Polar bears are unable to breathe underwater. As with other mammals, they need to breathe air to live. Unlike fish that have gills, polar bears have lungs and need the oxygen that’s only available above the water.
Still, they’re classified as marine mammals and their swimming skills are excellent. According to One World Ocean, polar bears excel at swimming due to their thick and water-repellent fur, as well as their large paws, tapered body shape, and fat layers.
They’re experts in seal hunting and this requires a constant presence on the sea ice. As marine mammals, most polar bears spend their lives in water or around it. Polar bears are also able to hold their breath for two minutes underwater.
Can Polar Bears Breathe Underwater?
Polar bears may not be able to breathe underwater as fish do, but they can hold their breath for up to three minutes underwater to help them hunt seals.
Breathing underwater for longer requires specific anatomical features like gills, which polar bears don’t have.
Gills, like those found on fish, take oxygen from the water and the water carries away the carbon dioxide. Fish force the water through the gills and it flows through the blood vessels.
The oxygen passes through these blood vessels into the blood while the carbon dioxide comes out. On the other hand, the respiratory system of polar bears is similar to that of other mammals.
This system uses the lungs, heart, blood, arteries, and veins to breathe in oxygen, deliver it throughout the body, and expel carbon dioxide.
Although it’s unable to breathe underwater, a polar bear can close its nostrils to prevent water from going in while swimming. They can hold off their breath like this for two to three minutes since their lungs are large.
For comparison, an average human can hold their breath for around 30 seconds whereas people who’re trained for underwater emergencies can hold it longer, for around 2 minutes, according to Health Line.
Polar bears are also excellent divers, although the exact depth to which they can go is unknown. Researchers note that they may go as deep as 20 feet.
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Why Are Polar Bears Good Swimmers?
Polar bears are very good at swimming because of their thick and water-repellent fur, a thick layer of fat, big paws for propelling, and tapered body shape.
According to a study published in the Nature journal, polar bears are excellent swimmers that depend on marine resources for food and habitat. They hunt seals in areas with ice and drifting ice and their environment is a blend of open waters and sea ice.
They also hunt on land or from the shore where there’s no ice or little of it. In this case, swimming is the only way they can get where they need to. They swim and dive to reach seals, hunt birds, and fish, and get to other marine food resources like seaweed or sunken cadavers.
Water is also where polar bears cool down or clean themselves. They have numerous reasons why they spend so much time in the water, which is also how they’re so comfortable and well adapted to it.
Polar bears swim in a manner similar to that of dogs, propelling themselves through the water using their large front paws and using their back feet and legs as rudders to guide them.
They’re also unbothered by the icy cold water. Their thick layer of fat and water-repellent fur protects them optimally. Their fat is up to 4 inches thick and is less dense than muscle tissue, ensuring optimal insulation from the cold.
Interestingly, each of the hairs on their fur is hollow and acts as a tiny float, resulting in a more buoyant bear.
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How Long Can Polar Bears Swim?
Polar bears are great at swimming long distances. A study from the Zoology journal notes that polar bears regularly swim over 30 miles and there was one case when they went as far as 220 miles!
Scientists believe that their capacity for long-distance swims is essential to their survival considering seasonal sea ice is decreasing as a direct result of climate change.
According to the study’s co-author Karen Oakley from the USGS Alaska Science Center, the summer sea ice conditions in the south of Beaufort Sea changed a lot in the past 30 years and there’s more open water in the summer and autumn.
Throughout history, there hadn’t been sufficient open waters for polar bears to swim long distances, unlike today, which is a common sight.
In addition to being quite capable of swimming long distances, polar bears are also pretty fast. That is, they can swim at an approximate speed of 6 mph. As a comparison, the average human can swim at a speed of 2 mph.
Related Article: Why Don’t Polar Bears Eat Penguins?
Can Other Species of Bear Breathe Underwater?
Similar to the polar bear, no other species of bears can breathe underwater since they have lungs and a respiratory system that needs oxygen above the water, not gills like aquatic animals.
However, some other bear species are excellent swimmers as well, including the brown and black bear.
For example, the brown bear has thick fur and a large body and is a pretty good swimmer. According to a grizzly bear biologist from the US Fish and Wildlife Service, Wayne Kasworm, their high percentage of fat and oily coat is what plays a role in keeping them afloat.
Moreover, they’re good at swimming long distances. According to Dave Garshelis, a research scientist of wildlife at the Minnesota Department of Natural Resources, he once saw a brown bear swim six miles.
Although polar bears are considered the best swimmers among the bear species, brown and black bears are great swimmers too. As noted on Discover Wildlife, black bears frequently go into the water when searching for fish.
Although polar bears can’t breathe underwater due to them being mammals, they are excellent swimmers and divers and can hold their breath underwater for up to three minutes!
Polar bears spend a lot of time in or around water so they have adapted accordingly. Their body is one of the biggest reasons why their swimming skills are so great-it’s thick, robust, and water-repellent. Their paws are large and used to propel them forward.
Long-distance swimming is no problem for the polar bear-they can swim over 30 miles!
Polar bears aren’t the only species of bears that excel at swimming. Namely, the black and brown bears often spend a lot of time in the water, whether to hunt for fish or to cool themselves down.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.