Spatial and temporal variations of zooplankton assemblage in Chiffa Wadi (North Algeria)

The spatial and temporal variations in the distribution, abundance, and assemblage structure of zooplankton were examined in the Chiffa Wadi River, north central Algeria. Samples were taken seasonally from autumn 2020 to summer 2022. Nine physical and chemical variables were recorded, and their relationship with the density of 39 zooplankton species was established using canonical correspondence analysis. In order to study the structure of the zooplankton, Shannon-Wiener diversity indices (H'), Margalef richness index (Dmg), Pielou evenness (E), and abundance were calculated. During the analysis, rotifera was the dominant group in the zooplankton community, represented by 27 taxa, followed by Cladocera (9 taxa) and Copepoda (3 taxa). The diversity index indicated the higher richness, abundance, and evenness of zooplankton at a eutrophic site (S2) compared with other sites. The canonical correspondence analysis (CCA) showed that the structure of zooplankton is influenced by local environmental factors. The present study demonstrates that anthropogenic activities including urban discharge and the construction of Algeria's Medea-Chiffa highway, which increased the nutrient load in the aquatic system, disrupted water quality. Consequently, the distribution and quantity of zooplankton were dramatically impacted by these changes in water quality.