To find food in the vast expanses of seemingly featurelessocean, seabirds may hunt with their noses, according to researchers from UC Davis and the University of Washington. The smell of certain gaseous emissions from planktonic algae appears to tell some Antarctic birds that tasty morsels of food may be lurking under the ocean's surface, says Gabrielle Nevitt, an assistant professor of neurobiology, physiology and behavior at UC Davis. The study was published in a recent issue of the weekly journal Nature. Identifying naturally occurring, biologically made aromatics has proven elusive for scientists in the past. The study provides clues for understanding how birds navigate using natural odor landscapes. Odor-sensitive seabirds, such as white-chinned petrels and prions, are attracted by a chemical known as dimethyl sulfide, intensively studied for its role in global climate regulation. It smells vaguely of oysters and the ocean and may be mildly nauseating to humans. Dimethyl sulfide is produced when tiny plants found in seawater, called phytoplankton, are grazed upon by zooplankton, small animals eaten by fish and seabirds.