How Radiation Affects Nature Thirty Years After the Chernobyl Disaster

Chernobyl, UkraineMarina Shkvyria watches animal tracks as she walks to an abandoned village in the Chernobyl Exclusion Zone, the area sealed to the public after a nuclear power plant exploded here 30 years ago, on April 26, 1986. Seeing one, she crouches down and takes care of her finger over the toes of a wolf trail in the loose sand.

It may seem strange that Chernobyl, an area known for the deadliest nuclear accident in history, could become a haven for all kinds of animals – from elk, deer, beaver and owls to more exotic species such as brown bears, lynx and wolves – but just that Shkvyria and some other scientists think it happened. Without people hunting them or destroying their habitat, wildlife is thought to thrive despite high radiation levels.

Shkvyria is a wolf expert at the National Academy of Sciences of Ukraine, and one of a handful of scientists following the fate of the Chernobyl fauna. She discovered the wolf at the village by unorthodox but inexpensive methods. “We came here late last spring and howled, and the young wolves howled from the top of that hill,” she says with a mischievous smile.

So far scientists are divided on how well the animals are really doing in the exclusion zone between Ukraine and Belarus, says biologist Jim Beasley of the Savannah River Ecology Laboratory at the University of Georgia, who studied wolves there with a grant from the National Geographic Society Committee for Research and Research.

In a new study published on Monday, Beasley says the population of large mammals on the Belarusian side has increased after the disaster. He was shocked by the number of animals he saw there in a five-week survey. Camera traps captured images of a bison, 21 wild boars, nine badgers, 26 gray wolves, 60 greyhounds (an Asian species also called a tanuki), and 10 red foxes. “It’s just incredible. You can’t go anywhere without seeing wolves, ”he says. (Watch a video of wolves picking up Chernobyl.)

Radiation, he argues in the study, does not retain Chernobyl wild populations.

Signs of Life

Researching this story, one biologist studying Chernobyl told me that I would not see a street kill in the exclusion zone – and that I would be lucky to hear some birds or see some animals.

So when I visited in early April, I aimed to count every animal I saw. Even in the occupied area between the main guard station and the remains of the Chernobyl power plant, signs of wildlife were everywhere.

Walking along sandy crevices used as forest highways with Shkvirja and her colleague, field specialist Olena Bumblebee, we found the tracks of a wolf, elk, deer, badger and horses. I counted twenty birds: crows, songbirds, three species of birds of prey, and dozens of swans rowing in the radioactive cool pond.

In a herd of wild horses from Przewalski, a rare and endangered subspecies of wild horse introduced into the reserve, I counted an adult male, two adult females and two juveniles. They charged at us across a large hairy field, with their brush-like black manes standing straight from taupe bodies, and stared at us for a long time as unused power lines swayed in the distance.

We also saw the workmanship of beavers – everywhere. The growth of their populations in recent years is perhaps one of the most important things happening in the ecology of the area. After placing the camera trap on the trunk of a pine tree, Squirrel, Bumblebee and I walk down a path, finally entering a village of rotting wooden cottages slowly engulfed by bush pines, birches and willows. Here the ground was torn apart by the sound of fodder wild boars.

On the opposite end of the village, a completely straight Soviet canal still drained the lowland. The bright pieces of freshly chewed birch were still lying at the base of a tree. Fallen birches, about three feet around, lay across the water, up and down the length of the ditch.

“Literally three weeks ago that tree was still standing,” Shkvyria says, pointing to the pale patches. “The beaver population is growing. Beavers can make it a little wilder, “she says. Then, as the beavers fell from trees, the land will return to swamps.

“The beaver in Ukraine resembles the elephant in Africa: it completely changes the look of the landscape.”

Debate continues

The combined territory of the exclusion zones in Ukraine and Belarus caused by the Chernobyl disaster is just over 1,600 square miles, making it one of the largest truly wild sanctuaries in Europe.

But what it means for animals to bounce back in Chernobyl became the scientific equivalent of a boxing match, with the latest blow on Monday when Beasley presented a study in the newspaper. Limits in Ecology and Environment.

His study cataloged 14 species of mammals, and “found no evidence to suggest that their distributions were suppressed in heavily polluted areas within the Chernobyl Exclusion Zone.” The abstract ends at the top. “These data support the results of other recent studies, and contrast with research that suggests natural populations are depleting in the CEZ.”

Anders Pape Møller, a Danish scientist at the University of Paris-Sud who studied swallows in nuclear environments, says his research shows otherwise. “These animals in Chernobyl and Fukushima live 24 hours a day in these polluted places. Even if the actual dose for one hour is not extremely high, after a week or after a month, it adds up to a lot. These effects are certainly at a level where you could see dramatic consequences. “

His research with biologist Timothy Mousseau showed that field mice have higher rates of waterfalls, beneficial bacterial populations on the wings of birds in the zone are lower, partial albinism among whales, and that cuckoos have become less common, among other results. Significant mutations, however, occurred only immediately after the accident.

