In a Sea of Melting Ice, These Polar Bears Are Doing One thing Surprising

In a warming world, the polar bear has change into the unofficial mascot of ecological collapse. We’ve all seen the pictures of those majestic predators diminished to pores and skin and bone, clinging to ever-shrinking chunks of sea ice as they struggle—and fail—to hunt. However on a distant Norwegian archipelago, a really totally different story is unfolding.

Svalbard is house to about 3,000 people, and roughly the same number of polar bears populate the Svalbard and Barents Sea area. An estimated 300 bears stay on the archipelago year-round. Throughout the Arctic, dwindling sea ice is depriving this species of its vital looking floor, and Svalbard is not any exception. But someway, its polar bear inhabitants is prospering, with bears truly gaining weight since 2000 regardless of fast lack of sea ice.

This discovering, printed Thursday within the journal Scientific Reports, understandably got here as fairly a shock to the examine’s authors. Lead creator Jon Aars, a senior researcher on the Norwegian Polar Institute, instructed Ireland Live that when he joined NPI in 2003, he would have anticipated the bears to be thinner and their inhabitants to be in decline by now.

“This paper highlights how totally different polar bear populations may be from each other, utilizing Svalbard for instance throughout greater than twenty years of fast sea ice loss,” co-author Andrew Derocher, professor of organic sciences on the College of Alberta, instructed the advocacy group Polar Bears International.

Defying the percentages

Earlier research has proven that the typical temperature within the Barents Sea area surrounding Svalbard has risen as much as 3.6 levels Fahrenheit (2 levels Celsius) per decade since 1980. Consequently, this space has misplaced sea ice habitat at a charge of 4 days per 12 months between 1979 and 2014, studies show. That’s greater than twice the speed of some other space house to polar bears, in response to Aars and his colleagues.

Regardless of this, the Barents Sea polar bear inhabitants has largely remained steady since Aars performed a census in 2004, which estimated 2,650 people throughout the area.

To research the drivers of this stability, Aars’s group analyzed physique composition information of 770 grownup polar bears measured on Svalbard between 1992 and 2019. The researchers then in contrast modifications within the bears’ physique composition index (BCI)—an indicator of fats reserves—with the variety of ice-free days within the Barents Sea area over the 27-year interval.

They discovered that the bears gained fats at the same time as sea ice continued to vanish, with their common BCI rising since 2000.

Complexities of a altering Arctic

The discovering poses an ecological puzzle, however Aars and his colleagues have a number of concepts about how Svalbard’s polar bears have managed to thrive regardless of fast habitat loss.

One cause could also be that populations of the bears’ land-based prey, resembling reindeer and walruses, are rebounding following years of overexploitation by people, the researchers counsel. These species may be supplementing the bears’ diets as looking marine prey—primarily ringed seals—turns into much less accessible.

Nevertheless, it’s additionally doable that sea ice loss is inflicting ringed seals to assemble throughout smaller areas of sea ice, permitting the bears to hunt extra effectively. With that mentioned, the authors predict that this profit will subside with additional reductions in sea ice, because the distances polar bears should journey throughout looking grounds will enhance. Researchers have already noticed this phenomenon in different populations.

Piecing collectively the complicated components which have allowed Svalbard’s polar bears to defy the percentages would require extra analysis, in response to the authors. For now, not less than, this inhabitants is a testomony to the truth that life usually finds a approach, however polar bears throughout the Arctic nonetheless face an existential menace.