Polar bears in Norway’s Svalbard archipelago are defying the odds by getting fatter despite the disappearing sea ice, marking a surprising trend in the face of rapid climate change. The northern Barents Sea, where Svalbard is located, has been experiencing a warming rate seven times faster than the global average. This has led to a significant reduction in sea ice cover, with the ice around Svalbard lasting two months less in winter and spring compared to two decades ago. As a result, polar bears now have to swim long distances of 200 to 300 kilometers between their hunting grounds on the ice and their snow dens on the islands where they give birth.
Researchers, led by Jon Aars from the Norwegian Polar Institute, have been tracking the body condition of polar bears in Svalbard since 2000. Despite the challenging conditions, they found that the average size and weight of the bears have increased over the years, defying expectations. While this may seem like good news for the Svalbard population, scientists are cautious about the future.
The Svalbard polar bear population, estimated at 1900 to 3600 bears two decades ago, is believed to be stable or possibly even growing. Researchers have been able to track this trend by tranquilizing and measuring the bears since 1995. They observed a decrease in body condition until 2000, followed by an increase until the end of their observations in 2019.
One of the reasons behind the bears’ increasing weight could be the changing hunting dynamics. With the shrinking ice area, ringed seals, a primary food source for polar bears, may be more accessible to hunt. Additionally, the bears are turning to new food sources such as bearded seals along the coast and expanding populations of harbor seals on Svalbard. They have also been seen raiding bird colonies for eggs and preying on reindeer as well as feasting on walrus carcasses.
Despite their adaptability, polar bears in Svalbard are not out of the woods yet. The changing climate continues to pose a threat to their long-term survival. With the Arctic nations banning hunting of polar bears in 1973, the focus now shifts to the impact of disappearing sea ice on the bears’ food chain, which starts with algae on the underside of the ice.
While the current situation in Svalbard shows signs of resilience among the polar bears, experts warn that there will be a threshold beyond which the bears will be negatively affected by continued sea ice loss. Extinction may be delayed for now, but the long-term prospects remain uncertain for these iconic Arctic predators.
