Macrobenthic Invertebrates in the Northern Part of Lake Nasser: Community Structure, Relative Abundance and Diversity, Egypt

Associations between macrobenthic invertebrates and 17 environmental variables at 12 sites in 4 khors were analyzed, with their main channel located in the northern part of Lake Nasser during winter and summer, 2022. The results showed that the different sites vary significantly in their macrobenthic invertebrates community, and these differences are strongly related to variations in depth, bottom texture (sand, silt and clay), transparency, total suspended solids (TSS), temperature, hydrogen ion concentrations (pH), dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrate (NO₃-N), ammonium (NH₄-N), total phosphorus (TP), carbonate (CO₃), bicarbonate (HCO₃) and chlorophyll-a. Twenty-five taxa represented the macrobenthic community at the littoral sites, compared to twelve species found in the offshore areas. The total mean values at the littoral sites reached 335 organisms/ m² with a biomass of 4.4GFW/ m², while the offshore ones hosted 118 organisms/ m² with 2.5GFW/ m². The relationship between the different macrobenthic phyla with different species and environmental parameters was determined by using canonical correspondence analysis (CCA).