Sperm Whales Blow Bubbles to Achieve Restful, Vertical Sleep
Our research reveals that sperm whales release gas bubbles to regulate buoyancy, allowing them to sleep vertically just below the ocean surface. This unique behavior counteracts their natural positive buoyancy from spermaceti oil and prevents drifting upward due to expanding lung gas. By analyzing tag data from the Norwegian coast, we confirmed these fine-scale adjustments enable restful sleep while submerged, a feat alien to terrestrial mammals.
This study confirms that Sperm Whales exquisitely control their buoyancy by releasing gases to remain submerged with near-neutral buoyancy just below the sea surface. It is particularly fascinating they are able to make these fine-scale adjustments while they are thought to be asleep, a challenge totally alien to terrestrial mammals like us humans.