Lake Victoria East Africa Introduce aspects of the ecology and management of Lake Victoria with...

Lake VictoriaEast Africa

Introduce aspects of the ecology and management of Lake Victoria with special emphasis on changes in its endemic fish fauna.

Mean depth = 40mMaximum depth = 79mSurface area = 68,000 km2

Altitude = 1,134mShoreline development index = 3.7

Basin size = 263,000 km2

Population = 27.7 million

Start of the rainy season (cool/windy)

Lake Victoria – water hyacinthEichhornia crassipes

Lake Victoria – papyrus

Cyperus papyrus

Source: Bootsma and Hecky 1993

Source: Verschuren et al. 2002. History and timing of human impact on lake Victoria.Proc. Royal Society London 269: 289-294

Core taken in 1996 from a depth of 68mDiscontinuity near 25cm depth in the core represents a hiatus of ca. 40 years (stippled zone)

Note: Increasing abundance of diatoms starting in the 1960s but decrease again in the 1980s. Diatoms replace by bloom-forming cyanobacteria

Anabaena

Cyanobacteria bloom

Microcystis

Haplochromine cichlids

Lake Victoria food web prior to the introduction of the Nile perch

[Haplochromids in black]

Lake Victoria food webfollowing the introductionof the Nile perch

Witte et al. 1992

Witte et al. 1992

Goudswaard et al. 2008