Using of phytoplankton and physicochemical parameters as indicator of pollution in El-Timsah lake, Ismailia,Eegypt.

Abstract

Samples were collected from six sites covering the lake Timsah during the period summer 2005-spring 2006, representing the four seasons, including water and phytoplankton samples, in order to evaluating phytoplankton algal community and physicochemical parameters. A total of One-hundard and two taxa have been identified. Most of them belong to Chlorophyceae (8); Bacillariophyceae (56); Dinophyceae (18); Cyanophyceae (20) were recrded. The maximum occurrence of the total phytoplankton density (1788 & 1718 cells.l^-1) was recorded in winter at sites I and II. The percentage of cell numbers was high for Bacillariophyta (60.2 & 59.5 %) and cyanophyceae (19.3 & 19.7 %) which may be attributed to concentrations of NH₄– - N, PO₄– -P and NO3-N, NO₂–-N and relatively higher values of salinity (33.8-32.2 ppt). Where the species richness (Alpha Diversity) was ranged between 6.586 during summer and 14.287 in winter while relative evenness (H\') was fluctuated between 1.684 in summer and 1.902 in winter Chlorophyll a varied between 0.3 at site I and 26 µg.l^-1 at site II. It exhibited high values during winter, while the lowest one during summer. Abundance of phytoplankton species may be attributed to High PO₄–, NH₄––N and NO₃–N were relatively high. The N:P ratio in Lake-Timsah, ranged between 1.07 and 9.45. The lowest value occurred at sites I, II and IV This could be attributed to eutrophication caused by wastewater and domestic input into the lake. This result indicate that The Lake Timsah classified as eutrophic. Most of the phytoplankton species recorded in this study was registered as pollution indicator species, others as toxigenic species for human beings and producing odor compound that impart water quality.

New Egyptian Journal of Microbiology Vol. 17 (2) 2007: pp. 297-313