Step-by-step explanation:
The polar bear's life cycle is closely tied to sea ice. Polar bears rely on the ice to travel, hunt seals, breed, and in some cases, den. Scientists believe polar bears are unlikely to survive if ice-free periods exceed their fasting ability (220 days), especially in areas that lack alternate marine mammal prey.
Polar bears are strong swimmers and divers, a characteristic that allows them to swim from one ice floe to the next. But there’s a limit to how far they can swim. Long swims are especially dangerous to young cubs.