zone.
     "We can compare relatively clean areas to the more contaminated ones," he explained.

Thriving or dying?
     But some researchers have challenged the study, claiming that the lack of human activity in the exclusion zone has been beneficial for wildlife.
     Dr Sergii Gashchak, a researcher at the Chornobyl Center in Ukraine, dismissed the findings. He said that he drew "opposite conclusions" from the same data the team collected on birds.
     "Wildlife really thrives in Chernobyl area - due to the low level of [human] influence," Dr Gashchak told BBC News.
     "All life appeared and developed under the influence of radiation, so mechanisms of resistance and recovery evolved to survive in those conditions," he continued.

"Chernobyl offers a unique opportunity to explore the potential risks of this contamination"
Timothy Mousseau
University of South Carolina
     "After the accident, radiation impacts exceeded the capabilities of organisms. But 10 years after the accident, the dose rates dropped by 100 to 1,000 times."
     Professor Mousseau responded that his aim is to use the site to discover the true ecological effects of radiation contamination.
     "The verdict is still out concerning the long-term consequences of mutagenic contaminants in the environment," he said.
     "Long-term studies of the Chernobyl ecosystem offer a unique opportunity to explore these potential risks that should not be missed."