It was the world’s worst nuclear power plant accident, but despite more than 25 years of ongoing research into the radiological consequences for the environment, scientists have failed to come to a consensus on the effects of the Chernobyl disaster on local wildlife. Some claim the Chernobyl exclusion zone (CEZ) has become a thriving wildlife haven in the absence of humans, whereas others have reported significant biological impacts at even tiny radiation doses.
The main problem with attempting to assess the ecological impact of the disaster is the fact that the radiation did not uniformly spread into the surroundings. This means that the amount organisms are exposed to depends on the distribution of the radioactive particles, the mobility of the species and also where they reside. Furthermore, the response to different doses of radiation varies considerably between species, and seasonal changes constantly alter the distribution of radioactive particles within the CEZ.
Estimating wildlife exposure and assessing the potential impacts of this is therefore no mean feat, but undeterred by this, scientists from the University of Salford have endeavored to design a study that could offer us the most comprehensive assessment of the risks to wildlife associated with radioactivity. The first stage of their ongoing investigation involves deploying a network of 42 cameras in 84 different locations across the 30-kilometer (19-mile) CEZ throughout the duration of 2015. These will capture images of any animals that stroll in front of the camera, providing a unique insight into the lives of the wildlife residing in this tainted land.
Although the cameras have only been up for a few months, BBC News reports they have already snapped 10,000 images of animals, indicating that the CEZ is rich in terms of biodiversity. The scientists will then use these images in order to identify the best species to trap and fit with collars, which will not only track the animal’s movements, but also measure radiation exposure both daily and over the entire study. Each animal will be tracked for one year, and the researchers will then combine this data with fecal DNA analysis to determine dietary composition.
Image Credit: TREE Research Project
“We want an animal that moves over areas of different contamination—that’s the key thing we need,” project leader Mike Wood explained to the BBC. “So we would consider some of the larger animals, such as wolves, because they would be ideal because the way the animal moves through the areas actually affects its contamination levels.”
Image Credit: Tree Research Project. Endangered Przeswalski's horses were deliberately released into the CEZ as part of a conservation project.
Although larger animals are preferable to small mammals due to the fact that hefty collars with big batteries cannot be fitted to slight animals like foxes, large animals, such as bears, require a trained marksman to be present, which necessitates extra permits. Ideally, they would select an animal, such as a raccoon dog, which would be trapped in a cage before being fitted with a collar and checked out by a vet before being released. Something else to take into consideration whilst selecting a species is poaching, which has become a problem within the CEZ. Obviously, if an animal is killed, then valuable data will be lost, but unfortunately poachers are often not overly selective with the animals they target, which means it is difficult to select a species based on the risk of poaching.
The researchers have another eight months of photographic data collection to get through before they need to make up their minds, but they hope to start tagging the animals throughout 2016.
Image credit: Tree Research Project