Lake Malawi

Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is the fifth largest fresh water lake in the world by volume, the ninth largest lake in the world by area—and the third largest and second deepest lake in Africa. Lake Malawi is home to more species of fish than any other lake in the world, including at least 700 species of cichlids. The Mozambique portion of the lake was officially declared a reserve by the Government of Mozambique on June 10, 2011, while in Malawi a portion of the lake is included in Lake Malawi National Park. Lake Malawi is a meromictic lake, meaning that its water layers do not mix. The permanent stratification of Lake Malawi's water and the oxic-anoxic boundary (relating to oxygen in the water) are maintained by moderately small chemical and thermal gradients. Lake Malawi is between and long, and about wide at its widest point. The lake has a total surface area of about . The lake is at its deepest point, located in a major depression in the north-central part. Another smaller depression in the far north reaches a depth of . The southern half of the lake is shallower; less than in the south-central part and less than in the far south. The lake has shorelines on western Mozambique, eastern Malawi, and southern Tanzania. The largest river flowing into it is the Ruhuhu River, and there is an outlet at its southern end, the Shire River, a tributary that flows into the very large Zambezi River in Mozambique. Evaporation accounts for more than 80% of the water loss from the lake, considerably more than the outflowing Shire River. The outflows from Lake Malawi into the Shire River are vital for the economy as the water resources support hydropower, irrigation and downstream biodiversity. Concerns have been raised over the future climate change impacts of Lake Malawi due to the recent decline in lake levels and the overall drying trend.