Environment

How Big Is Lake Victoria?

Lake Victoria in Africa is the world's largest tropical lake at 69,485 square kilometers in surface area.

5. Description

With a surface area of 69,485 square kilometers, Lake Victoria is Africa’s largest lake, and the world’s largest tropical lake, according to Diversity Inland Waters (DIW). After Lake Superior in the United States, Lake Victoria is also the second largest freshwater lake in the world by surface area. It’s shared by the three east African countries of Tanzania, Uganda, and Kenya. At 51 percent, Tanzania claims the biggest share of the lake’s waters, followed by Uganda at 43 percent, and Kenya at 6 percent. In the Kenyan portion, the lake is in the western region of that same country. Lake Victoria’s maximum depth is estimated to reach 84 meters, and the mean depth at 40 meters. The length of its shoreline is 3,450 kilometers in total. The lake has a water retention capacity of 140 years, and a catchment area of 194,200 square kilometers, which extends into Tanzania, Uganda, Kenya, Burundi and Rwanda, according to the Lake Victoria Fisheries Organization (LVFO).

4. Historical Role

The lake was named after Queen Victoria of England, with the honor bestowed by British Army officer and explorer John Hanning Speke, who was the first European to discover it in 1858. Speke also proclaimed Lake Victoria as the source of the Nile River. That claim was backed up by Henry Morton Stanley, an explorer, soldier. and journalist. after he successfully circumnavigated the lake in 1875, according to an American University report. However, explorer Dr. Burkhart Waldecker, of Germany, in 1937 disputed Stanley and Speke, and claimed the Nile River's source is at a bubbling spring in what is now Burundi. Through Stanley, traders and soldiers in Britain learned of the importance of Lake Victoria, and they came to East Africa to see for themselves. While in Kenya, these British colonialists decided to build a railway line from Mombasa to Lake Victoria, which was completed in 1902. The railway enabled the British government to move raw materials from landlocked Uganda, and transport processed goods from Britain to Uganda through Kenya’s Mombasa coast. The railway also helped reduce slave labor, which was then commonplace in East Africa, as initially slaves were used to transport these same goods that were now moving by rail.

3. Modern Significance

Today, over 30 million people from the three East African countries bounding the lake's waters depend on Lake Victoria for their livelihoods and even survival. Fishing is the main economic activity for those living along its shores. Over 2 million people from the three countries combined work in the fisheries industry, according to the LVFO. Fish from Lake Victoria is annually part of the diets of nearly 22 million people, thereby helping reduce food insecurity in the region. Also, 75 percent of the Nile perch harvested from the lake is exported to Europe, the United States, and the Middle East, earning the three countries foreign exchange revenues. The waters from Lake Victoria, like those of the Victoria-Nile River, are tapped into to produce hydroelectric power at Owen Falls, Uganda. The power plants at Owen Falls can generate 260 Megawatts of electric power, some of which is imported to Kenya. The Nile's waters that are sourced from the lake also support agricultural projects and tourism as far away as Sudan and Egypt.

2. Habitat and Biodiversity

Prior to the introduction of Nile perch and Nile tilapia into these waters in the 1950s and 1960s, Lake Victoria had over 500 endemic fish species. The most dominant were the tilapiine and haplochromines, both of which were cichlid species, and these lived alongside catfish, clarias, synodontis, schilbes, protopterus, and labeos. Lake Victoria's indigenous fish species' populations were reduced after being preyed upon by the invasive Nile perch and Nile Tilapia, according to the LVFO. That has contributed to the extinction of about 200 fish species since 1960, according to World Lakes. Lake Victoria's waters and immediately neighboring thickets serve as habitats for the Nile crocodile, African Rock python, mambas, cobras, and over 350 bird species. Mammals within the lake’s basin include the Sitatunga, oribis, Roan antelopes, hippopotamuses, Rothschild giraffes, and Jackson hartebeests. The dominant forms of vegetation in the Lake Victoria Basin varies across the three countries sharing it, and is comprised of dry forests and woodland in southern Tanzania, deciduous bush lands and thickets in northern Uganda, and dry, peripheral, semi-evergreen rainforests and scrub forests in eastern Kenya, according to a United Nations Habitat report. There are also swampy areas all around the lake’s margins.

1. Environmental Threats and Territorial Disputes

In recent years, the excessive accumulation of nutrients in Lake Victoria has caused eutrophication, resulting in a hyacinth weed population explosion. As a result, the weed has interfered with breeding, water purification, fishing, and transport, and become a breeding haven for human diseases, according to DIW. Eutrophication has also been cited by researchers as inducing losses of deep water oxygen levels, which began in the early 1960s. This loss of deep water oxygen could have also contributed to the annihilation of indigenous fish stocks, including certain endemic cichlids, in the 1980s. Furthermore, pollution due to urbanization around Lake Victoria is also still threatening its rich biodiversity. In Lake Victoria’s forest catchment areas, over 70 percent of the forest cover has been depleted, according to the World Wildlife Fund. All of those factors have caused the rivers flowing into the lake to carry large amounts of silt and nutrients that increase eutrophication further still.

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