We visited the Chernobyl fauna 33 years after the nuclear accident

On April 26, 1986, the No. 4 reactor of the Chernobyl nuclear power plant (Ukraine) suffered an explosion during technical tests. As a result of the accident, the radiation emissions emitted by the Hiroshima (Japan) nuclear bomb in 1945 were about 400 times larger than those emitted by the nuclear bomb. It is so far the largest nuclear accident in history.

Decontamination work started immediately. Around the nuclear power plant, an exclusion zone was created in which some 350,000 people were evacuated. The evacuees never returned home and today, the region remains reserved for the human being.

The accident had a considerable impact on the human population. Although the numbers are unclear, the physical (loss of life) and psychological consequences of the evacuation were serious.

The initial impact on nature was also important. One of the most affected parts was the pine forest, now called "red forest". This area received the highest radiation doses. The pines died instantly and all the leaves became red. Few animals survived the highest radioactive doses.

Therefore, after the accident, it was badumed that the exclusion zone would become a desert for life. Given the long decomposition time of some radioactive compounds, it has been badumed that the area would be uninhabited for centuries.

The nature of Chernobyl today

Today, 33 years after the accident, live bears, bison, wolves, lynx, Przewalski horses and about 200 species of birds, among other animals, live in Chernobyl.

From 4 to 6 March 2019, we met in Portsmouth (England) the main research groups working on the nature of Chernobyl. About thirty Ukrainian, French, Belgian, Norwegian, Spanish, Irish and British researchers present the latest results of our badyzes. These include studies of large mammals, breeding birds, amphibians, fish, bees, worms, bacteria and leaf decomposition.

The documents presented showed that currently the exclusion zone is home to a great biodiversity. In addition, they confirmed the general lack of negative effects of radiation on Chernobyl animal and plant populations. All the groups studied maintain abundant and perfectly functional populations in the region.

The TREE project (Transfer, Exposure and Effects) gives a clear example of the diversity of Chernobyl fauna. As part of this project, camera traps were installed for several years throughout the exclusion zone. The photos reveal the presence of abundant wildlife at all levels of radiation. These cameras have detected for the first time the presence of brown bears and bison from Europe in the Ukrainian region, as well as the expansion of wolves and horses populations of Przewalski.

Our work with Chernobyl amphibians has also been able to detect abundant populations of all species, even in areas of greatest radioactive contamination. We also found indications of radiation adaptation reactions, such as changes in frog coloring. Frogs in the exclusion zone are darker, which could protect them from radiation.

Yes, some negative effects of radiation have been detected at the individual level. Some insects, for example, seem to live less and be more affected by parasites in heavily irradiated areas. Some birds also have damage to their immune system, increased albinism and genetic alterations. In any case, these alterations do not seem to affect the maintenance of populations.

The general lack of negative effects of radiation on Chernobyl fauna may be due to several factors. On the one hand, living organisms could be much more radiation-resistant than expected. Another alternative is that the species could begin to show adaptive responses that would allow it to live in contaminated areas without negative effects. In addition, the absence of humans in the area could favor many species, especially large mammals.

This latter alternative would indicate that the pressure of human activities would be more negative in the medium term for wildlife than a nuclear accident. A rather revealing vision of the human impact in the natural environment.

In 2016, the Ukrainian part of the exclusion zone was declared biosphere radiology reserve by the Ukrainian government. Contrary to initial forecasts, the region now serves as a refuge for many threatened species at European and national level. These include the brown bear, the European bison, the Przewaslki horse, the black stork and the Pomeranian eagle.

Over the years, Chernobyl has also become an excellent natural laboratory for studying the evolution of extreme environments.

At present, several projects are trying to resume human activity in the region. Catastrophic tourism has become popular, with more than 70,000 visitors in 2018. It is planned to build solar power plants for the production of energy. Even last autumn, an electronic music festival was organized in the abandoned city of Prípiat.

In 33 years, Chernobyl, which was considered a desert for life, has become an area of ​​interest for wildlife conservation. Paradoxically, it is now necessary to maintain the integrity of the exclusion zone as a reserve if we want it to remain a refuge for living beings in the future.

Germán Orizaola: researcher of the Ramón y Cajal program, University of Oviedo