A 5500-year environmental history of Lake Nabugabo, Uganda

Lake Nabugabo is widely known as the home of endemic cichlid fishes, but virtually nothing has been published regarding the limnological setting in which those species evolved during the late Holocene. Analysis of a 2.7 m long sediment core collected near the center of the lake suggests that Nabugabo was first isolated from Lake Victoria ca. 5000 calendar years ago, which would make it ca. 1000 years older than was previously believed. The lake apparently shrank significantly around 2600 and 2000 years ago during century-scale droughts, but it did not dry out at any point in its history. The inferred lake-level history of Nabugabo is generally consistent with Holocene paleoclimate records from the adjacent Lake Victoria basin, and suggests that biota in this lake were subjected to at least two major environmental changes during the last 5 millenia.