The influences of the Samarra impoundment on the ecology of the downstream sector of the river Tigris are investigated. Zooplankton were collected monthly from July 1987 to July 1988. It was found that zooplankton were most abundant during high river discharges in March. During the month of low river discharge, September, the zooplankton population was greatly reduced immediately below the barrage and remained so to the last downstream station. Several factors seem to explain such differences. The high discharge from the impoundment was found to be the dominating factor and may flush the small backwaters in which zooplankton were abundant, thus increasing the population in the river. Zooplankton species vary in their ability to sustain populations in the river, variations which are due mainly to speciesspecific characteristics.
The effect of Rustamia sewage treatment plant on the species composition, spatial and temporal variations of phytoplankton population in Tigris and Diyala rivers were studied for the period between October 1991 to May 1992. Diyala River had more algal taxa (85 tiixa) than Tigris (36 taxa). Bacillariophyta was dominated in both rivers (40 and 46 taxa, respectively) followed by Chlorophyta then Cyanophyta. Other phyla were also observed. The total phytoplankton and diatom biomass at both rivers showed seasonal variation with low densities in January ( 10544 X index was observed at stations which affected by wastewater inflow. The saprobiological investigations for both rivers were discussed. The water of Tigris and Diyala rivers considered as β-to α-mesosaprobic.Introduction:
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.