How do scientists determine what the long-term impacts would be to humans living in a radiation-contaminated environment? An ecological study of wolves in the Ukraine may provide the answer.
Most people have heard of the Chernobyl nuclear accident, which occurred in the Soviet Union in 1986. A reactor exploded, killing more than 30 workers and radioactively contaminating a vast region of Europe and Asia. The landmark nuclear event resulted in the complete evacuation of more than 100,000 people from the Chernobyl Exclusion Zone, an area of about 1,000 square miles. Ironically, the habitats abandoned by humans became ideal for certain wildlife species that no longer faced their most serious threat to survival – people. Included among the beneficiaries of the Chernobyl tragedy was one of the largest and most effective predators in the Northern Hemisphere–the gray wolf.
Not being shot, trapped, or indirectly affected by humans is the upside for wolves occupying the CEZ. But what complications might they face from chronic exposure to radiation in the food they eat and where they sleep? Drs. Jim Beasley and Stacey Lance, research ecologists from the University of Georgia’s Savannah River Ecology Lab, say that whereas radiation concentrations immediately after the accident were known to be “extremely high and dangerous, we don’t know what levels of radiation the wolves or other animals are exposed to now.” The researchers and their students are trained to study how human activities and disturbances affect the ecology of wildlife populations.
The CEZ wolves can serve as a proxy for determining the risks to human safety in low-level radiation areas. Among the questions being asked are whether cancer rates in the wolves are above normal levels, which can be determined indirectly with genetic studies. The researchers will also estimate wolf population sizes and distribution patterns across a gradient from high to low levels of contamination to look for demographic impacts. The findings can be applied to how humans might be affected.
Habitat disruption is often obvious, and the consequences for wildlife are highly predictable. But the CEZ presents a new challenge because the source of the problem is invisible. How can researchers determine how much radiation the wolves are exposed to? Equating exposure levels of wildlife to potential health effects is critical for predicting the extent of the problem. Beasley says, “If the health effects are bad enough, the CEZ could become an ecological trap, meaning wolves and other wildlife move into the landscape, but their survival and reproduction [are] lower than that of healthy populations.” Such a scenario could have a negative impact not only on wildlife within the CEZ but also in the surrounding landscape.
How will the scientists catch wolves, track where they roam, and determine their exposure to radiation? The researchers have developed a novel technology that will allow them not only to track wolves but also to continually measure radiation exposure levels. Live trapping, fitting the animals with radio collars, and using wildlife cameras are techniques used for decades by biologists to reveal movement patterns of wildlife. But what about the radiation measurements? To solve that problem, the researchers have combined GPS radio collars with a dosimeter, a small device that measures the radiation dose an individual has received. Every half hour a wolf’s location and its exposure to radiation are recorded.
If you want to find out more about how wildlife biologists study wolves and see lots of great photos, check out the Chernobyl Wolves Research Project website (http://bit.ly/RadWolves). You can also make a contribution to help fund the research. Visitors to the website can sign up to receive regular updates on the movement patterns of the CEZ wolves, including maps showing where each one with a collar is going each day. Once a wolf has a collar, it will be identified by a name chosen from those suggested by website visitors. If you’ve ever wanted to name a wild wolf, here’s your chance.
Whit Gibbons is an ecologist and environmental educator with the University of Georgia’s Savannah River Ecology Laboratory. Send environmental questions to ecoviews@gmail.com.