Scientists Study How Polar Bears are Affected by Climate Change in Svalbard
A Polar Bear in Svalbard by Florian Ledoux
There is something especially alluring about apex predators- great white sharks, king cobras, and lions, just to name a few. But the magic of the creamy-white apex predators of the North is incomparable.
Weighing an average of 700 kilos, polar bears lumber over land and paddle glide light as a feather through the sea.
They’re fuzzy looking and jovial from afar, yet sobering and alarming if ever up close. In many ways, they are enigmas wrapped in riddles, as they are both the protagonists and antagonists for Svalbard residents and the visitors lucky enough to spot them.
Renowned Senior Research Scientist Dr. Jon Aars leads the Norwegian polar bear program at the Norwegian Polar Institute. When he started his position in 2003, he hadn’t ever seen a polar bear, and since then, every April (weather permitting) he has helped to track between 70 and 80 bears to take samples, affix tracking devices, and carry out population surveys to assess the size of the Svalbard polar bear population.
Aars says that while working with the animals after all this time has become a routine, he never loses respect and fascination for the bears.
“It feels more special handling the first polar bear you have ever seen than number 1000, but that does not mean you do not [appreciate] they are special animals every time,” he reflects.
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Tracking The Mighty Polar Bear
A Young Polar Bear in Svalbard by Chase Teron
Today, polar bears are an important example of an entire species fighting to overcome habitat destruction, environmental pollutants, and the impact of climate change.
Research is helping to paint a clearer picture of just what needs to be done to help the polar bear by learning more in-depth about its ecology, movement and behaviour in response to negative human influence.
One of the ways scientists are accomplishing this research is through tracking. Tracking starts when scientists fit a polar bear with a radio collar or ear tag, measure its length and weight, take samples of blood, fat, hair, and other tissues to identify any toxic contamination, and estimate its age from the rings of a tooth. With this initial information, they can determine a lot about the bear’s health.
Once fit, the collar sends out a signal via satellite so that scientists can follow the polar bear on its life journey.
These signals help scientists to determine when a tagged female enters a den and when she emerges with new cubs months later, how far she will travel, and where she will or won’t go (they are more likely to live closer and share territory with other blood-related polar bears!).
Aars details that in order to carry out this fieldwork, he and other scientists usually first tranquilize the bear with a dart gun.
Once the tracking and sample-taking procedure is over, scientists follow up with a drug antidote to reverse the effects of the bear immobilisation.
“The bears then mostly get up quite fast, and we have not had problems having to go back to the bear [due to procedural issues],” he says. “We have, as for all long-term programs, had very few accidents where we have lost bears under immobilisation; five total cases out of more than 2000 captures, which is [statistically] lower even than under controlled situations for e.g. dogs and cats.”
Once back in the lab, scientists use all of the data to study the tagged polar bears over their average 15-18 year lifespans. Multi-year observations and data-tracking have led to some of the most revealing information; the general yearly movements of the bears are changing in conjunction with recessions in the sea ice.
The research also shows that polar bears are mostly solitary when not mating, and that, in many areas, they are spending less time overall on sea ice and more time on land, leading to longer periods of fasting, weight loss, and less offspring.
An example of the effects of the sea ice recession can be seen in the Barents Sea polar bear population. About 3,000 polar bears are part of the population, and most hunt on the ice edge the majority of the year.
In this group, adult female polar bears have traditionally built their dens on Svalbard or Franz Josef Land. Before so much sea-ice recession, these females would walk the ice that extended south to reach their denning areas in Svalbard by autumn.
Now, the bears are forced to choose whether to burn precious calories and venture further north, far out onto the sea ice to look for food, or to stay close to home with reduced access to hunting—an issue that scientists believe will only get worse in the years to come.
Females looking to den sometimes then have to swim a calorie-consuming journey of hundreds of kilometres, right when they need calories the most.
Scientists believe that this journey might already be too difficult for some of the polar bears, so they may be choosing to den more exclusively in Franz Josef Land.
Unfortunately, in the next couple of decades, arriving to Franz Josef Land may also require an arduous swim.
There is a small subset of the Barents Sea polar bear population that already chooses to generally avoid the ice edge.
In Svalbard, there are around 300 bears that choose to stay close to the areas where they typically den year-round instead of travelling far out onto the sea ice to feed.
How polar bears are affected by climate change is highlighted in the challenge of the Svalbard polar bear. It remains similar to that of the rest of the Barents Sea population; as the retreating sea ice shortens their possible hunting season, females have to retreat to their dens with less fat and milk than ideal for their cubs for as long as six months at a time.
You might think that this information would be devastating for the population, but tracking has helped to show that the Svalbard population has so far been able to cope with these environmental changes.
Photo by Hans-Jurgen Mager on Unsplash
In an article for The Circle, a World Wide Fund for Nature (WWF) publication, Aars posits the question of why those polar bears seem to be thriving despite having access to less sea ice.
