Bioassessment and Biomonitoring of the Protectorate Wadi El-Rayan Lakes (Egypt) Using the Recommended Water Framework Directive (WFD) Indices Based on the Macrobenthic Invertebrates

Abstract

Rivers, reservoirs, and lakes are essential constituents of the global water system, supplying water for various purposes, such as drinking, irrigation, and power generation, as well as serving as habitats for all plant and animal species (Ayres et al., 1997). The lakes in the Wadi El-Rayan Depression (WRD) are exceptionally fertile and diverse ecosystems, supporting a wide range of life cycles for numerous species. The WRD was selected as a wastewater reservoir for Fayoum Governorate. Water began flowing into the first lake, the Upper Wadi El-Rayan Lake (UWRL), in 1976, followed by the second lake, the Lower Wadi El-Rayan Lake (LWRL), in