Water is an increasing challenge in Africa, not only the quantity, but the quality, says DPhil graduand Lindah Mhlanga, whose doctoral thesis examines water quality in Zimbabwe's Lake Civero.

A vital water resource for Harare, the lake is one of the world's most eutrophic reservoirs, characterised by excessive plant and algal growth.

"In sub-Saharan Africa we must conserve the limited amount available, and both the quality and the quantity through proper management."

For the past 12 years, the University of Zimbabwe has employed Mhlanga at the University Lake Kariba Research Station where her research has focused on aquatic ecology.

Her thesis was conducted through UCT's Freshwater Research Unit and examines a system under extreme pressure, both as a water source and means of waste removal, two opposing functions.

Mhlanga's work showed that the character and intensity of cynobacterial blooms in Lake Chivero can be managed by controlling the concentrations of nitrate, relative to phosphorous.