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. reefers

    wow good thing we know the butterflies are affected, how about the people

    August 14, 2012 at 11:24 am | Report abuse |
    • johnqpublic

      insects are a leading indicator of contamination and mutations because of their very short life cycles. many generations of butterflies can be studied in a very short period of time, as opposed to humans and other mammals which would take significantly longer to draw conclusions.

      August 14, 2012 at 11:36 am | Report abuse |
    • cpc65

      Their wings and antennae are deformed as well.

      August 14, 2012 at 4:35 pm | Report abuse |
  2. Superman

    @phillip/typical stay at home mom phillip your an idiot go back to tuesdays live where you belong and show your woman hater ways there you really need to go back to tuesdays live there is a message there for you

    August 14, 2012 at 11:26 am | Report abuse |
  3. tansyobryant

    I live around Shearon Harris Nuclear Plant – all the clover has 4 leaves instead of 3 ... and we have never had an accident

    August 14, 2012 at 11:27 am | Report abuse |
    • cjm71

      You should pick and sell them. I bet that you could preserve them in a type of platic and sell them for $1 or $2. Look at the pet rock. Then you can put some of the money toward an anti-nuck association. Or put your kids through college.

      August 14, 2012 at 11:35 am | Report abuse |
  4. natere2ster


    August 14, 2012 at 11:27 am | Report abuse |
  5. jigar

    GODZILLA !!!

    August 14, 2012 at 11:28 am | Report abuse |
    • reaganrepub

      you mean "godrilla"

      August 14, 2012 at 11:29 am | Report abuse |
  6. reaganrepub

    Calling Dr. Xavier. The mutants have shown themselves...

    August 14, 2012 at 11:28 am | Report abuse |
  7. mplaya

    like George Carlin stated years ago: "the world's gonna shake us off like a bad case of fleas". In this case, it starts with the smaller animals – all because of the human impact on the planet. Next they'll discover 10 -yed squirrels like they had in the Simpson's movie !.....


    August 14, 2012 at 11:31 am | Report abuse |
  8. mplaya

    like George Carlin stated years ago: "the world's gonna shake us off like a bad case of fleas". In this case, it starts with the smaller animals – all because of the human impact on the planet. Next they'll discover 10 -eyed squirrels like they had in the Simpson's movie !.....


    August 14, 2012 at 11:31 am | Report abuse |

    @ weezer: I love you too. I am guessing you didn't get your morning hug today. Sorry. 🙁

    August 14, 2012 at 11:32 am | Report abuse |
  10. Zombie King

    Zombies to follow, news at 11.

    August 14, 2012 at 11:34 am | Report abuse |

    Oh no...RADIATION! Oh wait..its a study from an anti-nuke organization which found a couple of dead butterflies, bent/folded the wings and cried wolf.

    August 14, 2012 at 11:34 am | Report abuse |
    • mendrys

      Well said. Most likely this is all being made up by the evil scientists to fund their project for world assimilation. I mean, I didn't see any radiation so the meltdown, explosions and subsequent release of radiation in the atmosphere was all a sham. Maybe the tsunami was all made up as well. I certainly didn't see any extra water where I live. As well, I've read that I absorb a certain amount of radiation every year (could be a lie too.) and I don't have cancer. I've also heard that radiation is used in the treatment of cancer so that means that radiation is good for you doesn't it?

      August 14, 2012 at 1:28 pm | Report abuse |
    • Nicko

      So then, I guess you are for nuclear-induced mutations? You know, this place used to be populated by people. And since insectsw have a short life, it's an easier study to see 2 and 3 and 4 generations later what happens to life in general after meltdowns occur

      August 14, 2012 at 2:35 pm | Report abuse |
    • Work2snowski

      You do know that No mutations have shown up in either Hiroshima or Nagasaki and that there are people that are now in their 80's and 90's that survived. Also at Chernobyl there is the biggest diversity in wildlife than all of Russia, they have been studying the wolves there ever since their meltdown and they are the biggest and healthiest packs in all of Europe, sans mutations! Just Sayin

      August 15, 2012 at 7:26 pm | Report abuse |
    • cpc65

      Well go ahead and move there and sunbathe in your back yard and drink the well water and prove them wrong. The nuke plant owners and workers even reported high levels of radiation escaping the reactor. I guess they're lying too?

