Mutant butterflies a result of Fukushima nuclear disaster, researchers say
This image from a study on Fukushima's impact on butterflies shows wings mutated by the radiation.
August 14th, 2012
10:35 AM ET

Mutant butterflies a result of Fukushima nuclear disaster, researchers say

In the first sign that the Fukushima nuclear disaster may be changing life around it, scientists say they've found mutant butterflies.

Some of the butterflies had abnormalities in their legs, antennae, and abdomens, and dents in their eyes, according to the study published in Scientific Reports, an online journal from the team behind Nature. Researchers also found that some affected butterflies had broken or wrinkled wings, changes in wing size, color pattern changes, and spots disappearing or increasing on the butterflies.

The study began two months after an earthquake and tsunami devastated swaths of northeastern Japan in March 2011, triggering a nuclear disaster. The Fukushima Daiichi plant spewed radiation and displaced tens of thousands of residents from the surrounding area in the worst nuclear accident since the 1986 Chernobyl disaster in Ukraine.

In May 2011, researchers collected more than 100 pale grass blue butterflies in and around the Fukushima prefecture and found that 12% of them had abnormalities or mutations. When those butterflies mated, the rate of mutations in the offspring rose to 18%, according to the study, which added that some died before reaching adulthood. When the offspring mated with healthy butterflies that weren't affected by the nuclear crisis, the abnormality rate rose to 34%, indicating that the mutations were being passed on through genes to offspring at high rates even when one of the parent butterflies was healthy.

The scientists wanted to find out how things stood after a longer amount of time and again collected more than 200 butterflies last September. Twenty-eight percent of the butterflies showed abnormalities, but the rate of mutated offspring jumped to 52%, according to researchers. The study indicated that second-generation butterflies, the ones collected in September, likely saw higher numbers of mutations because they were exposed to the radiation either as larvae or earlier than adult butterflies first collected.

To make sure that the nuclear disaster was in fact the cause of the mutations, researchers collected butterflies that had not been affected by radiation and gave them low-dose exposures of radiation and found similar results.

"We conclude that artificial radionuclides from the Fukushima Nuclear Power Plant caused physiological and genetic damage to this species," the study said.

The results of the study bring up concerns about the larger impact of the Fukushima disaster and the impact it will have on the ecosystem in Japan and nearby areas, as well as what we can learn for future nuclear disasters.

"Our results are consistent with the previous field studies that showed that butterfly populations are highly sensitive to artificial radionuclide contamination in Chernobyl and Fukushima," the study said. "Together, the present study indicates that the pale grass blue butterfly is probably one of the best indicator species for radionuclide contamination in Japan."

One of the researchers, Joji Otaki, an associate professor at the University of the Ryukyus in Okinawa, told reporters that while butterflies may be the best indicator, the study should also lead to more research on what else may be affected by the radiation.

"Sensitivity (to irradiation) varies between species, so research should be conducted on other animals," Otaki told the Japan Times.

Otaki said while there is still plenty of research to be done on radiation, there shouldn't be large-scale concern about this kind of mutation in humans.

"Humans are totally different from butterflies and they should be far more resistant" to radiation, he told the newspaper.

Read more:

Inside Fukushima's meltdown zone

What Fukushima did to the ocean

Gallery: Then and now

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Filed under: 2011 tsunami • Animals • Insects • Japan
soundoff (316 Responses)
  1. jack frost

    The Mothra Song!! Now together everyone: 1, 2, 3.......

    Mothra oh Mothra
    Hear our call for you to save us
    over time, over sea
    like a wave you come
    our guardian angel
    Mothra oh Mothra
    the people have forgotten kindness
    their spirit falls to ruin
    we shall pray for the people as we sing
    this song of love

    August 14, 2012 at 11:03 am | Report abuse |
    • Archer

      Well played, sir. Well played.
      You are my new hero.

