Lake Tanganyika

Lake Tanganyika is a very big lake. It is in Africa. The lake sits in a valley with high mountains. Four different lands share the water.

This lake is very deep. It is the second deepest lake in the world. It is also the longest lake of its kind.

Many fish live in the water.

Most of these fish live only in this lake. They cannot be found anywhere else.

Rain helps keep the lake full. Some water flows out through a river. It is a very special place.

Lake Tanganyika is a massive lake in Africa. It sits in a deep valley with high mountains. Four countries share the water. These are Tanzania, the DRC, Burundi, and Zambia. Tanzania and the DRC hold most of the lake.

This lake is very special. It is the longest freshwater lake in the world. It is also the second deepest lake on Earth. It holds a huge amount of fresh water. In fact, it holds 16% of the world's fresh water!

The water stays very still in deep parts. Because of this, there is no oxygen deep down. Most fish can only live in the top layers.

Many unique fish live here. Most of them are cichlids.

Nearly all these cichlids live only in this lake. You cannot find them anywhere else. Some are very tiny. Others, like the giant cichlid, can grow quite large. The lake also has crocodiles and special water cobras.

Rain is the main way the lake stays full. Some water flows out through the Lukuga River. This river leads to the Congo River system.

Lake Tanganyika is a massive and ancient body of water in Africa. It sits inside a deep valley called the Albertine Rift. High, steep mountains surround the lake on all sides. Four different countries share this huge lake. These countries are Tanzania, the Democratic Republic of the Congo, Burundi, and Zambia. Tanzania holds 46% of the water, while the DRC holds 40%. This makes the lake a very important place for these nations. It is the longest freshwater lake in the entire world.

This lake is famous for its incredible size and depth. It is the second deepest lake on Earth. It also holds the second most freshwater by volume. In fact, it holds 16% of all the fresh water on our planet!

Most of the water comes from rain falling on the surface. At least 90% of the water comes from rain. Another 90% of the water is lost when it evaporates into the air. Two main rivers flow into the lake to help keep it full. The Ruzizi River flows in from the north. The Malagarasi River flows in from the east side.

Lake Tanganyika has a very long and changing history. It is an ancient lake that is over a million years old. It actually has three different basins that formed at different times. The middle basin began to form 9 to 12 million years ago. The northern basin is younger, starting 7 to 8 million years ago. The southern basin is the youngest, forming 2 to 4 million years ago. In the past, these basins might have been separate lakes. The lake has also had different ways of flowing in and out over time.

The water in the lake has very specific features. The surface water is alkaline, which means it has a certain chemical balance. The temperature at the surface changes with the seasons. However, the temperature becomes very stable deep down.

The deep parts of the lake are very different from the top. There is almost no oxygen in the deepest sections. Because there is no oxygen, these areas are mostly lifeless. Only bacteria can live in those dark, deep places. This means most fish must stay in the upper layers of water.

Many amazing animals live in these waters that you cannot find anywhere else.

The lake is home to at least 250 species of cichlid fish. About 98% of these cichlids live only in Lake Tanganyika. Some are tiny, like the shell dwellers that are only 2 centimeters long. Others are huge, like the giant cichlid which can reach 60 centimeters.

You can also find Nile crocodiles and special water cobras here. Even the fish have different jobs, like eating plants or even scales. This makes the lake a very special place for scientists to study life.

Lake Tanganyika is a massive African Great Lake. It is a vital part of the Earth's water system. This lake is the longest freshwater lake in the world. It is also the second deepest and second largest by volume. Only Lake Baikal in Siberia is larger in these ways. The lake sits within the Albertine Rift. This is the western branch of the East African Rift. High, mountainous walls confine the valley where the lake lies. It is the largest rift lake on the African continent.

Four different countries share the waters of Lake Tanganyika. These nations are Tanzania, the Democratic Republic of the Congo (DRC), Burundi, and Zambia. Tanzania possesses 46% of the lake. The DRC holds 40% of the water. The lake drains through the Lukuga River. This river flows into the Congo River system. Eventually, that water reaches the Atlantic Ocean at Banana.

The lake's water levels determine if it can reach the sea. When levels are low, sand bars and weeds block the Lukuga River. In those times, the river relies on its own tributaries like the Niemba River.

Water movement in the lake is a complex process. Most of the water comes from rain. At least 90% of the water influx is from precipitation. At least 90% of the water loss is from direct evaporation. Two major rivers flow into the lake. The Ruzizi River enters from the north. It was formed about 10,000 years ago from Lake Kivu. The Malagarasi River enters from the east side. This river is Tanzania's second largest river. It is older than Lake Tanganyika itself.

Lake Tanganyika is an ancient feature of the Earth. It is one of only twenty lakes older than one million years. The lake is made of three distinct basins. These basins have different ages. The central basin began forming 9 to 12 million years ago. The northern basin formed 7 to 8 million years ago. The southern basin is the youngest at 2 to 4 million years old. In the past, these basins may have been separate lakes. The lake's history includes many changing flow patterns due to volcanic activity.

The chemistry and temperature of the water are very specific. The water is alkaline, meaning it has a high pH. At depths of 100 meters, the pH is around 9. In the deepest parts, it decreases to between 8.3 and 8.5.

Surface temperatures change with the seasons. In the south, temperatures range from 24°C in August to 28°C in March. Below 200 meters, the temperature is very stable at 22°C. The lake is stratified, which means it has distinct layers. Seasonal mixing usually does not go deeper than 200 meters. This leaves the deep sections with "fossil water."

This stratification creates a difficult environment for life. The deep sections are anoxic, meaning they have no oxygen. These deep areas contain high levels of toxic hydrogen sulfide. Consequently, these sections are essentially lifeless except for bacteria. Most fish and aerobic organisms are limited to the upper layers. In the north, this limit is typically around 100 meters. In the south, the limit is similar.

Some deep-water cichlid genera live in places with almost no oxygen. Scientists are still unsure how they survive there.

The lake is a massive center for biological diversity. It is home to at least 250 endemic species of cichlids. Endemic means they are found nowhere else on Earth. About 98% of the lake's cichlid species are unique to Tanganyika.

These fish show incredible adaptive radiation. This means they have evolved many different forms to fill different roles. Some eat plants, while others eat insects or even scales. Some are tiny, measuring only 2 centimeters. Others, like the giant cichlid, reach 60 centimeters.

The lake also hosts over 80 non-cichlid fish species. About 60% of these are also endemic. This makes the lake a precious resource for studying evolution.