“There are a few possible answers”, Aars says. “It could be that the density of bears is still low compared to what it was before people started to hunt. That would mean less competition for food resources.”
“Another relevant factor is that polar bears are good at adapting and using every resource they can find…. polar bears used to hunt seals near glaciers on the fjord ice in summer. Now that the sea ice is often lacking, they spend more time plundering bird colonies for eggs and chicks…. the bears also take reindeer, something they were not known to do in decades past.”
“However, as the sea ice continues to disappear, it is likely they will be challenged at some point. Being a polar bear in Svalbard today is already a very different experience compared to 30 or 40 years ago, and the environment is changing swiftly.”
Time-tested Polar Bear Adaptations Put Them At Higher Risk Today
Photo by Hans-Jurgen Mager on Unsplash
The origins of the 20,000 to 25,000 endangered polar bears alive today are still in dispute. Various studies about when polar bears genetically split from North American brown bears come to different conclusions.
They may have been around for as little as 130,000 years (according to the mitochondrial DNA of a jawbone found in Svalbard), 600,000 years (according to nuclear DNA), or maybe they have been roaming around in a closely-related ancestral form for five million years (according to a full-genome study).
Their true age aside, polar bears evolved from their brown bear cousins in all the ways that make them better adapted to their traditional Arctic homes. They’re bigger– grown males can weigh up to 1,700 pounds. Plus, they have adapted to the cold and the water– besides the camouflaging fur difference, they have larger, slightly webbed paws for swimming and sharply curved claws for better ice grip.
Their heads are smaller than those of the brown bear for fitting into seal holes, but their teeth are longer and sharper. Their swinging, pendulous bellies and fuzzy, stocky appearance is really a thick layer of fat and two layers of fur, allowing polar bears to withstand temperatures as low as -50° Fahrenheit and no downtime for hibernation.
And of course, while ringed and bearded seals make up the traditional polar bear diet, they are now displaying able foraging skills to supplement their diets with more variety than ever experienced before.
But will their adaptations help them survive?
Unfortunately, to date, the above-listed incredible adaptations haven’t lead to making life in 2022 any easier for most polar bears. Instead, a couple of human factors have concretely served to put polar bears’ lives at risk.
Overhunting practices starting in the 1700s were spurred by European, Russian and North American hunters and trappers enticed by the desire to make money from their beautiful fur, massive size and fierce nature. In Svalbard alone, commercial hunters killed more than 30,000.
In the 1950s, another risk factor was introduced– the burning of fossil fuels contributing to sea levels rising and the melting away of the polar bear’s habitat. From 2001 to 2010 alone, some areas reported as much as a 40% polar bear population decline due to climate change.
Luckily, governmental organizations decided they could do something to prevent further decimation starting in 1973. It was then that the U.S, Denmark, Norway, and the former USSR signed an International Agreement on the Conservation of Polar Bears and their Habitat, which finally regulated commercial hunting.
Since that turning point, there have been many initiatives to establish domestic and inter-jurisdictional arrangements for polar bear research and management, which have served as the cornerstone for governmental regulation for new initiatives today.
Regulation has helped to keep several polar bear populations stable and, in a couple of cases, has helped small populations to increase in number, although many populations continue to decline.
When asked whether there may be reason to think that polar bears/ lifespans could be impacted by long-term foraging and the hunting of species unusual to the polar bear diet, Aars says, “Yes, but it is not obvious how much, and likely this will vary much between areas/populations.”
He adds that the role of the scientific community will be important to understanding the long-term effects of these adaptations.”You need long-term studies on decent sample sizes combining capture-recapture and diet study to reveal such effects,” Aars says.
Helping With Svalbard Polar Bear Conservation
If you’re looking for ways to help with polar bear conservation, Aars suggests going through two organizations.
His first recommendation is Polar Bears International. Polar Bears International is made up of a passionate team of conservationists, scientists, and volunteers—working to secure a future for polar bears across the Arctic. Through the organization, you can start your own fundraisers, sign petitions, contact your local representatives, access educational resources, and more. Learn more about Polar Bears International.
Aars second recommendation is to go through WWF, as it takes a multilevel approach to helping polar bears. WWF backs scientists and the important research being done with polar bear trackers, as well as the activities of Norwegian Polar Institute researchers.
It helped set up a partner organization to track illegal wildlife trade, while working with indigenous communities to sustainably hunt the local animals that make up a part of the traditional staple diet.
Most notably, it has successfully advocated for stronger conservation plans from governments around the world as well as a set of principles for Arctic tourism to guide sustainable polar bear tourism.
One of the most promising projects WWF scientists are pursuing is the study of “high value habitat areas” in order to work with partners to conserve places in the world where polar bears can den, feed, and give birth.
If you want to learn more about how to help the WWF with their work on polar bear conservation, head to their support page for membership information, donation details, and for the option to “adopt” a polar bear in the wild.
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If you are interested in seeing polar bears in the wild check out this article on polar bear viewing.