      August 14, 2012 at 11:13 am | Report abuse |
    • shirodx

      LOVE IT!!

      August 14, 2012 at 11:14 am | Report abuse |
  2. Laura B


    August 14, 2012 at 11:04 am | Report abuse |
  3. Barry Santero (obama)

    Pilots are losing their hair when flying in the upper hemosphere as well but CNN (cartoon news network) wont cover that because the globolist control them. America is full of sheep.

    August 14, 2012 at 11:06 am | Report abuse |
    • Politico

      OMG – I'm losing my hair. You mean those dreams are REAL? What can I do, oh wise one?

      August 14, 2012 at 11:47 am | Report abuse |
    • Rich

      Hey I'm a pilot, and I lost my hair!!! Oh, wait...That happened before I became a pilot. Nevermind.

      August 14, 2012 at 12:48 pm | Report abuse |
    • Bill

      If you think you are not one of the flock, you are sadly mistaken my friend. We're all in the same boat.

      August 14, 2012 at 1:26 pm | Report abuse |
  4. NooYawkah

    Radiation, or just having been stepped on? The debate rages on...

    August 14, 2012 at 11:06 am | Report abuse |
  5. CNNuthin

    Cool! I bet to a butterfly collector, these would be an excellent addition to his collection. And the scientific community would love to examine these in detail. And....Oh yeah, I guess nuclear reactors are bad and stuff too.

    August 14, 2012 at 11:08 am | Report abuse |
  6. kangkungan

    gochilla! gochilla!

    August 14, 2012 at 11:12 am | Report abuse |
  7. Rebecca

    Anyone who thinks the same thing isn't happening to people who are exposed to nuclear radiation is not very smart.

    August 14, 2012 at 11:14 am | Report abuse |
  8. mecatfish

    Butterfly effect?

    August 14, 2012 at 11:14 am | Report abuse |
  9. Mazsolamama

    Finally, after brainless children, 3 legged cats, 2 tailed frogs, etc. butterflies also adapt.

    August 14, 2012 at 11:14 am | Report abuse |
  10. snowdogg

    It is a good thing that nothing like this could EVER happen in the USA.

    August 14, 2012 at 11:16 am | Report abuse |
  11. Jenni

    Who is funding this research?

    August 14, 2012 at 11:16 am | Report abuse |
  12. Nut and jam

    and keep in mind they did not take into account mutations that may be occuring inside the butterfly as well.

    August 14, 2012 at 11:16 am | Report abuse |
  13. ZepLedHead

    too many trolls commenting on CNN articles.

    August 14, 2012 at 11:17 am | Report abuse |
  14. JGN

    You wouldn't be singing your stupid Mothra song if the nuclear disaster happened near you, tiny brained man missing a heart. Amazing how the thoughtless racists come out in droves in response to news articles. Speaking of mutations.

    August 14, 2012 at 11:19 am | Report abuse |
  15. no nukes

    Regardless of what the Nuclear Lobby pays politicians to say. Nuclear reactors are not safe.

    They pushed alot of propaganda to get alot of reactors put in, saying theyre safe, cheap, better for the environment, all of it bullcrap. Its just a hell of a way to boil water.

    Theres better ways to generate electricity, theres just not big money pushing them.

    August 14, 2012 at 11:22 am | Report abuse |
    • BigHwasdemo

      It's called natural selection, if these mutations don't help they will fade away in a few generations. Just confirmation of evolution folks.

      August 14, 2012 at 11:32 am | Report abuse |
    • runswithscissors95

      I suggest you look at all of the stuff coal fired plants cause. I also suggest looking at the salts used in solar installations.

      August 14, 2012 at 11:40 am | Report abuse |
    • johnqpublic

      BigHwasdemo – mutations due to human contamination is not part of natural selection. as stated in the article, the mutations are significantly accelerated causing a large percentage of the butterflies to not even mature to adulthood.

      August 14, 2012 at 11:53 am | Report abuse |
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