Three decades after the world’s worst nuclear accident turned a vast area around Chernobyl into an uninhabitable “exclusion zone,” scientists are surprised to find it packed with wildlife. Wolves, elks, lynx, red deer and wild boar have reclaimed this abandoned site despite the radiation exposure, finds a study published in Current Biology .
As many as 116,000 people were evacuated from the Chernobyl exclusion zone after the nuclear disaster in 1986. The proliferation of animals is “unique evidence of wildlife’s resilience in the face of chronic radiation stress,” says the paper. While there may be some effects on individual animals, the populations are thriving, particularly in the absence of people, co-author J.T. Smith, Professor at School of Earth & Environmental Sciences, University of Portsmouth told this Correspondent.
A helicopter survey revealed rising numbers of elk, roe deer and wild boar 10 years after the accident. But most notably, the wolf density was found to be seven times higher in the exclusion zone than it is in other nature reserves in the region. “Before the Chernobyl accident, mammal population densities were likely depressed due to hunting, forestry and agriculture,” say the authors. The study also looked at animal tracks on the snow to test whether the more contaminated routes had fewer tracks. “We didn't find a correlation. We couldn't see a difference in the number of tracks between more and less contaminated areas,” says Prof. Smith. The winter track censuses identified over a dozen species including, weasel, lynx, pine marten, raccoon dog, mink, ermine, stone marten, polecat, European hare and red squirrel.
Radiation is known to damage DNA, “but we have to remember that radiation dose rates now are more than 100 times less than in the first days after the accident,” says Prof Smith. “While still very significant, the radiation levels we see now aren't expected to do major damage to animals' physiology and reproductive systems.”
The very high radiation dose rates during the first six months after the accident “significantly affected animal health and reproduction at Chernobyl,” but long-term radiation damage to wildlife “is not apparent from our trend analysis of large mammal abundances,” the paper concludes.
