The South American rivers discharging to the Southern Pacific are located between 30° and 54° latitude south, encompassing a wide range of climates, from Mediterranean in the north to cold climate in the south. Rivers have a low diversity of fauna and flora but a high number of endemic species and groups with restricted distribution such as Galaxiformes fishes. The rivers are short but with fast-flowing waters. Many rivers are associated with numerous oligotrophic lakes in the Southern Andes. Basins in the north are under strong pressure due to water deviation and use for urban centers, agriculture, industry, and hydropower generation. In the south, human presence is much more limited and vast areas are very well conserved and protected with near pristine conditions, except for the introduction of nonnative salmonids.