Oil spills. Burning fossil fuels. Dumping chemical waste. Littering. These are the things that we are taught endanger the natural world every Earth Day. From a young age, we learn about the perils of discarding our waste into natural ecosystems. But some dangers are not as obvious. Radiation cannot be seen, but it has a dramatic effect on any ecosystem that is affected by it. One of the most profound examples of this phenomenon is Chernobyl. Over twenty years after the reactor meltdown, I could only imagine that the landscape would be barren of life except for those microorganisms that had managed to feed on whatever remained after the incident. I could not be more wrong.
Biodiversity has only increased since the Chernobyl
disaster. Research conducted by James Morrison of the University of South Carolina
shows that nature as a whole is actually thriving1. In fact, many of
the species that exist there now, such as bears and wolves, did not before the
reactor failed, and the presence of these apex predators indicates that many
other species must be surviving in order to maintain the food chain2.
It is hypothesized that these organisms have developed more efficient ways of
dealing with radiation damage. Only those individuals that can cope with the conditions
make it to adulthood, eliminating those most highly affected by the radiation3.
Some species of fungi have even demonstrated increased fitness in the presence
of radiation4.
But this is not to say that we should begin irradiating all
of our natural ecosystems. Humans and some animals such as birds are
particularly vulnerable to the effects of radiation. Some bird species have
demonstrated a distinct increase in juvenile mortality5. Morrison
makes it very clear that such effects would also translate to humans who would
suffer from significantly shorter life spans and a similarly increased infant
mortality rate6. While nature as a whole may be able to combat the
damages humans cause with radiation, humans would be unlikely to survive in
such hostile conditions.
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1,2,3,5,6http://www.nature.com/news/2005/050808/full/news050808-4.html
4 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2677413/
I wonder what makes fungi, trees, and even certain mammals thrive in the presence of radiation. Could it be that they are better at producing anti-oxidants that trap free radicals induced by radiation? Also, speaking of Russia, after the Tunguska meteorite fell in Siberia in the 90's, local scientists observed extremely dense growth of shrubs and saplings in the area surrounding the meteorite site.
ReplyDeleteThis topic is really interesting. I would have never thought that so many species would not only be able to survive, but thrive, in such an environment. I experienced a similar shock with my research on the Atlantic tomcod and how it is capable of withstanding high levels of toxic chemicals. In your research did you happen to come about a discussion of how this tolerance for radiation is seen in the genotypes of these species?
ReplyDeleteI wonder if similar observations can/will be made at the Fukushima reactor site in Japan? Assuming that this adaptation phenomenon at Chernobyl is independent of some local factor, this would represent a sliver of hope for the long-term viability of other areas impacted by radiation disasters. True, human resettlement is most likely out of the picture, but as long as nature can make a comeback that should count as some sort of victory.
ReplyDeleteThanks for posting this. I had no idea that Chernobyl was on the rebound.
This is a great example of increased environmental pressure impacted rapid evolution. It's pretty horrid from a human perspective, as many animals had to die. But evolutionary, it's pretty amazing to watch the increase in average fitness of these animals.
ReplyDeleteThis is really interesting because I just watched a documentary about how the coral reefs around Bikini Atoll have been able to recover since the testing of nuclear weapons. Its great to see another example of how resilient nature is in the face of these man-made catastrophes! However, the fact that organisms need to adapt to radiation in the first place is still a bit disheartening.
ReplyDeleteThe increase in biodiversity may be mostly due to the missing presence of humans around the area (=no activity that harms the environment), but it still amazes me how fast the nature recovered. Here is PBS documentary explicitly talking about the environment of Chernobyl http://www.youtube.com/watch?v=U1Z5__IkaCs. Most animals still have high radiation levels but seems to withstand it.
ReplyDeleteWe humans are severely impacted by radiation--it is amazing that other animals, plants, and fungi can manage to thrive when we cannot. It would be interesting to see if there are any humans who are less affected or who are able to recover and thrive after a radiation event.
ReplyDeleteThis reminds me of an IMAX film we saw for Coral Reefs class recently. They talked about Bikini Atoll, where the U.S. tested many of its nuclear bombs post-WWII. You would not expect reefs to still exist there, but they are actually thriving. The resilience of nature is amazing.
ReplyDeleteIt'll be interesting to see how the exposure of radiation affects the seemingly unaffected animals in the future, and whether or not this exposure poses unknown longterm effects. Similarly, I wonder if the animals not as prone to survival, such as the bird species you mention, will begin to adapt, as well. I'm just glad Morrison did not find any radiated human survivors, like those seen in the recent horror movie Chernobyl Diaries. :)
ReplyDeleteWhat makes some animals more vulnerable to radiation than others? I wonder if its a specific genetic variation that makes some animals more susceptible to radiation than others. It's surprising that a good amount of species were able to survive and do well in an environment with heavy radiation.
ReplyDeleteAs was mentioned, is the presence of larger species such as bears due to their ability to survive radiation or more due to a lack of human presence? It would be interesting to study why these larger organisms are capable of surviving in high-radiation areas and what allows them to remain relatively unharmed, and if there is a reason they contain those genetic abilities.
ReplyDeleteI'd be interested to see if other studies have been done that take a closer look at the correlation between this particular disaster and the increase in biodiversity. Is there a direct relationship as hypothesized, in which organisms with higher fitness in the radiation conditions are subsequently able to have higher levels of reproductive success? Or is the effect more indirect, as is the case in many natural disaster-linked cycles, in which certain species rely on disturbances to limit competition and provide more favorable environments for success?
ReplyDeleteInteresting article! I'm curious if the human population will evolve to favor those who are more resistant to radiation as we become more exposed to it and what characteristics in humans will be beneficial in resisting radiation.
ReplyDeleteGreat article! I wonder whether we'll see any long term effects (more than 20 years later) on the species that have thrived in the post-Chernobyl. It'd be interesting to also see which specific genes and traits are the ones that increase survival in irradiated environments, and whether or not these traits persist if those species are translocated to another non-irradiated environment.
ReplyDelete