Africa's largest and the world's second-largest freshwater lake by area, Lake Victoria lies along the Equator and is shared among Uganda, Kenya, and Tanzania. Located on a plateau between two rift valleys, its lone outlet is the Victoria Nile, a precursor of the White Nile. Named by the British explorer John Hanning Speke after Queen Victoria, the introduction of the predatory Nile perch in the 1950s has caused environmental degradation, sending many native cichlid species into extinction.