New Scientist is carrying this report summarizing the discovery of mammals which can sniff under water. By using high-speed camera work along with some carefully designed experiments, scientists have been able to determine that at least two kinds of semi-aquatic mammals, the star-nosed mole and the water shrew, are able to track scents underwater by rapidly inhaling and exhaling small bubbles. The site includes a creepy but fascinating video of one of these critters in action.