Geography

The lake is situated within the Western Rift of the geographic feature known as the Great Rift Valley formed by the tectonic East African Rift,
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).^[3] It has an average surface temperature of 25 °C and a pH averaging 8.4. Additionally, beneath the 500 m of water there is circa 4,500 metres of sediment laying over the rock floor.

The enormous depth and tropical location of the lake prevent
'turnover' of watermasses, 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 pre-dates 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 shore
line down to a depth of approximately 600 feet (180 m). Lake Tanganyika
is thus an important biological resource for the study of speciation in
evolution.^[4][2] 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%) of the Tanganyikan cichlid species are endemic (exclusively native) to the lake and many, such as fish from the brightly coloured 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 molluscs (which possess similar forms to that of many
marine molluscs), crabs, shrimps, copepods, jellyfishes, leeches, etc.

 Industry

It is estimated that 25–40% of the protein in the diet of the people living around the lake comes from lake fish,^[5] and that population amounts to around one million.^{[citation needed]}
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.^{[dead link]}

Lake Tanganyika fish can be found exported 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 tonnes. Former industrial fisheries, which boomed in the
1980s, have subsequently collapsed.

Transport

There are two ferries which 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 D.R. Congo rail network.
• The port town of Mpulungu is a proposed railhead for Zambia.^[6]

Lake Tanganyika
map
Coordinates	6°30′S 29°30′ECoordinates: 6°30′S 29°30′E
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	570 m
Max. depth	1,470 m
Water volume	18,900 km³
Shore length1	1,828 km
Surface elevation	773 m[1]
Settlements	Kigoma, Tanzania Kalemie, DRC
1 Shore length is not a well-defined measure.

Geography

The lake is situated within the Western Rift of the geographic feature known as the Great Rift Valley formed by the tectonic East African Rift,
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).^[3] It has an average surface temperature of 25 °C and a pH averaging 8.4. Additionally, beneath the 500 m of water there is circa 4,500 metres of sediment laying over the rock floor.

The enormous depth and tropical location of the lake prevent
'turnover' of watermasses, 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 pre-dates 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 shore
line down to a depth of approximately 600 feet (180 m). Lake Tanganyika
is thus an important biological resource for the study of speciation in
evolution.^[4][2] 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%) of the Tanganyikan cichlid species are endemic (exclusively native) to the lake and many, such as fish from the brightly coloured 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 molluscs (which possess similar forms to that of many
marine molluscs), crabs, shrimps, copepods, jellyfishes, leeches, etc.