      August 14, 2012 at 4:33 pm | Report abuse |
  12. alex

    Saying that humans are totally different from butterflies is assinine. Mutations occur in cells. The more cells, the greater the chance of mutation. The shorter the generation time .... the faster the mutation will be expressed in an offspring. Human bodies pose a prominent target for mutational events. If the mutation is viable. The cell will divide, and divide again...producing a clone of mutatnt cells. These may be cancerous. They may also be benign, possibly showing only pigmentation effects. If thew mustation is in sperm or egg.....and a zygote results.....and lives....the result is a mutated organism. If the study involving butterflies is valid, you can bet your ass that the danger to humans from this melt-down is astronomical.

    August 14, 2012 at 11:37 am | Report abuse |
  13. Moogly

    Mothra! (couldn't help it)

    August 14, 2012 at 11:38 am | Report abuse |
    • JOJO IAM

      Yes, I saw it has interfered with nature and now we are being attacked by mutant moths and butterflies.

      August 14, 2012 at 11:49 am | Report abuse |
    • FreeReally

      Thank you, my first thought too!

      August 14, 2012 at 12:04 pm | Report abuse |
  14. fine example

    Nuclear power is another example that lobbyists and their money is what politicians obey, not the votes of you, or I.. Regardless of which party you vote for.

    August 14, 2012 at 11:38 am | Report abuse |
    • Jason

      You got a better alternative for energy production? We're running low on petroleum and will eventually use up our natural gas and coal as well, solar and wind still provide relatively little power compared to conventional plans, and hydroelectric and geothermal are limited to places with large rivers and volcanic hot spots.

      August 14, 2012 at 11:45 am | Report abuse |
    • Dant

      You mean lack of nuclear power right? Nobody is bigger than big oil and big coal.

      August 14, 2012 at 11:58 am | Report abuse |
    • John in WNY

      Well that would explain why there are thousands of reactors currently being built in the US?

      Oh wait....... you mean there isn't?

      Well I guess your just spewing garbage then.

      August 14, 2012 at 12:05 pm | Report abuse |
    • WASP

      @jason: solar and wind can be some of the best producers of power, if we put more effort in these areas. did you know that if we put solar panels in the mojave desert it would produce enough power to provide all of europe with energy? imagine what we could do in the U.S. if we put miles of solar panels in arizona, texas, nevada, etc etc etc we could power the western seaboard, as far as the eastern seaboard we could use a combo of wind and seacurrents to power that side of the states. wind turbines in our mid-west could help in adding al the power this country would need for years to come.

      August 14, 2012 at 12:05 pm | Report abuse |
    • Tesla

      Except for the fact that green energy is the most subsidized energy source right now, and it still doesn't make money. Even worse, compare the deaths per terawatt-hour of nuclear, fossil fuels, and green sources. Even better, take a look at the pollution created by each, from raw materials to finished product. Nothing compares with nuclear for safety. Sorry, it's the truth.

      August 14, 2012 at 2:02 pm | Report abuse |
  15. Beam

    Bent and broken wings? Seriously? That happens to the butterflies here due to how fragile they are...not because of radiation. I really think they need to do a more controlled study to make sure this is really an affect of radiation and not just butterflies being butterflies and running into things. High wind can be really tough on them too!

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

      It appears that you do not know how to read.

      August 14, 2012 at 11:45 am | Report abuse |
    • But

      ...if you took 2-minutes to read the article you'd know why you have no idea what you are talking about.

      August 14, 2012 at 11:48 am | Report abuse |
    • ViperGuy

      Beam, are you even seeing the same picture we see? These are abnormalities. I'm sure they have a control in place to determine that these abnormally bent and broken wings are not natural. The picture caption highlights the obvious bent wing. Last I check, I have never seen a butterfly with a bent wing like that, let alone a different color and complete pattern change on one wing.

      August 14, 2012 at 11:54 am | Report abuse |
    • Durundal

      yes, because no-one EVER would have thought to check for that. dolt.

      August 14, 2012 at 11:56 am | Report abuse |
    • sbp

      Gee, Beam, it seems that scientists with PhD's are no match for your keen powers of observation. I'm sure they never even thought of checking for physical trauma.

      August 14, 2012 at 11:57 am | Report abuse |
    • Lyndy Lou

      its a study of the OFFSPRING – jeez. Their wings GREW bent and mangled. Maybe you should consider reading the whole article more than once before posting.

      August 14, 2012 at 11:58 am | Report abuse |
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