This study was carried out during a period extending between February 2016 and
January 2017 in both Damietta and Rosetta branches of the Nile. Water samples were
collected at eight sampling sites; four at Damietta and the others at Rosetta branch so as to
detect the variability of the protozoan organisms and evaluate some physico-chemical
parameters. It was proved that the protozoan genera of Rosetta branch showed more diverse
as compared with those of Damietta one ( 46 and 35 genera respectively). These organisms
were belonging to three main phyla ; Sarcodina, Mastigophora and Ciliophora where the
latter predominated the preceding two phyla at the various sampling sites in both river
branches. Simultaneously, organic matter, ammonia and nitrates exhibited higher levels in
Rosetta than Damietta, while phosphates, dissolved oxygen and pH behaved in an antagonistic
manner at the different seasons. The abundance of the sewage protozoan organisms was
higher in Rosetta branch relative to those of Damietta which could be attributed mostly to the
illegal runoff of the sewage wastes from certain villages on Rosetta branch that consequently
affect oxygen and organic matter contents at these stations. These unicellular organisms were
influenced and proved to be statistically significant to a certain limit with water temperature,
phosphate salts, ammonia and organic matter.