Lake Titicaca, because of its area and volume and its situation at high attitude within the tropics, is a unique hydrological site in the world. It should be noted that it stands at the transition point between two very distinct geographical regions: the desert fringe of the Pacific coast to the west and the great Amazonian forest extending to the Atlantic coast to the east. Many scientists have been attracted to the lake in the past because of its unusual limnological features. In this book the editors have compiled an exhaustive review of current knowledge from the existing literature and from the results of more recent