Lake Tana is the largest lake in Ethiopia and the source of the Blue Nile. Located in Amhara Region in the north-western Ethiopian Highlands, the lake is approximately 84 kilometres long and 66 kilometres wide, with a maximum depth of 15 metres, and an elevation of 1,788 metres. Lake Tana is fed by the Gilgel Abay, Reb and Gumara rivers. Its surface area ranges from 3,000 to 3,500 square kilometres, depending on season and rainfall. The lake level has been regulated since the construction of the control weir where the lake discharges into the Blue Nile. This controls the flow to the Blue Nile Falls and hydro-power station.
Lake Victoria is one of the African Great Lakes. With a surface area of approximately 59,947 km2 (23,146 sq mi), Lake Victoria is Africa's largest lake by area, the world's largest tropical lake, and the world's second-largest fresh water lake by surface area after Lake Superior in North America. In terms of volume, Lake Victoria is the world's ninth-largest continental lake, containing about 2,424 km3 (1.965×109 acre⋅ft) of water. Lake Victoria occupies a shallow depression in Africa. The lake has an average depth of 40 m (130 ft) and a maximum depth of 80–81 m (262–266 ft). Its catchment area covers 169,858 km2 (65,583 sq mi). The lake has a shoreline of 7,142 km (4,438 mi) when digitized at the 1:25,000 level, with islands constituting 3.7% of this length.
The Nile perch, also known as the African snook, Goliath perch, African barramundi , Goliath barramundi, Giant lates or the Victoria perch, is a species of freshwater fish in family Latidae of order Perciformes. It is widespread throughout much of the Afrotropical realm, being native to the Congo, Nile, Senegal, Niger and Lake Chad, Volta, Lake Turkana, and other river basins. It also occurs in the brackish waters of Lake Maryut in Egypt. The Nile perch is a fish of substantial economic and food-security importance in East Africa. Originally described as Labrus niloticus, among the marine wrasses, the species has also been referred to as Centropomus niloticus. Common names include African snook, Victoria perch, and many local names in various African languages, such as the Luo name mbuta or mputa. In Tanzania, it is called sangara, sankara, or chenku. In Francophone African countries, it is known as capitaine. Its name in the Hausa language is giwan ruwa, meaning "water elephant".
Lake Albert, originally known as Lake Mwitanzige and temporarily Lake Mobutu Sese Seko, is a lake located in Uganda and the Democratic Republic of the Congo. It is Africa's seventh-largest lake, as well as the second biggest of Uganda's Great Lakes.
Lake Kyoga is a large shallow lake in Uganda, about 1,720 km2 (660 sq mi) in area and at an elevation of 1,033 metres. The Victoria Nile flows through the lake on its way from Lake Victoria to Lake Albert. The main inflow from Lake Victoria is regulated by the Nalubaale Power Station in Jinja. Another source of water is the Mount Elgon region on the border between Uganda and Kenya. While Lake Kyoga is part of the African Great Lakes system, it is not itself considered a great lake.
The African Great Lakes are a series of lakes constituting the part of the Rift Valley lakes in and around the East African Rift. They include Lake Victoria, the second-largest fresh water lake in the world by area, Lake Tanganyika, the world's second-largest freshwater lake by volume and depth, and Lake Malawi, the world's eighth-largest fresh water lake by area. Collectively, they contain 31,000 km3 (7,400 cu mi) of water, which is more than either Lake Baikal or the North American Great Lakes. This total constitutes about 25% of the planet's unfrozen surface fresh water. The large rift lakes of Africa are the ancient home of great biodiversity, and 10% of the world's fish species live in this region.
The Tanganyika sardine is known as kapenta or matemba in Zambia, Malawi and Zimbabwe. Kapenta is two species, both of which are small, planktivorous, pelagic, freshwater clupeid originating from Lake Tanganyika in Zambia. They form the major biomass of pelagic fish in Lake Tanganyika and Lake Malawi, swimming in large schools in the open lake, feeding on copepods and potentially jellyfish. Their major predators are four species of Lates which are also endemic to Lake Tanganyika, and are related to the Nile perch in Lake Victoria. All of these pelagic fish have suffered from overfishing in the last two decades.
The marbled lungfish is a lungfish of the family Protopteridae. Also known as the leopard lungfish, it is found in Eastern and Central Africa, as well as the Nile region. At 133 billion base pairs, it has the largest known genome of any vertebrate and one of the largest of any organism, along with Polychaos dubium and Paris japonica at 670 billion and 150 billion, respectively.
