When foraging, pelicans may fly a few feet or a considerable height over a school of fish and dive at high speed into the water, often submerging completely below the surface momentarily as they snap up prey. Upon surfacing they spill the water from the throat pouch before swallowing their catch. Only the Peruvian Pelican shares this active foraging style, while the six other pelicans forage more inactively by scooping up corralled fish while swimming on the surface of the water.

http://en.wikipedia.org/wiki/Brown_Pelican