Blowing bubbles helps resting sperm whales avoid floating to the surface

Aug 7 : Anyone who has tried to keep a cork underwater knows it takes effort. Yet sperm whales can rest suspended beneath the ocean surface despite having massive heads filled with oil, wax and air that would seem to send them drifting upward — a feat scientists now think is made possible by blowing bubbles.Sperm whales are the only whales known to rest vertically in the water, with their heads pointing upward. Scientists believe this position helps protect them from the movement of surface waves without requiring the energy needed to dive deeper, but exactly how they remain submerged had remained unclear.Now researchers have found that the whales use bubble releases to regulate their buoyancy — the tendency to float or sink in water — while resting in a distinctive vertical posture just b