Lake Tanganyika
| Lake Tanganyika | |
|---|---|
 | |
| Coordinates | |
| Lake type | Rift Valley Lake |
| Primary sources | Ruzizi River Malagarasi River Kalambo River |
| Primary outflows | Lukuga River |
| Catchment area | 231,000 km² |
| Basin countries | Burundi The DRC Tanzania Zambia |
| Max length | 673 km |
| Max width | 50km / 72km |
| Surface area | 32,900 km² |
| Average depth | 570m |
| Max depth | 1,470m |
| Water volume | 18,900 km³ |
| Shore length1 | 1,828 km |
| Surface elevation | 773m[1] |
| Settlements | Kigoma, Tanzania Kalemie, DRC |
| 1 Shore length is an imprecise measure which may not be standardized for this article. | |
Lake Tanganyika is a large lake in Central Africa that is estimated to be the second largest freshwater lake in the world by volume and the second deepest, in both cases after Lake Baikal in Siberia. It is also the world's longest freshwater lake and one of the world's oldest lakes, having been formed around twenty million years ago.
Located at the southern end of the Western Rift Valley, the lake is divided among four countries — Burundi, Democratic Republic of Congo (DRC), Tanzania, and Zambia. The water flows into the Congo River system and ultimately into the Atlantic Ocean. During the slave trading period, it was a major transshipment route for slavers. The old Arab slave-trading town of Ujiji, on the eastern shore of the lake, is where Henry Morton Stanley greeted David Livingstone with the words, "Dr. Livingstone, I presume?"
Geography
The lake is situated within the Western Rift of the Great Rift Valley that runs from Lebanon to Mozambique and is confined by the mountainous walls of the valley. It is the largest rift lake in Africa and the second largest lake by surface area on the continent. It is the deepest lake in Africa and holds the greatest volume of fresh water. It extends for 673 km in a general north-south direction and averages 50 km in width.
The lake covers 32,900 km², with a shoreline of 1,828km and a mean depth of 570 m and a maximum depth of 1,470 m (4,823 ft) (in the northern basin). It holds an estimated 18,900 km³ (4500 cubic miles). It has an average surface temperature of 25°C and a pH averaging 8.4. Additionally, beneath the 500 meters of water there is circa 4,500 meters of sediment overlaying the rock floor.
Of the four countries into which it is divided, the DRC (45 percent) and Tanzania (41 percent) possess the majority of the lake.
The enormous depth and tropical location of the lake prevent "turnover" of water masses, which means that much of the lower depths of the lake are so-called fossil water and are anoxic (lacking oxygen). The catchment area of the lake covers 231,000 km², with two main rivers flowing into the lake, numerous smaller rivers and streams (due to the steep mountains that keep drainage areas small), and one major outflow, the Lukuga River, which empties into the Congo River drainage.
The major inflows are the Ruzizi River, entering the north of the lake from Lake Kivu, and the Malagarasi River, which is Tanzania's second largest river, entering in the east side of Lake Tanganyika. The Malagarasi predates Lake Tanganyika and was formerly continuous with the Congo River.
Biology
The lake holds at least 250 species of cichlid fish and 150 non-cichlid species, most of which live along the shoreline down to a depth of approximately 600 feet. Lake Tanganyika is thus an important biological resource for the study of speciation in evolution.
The largest biomass of fish, however, is in the pelagic zone (open waters) and is dominated by six species — two species of "Tanganyika sardine" and four species of predatory Lates (related to, but not the same as, the Nile Perch that has devastated Lake Victoria cichlids).
Almost all (98 percent) of the cichlid species are endemic (exclusively native) to the lake and many, such as fish from the brightly colored Tropheus genus, are prized within the aquarium trade. This kind of elevated endemism also occurs among the numerous invertebrates in the lake, most especially the mollusks, (which possess similar forms to that of many marine mollusks), crabs, shrimps, copepods, jellyfishes, leeches, etc. Other animals found are the hippopotamus and the crocodile.
The Gombe Stream National Park and the Mahale Mountains National Park, both on the eastern shore, are famous for their chimpanzees.
Industry
It is estimated that 25–40 percent of the protein in the diet of the people living around the lake comes from lake fish, and that population amounts to around one million. Currently there are around 100,000 people directly involved in the fisheries operating from almost 800 sites. The lake is also vital to the estimated 10 million people living in the basin. Lake Tanganyika fish can be found throughout East Africa.
Commercial fishing began in the mid-1950s and has had an extremely heavy impact on the pelagic fish species; in 1995 the total catch was around 180,000 tons. Former industrial fisheries, which boomed in the 1980s, have subsequently collapsed.
Transport
Two ferries carry passengers and cargo along the eastern shore of the lake - the MV Liemba between Kigoma and Mpulungu and the MV Mwongozo, which runs between Kigoma and Bujumbura.
- The port town of Kigoma is the railhead for the railway from Dar es Salaam in Tanzania.
- The port town of Kalemie is the railhead for the DRC rail network.
History
Slaves captured by Arab traders from as far west as the Congo River basin were transported in the nineteenth century across Lake Tanganyika to Ujiji. From there they were marched to the Indian Ocean, a 1,200-kilometer walk that took from three to six months. It has been estimated that during the fifty years that the Omani Arabs controlled the route, over a million East Africans were shipped to the coast this way.
The first known Europeans to find the lake were the explorers Richard Burton and John Speke, in 1858. They located it while searching for the source of the Nile River.
World War I
The Lake was the scene of two famous battles during World War I. The Germans had complete control of the lake in the early stages of the war. When the Allies cut off the railway link in July 1916, the Germans abandoned the area. To avoid his prize ship falling into Allied hands, they scuttled the vessel, which was later resurrected and renamed as the MV Liemba.
Recent history
Since 2004 the lake has been the focus of a massive Water and Nature Initiative by the IUCN. The project is scheduled to take 5 years at a total cost of US$ 27 million. The initiative is attempting to monitor the resources and state of the lake, set common criteria for acceptable level of sediments, pollution, and water quality in general, and design and establish a lake basin management authority.[2]
The lake has also been a place where man-eating crocidile Gustave has been known to hide out. Gustave has killed many humans over the years and many scientists are interested in studying him.http://www.nationalgeographic.com/adventure/news/gustave-primeval/article.html
See also
- 2005 Lake Tanganyika earthquake
- Great Lakes (Africa)
- List of lakes
- List of lakes by area
- Rift Valley lakes
- Primeval (film)
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External links
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