It's been discovered in a recent study that a magnificent polar bear swam a gruelling 426 miles (687km) continuously for nine days after what is thought by scientists could be a result of climate change.
Polar bears usually only swim between land and sea ice floes to hunt for food, not over such long periods of time.
Researchers believe that the increased sea melts are pushing these polar bears to swim longer distances causing risks to their own health and future generations.
Research zoologist, George M. Durner has said; “This bear swam continuously for 232 hours over 687km through waters that were 2-6 degrees C.”
"We are in awe that an animal that spends most of its time on the surface of sea ice could swim constantly for so long in water so cold. It is truly an amazing feat."
Polar bears have previously been observed in open water, however, this is the first time an entire journey has been followed.
The researchers were able to plot the movements of the female polar bear accurately for two months as it searched for hunting grounds by fitting a GPS collar.
This allowed the scientists to determine when the bear was in the water by the data from the collar and a temperature logger which was implanted beneath the skin of the polar bear.
This journey made by the polar bear came at quite a cost. The results showed that she lost 22% of her body fat over the two months as well as her yearling cub. Swimming these long distances puts cubs at risk, they simply don't have the same energy as the parents.
Polar bears live within the Arctic circle and to survive these freezing conditions the eat a calorie-rich diet of ringed seals (Pusa hispida).
Their habitat – frozen sea ice, where the polar bears hunt for the prey, changes according to the temperature.
The polar bears become dependant on the sea ice, which makes the species one of the most at-risk large mammals to climate change.
The International Union for Conservation of Nature (IUCN) red list identifies polar bears as a vulnerable species, stating global climate change as a “substantial threat” to their habitat.