Lake Victoria is like an ocean in the middle of Africa with a huge importance to the region. It is the biggest lake in Africa and the second biggest in the world. Only the Caspian Sea is bigger. The average depth is 40 meters which is pretty shallow. You cannot swim in the lake because of the parasites that carry the dangerous bilharzia infection. The parasite perforates the skin and destroys inner organs as the liver and kidneys. With the right medication the bilharzia attack can be stopped but very few Tanzanians have the possibility to get that treatment and die within a couple of years. You can swim in the lake from islands with sandy beaches because the parasites do not live in sand.
The lake has more than 3000 islands of which many are inhabited. 30 million people live in the vicinity of the lake and are more or less dependent on what it provides. The ecosystem of the lake is practically destroyed by the Nile perch planted here by the English during the 50s. They wanted a fish that tasted good and was fun to catch. The hungry perch ate all the other fish in the lake and from the couple of hundred species of fish living there only a few have survived extinction. The Nile perch is shipped out over the entire world. A very small amount of the income generated from this industry reaches the locals.
The water hyacinth was imported from South America because of its beautiful violet flowers. It started growing uncontrollably and covered more and more of the surface of the lake. 75 percent of the coast of Uganda was covered in 1995. This resulted in huge problems for the fishing and shipping. Chemical and mechanical means of control have been unsuccessful but the planting of a beetle that eats the hyacinth has worked out well.