Dolphins are conscious breathers: they actively decide when to come to the surface to breath. This make sleeping very difficult, as what happens if the dolphins go into a deep sleep? Probably they would suffocate.
Happily, this does not happen. They have their own method to get their zzz’s. Dolphins do not go into a deep sleep: they let half of the brain to sleep at a time. The other half of the brain reminds dolphins to go to surface to breathe.
Dolphins sleep in this fashion around 8 hours a day. Sometimes they can get even more sleep if they spend their resting time floating at the surface with their blowhole exposed.
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