Do seals haul out on to the ice to sleep or do they sleep in the water?

Question

I guess I thought they could float in the water and breathe while sleeping. Guess not. Wasn't sure why they hauled themselves out like that unless just sick and tired of swimming and needing to rest.

Answer 1

Although harbor seals prefer to sleep on land, they often sleep in the water. They can sleep underwater, though they then have to wake up frequently and regularly to surface and breathe. So, this is not something subconcious, but something they have to conciously do.

Harbor seals sleeping on the water's surface often assume a posture known as bottling: most of the seal's body remains submerged, but the animal's face pokes above the surface like a snorkel, allowing the animal to breathe regularly while sleeping or resting. Elephant seals sometimes rest in the water in a similar manner. Northern elephant seals may possibly sleep hundreds of meter underwater. Walruses can inflate pouches in their throat which can help them float at the water's surface as they sleep. From studies of sleep in grey seals, we know that grey seals have REM sleep (rapid-eye-movement; lightest stage of sleep, in which brain-wave activity is highest and dreaming takes place) which does not occur in all animals, and it doesn't take place when pinnipeds during underwater sleep. It does take place when pinnipeds sleep at the surface of the water and on land.

Answer 2

They are mammals, so they breathe air. They must sleep on rocks or ice or something out of the water.

Answer 3

They sleep on land and on ice chunks that float by.