In the hilly terrain of Japan, in an area largely abandoned for more than 10 years, rat snakes adorned with duct tape, super glue and specialized equipment slither in the trees, across roadways, coil in the dirt and maneuver among idled rice paddies.
Wherever they move, and even whenever they don’t, every 30 minutes they are transmitting crucial information that details their location and their exposure to radiation left over from the Fukushima nuclear accident in 2011 — one of the largest anthropogenic releases of radioactive contamination in history.
A lead architect of this research effort believes the tale that rat snakes are telling in Japan has utility for places like Utah, which has its own entanglements with radiation that include tons of contaminated mill tailings parked on the banks of the Colorado River near Moab and fallout from above-ground nuclear testing in Nevada in the 1950s and 1960s.
“These sort of technologies — whether on a burrowing species or not — could be applied to a whole variety of species,” said James Beasley, an associate professor at the University of Georgia’s Savannah River Ecology Laboratory and the Warnell School of Forestry and Natural Resources.
“When you place these tools on wildlife, they are going out and sampling the environment for you. They are collecting radiation measurements throughout the landscape.”
The research efforts involving rat snakes in Japan was one of the first to use GPS transmitters on snakes and represents one of the most comprehensive radio-ecological studies to determine the impacts of contamination on wildlife.
The research team, in order to determine where the snakes were spending their time and how far they were moving, tracked nine rat snakes using a combination of GPS transmitters and manual very-high-frequency tracking.
Use of the VHF transmitters allowed the team to physically locate a snake every few days to identify if it was underground or in arboreal habitat.
The researchers placed the transmitters on the rear back of the snakes using tape and super glue. The glue ensured the transmitters were secured to the tape, which allowed the transmitters to be easily removed when the study was over.
Tracking the movement of the snakes over the summer and being able to detect the degree of exposure proved invaluable in understanding what contamination remains.
Beasley said snakes were an ideal species for this study because they don’t move far and are in close contact with the soil.
“The radiation measurements you get are really localized to a specific area.”
The team, which included Beasley, Hannah C. Gerke and Thomas G. Hinton, had their study published this summer in the journal of Ichthyology & Herpetology.
Their findings emphasize that rat snakes are an effective bioindicator of residual radioactivity, especially given that they moved just 213 feet per day over the course of research period.
In the aftermath of Chernobyl and Fukushima, the study notes there has been a surge of interest in determining the effects of chronic low-dose radiation to humans, wildlife and vegetation.
“Relatively few studies have measured external dose rates on free ranging wildlife because of the difficulty in attaching and recovering the dosimeters from animals,” the study reported.
Instead, researchers generally rely on computer modeling to assess exposure to radionuclide activity.
Animals have an advantage over modeling, Beasley emphasized, because they are not static. It’s not just one soil sample from a few locations but rather real-time probing that uses an animal’s range to give scientists a more comprehensive picture of radioactive contamination distribution.
In another study, wolves in the region of the Chernobyl power plant were captured and outfitted with GPS transmitters and dosimeters to survey the landscape for residual radioactive contamination.
The wolves painted a different, less complete picture than that of the snakes, he said, pointing to their widespread range and the inability to precisely determine at what area in the range the exposure was amplified.
What they found in Japan is the radiation exposure varied from snake to snake, which didn’t surprise researchers.
“Radiation is not uniformly distributed,” Beasley said. “It is patchy on the landscape.”
Beasley said research showed that one form of contamination that has a half-life of 30 years is still really high in Japan where the Fukushima accident happened.
“We are not seeing any major health effects in the species we have studied so far,” such as negative impacts to the genetic makeup of the animal or reproductive systems.
“That is a sign of optimism, but there is still a lot more work that needs to be done on all these kind of questions,” Beasley said. “But these are pretty promising findings, especially for places that are not as contaminated like Fukushima.”
Stevie Norcross, assistant director of the Utah Division of Waste Management and Radiation Control, found the snake research in Japan intriguing.
“It was interesting to read how the University of Georgia uses snakes to track radiation bioaccumulation from the Fukushima nuclear disaster. However, we do not do anything to track radiation using animals in Utah,” Norcross said. “We do try to limit animal exposure to radiation by putting up fences and reducing vegetation that would attract animals to Utah’s uranium mills, for example.”
Beasley said if it is snakes or some other critter, the science that may be developed in Utah over radiation exposure via wildlife tracking might prove fruitful.
It could have implications for Utah’s western desert, which is home to EnergySolutions’ Clive facility where low-level radioactive waste is buried, as well as depleted uranium that gets “hotter” over time.
Utahn Steve Erickson, who has advocated on behalf of Utah residents and others exposed to fallout from above-ground nuclear tests decades ago in Nevada, said the research approach using snakes is interesting.
“To use a biomarker for those purposes — it is imaginative as well as good science.”
While he said he is not sure about its utility for “downwinder” areas from that testing so long ago, he believes it might be potentially useful for wildlife to be used as a “tracking” device along uranium belt areas in Utah and other regions of the Southwest.
“It’s pretty cool science,” Erickson said.