Among the 19 water samples collected year round during (2010 – 2011) from
Ashtoum El-Gamil Park, 12 samples succeeded to cluster above similarity level of
60%. The samples of similarity less than 60% were mainly sampled during summer.
Total phytoplankton diversity marginally changed between lake stations. The highest
diversity of 3.1 was found at station No. 4 in winter where a minimum diversity of
1.14 was found at station No. 1 in spring. The dominant classes in Lake Manzala
(Ashtoum El-Gamil Park) were chlorophytes, diatoms and cyanoprokaryotes. The
three groups altogether constitute more than 95% and 85% of the total phytoplankton
abundance and total number of taxa, respectively. Based on cell number, the
chlorophytes ranked the first position of dominance with relative abundance of
84.23% and they exclusively dominated the phytoplankton communities year round.
Regarding the species composition, chlorophytes dominated the phytoplankton
species composition with percentage occurrence of 44% to the total number of
recorded species. The phytoplankton abundance showed major peaks during spring at
different stations except at station No. 2 where the highest abundance of 28716 cells x
105 l-1 was found, whereas the minor peaks were irregularly distributed between other
seasons with the least abundance of 704 cells x 105 l-1 which was detected during
winter at station No. 4. Generall, the total number of taxa per site showed no obvious
pattern of variation. It is concluded that presence and biodiversity of phytoplankton
are affected by locations and seasons, and the pollution is under the critical levels.