Evaluation of the ecological health and food chain on the shores of four River Nile Islands, Egypt.

This study was conducted to evaluate the impact of human activities on the ecological health and food chain at the shores of four Nile Islands in Great Cairo including El-Qeratten, El-Waraq, El-Zamalek, and El-Manial. Water quality, bacteria, phytoplankton, benthic algae, zooplankton, macrobenthic invertebrates, and bony fishes were examined at each island shore over two seasons including the lowest and the highest flow (February and July 2020, respectively). The obtained results showed that the average values of most of the chemicals in Nile Island's water were within the Egyptian water quality limits. Discriminant analysis of physicochemical factors revealed a similarity between El-Waraq and El-Qerateen and between El-Manial and El-Zamalek. El-Qeratten was the most polluted island. It has the highest total and fecal coliform bacteria count (3.155 and 3.050 Log MPN/100 mL, respectively). El-Zamalek shores have the highest phytoplankton (33,582 cells × 104 L-1) and zooplankton count (310,891 organisms × m-3) and phyto-biochemical values. Biochemical analysis of phytoplankton demonstrated the richness of the bulk by protein (> 85% of biomass), indicating that phytoplankton has a high nutritional value. Elevated zooplankton count was recorded at El-Zamalek, which coincided with the peak of phytoplankton abundance. Mollusca were the dominant macrobenthic invertebrates on most of the island's shores. Bony fishes were represented by 27 species and two crustaceans. The levels of the metals in fish samples were compared with the food safety guideline endorsed by the World Health Organization and Food and Agriculture Organization (WHO/FAO) to evaluate the toxicity level.

An integrated water quality assessment of Damietta and Rosetta branches (Nile River, Egypt) using chemical and biological indices.

Rosetta and Damietta are the main branches of the Nile River in Egypt. They provide the required freshwater for different usage for about 20 million people. In the present study, chemical and biological indices were used to assess the water quality and provide a full image of the environmental status in the investigated area. Generally, the chemical parameters, except the dissolved oxygen, were at higher levels in Rosetta Branch when compared to Damietta Branch. Also, Damietta Branch frequently showed the presence of the macroinvertebrate families that are bioindicators of moderate and good water quality. Contrarily, the most resistant species to pollution were frequently recorded in the Rosetta Branch. According to Canadian WQI, the water of Rosetta Branch is classified from "marginal" to "poor" for the drinking and aquatic life uses and "fair" to "good" for irrigation usage. On the other side, the water quality of Damietta Branch is classified as "fair" with respect to drinking water and "good" to aquatic life and irrigation. Based on using macroinvertebrate families as bioindicators, the Biological Monitoring Working Party (BMWP) index and the Nile Biotic Pollution Index (NBPI) indicated that the water quality of the Damietta Branch was within "moderate" class, while Rosetta Branch is categorized from "very polluted" to "extremely polluted" classes. The results proved that both BMWP and NBPI have coincided with the CWQI for the drinking and aquatic life indices (p < 0.0001) indicating the validity of BMWP and NBPI to assess the water quality of the investigated area.