Biodiversity of Cladocera and Water Quality for Euphrates River in the Eastern of Al- Qadisiyah Governorate, Iraq

This study was conducted to evaluate the effect of urban wastewater on the characteristics of the Cladocera community in the Euphrates River. Three sampling sites were selected along the Euphrates River near Al-Shinafiyah town on the eastern side of Al-Qadisiyah Governorate, Iraq. The first site was upstream of Al-Shinafiyah town as a control site, and the second site was inside the town, whereas the third site was downstream of the town. Twenty-four taxa of Cladocera were investigated in this study. The higher mean density and richness index in the Euphrates River was in site (1), with values of 1237.5Ind./ m3 and 0.89, respectively.  While, the second site recorded The lower mean density and richness index with 587.3Ind./ m3 and 0.70, respectively. The similarity index was at a higher value between sites 1 and 2 reaching 58.3%, while the lowest value was between sites 2 and 3 reaching 45.8%. WQI_min (minimum Water Quality index) recorded a drop in the water quality by 63.3% compared with other sites, especially in summer. This decline can be attributed to the combined effect of the city sewage and the channel with industrial effluents, particularly site 2 inside Al-Shinafiyah City, which is associated with a low density of Cladocera.