|Fig. 1: An image from the "red forest," an effect of the 1986 Chernobyl disaster in Ukraine that proved to be positive for wildlife in the area, serving as a refuge for many endangered species in the years following the disaster. (Courtesy of Tim Suess)|
Nuclear energy can effect animal populations in complex ways through the impacts of radiation from power plants, warfare, disposal, and more. Disaster areas such as Fukushima Daiichi Nuclear Power Plant in Japan and the Chernobyl Nuclear Power Plant in the USSR shows some of these effects on animals as the environments are studied years later. The data gathered from the immediate aftermath of a nuclear disaster to decades later can help us learn more about radiation's effects on organisms and may perhaps help us better approach the future of nuclear energy.
After the Chernobyl Nuclear Power Plant disaster occurred in 1986 in the USSR (modern-day Ukraine), only a limited amount of research could be performed on the biological and ecological effects in the area due to delays in accessing the area.  For a 25+ year period after the event, ecological devastation was noted to the extreme. A 10-square-kilometer region of pine trees turned orange, leading it to be nicknamed the red forest.  This forest can be seen in Fig. 1. Soil fauna such as mice, moles, and insects were hard-hit by the radioactive fallout, heavily impacting these organisms population sizes due to the impact on the affected organisms young. Later, some insect populations bounced back, but it was due to migration into the area rather than recovery of affected populations.  In the years following the Chernobyl disaster, animal species sustained negative effects in the aftermath due to radiation and changes to their habitats, yet it can be argued that 30 years later, animals that call Chernobyl home are experiencing one of the few positive consequences of the disaster. The Chernobyl area, now abandoned by humans, has transformed itself into a refuge for the wildlife, allowing them to increase in population and escape human influence. 
Having learned a lesson after Chernobyl's difficulties, scientists began gathering data on the biological and ecological effects of the 2011 Fukushima disaster as early as a few months after it occurred. What these scientists found, over time, was the presence of morphological defects in certain species of animals, due to increased mutation in rates in somatic and germ cells.  Results from their studies show that many species of non-human organisms may have had their genes adapt over time in response to the survival mechanisms employed by these organisms to cope with radiation.  One of the species studied, the pale grass blue butterfly, showed decelerated growth, reduced size among the organisms, and even possible evolution in radiation resistance. 
© Elisa Graue. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 T. Mousseau and T. Steen, "Outcomes of Fukushima: Biological Effects of Radiation on Nonhuman Species," J. Hered. 105, 702 (2014).
 C. Goldenstein, "Ecological Consequences of the Chernobyl Disaster," Physics 241, Stanford University, Winter 2012.
 D. Krivolutsky and A. Pokarzhevsky, "Effect of Radioactive Fallout on Soil Animal Populations in the 30-km Zone of the Chernobyl Atomic Power Station," Sci. Total Environ. 112, 69 (1992).