Biodiversity in Lake Victoria

Lake Victoria is located in East Africa, and the three bordering countries - Kenya, Uganda and Tanzania - share its resources.

Until the 1950s, the lake's hundreds of indigenous fish species provided great benefits to local people, both as a source of protein and also of local business. But then a disastrous change occurred.

In order to provide more food for local people, increase the commercial catch, and improve sports, British officials introduced a predator in the lake - the Nile perch. This changed the ecosystem of the lake irreversibly.

By the late 1970s, the Nile perch represented 80% of the biomass of the lake, and the indigenous species had been reduced to only 1%.

An economic boom was generated, as European countries seeking profit invested in the industry around the Nile perch. But apart from financial gain, the effect on the local people has been entirely negative. Development around the lake shore has increased pollution and speeded up the death of native species. Deforestation of the lake margins has increased topsoil erosion and silting.

The introduction of the Nile perch changed the lives of millions of people, particularly the 2 million of them who depend on fishing activities. The new fish is even too expensive for them to eat, as hotels and foreign customers pay so much more than what local people could afford. This contributes to malnutrition amongst local children.

The economic boom has had other knock-on effects. The income from fisheries is not evenly distributed, and poverty has increased. Women have been forced into working as prostitutes for the local fishermen and cargo plane pilots. Children get high off fish bones that are cooked into potent glue: they mainline it so as to sleep better on the streets.

A Tanzanian journalist found that Russian cargo planes transporting the fish to Europe then bring back guns and ammunition, to fuel wars in African countries.

This terrible story has been turned into a documentary film, Darwin's Nightmare. Watch it to see what a devastating effect we have when we mess with the environment.