ABSTRACT
Aliphatic and aromatic hydrocarbons and organochlorines in a recent sediment core (Site 103) of Lake Victoria (East Africa) support the hypothesis that the lake has increased productivity since 1900, as reflected in the cyanobacteria population increase. This is evident by the increase in the accumulation rate of algal n-alkanes and organic carbon, n-alkanes indicative of terrestrial higher plants show an increased or stable accumulation rate during the same period. Good preservation of organic matter and organic indicators in the sediment suggest anoxic conditions have existed for the last 200 years. Increased human population of the basin and subsequent deforestation is indicated by the increase of the PAH derived from low temperature combustion processes. The hydrocarbon composition suggests an absence of petroleum inputs in the lake. The accumulation rates of PAH and organochlorines, although three times higher than 1900, remain low and are typical of remote environments.
