South America’s largest lake is a slightly brackish Andean sea
Lake Titicaca straddles Peru and Bolivia atop the Altiplano and is often called the world’s highest navigable lake. It leads South America in both volume and surface area even though its waters run slightly brackish rather than purely fresh.
Its 8,372 square kilometres of water lie 3,812 metres up at the northern end of the endorheic Altiplano, and the highest-navigable label really applies to commercial vessels, since many smaller lakes sit higher. Two nearly separate basins meet at the Strait of Tiquina, barely 800 metres wide. Lago Grande averages 135 metres deep and plunges to 284; smaller Wiñaymarka averages only nine. Five main river systems—Ramis, Coata, Ilave, Huancané, Suchez—plus more than twenty lesser streams feed forty-one islands, some densely settled. Peru’s Puno Region holds the west; Bolivia’s La Paz Department the east.
The lake is monomictic: one mixing season, then stratification. Only about ten percent of the water budget exits via the Río Desaguadero toward Lake Poopó; fierce high-altitude sun and wind evaporate the rest. Since 2000 levels have trended down; April–November 2009 alone fell eighty-one centimetres to the lowest mark since 1949 as rains shortened and feeder glaciers melted.
Before the Spanish came, the many peoples around the shore probably used no single shared name. In Aymara, titi can mean puma or lead, while caca can mean grey hair and a similar word means crack. The archaeologist Stanish traces the name instead to thakhsi cala, the fifteenth- and sixteenth-century name of a sacred rock on the Isla del Sol. Bolivians call the small south-eastern basin Lago Huiñaymarca, Aymara for Eternal City, and the main body Lago Chucuito.
More than 530 aquatic species live in the lake. It became a Ramsar wetland on 26 August 1998, and BirdLife lists it as an Important Bird Area in both countries for birds such as the threatened Titicaca grebe, the Puna ibis and the Chilean flamingo.
Source: Lake Titicaca
