After the Chernobyl accident in April 1986, more than 100,000 people were evacuated from what was called the “exclusion zone”: an area of 30 kilometers in radius around the nuclear reactor in which the explosion occurred. This place is now a perfect laboratory that allows analyzing, under natural conditions, how radioactivity affects living organisms, and also the recovery capacity of species after disturbance , a characteristic that in ecological terms is called resilience.
The latest work, published in the scientific journal Current Biology , reveals that, almost three decades after the accident, the relative abundances of elk, roe deer, deer and wild boar are similar to those found in other uncontaminated nature reserves in the area. . Furthermore, wolf abundances are more than seven times higher in the exclusion area.
It is not the first work that points to a greater occupation of wildlife in the area of the accident. In a study published in 2014, scientists from the University of Salford confirmed that the brown bear, which disappeared from this area of Ukraine before the nuclear accident, was beginning to recolonize the territory .
Does this mean that radiation is good for wildlife? Absolutely. What could indicate, as Jim Smith, coordinator of the work, “is that the effects of human occupation and their activities are much worse .” James Beasly, another of the authors and professor at the University of Georgia (USA), corroborates this hypothesis: “Our data demonstrate the resilience of fauna when it is freed from direct human pressures, such as habitat loss, fragmentation and persecution ”.
Human activity versus radioactivity
Obviously, radioactivity is not safe for organisms. Previous work has revealed damage to insect and bird communities, and high levels of radiation exposure have been detected in animals found far away from the accident area.
However, the authors of this study emphasize that they have not analyzed the specific effects of pollution at the individual level, nor on population parameters such as reproductive success or longevity. But their results show how these effects are not relevant in the long-term evolution of populations. Human activity, on the other hand, does seem to play an important role in this process . In fact, populations of these mammal species suffered sharp declines in other areas of the Soviet Union that were not affected by the accident. A fact that is explained by the socio-economic changes that occurred in the 90s: the intensification of human activities in these areas was much more harmful to mammals than the worst nuclear disaster of the 20th century.
Photo: Valeriy Yurko / Polessye State Radioecological Reserve
