Polar Bears On A Road To An Iceless Land

Polar bears are native to places within the Arctic Circle; the habitat encompasses locations throughout the Arctic Ocean in Canada, Alaska, Russia, Greenland, and Norway (Svalbard). To find food or reproduce, they can walk or swim long distances, sometimes covering up to 600,000 square kilometers.

In the Arctic Circle, you can find ice over the frozen ocean throughout the year. Polar bears, like their prey, the seals, can alternate the stance between land or ice. Today polar bears are considered a vulnerable species; due to environmental pollution, which triggers global warming, the ice is progressively disappearing.

Global warming has caused a progressive decrease in the ice sheet, is forcing these two species (polar bears and seals) to change their life habits, and, at the same time, hinders their survival, putting the lives of many animals at risk.

The Arctic is warming twice as fast as the world average in recent years, leading to accelerated thaw. The little ice in 2020 has caused polar bears to use 60% more energy; due to the difficulty of getting food, they lose more weight than they gain.

Image 1: It becomes difficult for bears and their cubs to reach their meals.

The loss of sea ice also threatens seals, the main prey for polar bears. Without food, polar bears are vulnerable and must travel even greater distances to find seals.

By helping protect the polar bear, we help make sure the Arctic food chain stays healthy; for the benefit of wildlife and people in and beyond the Arctic; due The Arctic provides fish for millions of people.

The bear's food is at risk

Without the ice, the seals cannot survive either; they live near the Village, they cannot have a place to give birth, their calf dies, further decreasing food for polar bears. The lack of ice causes the scarcity of seals that constitute 95% of the polar bear's diet.

As for the seals, "the ice is quite compact in a good ice year and stays together. But in bad ice years, there is a lot of space, the ice is much more mobile and moves with the wind and current". - says Garry Stenson, a harp seal expert with the Department of Fisheries and Oceans.

The mortality of seals increases enormously with global warming and ice breakdown, so they lose the ability to adapt to the temperature necessary to live and swim in the ocean.

Image 2: Ice breakdown causes disintegration of seal colonies.

"Polar bears are not likely to walk, but thanks to their high-energy diet of seals, they can roam an area of up to 95,000 square miles." Bears can lose weight quickly, but they can also regain it faster if they can catch seals. "I've seen a 1,100-pound (500-kilogram) male consume 200-pound (100 kilograms) of a seal at one meal," said Andrew Derocher, Canada's leading polar bear expert and professor at the University of Alberta.

How is it globally

NASA satellites report that Arctic sea ice has been declining at a rate of about 13% per decade since satellite records began in the late 1970s. According to this, in the 2020s, the ice sheet was lost by 65%, in contrast to what was initially reported. The Gulf of Saint Lawrence in Canada is an example of the remarkable change between 2008 and 2021.

Image 3: The Gulf of San Lorenzo lacks its sea ice.

The Arctic ice sheet changes with the seasons; it grows in winter and melts in summer. Due to climate change, the ice is shrinking and thinning year after year; Also, less accumulates, and its thaw starts earlier

"But because the ice is shrinking, the bears are having a harder time catching seal pups even during prime hunting time," says Anthony Pagano, a wildlife biologist with the Unites sates Geological Survey (USGS). 

Polar bears hunt the seals waiting for them to come out of the holes in the ice for air, and other times they swim after the seals. Today, bears have to travel farther because there is less ice in the sea; also, it can break. The consequences include weight loss, hypothermia, and the risk of death. Heating causes the thaw; this forces the polar bears to hunt while they swim, increasing their exercise and energy expenditure.

It is a must for polar bears to catch at least one seal every five to 10 days to break an acceptable weight; if they don't, they will lose weight. This food shortage poses long-term problems for the population, giving birth to small bears that produce fewer cubs and have lower survival rates. 

Image 4: Swimming in icy waters takes more weight off than walking.

Global warming results in the thinning of the sea ice is also causing microscopic plant life to flourish intensely at the North Pole, potentially disrupting the cycles and the marine food chain. Twenty years ago, only about three to four percent of Arctic sea ice was thin enough to allow large colonies of plankton to flourish underneath. Today, researchers found that nearly 30% of the ice-covered Arctic Ocean allows for under-ice blooms in the summer months.

If we reduce our carbon emissions and fuel sources, we can slow and even stop global warming; to preserve and save our sea ice and polar bears. Polar bears need sea ice for efficient hunting. Without sea ice, polar bears will decline in range and numbers, making them vulnerable to extinction in the future.

Oil and gas exploration, shipping, and industrial development cause devastating effects on this habitat - for example, an oil spill disrupts all life in the area. Polar bears have to stay longer on land with the lack of ice, increasingly putting them in contact with the local population in villages and trailers, reporting bears and people injured or killed in self-defense.

References

• National Geographic. Stephen Lehany Polar Bears Really Are Starving Because of Global Warming, Study Shows. Published February 1, 2018. Link https://www.nationalgeographic.com/science/article/polar-bears-starve-melting-sea-ice-global-warming-study-beaufort-sea-environment

• Dyck, Markus & Soon, Willie & Baydack, R.K. & Legates, David & Baliunas, S. & Ball, T.F. & Hancock, Lucy. (2007). Polar bears of western Hudson Bay and climate change: Are warming spring air temperatures the “ultimate” survival control factor?. Ecological Complexity. 4. 73-84. 10.1016/j.ecocom.2007.03.002. 

• BBC News. By Helen Briggs and Victoria Gill. Climate change: Polar bears could be lost by 2100. 20 July 2020. Link https://www.bbc.com/news/science-environment-53474445.

• National Geographic. Saroja Coelho. Harp seal pups dying on the beach as winter sea ice fails. March 18, 2021. Link https://www.nationalgeographic.com/animals/article/harp-seals-dying-blanc-sablon-amid-record-low-sea-ice

• PTI. Hindustan Times. There’s a reason Arctic sea ice is turning green: Global warming.Mar 31, 2017 01:19 PM IST. https://www.hindustantimes.com/world-news/there-s-a-reason-arctic-sea-ice-is-turning-green-global-warming/story-B4fPc5MqQCpy5gGm1RDBiK.html

• Stirling, Ian & Derocher, Andrew. (2012). Effects of climate warming on polar bears: A review of the evidence. Global change biology. 18. 2694-706. 10.1111/j.1365-2486.2012.02753.x.