Tanzania and Lake Tanganyika
After gaining independence from Britain, the East African territory called Tanganyika and the island of Zanzibar merged to create Tanzania in 1964. Tanzania borders the Indian Ocean, lies south of Kenya and north of Mozambique. It has a total area of 365,754 square miles (947,300 square kilometers), a bit less than one and a half times the area of France.
Mount Kilimanjaro is in Tanzania, as well as the Serengeti Game Reserve and the mythical island paradise of Zanzibar. It is where Mary Leaky discovered the footprints of our earliest known ancestors, Australopithecines, and Jane Goodall lived with her chimpanzees. It’s where Henry Morton Stanley spoke the immortal words, “Dr. Livingstone I presume?” and it houses Africa’s largest refugee camp. Two Rift Valley Lakes can be found in Tanzania: Lake Victoria and Lake Tanganyika.
Our story focuses on Lake Tanganyika.
Lake Tanganyika lies in Tanzania, Zambia, The Democratic Republic of Congo, and Burundi. Tanzania possesses 41% of the lake, and the DRC has the other lion’s share.
Lake Tanganyika incredibly old (around 6 million years) and is the second deepest lake in the world (just behind Lake Baikal in Siberia). At its deepest point, the lake is 4,800 feet (1,470 meters) deep. Because of this immense depth (nearly a mile), the waters in its deepest regions have been sealed off, like an underground aquifer. When water is cut off in this way for thousands or millions of years, it loses its oxygen and becomes known as ‘anoxic’ or ‘fossil water.’
There are two kinds of water in the lake. Freshwater and anoxic (fossil) water. In the southern end of the lake, the top 200 meters (656 feet) of water is freshwater, and the rest is anoxic. In the north only 100 meters (328 feet) is freshwater. This means that, in the north where our story takes place, the bottom 93% of the lake’s depth is uninhabitable anoxic water, and all life happens in the top 7%. There is a clear division between the fresh and anoxic waters, and they rarely mix. On the occurrences that they do, because of strong weather effects, for example, there are deadly effects on the animals in the lake.
Our story is concerned with fish called cichlids (pronounced “sick-lids”). They are of the Perciform order of vertebrates which comprise 41% of all bony fish. There are 250 species of cichlids in Lake Tanganyika, and 150 non-cichlid species. Most of the cichlids (98%) and other water creatures (including molluscs, crabs, shrimp, and jellyfish) living in the lake are endemic, meaning they cannot be found in any other place in the world. Because of this, scientists are drawn to studying the endemic species of Lake Tanganyika as well as other Rift Valley Lakes.The
