Ten years after one of the largest nuclear accidents in history dumped radioactive contamination over Fukushima, Japan, a study by the University of Georgia (United States) has shown that radioactive contamination in the Fukushima Exclusion Zone can be measured through the resident snakes.
The research findings, published in the journal Ichthyology & Herpetology , state that rat snakes are an effective bioindicator of residual radioactivity.
The journey of the serpents
Rat snakes, one of the most abundant species in Japan, travel short distances and can accumulate high levels of radionuclides.
According to the scientists, the movement of snakes and contact with contaminated soil are key factors in their ability to reflect the different levels of contamination in the area.
“Animal behavior has a huge impact on radiation exposure and pollutant build-up,” Gerke explained. Adding that “studying how they use polluted landscapes increases our understanding of nuclear impacts such as those from Fukushima and Japan.”
Why do snakes indicate radioactivity?
Snakes are able to indicate contamination more accurately than other local species such as raccoon dogs, wild boars or songbirds. This is because they spend a lot of time in the ground and have a relatively long life.
To find out where they spent most of their time and whether they were moving very far, the scientists tracked nine rat snakes using a combination of GPS transmitters and high-frequency manual tracking.
Study development
Scientists discovered snakes in trees, grasslands, and streams along roads. Additionally, the researchers found that snakes avoided inside coniferous forests, but could be found in deciduous forests and inside abandoned buildings.
In fact, more than half of the tracked snakes spent time in abandoned barns and sheds, which could help protect them from contamination in the surrounding soil.
During the winter months, however, their risk of exposure increases when they seek shelter underground, near the most contaminated soils.
Now, scientists want to analyze the health risks of snakes (and other wildlife) due to increased radiation exposure. This will be critical to understanding the effects of the Fukushima accident on wildlife.
