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.

Raccontata dachannelnewsasia.com