Global warming, according to scientific reports, is responsible for giving polar bears new hunting ground, due to the shrinking of sea ice in the Arctic region. As a result of the rising temperatures across the globe, the Arctic region now faces a genuine threat. The average temperatures in the region are rising faster than in the rest of the world and this is causing the ice to get thinner, melt faster and even break. A good example of this disturbing process is the Ward Hunt Ice Shelf in the Arctic region that has existed as a dense block of ice for 3,000 years. However, in 2000, this largest block of ice began cracking and by 2002, it had cracked down the middle. Now, this ice block is breaking and forming icebergs.
According to satellite images from NASA, as a result of global warming, the ice cap in the region is shrinking at an alarming rate. Scientists reckon that if this continues, the Arctic region will have no ice during summer by the end of the 22nd century. The melting and shrinking of sea ice is having a profound effect on the native flora and fauna of the region. The Ward Hunt Ice Shelf enclosed a freshwater epishelf lake in the Disraeli Fiord, which had for years supported a rich and delicate ecosystem. However, with this block of ice rupturing, the waters of the lake poured into the Arctic Ocean, spelling the dramatic end to the unique ecosystem it harbored. The feeding habit of animals, such as polar bears, whales and seals is also seen to be shifting.
Researchers have found that polar bears, especially those in the western Hudson Bay area, are having to change their feeding preferences due to the shrinking sea ice. “We found they were eating more of what is available on the land,” states Linda Gormezano, a vertebrate biologist associated with the American Museum of Natural History based in New York. She is the co-author of a study that has been tracking how the results of global warming is giving or rather forcing polar bears to new hunting grounds. Based on the study, Gormezano also claims that polar bears are eating more snow geese, caribou and eggs than ever before.
A polar bear’s diet of choice comprises of seals and other marine mammals. The bears wait at the holes in the ice made by the seals and when these mammals surface to breathe, the bears kill them for food. Seal fat is a good source of energy that the bears must store up for the lean months which can sometimes be more than four months of the year. However, with the melting and shrinking of the sea ice, polar bears are being forced to change their feeding habits. This is primarily during late spring, when the animals require increased fat reserves to prepare for the long winter hibernation. With sea ice shrinking, the distance from the shore is growing and causing polar bears to risk hazardous swimming conditions in order to come back to the shore with their kill.
Gormezano has recorded polar bears in the Hudson Bay area chasing and killing snow geese. A study conducted in 2013 found polar bear scat containing increased remains of snow geese and the findings of this study were published in the Ecology and Evolution Journal. Researchers have also found polar bear scat containing the remains of caribou and goose eggs, proving that global warming is definitely making polar bears move to new hunting grounds further inland in their quest for survival.
By Grace Stephen