New research   from the University of St Andrews and Université de Neuchâtel, has uncovered the mechanism which allows sperm whales to sleep in a unique vertical position, just under the ocean surface. Sperm whales are the only whale known to rest vertically. It’s thought to enable them to sleep effectively by buffering them from surface wave action, while avoiding the energy needed to dive to deeper depths. However, until now, it’s been unclear how they maintained their position just below the sea surface. In a paper published today (23 rd   July) in the   Journal of Experimental Biology,   researchers discovered that while resting, sperm whales release gas bubbles to help them regulate their buoyancy and remain below the sea surface. This regulation is crucial as Sperm Whales are positively buoyant naturally due to the large amounts of spermaceti oil in their heads.…