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  National Geographic 26 Apr 06
Despite Mutations, Chernobyl Wildlife Is Thriving
Kate Ravilious for National Geographic News

BBC Online 20 Apr 06
Wildlife defies Chernobyl radiation
By Stephen Mulvey
Thanks to alert from Kevin Lam who adds: "its strange how humans don't consider themselves to be a parasite or pest when I would argue that as a species our overall biomass is probably more than cockroaches".

It contains some of the most contaminated land in the world, yet it has become a haven for wildlife - a nature reserve in all but name.

The exclusion zone around the Chernobyl nuclear power station is teeming with life. As humans were evacuated from the area 20 years ago, animals moved in.

Existing populations multiplied and species not seen for decades, such as the lynx and eagle owl, began to return. There are even tantalising footprints of a bear, an animal that has not trodden this part of Ukraine for centuries.

"Animals don't seem to sense radiation and will occupy an area regardless of the radiation condition," says radioecologist Sergey Gaschak. "A lot of birds are nesting inside the sarcophagus," he adds, referring to the steel and concrete shield erected over the reactor that exploded in 1986. "Starlings, pigeons, swallows, redstart - I saw nests, and I found eggs."

There may be plutonium in the zone, but there is no herbicide or pesticide, no industry, no traffic, and marshlands are no longer being drained. There is nothing to disturb the wild boar - said to have multiplied eightfold between 1986 and 1988 - except its similarly resurgent predator, the wolf.

Inedible

The picture was not quite so rosy in the first weeks and months after of the disaster, when radiation levels were much, much higher. Four square kilometres of pine forest in the immediate vicinity of the reactor went ginger brown and died, earning the name of the Red Forest.

Some animals in the worst-hit areas also died or stopped reproducing. Mice embryos simply dissolved, while horses left on an island 6km from the power plant died when their thyroid glands disintegrated. Cattle on the same island were stunted due to thyroid damage, but the next generation were found to be surprisingly normal.

Now it's typical for animals to be radioactive - too radioactive for humans to eat safely - but otherwise healthy.

Adaptation

There is a distinction to be made between animals which stay in one place, such as mice, and larger animals - elks, say - which move in and out of contaminated land as they range over large areas.

The animals that wander widely end up with a lower dose of radiation than animals stuck in a radiation hotspot. But there are signs that these unfortunate creatures can adapt to their circumstances.

Sergey Gaschak has experimented on mice in the Red Forest, parts of which are slowly growing back, albeit with stunted and misshapen trees. "We marked animals then recaptured them again much later," he says. "And we found they lived as long as animals in relatively clean areas."

The next step was to take these other mice and put them in an enclosure in the Red Forest.

"They felt not very well," Sergey says. "The distinction between the local and newcomer animals was very evident."

Mutation

In all his research, Sergey has only found one mouse with cancer-like symptoms. He has found ample evidence of DNA mutations, but nothing that affected the animals' physiology or reproductive ability. "Nothing with two heads," he says.

Mary Mycio, author of Wormwood Forest, a natural history of the Chernobyl zone, points out that a mutant animal in the wild will usually die and be eaten before scientists can observe it.

And in general, she notes, scientists study populations as a whole, and are not that interested in what happens to particular individuals.

Nuclear guardian

But she too argues that the benefits to wildlife of removing people from the zone, have far outweighed any harm from radiation.

In her book she quotes the British scientist and environmentalist James Lovelock, who wrote approvingly in the Daily Telegraph in 2001 of the "unscheduled appearance" of wildlife at Chernobyl.

He went on: "I have wondered if the small volumes of nuclear waste from power production should be stored in tropical forests and other habitats in need of a reliable guardian against their destruction by greedy developers".

A large part of the Chernobyl zone within Belarus has already officially been turned into a nature reserve. Sergey Gaschak wants Ukraine to follow suit and to turn its 2,500 sq km of evacuated land into a reserve or national park.

Unlike the Ukrainian Green Party, he is not bothered if the government goes ahead with plans to build a deep deposit in the zone for nuclear waste from all over the country. He says the eagle owl will not care two hoots.

National Geographic 26 Apr 06
Despite Mutations, Chernobyl Wildlife Is Thriving
Kate Ravilious for National Geographic News

Twenty years ago today, reactor number four at the Chernobyl Nuclear Power Plant exploded. The blast covered vast areas of Belarus, Ukraine, and Russia with dangerous radioactive material. The effects of the Chernobyl catastrophe are still being felt today--whole towns lie abandoned, and cancer rates in people living close to the affected areas are abnormally high.

But it turns out that the radioactive cloud may have a silver lining. Recent studies suggest that the 19-mile (30-kilometer) "exclusion zone" set up around the reactor has turned into a wildlife haven. Roe deer bounce though the deserted houses while bats roost in the rafters. Plants and trees have sprung back to life, and rare species, such as lynx, Przewalski's horses, and eagle owls, are thriving where most humans fear to tread.

From Red to Green

The situation is a far cry from the way things looked just after the accident. Initially many animals died from the huge doses of radiation they received. The red color of withered pine needles earned one large area near the reactor the name Red Forest.

"Now it is not the Red Forest but a real green forest, due to [growing] birch trees," said Sergey Gaschak from the International Radioecology Laboratory in Kiev, Ukraine.

And in the towns where humans have moved out, plants and animals seem to have moved in. "Wild boar like to live in former villages, and I have found many birds' nests in the buildings," Gaschak said.

Even the site of the explosion seems to be bursting with life. "I met a hare in the sarcophagus area, and birds nest there," said Gaschak, referring to the concrete and steel shell that encases the still smoldering reactor.

But while wildlife seems to be proliferating in the Chernobyl exclusion zone, not everyone is convinced that these plants and animals are healthy.

Anders Moller from the University of Pierre et Marie Curie in Paris, France, and Tim Mousseau from the University of South Carolina (USC) in Columbia have been studying Chernobyl's bird populations.

They have shown that certain species in the area have a higher rate of genetic abnormalities than normal. "We find an elevated frequency of partial albinism in barn swallows, meaning they have tufts of white feathers," Mousseau said.

Late last year Moller and Mousseau published a paper in the Journal of Animal Ecology showing that reproductive rates and annual survival rates are much lower in the Chernobyl birds than in control populations.

"In Italy around 40 percent of the barn swallows return each year, whereas the annual survival rate is 15 percent or less for Chernobyl," Mousseau said. Moller and Mousseau think that migratory species, such as the barn swallow, are particularly vulnerable to radioactive contaminants, because they arrive in the area exhausted and with depleted reserves of protective antioxidants due to their arduous journey.

The scientists are also concerned that the mutated birds will pass on their abnormal genes to the global population. "In the worst case scenario these genetic mutations will spread out, and the species as a whole may experience enhanced levels of mutation," Mousseau said.

"Great Irony"

Mutation isn't the only adverse effect of the radiation.

Working in the Red Forest area, James Morris, a USC biologist, has observed some trees with very strange twisted shapes. The radiation, he says, is confusing the hormone signal that the trees use to determine which direction to grow. "These trees are having a terrible time knowing which way is up," Morris said.

Gaschak, the Kiev ecologist, believes such radiation effects will diminish over time. He is celebrating the way that Chernobyl has burst into life and hopes that the area will become a national park one day.

But Mousseau is less optimistic. "One of the great ironies of this particular tragedy is that many animals are doing considerably better than when the humans were there," he said. "But it would be a mistake to conclude they are doing better than in a control area. We just don't know what is normal [for Chernobyl]. There just haven't been enough scientific studies done."
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