The Effects of Climate Change on Polar Bears

When most people think about climate change in the Arctic region, the first animal they might think of is the polar bear. In this blog, I will be discussing polar bear adaptations in the Arctic, diet of a polar bear, polar bear changes due to climate change, and resources for how you can help save the polar bears. Polar bears are the world’s largest land carnivores. The average adult polar bear is 6-8 feet on its hind legs and about 3.5-5 feet at its shoulder. Male polar bears weigh between 775-1,300 pounds while female polar bears weigh between 330-650 pounds (Polar Bears International, 2022). Male polar bears are generally 8-10 feet in length and female polar bears are 6-8 feet (PBS, 2020). The scientific name of the polar bear is Ursus maritimus (National Wildlife Federation). Polar bears deviated from brown bears about 500,000 years ago, but the actual estimate is still being debated and researched. They had to adapt to survive in the Arctic environment. As they moved and settled around the North Pole, they took on characteristics that made them protected from the cold and better hunters. Polar bears live in parts of Canada, Alaska, Russia, Greenland, and Norway. They will travel long distances across the north for food or breeding purposes (World Wildlife Fund, 2022).

Polar Bear Adaptations in the Arctic

In the winter, Arctic temperatures can reach -50 degrees Fahrenheit. Polar bears have adapted to the cold in many different ways. First, they have two layers of fur to prevent heat loss. The hair of a polar bear is actually translucent and they have black skin to absorb heat. They also have a thick layer of fat that can be up to 4.49 inches in thickness. This is beneficial when they are swimming in cold waters of the Arctic as the fat layer acts as an insulator. The paws of a polar bear help them live in Arctic conditions. They have large paws that are 11.8 inches across that enable them to walk on thin ice and swim. Each paw has a black footpad covered in small bumps (papillae) which acts act traction for them so they do not slip on the ice. They also have large, curved, sharp claws for traction purposes and to grab onto prey. Their ears and tails are small and round to try to keep in heat (Polar Bears International, 2022).

Polar Bear Adaptations – Youtube. Polar Bears International, 31 Jan. 2020, https://www.youtube.com/watch?v=Xbx6bqCjT0E.

Polar Bear Diet

The main source of food for polar bears comes in the form of ringed and bearded seals. These seals emerge from their breathing holes in the ice and that is when polar bears will attack from above with their powerful claws. They will also attack when they see seals basking on the ice. Seals are high in fat which is beneficial to the polar bear for maintaining their fat layer. It helps them stay warm and survive when there is a limited food supply (Polar Bears International, 2022). Polar bears spend most of their time on sea ice. Polar bears heavily depend on Arctic sea ice for traveling, hunting, and breeding. Sea ice allows them to walk, find food (mostly seals that emerge from the water), and breed. These natural patterns of this animal are becoming disrupted because of melting sea ice due to climate change.

Effects of Climate Change on Polar Bears

The Arctic Region is one of the most threatened, if not, the most threatened region when it comes to the impacts of climate change. The temperature that is seen here, is warming twice as fast as the global average temperature (WWF). Polar bears will see direct effects of climate change on their habitat, diet, and behavioral patterns because they rely on sea ice which is continuously melting. There has already been a decline in polar bear population in parts of the Arctic region where there have been longer ice-free periods. These areas are in the southern region of the Arctic around Hudson Bay, Canada. In this area, there is no sea ice present in the summer months. In the summer, polar bears who live here must stay on land until Hudson Bay freezes again so most of them will barely eat anything during this time. The ice is freezing in late fall and melting in early spring. This time frame is significantly shortening the interval that polar bears have to be on sea ice and hunt for seals. Their hunting season is being cut short by at least three weeks. Less food will cause them to have less cubs. Bear cubs born from malnourished parents will have a difficult time surviving to adulthood. Populations in the Hudson Bay area of Canada are down by 20% (National Wildlife Federation).

Polar Bear Subpopulation Short-Term Trends (2021). Polar Bears International [Photograph] https://polarbearsinternational.org/polar-bears-changing-arctic/polar-bear-facts/status/

Polar bears are having a difficult time moving around their habitat. Arctic sea ice is continuously drifting apart. Ice is beginning to be further from the shore and less easy to get to. Because of this, polar bears have to swim longer distances to get to the ice. They often have to swim in areas with less prey and in harsh conditions as they can encounter hazardous waves. Polar bears are great swimmers, but they can get caught in open waters or dangerous waves and drown. For example, four polar bears who drowned were found in the Beaufort Sea in 2004 (National Wildlife Federation). Scientists later found that the drowning incident was due to both melting ice and rough ocean waters. Also, during a period of rapidly melting ice in 2011, a female polar bear had to swim for nine days straight. Because of these impacts of climate change that are negatively impacting these animals, the U.S. Geological Survey predicts that we will lose two-thirds of polar bears by the year 2050 if the statistics continue on this current path (NWF).

KT Miller/Polar Bears International [Photograph] https://polarbearsinternational.org/news-media/articles/arctic-sea-ice-climate-model-projections.

Polar bears have very limited time to hunt for seals, their main source of food because the time period where they can hunt on sea ice is decreasing. The population of seals is being affected due to climate change as well and there is a scarcity of them for polar bears to eat. There are less places for seals to eat fish which is affecting the seals’ nutrition and reproduction. Because the seals are having a difficult time getting food, polar bears are too. It affects the entire Arctic food chain. In addition, as the Arctic warms, there is a great concern for diseases in much of the Arctic wildlife. There are already known viruses that were found in Alaskan and Russian polar bears. Diseases such as Trichinella, which is a parasite, have affected many polar bears. Due to increased warming because of climate change and human activities, scientists are concerned that more diseases will become present in Arctic wildlife.

