Humans are worse for wildlife than nuclear disaster, according to the first long-term study at Chernobyl, site of the world’s worst nuclear accident, which found wildlife was thriving.
The results pose profound questions about both the effect of humans on nature and of the safety for humans of sites devastated by nuclear accidents.
An international group of scientists coordinated by Professor Jim Smith from the University of Portsmouth’s School of Earth and Environmental Sciences published their findings in Current Biology today.
It is the first large scale study of mammal populations in the 4,200 square kilometre human exclusion zone around Chernobyl. The zone was exposed to chronic radiation following the 1986 accident but, 30 years later, the researchers found no evidence of a drop in the number of animals.
On the contrary, the number of large mammals, including elk, roe deer, red deer, wild boar and wolves are similar to those in four uncontaminated nature reserves in the region.
Professor Smith said: “We know that radiation can be harmful in very high doses, but research on Chernobyl has shown that it isn’t as harmful as many people think.
“There have been many reports of abundant wildlife at Chernobyl but this is the first large-scale study to prove how resilient they are.
“It’s very likely that wildlife numbers at Chernobyl are much higher than they were before the accident.
“This doesn’t mean radiation is good for wildlife, just that the effects of human habitation, including hunting, farming and forestry, are a lot worse.”
At Fukushima, site of the world’s second worst nuclear accident, there have also been reports of wild boar thriving in the evacuated area.
After the nuclear disaster at Chernobyl the region’s 116,000 residents were permanently excluded, and animals in the area were exposed to extremely high doses of radiation. The research shows that their populations recovered within a few years. Aerial counts of wild boar, elk and deer from 1987, almost immediately after the disaster, to 1996 increased several times. Wild boar reached very high population densities then dipped, which the researchers say was caused by the soaring wolf population and a disease outbreak not linked to radiation.
Increases in the area’s wildlife are in stark contrast to a decline in elk and wild boar populations in other parts of the former Soviet Union in the 1990s, as major socio-economic changes brought rural poverty and poorer wildlife management.
The research included an analysis of historical data from aerial surveys of the exclusion zone and counts of animal tracks in the snow.
The census data covers 20 times the area of previous studies of mammal populations in the area and was repeated in different years, to result in the most in-depth analysis of the zone’s animal numbers to date.
The data does not include information about the health or reproductive success of animals, but the researchers have ruled out the current population being significantly influenced by an influx from other areas as highly unlikely.
Professor Smith said: “The Chernobyl area is a fascinating experimental area because it allows us to investigate the transfers and effects of radioactivity in the long term. There have been many laboratory experiments on the effects of radiation on animals and plants but these are usually quite short term. Chernobyl allows us to study the effects on animals after years of radiation exposure.”
Dr Jim Beasley, of the University of Georgia, is a co-author on the paper.
He said: “These unique data showing a wide range of animals thriving within miles of a major nuclear accident illustrate the resilience of wildlife populations when freed from the pressures of human habitation.”
Professor Tom Hinton, of Fukushima University in Japan, site of the second worst nuclear disaster, is a co-author of the new research, and said: “These remarkable data from Chernobyl will help us understand the potential long-term environmental impact of the Fukushima accident.”
Lead author, Dr Tatiana Deryabina, is from the Polessye State Radioecological Reserve in Belarus, a few miles from Chernobyl’s nuclear power plant where the accident happened and part of the human exclusion zone.
She said: “I’ve been working, studying and taking photos of the wonderful wildlife in the Chernobyl area for over 20 years and am very pleased our work is reaching an international scientific audience.”
The research was funded by the Natural Environment Research Council, Environment Agency and Radioactive Waste Management Ltd, the US Department of Energy and the University of Georgia Research Foundation.