Comparison of P, N and C in catchments sediments around Lake Victoria

Sammanfattning: Lake Victoria is the largest lake by area in Africa as well as the source of River Nile. The lake has undergone environmental changes during the last four decades, particularly rise in its trophic condition and decline in oxygen level, which affects the water quality and fish population. Carbon (C), nitrogen (N) and phosphorus (P) are three vital elements required for algal growth that affect eutrophication in lakes. The aim of the study is to examine the P concentrations in sediment cores retrieved from the catchment around Lake Victoria, and compare this with data on N and C concentrations from the same samples. The results show that there is a difference in P levels between the urban versus rural sites. Moreover, concentrations for P, N and C are generally high in younger sediments (near surface samples), meaning that nutrients have most likely been added due to anthropogenic activities in the catchment. In addition, factors like erosion and weathering are also likely to have contributed to nutrient inputs, and thereby the eutrophic status in Lake Victoria.