Impact of Water Quality on Ecosystems of the Nile River

The Nile River is the most important freshwater resource for life and the main source for drinking and irrigation along the basin from its origin until its estuary in Northern Egypt. In order to secure water from African countries located on the Nile River, the sustainable use of water and maintenance of its good quality is a fundamental objective. The pollution status of the water of the Nile River is an important indicator of water quality. In this chapter, the different pollutants of the Nile River are discussed in relation to the biotic and abiotic factors that affect water quality and the aquatic ecosystem. Human activities and increase in population have had a large impact on water quality, for example, through discharge of treated and untreated sewage, manufacturing, mining, construction, agricultural wastes, and transportation and oil spills. Other toxic substances which can be secreted by certain types of algae and cyanobacteria can affect the water quality and are expressed by deterioration in color and taste of water. The Nile River in Egypt is considered the principal artery of life in Egypt, and its water quality is characterized by high nutrient concentrations such as nitrates, nitrite, ammonia, nitrogen, phosphates, sulfates, and silicates. Heavy metals from industrial wastewater and other sources may affect the distribution and growth of some undesired microorganisms. Heavy metals also affect the aquatic organisms especially fish which affects the human health. The Nile River is subjected to different organic pollution levels from human activities. These organic pollutants may derive from industrial, agricultural, or domestic wastewaters in the Delta region where the industrial and agricultural activity increase due to the increase of population. The industrial wastewater contains organic matter, suspended materials, heavy metals, as well as oils and other pollutants which include chemicals, fertilizers, insecticides, sugar, aluminum, steel, soap and paper, and oil spills from navigation and other activities. The water quality assessment methods as well as water characteristics are discussed. The effect of fish cages and fish farming on the water quality and freshwater aquatic ecosystem of the Nile River is also discussed in relation to pollutants secreted by the fish and the feed. Monitoring the Nile River water regularly and continuously can help to achieve an understanding of how this system functions which in turn can help to identify the sources and fates of contaminants to inform how to keep the water quality within safe limits for different uses.