Human Influence on Polar Bears

Human activities that worsen climate change in the Arctic region include oil and gas extraction, shipping, mining, and tourism. Oil and gas extraction processes poses a threat to Arctic wildlife because of the possibility of oil spills that can last in the area for many years. These processes can also disrupt polar bear families in their dens below the snow (Polar Bears International).

As the Arctic becomes warmer, polar bear encounters with humans will become more frequent as polar bears will spend more time on land rather than on sea ice. It is important that people around Arctic coastal areas know what to do in the event of a polar bear encounter.

Polar bears at Cape Zhelaniya weather station. – Copyright  Ivan Mizin/WWF-Russia [Photograph]

Pollution is a major human activity concern for the world, but specifically for the Arctic location because wind and ocean currents drive much pollution and toxic chemicals to this area of the world and they become concentrated as they travel up the food chain in a process called biomagnification. Since polar bears are at the top of the food chain, they will experience higher levels of toxic chemicals.

Other harmful human activities that affect polar bears are overfishing and hunting. Overfishing affects the Arctic food chain. As previously stated, there is less room for seals to eat fish, which affects the food chain, but overfishing by humans worsens this concept. By removing much of the fish of the Arctic, animals cannot eat and then other animals cannot eat those animals. Also, hunting polar bears used to be common and unregulated. Luckily, in recent years, this has become regulated and closely managed. There is still the present challenge that remains for indigenous people being able to still legally hunt polar bears for cultural and traditional reasons. Quota systems have been put in place for them (Polar Bears International).

Currently, the status of polar bears is vulnerable as listed by the IUCN Polar Bear Specialist Group. There are about 26,000 polar bears in the world (Polar Bears International). In 2008, the polar bear was an endangered species (National Wildlife Federation). Since then, polar bears have been moved to the vulnerable category which is an improvement from endangered. Polar bears are still directly experiencing impacts of climate change as the ice continues to melt. We must continue to make efforts to try and protect vulnerable species from effects of climate change.

How Can We Help Polar Bears?

There are quite a few organizations with the goal of helping polar bears. Examples are the World Wildlife Federation, the National Wildlife Federation, and Polar Bears International; all were mentioned previously. WWF has a program where you can “adopt” or sponsor a polar bear. This involves paying to help save and protect polar bears. The money goes to the organizations who work towards the protection of these animals. It often comes with a card, letter, or stuffed animal of the animal. Of course, there are many places where you can donate money to support a vulnerable or endangered animal which includes all of the ones listed above. Another thing you can do to help the polar bears or wildlife in general, that does not require money is volunteering for wildlife organizations such as the ones that were discussed and many others. Another way is to reduce your carbon footprint. This can be done in many different ways such as carpooling or biking, buying local products, and minimizing plastics. You can also create a project in your community such as a garden, a trash cleanup day, or a tree planting event. I hope this was beneficial for understanding the effects of climate change on polar bears and what you can do to help. Thank you for reading!

Additional Links

https://support.wwf.org.uk/adoptions?_ga=2.134282418.2135839209.1646599412-2021894234.1644619826

https://polarbearsinternational.org/act-now/donate/

https://polarbearsinternational.org/act-now/take-action/

https://www.takeactionforwildlifeconservation.com/11waystohelppolarbears.html

https://www.worldwildlife.org/species/polar-bear

References

“Polar Bear.” WWF, https://www.wwf.org.uk/learn/wildlife/polar-bears#challenges-affecting-polar-bears.

Polar Bears International, https://polarbearsinternational.org/.

“Polar Bear Fact Sheet.” PBS, Public Broadcasting Service, 8 Dec. 2020, https://www.pbs.org/wnet/nature/blog/polar-bear-fact-sheet/.

“Polar Bear.” National Wildlife Federation, https://www.nwf.org/Educational-Resources/Wildlife-Guide/Mammals/Polar-Bear#:~:text=Male%20polar%20bears%20are%20much,(up%20to%201%2C000%20pounds).

YouTube Videos:

Polar Bear Adaptations – YouTube. Polar Bears International, 31 Jan. 2020, https://www.youtube.com/watch?v=Xbx6bqCjT0E.

When Will Polar Bear Populations Collapse? the … – YouTube. Polar Bears International, 27 Aug. 2020, https://www.youtube.com/watch?v=I7Z1H4pUfIQ.

Images:

“Status.” Polar Bears International, https://polarbearsinternational.org/polar-bears-changing-arctic/polar-bear-facts/status/.

Miller, Kt. “Arctic Sea Ice Climate Model Projections: Polar Bears International.” Arctic Sea Ice Climate Model Projections | Polar Bears International, Polar Bears International, 16 Sept. 2021, https://polarbearsinternational.org/news-media/articles/arctic-sea-ice-climate-model-projections.

Марина Шибалова. “Climate Change Is Bringing Polar Bears Dangerously Close to Humans.” Euronews, 31 Dec. 2021, https://www.euronews.com/green/2021/12/31/climate-change-is-bringing-polar-bears-dangerously-close-to-humans.

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