The New Zealand smelt, also known as the New Zealand common smelt, New Zealand cucumber fish, or silveries is a smelt of the family Retropinnidae, found only in New Zealand at shallow depths in estuaries and rivers. Their length is between 8 and 13 cm.
Lake Kwania is in the districts of Lira, Apac and Amolatar in the Northern Region of Uganda. It is part of a large wetland along the White Nile between Lake Victoria and Lake Albert. The wetland, which includes Lake Kwania, the even larger Lake Kyoga, and other water bodies and swamps, consists of about 3,420 square kilometres (1,320 sq mi) of open water and about 2,180 square kilometres (840 sq mi) of permanent swamps. Of this total, Lake Kwania accounts for 540 square kilometres (210 sq mi), about 16 percent, of the open water.
Oreochromis esculentus, the Singida tilapia or Graham's tilapia, is a species of cichlid endemic to the Lake Victoria basin, including some of its satellite lakes such as Kyoga, in Tanzania, Uganda, and Kenya. Its common name refers to Lake Singida, but this population is the result of an introduction that happened in the 1950s. This fish is highly valued by local fishermen, who know it as ngege.
There are two major sources of fish in Uganda; one is from aquaculture, the other from fishing in rivers and lakes. The latter has made up the largest and most significant share of all fishing. Open water covers 15.3 percent of Uganda's surface and comprises five major lakes which are the main sources of fish in the country. Lake Victoria continues to be the most important water body in Uganda both in size and contribution to the total fish catch, followed by Lake Albert and Lake Kyoga.
Lake Victoria supports Africa's largest inland fishery, with the majority of the catch being the invasive Nile perch, introduced in the Lake in the 1950s.
Lake Bisina, also known as Lake Salisbury, is a freshwater lake in eastern Uganda. It is a satellite lake of Lake Kyoga, which it drains into, and the two are to some extent directly connected by papyrus swamps. During the high-water rainy season, Lake Bisina can be up to 6 m (20 ft) deep and it is often directly connected to the smaller Lake Opeta, but during the dry season the two are clearly separated.
There are two major sources of fish in Uganda; one is from aquaculture, the other from fishing in rivers and lakes. Different types of fish flourish in different water sources. The waters of Uganda contain an impressive array of fish species—over 90 in all. This count does not include the Haplochromis complex, which itself is made up of more than 200 species.
Fishing gear and methods used in Uganda are both modern and traditional. Fish in Uganda are caught mostly with plank canoes and to a lesser extent, fiberglass boats. Some dugout canoes are also still being used. The plank canoes are generally 4–12 m (13.12–39.37 ft) in length and dugout canoes average 3.5 m (11.48 ft). The total number of vessels is about 17,000 and about 20% of these are motorized. Artisanal fishermen use various gear including gillnets, seines and hook and line. In a number of localities, traditional methods including baskets, traps and mosquito nets continue to be used. The gear commonly used includes gillnets, lift nets, scoop-nets used in light fishing; hook and line gear and fish traps.
Lake Victoria supports Africa's largest inland fishery, with the majority of present catch being the invasive Nile perch, introduced to the Lake in the 1950s. Prior to the introduction of Nile perch as well as Nile tilapia, the fish community was very different and consisted mainly of 'Ngege' and Victoria tilapia as well as vast numbers of Haplochromis species. Fish communities in the first half of the 20th century are known primarily from a unique fisheries survey conducted in 1927-1928 by the Colonial Office.
Lake Kanyaboli is a lake in the Yala Swamp in western Kenya. It is important as a refuge for fish species that have almost disappeared from Lake Victoria.
Lake Sare is a lake in western Kenya that lies between the Yala Swamp and Lake Victoria. It has potential as a site for restocking fish species that have become endangered in Lake Victoria, but due to lack of management the lake ecology is steadily degrading.
Nile crocodiles are apex predators throughout their range. In the water, this species is an agile and rapid hunter relying on both movement and pressure sensors to catch any prey that presents itself inside or near the waterfront. Out of the water, however, the Nile crocodile can only rely on its limbs, as it gallops on solid ground, to chase prey. No matter where they attack prey, this and other crocodilians take practically all of their food by ambush, needing to grab their prey in a matter of seconds to succeed. They have an ectothermic metabolism, so can survive for long periods between meals—though when they do eat, they can eat up to half their body weight at a time. However, for such large animals, their stomachs are relatively small, not much larger than a basketball in an average-sized adult, so as a rule, they are anything but voracious eaters.
