Description and Main objective of study Lake Nasser is an Egyptian reservoir, which prevent it from water crisis. So the research and implementing Governmental authorities control the sources of pollution, which causes eutrophication phenomenon. The aim of this project is to study the algal and aquatic weed community structure in Lake Nasser, and their environmental impacts on water, plant, animal, and man through the environmental cycle. Procedures: - Field investigation conducted three files trips for 12 sectors along the Lake. - Ecological survey of the algal vegetation and zooplankton.