الفهرس 
MATERIALS AND METHODSOnly 14 pages are availabe for public view
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Abstract
The idea to conceive this research study originated from the previous hydrobiological study of this area before the construction of Faraskour barrage and during the presence of the silty Faraskour Dam. where, the study area was subjected to different pollution sources due to different agriculture, industrial and other anthropogenic human activities. Five different sampling sties namely station 1 (after Faraskour barrage), station 2 (before Faraskour barrage), station 3 (Damietta), station 4 (ElGerby) and station 5 (sea water at RasElbar) were selected to cover the estuarine of the Damietta branch, which extended from Faraskour northwards to the Mediterranean . At each station two water samples were collected, one from the surface water and the other was near bottom. The monthly sampling collection was continued for 15 months, starting from October, 2002 until December, 2003. Physical and chemical properties of water The investigation of the physicochemical properties of water was one of the essential goals of this study. Water temperature, water depth conductivity, salinity, total dissolved slates, pH, total alkalinity, total & free carbon dioxide, dissolved oxygen & its saturation percent, biological oxygen demand, ammoniaN, nitrateN, nitriteN, organic nitrogen, total nitrogen, orthophosphate, organic phosphorous, total phosphorus, silicate, sulfate, total hardness, calcium, magnesium, sodium, potassium and chloride were the measured parameters. Phytoplankton and related parameters from the taxonomical point of view, a total of 353 algal taxa belonging to 346 different genera were identified. The phytoplankton community was quite diverse with Bacillariophyta (106 taxa), Chlorophyta (104 taxa), Cyanophyta (34 taxa), Pyrrhophyta (60 taxa) and Euglenophyta (32 taxa) formed the considerable part of the species composition, while Chrysophyta (12 taxa) and Cryptophyta (5 taxa) formed the small one. It is really obvious that, the distribution, dynamics and flourishing of planktonic algae sustained spatial and temporal differences, according to the water quality and seasonality at different stations. This study paid considerable attention for the biological indices of water quality in the study area. A number of biological indices were used for this purpose. Those approaches rely mainly on the species composition of phytoplankton and the distribution of individual among the species. Toxicity Assessment The harmful effect of the red tide forming species (bloom of Dinoflagillates) was tested by using fry of Mugil cephalus L. The undiluted filtered red tide water was highly toxic, since it kill 100% of the exposed fishes after nine hours only. The result which reflect the toxicity of this water on the flora and fauna at the study area.