New Study: Polar Bears under Pressure

An international group of researchers, including representatives from Canada, the United States, and Norway, has published a new report in the scientific journal Ecological Monographs on the effects of climate change on the genetics and evolution of polar bears.

Scientists examined all 20 polar bear populations. Some are declining sharply, while others remain stable, and some are even thriving due to factors such as high biodiversity, abundant prey, and access to glacier ice that supplements the shrinking sea ice.

Nevertheless, polar bears are becoming smaller on average. This is a form of maladaptation, as it offers no advantage: smaller body size makes the bears more vulnerable, shortens the time they can survive without food, and results in smaller cubs with lower chances of survival.

In addition, the researchers confirmed that polar bears are not adapting evolutionarily to climate change. Although some individuals show behavioral flexibility, such as adopting new hunting strategies, these traits are not being passed on to future generations through evolutionary mechanisms.

Moreover, the reduced gene flow between populations is leading to decreasing genetic diversity in many groups. This decline, together with increasing inbreeding, points to reduced adaptability and greater vulnerability.

The authors of the report emphasize that maintaining contact between populations is crucial for the survival of the species as a whole.

“Our research shows that one of the most effective ways to protect polar bears in the warming Arctic is to maintain ecosystem connectivity by preserving their habitats. Through marine protected areas, the strategic planning of shipping routes, and other measures, we can ensure that polar bears and other Arctic species are still able to disperse and maintain contact with other populations. This is essential for preserving genetic diversity and the long-term resilience of species,” said Dr. Ruth Rivkin, lead author of the study and researcher at the University of Manitoba (Canada), who also works with the conservation organization Polar Bears International.

At the same time, Rosatom emphasizes that shipping along the Northern Sea Route has no negative impact on the environment. This suggests that Russia is not planning additional measures to protect Arctic species in the context of maritime traffic.

Rosamaria Kubny, PolarJournal