Document Type: Primary Research paper
The research was conducted to study the diatoms in a lotic ecosystem (Al-ShamiyahRiver) and related physicochemical factors for the period from March 2013 to January 2014. Four sites were selected along the river and the study included measuring the temperature (air and water), water flow rate, turbidity, light penetration, pH, total available carbon dioxide, dissolved oxygen, biochemical oxygen demand, electrical conductivity, salinity, total suspended solids, total dissolved solids, total alkalinity, hardness, calcium, magnesium, nitrite, nitrate, phosphate and silicate. Furthermore, the quantitative and qualitative studies of diatoms were done. A total of 144 taxa of diatoms was identified with predominate of pennate diatoms (129 species), while the centric diatoms were 15 species. The recorded identified diatoms were 83, 68, 74 and 81 species in sites 1, 2, 3 and 4, respectively. Total number of diatoms ranged 16347.7- 31514.6 cell × 103/l. High values of diversity indices were recorded in this study. The results revealed that the river was not under pollution stress.