Seasonal Variation of Environmental Properties and Phytoplankton Community in Al- Hussainya River, Holly Karbala - Iraq

A comprehensive ecological study was conducted on Al-hussainya river during the period from October , 2012 To Septemper 2013 . This study includes measuring some chemical and physical properties of water , in addition to the study of Phytoplankton community quantitatively and qualitatively .The values of the parameters ranged between 12.7 ? 31.3 C°, 8.5 ? 45C° for water and air temperature respectively , 7.5 ? 9.4 for PH , 840 ? 1416.67 μs/cm , 413.33 ? 700 mg/l , 6.33 ? 55.07 mg / l , 0.54‰ ? 0.91 ‰ for each of electrical conductivity (EC ) , Total dissolved solids (TDS) , Total suspended solids (TSS) and salinity respectively , 11.68 ? 37.77 cm / sec. , 33.67 ? 148.67 cm for each of water current velocity and water penetration respectively , 4.97 ? 12.63 mg/l , 0.4 ? 4.84 mg/l for dissolved oxygen (DO) and BOD5 respectively. Nutrients such as silica , total nitrogen and total phosphorous showed variation during this study , their values ranged between 1.63 ? 6.26 mg / l , 1.4 ? 3.5 mg/l and 1.33 ? 17.29 μg/l for each of them respectively . A total of 242 taxa of phytoplankton identified during this study belonged to six classes of algae dominated by Bacillariophyceae which constitute 62.81 % of the total number of the species followed by Chlorophyceae by 20.66 % and Cyanophyceae by 11.16 % respectively . Dinophyceae and Euglenophyceae constitute the 2.07 % , while the the Cryptophyceae constitute the lower percentage which amounted to 1.24 % of the total species , some genera like as Nitzschia , Navicula , Cymbella , fragilaria , Scenedesmus and Oscillatoria were dominated by their species numbers in the Phytoplankton community .The total numbers of Phytoplankton cells ranged between (446.8 - 9177) × 103 cell / l recorded for March and October respectively .