Over time, aquaculture has been able to fill the gaps in global national fish output, but the deficient management in aquaculture facilities caused huge negative effects on the environment. For this reason, the present work aimed to conduct an environmental assessment of the impacts of aquaculture practices on the ecosystem and water quality of Lake Mariout. This target was achieved by evaluating the aquaculture impacts on the zooplankton communities and describing the environmental aspects of zooplankton in relation to aquaculture. Seven stations were chosen to cover all major aquaculture features in the lake. Seasonal field scurvies were performed during the period from summer 2020 to spring 2021. A total of 63 zooplankton species and other immature forms were recorded during the current study. Rotifera was the main diverse (44 species) and quantitative (91.28 % of the total count of zooplankton) group. Copepoda come second then Protozoa and other groups that were rare and low in diversity. The rotifer Brachionus angularis was the most dominant zooplankton species. Zooplankton flourished in spring and low during winter. The results revealed that species richness ranged between 0.65 and 3.09, which means that the lake tends from moderate to high pollution. Moreover, the Shannon index ranged between 0.46 and 2.93, indicating that the lake is moderately polluted. The Evenness index showed clear effects of aquaculture activities on the equitability of the zooplankton distribution within the lake. In the same context, the total zooplankton density only negatively correlated with the salinity and ammonia concentration; rotifers density also showed the same; copepods were weakly negatively correlated with temperature; protozoans density showed significant correlation with water temperature and negative correlation with hydrogen ion concentration. On the other hand, zooplankton showed no significant correlation with any measured heavy metals. In conclusion, all human activities produce some impact on the surrounding environment, and aquaculture is not an exception, as it utilizes natural resources and releases waste into the environment.  The present study indicated that the unmanaged practices of aquaculture can negatively impact the environment. Regulation of aquaculture can create better products for human consumption, and making sure it runs properly for the safety of our environment is a must.