On March 11, 2011, the Fukushima Daiichi nuclear power plant experienced a catastrophic failure that resulted in the meltdown of 3 of the plant’s 6 nuclear reactors. The event was triggered when a tsunami hit the area, which was the aftermath of a magnitude 9.0 earthquake. The plant started spilling out large amounts of radioactive material the day after the event, which will leave lasting scars on the environment for years to come.
Unlike the infamous 1986 Chernobyl disaster where serious delays resulted in significant gaps in impact data on both humans and non-human species, scientists started collecting biological information just a few months after the Fukushima catastrophe. Researchers hoped to gather information on the long-term genetic outcomes of varying levels of radiation exposure and also to identify strategies to assess the overall biological effects of ionizing radiation. Now, in a series of papers published in the Journal of Heredity, scientists are starting to reveal the damaging effects on several non-human organisms.
For one of the papers, researchers set out to look at population changes in birds, butterflies and various insect species and then compare this information with previous data obtained from the Chernobyl disaster. While a limited number of studies have been conducted, it is evident that all of the animals investigated suffered reduced population sizes in the Chernobyl Exclusion Zone. Similarly, birds, butterflies and cicadas experienced population declines in Fukushima as a result of radiation exposure. However, other groups such as dragonflies and bees did not seem to be affected. Furthermore, they also observed morphological effects on some species such as abnormal feathers on barn swallows.
The second study focused on the pale grass blue butterfly which is the most common butterfly in Japan. They discovered that this species suffered a reduction in forewing size, growth retardation and high mortality and abnormality rates. However, their results also hinted that the Fukushima butterflies were evolving radiation resistance.
The final study looked at the effects of gamma radiation on healthy rice seedlings at a highly contaminated field near the plant. In just three days, DNA sequence analysis revealed various changes such as the activation on DNA repair mechanisms. Furthermore, stress responses were triggered which resulted in the induction of genes involved in cell death.
The take home message from this work is that early and ongoing monitoring is critical to understand the long-term impacts of radiation exposure at sites of accidental release. “Detailed analyses of genetic impacts to natural populations could provide the information needed to predict recovery times for wild communities at Fukushima as well as any sites of future nuclear accidents,” researcher Dr. Timothy Mousseau said in a news-release. “There is an urgent need for greater investment in basic scientific research of the wild animals and plants of Fukushima.”