Scientists analyzed more than 267 thousand pictures of wild vertebrate animals in the evacuation zone of the nuclear power plant Fukushima-1, obtained with remote cameras, and set what kinds there are and how many. It turned out that in the zone of action of high doses of radiation in animals more than in populated districts, and the number of wild boars so high that they begin to pose a threat to other species — Japanese serow they are already ousted from the exclusion zone. The results of a study published in the journal Frontiers in Ecology and the Environment.
On 11 March 2011 at Fukushima-1 there was a radiation accident the maximum seventh level of danger on the international nuclear event scale. After this event the Japanese government evacuated the population of the Prefecture with an area of 1152 square kilometers and formed three zones with different status of stay in them of people depending on the annual dose: zone with a complete ban on visits and two additional zones with restriction of entry and residence.
Five years later, the radiation dose in two additional areas has decreased to a safe level — this was due to reclamation works and almost completed the decay of cesium-134. However, only about five percent of the population chose to return to their former place of residence and upon arrival discovered that the rice fields and households ravaged by wild boars. Against them began to build traps and various traps in the hope to reduce the population, but in an area with restricted access such measures was impossible. For over 40 years in these regions remained fairly high population density, and natural landscapes actively transformed during the construction of villages and ploughing of the rice fields. But after the radiation accident the whole evacuation zone, and particularly the exclusion zone of the nuclear power plants represent a unique wildlife habitats where you can observe their life away from people. However, local authorities have not attempted to account for any vertebrate animals except wild boars.
American and Japanese scientists headed by Philip Lyons (Phillip C. Lyons) from the University of Georgia investigated populations of wild mammals in the area affected by the impact of the accident at the nuclear power plant. To do this, they identified three zones: the first people missed completely, the second their time was limited, and the third area was settled (her people never evacuated, as radiation dose there did not rise above background levels).
Professionals selected 120 plots located along the paths with the footprints of animals and are evenly distributed throughout each of the three zones. Half of them were in the lowlands at elevations below 90 m above sea level, and the other half above this level. Each plot was equipped with an unmanaged remote camera Reconyx PC900, which when motion is detected did three shots in increments of one second. Areas and zones separated from each other, a buffer zone of one kilometre, to minimize the risk of re-shooting the animal.
The shooting took place in two stages: 60 days in the period from may to September, 2016 and 60 days between October 2016 and February 2017. At 14 sites the camera is out of order, therefore, obtained from them the images had to be discarded. The sample included animals caught in the lenses of not less than 80 times (except domestic cats and dogs). Only treatment were more than 267 thousand photographs of wildlife, which allowed to establish the presence of 13 vertebrate species (seven species have not been photographed enough times).