As Their prey is aquatic, polar bears are great swimmers, and they're even recognized to kill beluga whales. In swimming, the polar bear employs only its entrance limbs, an aquatic adaptation present in no other 4-legged mammal. Polar bears are opportunistic and also predatory: they're going to eat useless fish https://www.youtube.com/channel/UCCoZfLHRsYsRsVHqS-CSAWA