Dynamics of Phytoplankton Succession in The River Nile At Minia (Upper Egypt); As Influenced by Agricultural Runoff

The influence of agricultural wastewater effluents dumped to the Nile water at Minia (Upper Egypt) on phytoplankton distribution, diversity, succession, and standing crop was monthly evaluated in a comprehensive study for one year. Autumn harbored the highest standing crop at all sites. Bacillariophyta contributed the highest percentage composition. Chlorophyta and Cyanophyta rated second and third in the order of dominance, Euglenophyta was poorly represented. However, some members of the three groups tended to form blooms at certain times. The agricultural runoff induced gross changes in physicochemical characteristics of the Nile water and community structure of phytoplankton populations. Species of high occurrence being densly encountered at all sites were excelled by: Tabellaria fenestrata, Cyclotella bandanica, Cocconeis caespidata and Microcystic aeruginosa.