Both sides agree that radiation is bad for humans and bad for animals; the debate ended on how bad and whether it caused a decline in populations.

The debate among scientists about the effects of low levels of ionizing radiation on wildlife and humans is heated and political, especially after the Fukushima disaster five years ago. With now 30 years of history to extract, Chernobyl is the test site. (Read “The Long Shadow of Chernobyl” to see the site 20 years after the disaster.)

Gain Radiation

This year will mark the half-life of cesium-137, one of the most widespread and dangerous of the released radionuclides. This means that the amount of cesium has decreased by about half in the 30 years since the accident, and has decayed into the short-lived baryon-137m.

For animals, radioactive material enters the system through the food chain.

While Schvyria places a camera trap on a pine tree near the hillside, Bumblebee explains. “Fungi concentrate radiation. Will love mushrooms. When they eat contaminated fungi, they concentrate the radiation in their bodies. When wolves eat field mice, they pick up the contamination. “

But the level of radionuclide contamination in an animal depends both on concentrations in its habitat and on the animal’s diet and behaviors, she says. Radiation deposited from a remnant of Chernobyl was measured as far away as Norway in reindeer, but it is slightly diffused in the exclusion zone.

Wolves, in particular, may get at least some protection from radiation because they have a large range and move a lot, even outside the zone into cleaner areas.

“I would argue that for many of those species [the effects of radiation], even if they’re there, it’s probably not enough to suppress populations so they can’t support themselves, “says Beasley. In the zone,” people have been removed from the system and this greatly overshadows some of those potential radio effects. “

Basically this means that human populations have a greater negative impact than radiation.

Poaching and Protection

In his research laboratory in Slavutych, the surreal tiny Soviet town built immediately after the disaster for physicists, workers and scientists affiliated with Chernobyl, Sergey Gaschak emphatically agrees. The wild population has grown “dramatically,” says Gaschak, who has worked in the area for the past 30 years. (Read about people in the Chernobyl exclusion zone in “The Nuclear Tourist.”)

“Before the accident it was an area absolutely inhabited by people.” But he says there is a “myth” that new animals have appeared in the exclusion zone. “It simply came to our notice then. Almost all the species we have now we had before the accident, only in lower densities. “

Gaschak has been using camera traps for a few years and has a more complete list than almost any other researcher on the Ukrainian side. “We have all the big mammals: red deer, roe deer, wild boar, moose, horse, bison, brown bear, lynx, wolves, two species of hare, beaver, otter, badger, a few swallows, some mink and putters,” he says, without inhaling, adding that there may be 20 other mammals including bats as well as ten or more species of large birds, including hawks, eagles, owls, storks and swans.

Reserving the camera traps, Shkvyria entered the old Soviet archives, with heaps of paper reports in the National Academy of Sciences. What she found agrees with Gaschak’s research, and moderates international excitement due to a popular explosion in the area.

“We looked at official state censuses of all hunted species, and it was interesting for us not to see a really big difference between the 1960s, 1980s, 1990s and today. It was a stable structure – 40, 50, 60 wolves, no more ”on the Ukrainian side, she says. “Illegal hunting still affects it, so it’s a dynamic system, but it’s more or less stable.”

Indeed, the people living on the edge of the zone, even the poachers, are a good barometer to anecdotally measure increases in the number of animals, as animals do not need a pass to enter or leave the zone, as one villager said.

“There are more animals now than 30 years ago. We have a horse, deer, elk, wolves, a wild boar, a hare and others, “says Anatoly Tsiganenko, standing in the warm afternoon sun next to his neighbor’s oil-repaired garage in the village of Radcha, just a mile from the Belarusian border and a few hundred yards from the edge of the exclusion zone.Last autumn, he says, he saw a wolf walking through his neck from the village.He guesses that it is around 140 pounds and stands well above his knees.

Although it helps to confirm that today there are more animals than just before the accident, it also means that there is more poaching, especially on the Ukrainian side. A decree by Ukrainian President Petro Poroshenko, which would transform the exclusion zone into a nature reserve, aims to help solve that problem, although Ukrainian researchers fear it will ultimately weaken the protected status.

“Illegal fishing and hunting sometimes happen. It is at their own risk to do this. Unfortunately we cannot control all such cases, ”says Hanna Vronska, Ukraine’s interim minister of ecology and natural resources, who hopes the new status will make it easier to raise money from international donors for more guards.

While Beasley stops calling the landscape “ruined” by radioactive pollution, he knows it will be there for centuries or millennia when it comes to plutonium. But, without people around, his findings show that the wildlife seems to be doing well.

“The pre-density estimates we see suggest that in Chernobyl the density of wolves is much, much higher than even Yellowstone.”

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