The zooplankton community of Lake Abo Zaabal, a newly-formed mining lake in Cairo, Egypt
AbstractAbo Zaabal Lake, a new mining lake at the outskirts of Cairo, receives domestic sewage from a nearby village. We examined its chemical and biological properties in order to develop a plan to improve its ecosystem services. The pH ranged between 7.8 and 8.5, salinity was 17ppt and conductivity was 28 mS cm–1, indicating brackish water. The pelagic zooplankton community comprised Rotifera (16%), Protozoa (Ciliophora and Rhizopoda) (18%) and Copepoda (16%). Cladocera were seldom recorded. Hexarthra, Brachionus and Rotaria were the dominant rotifer taxa. Several characteristics — including the community composition, the dominance of small ciliates and nauplii, the abundance of Cyanobacteria, and the absence of macrophytes — indicated that it is a severely eutrophic lake. To improve the water quality we recommend that: (1) domestic sewage inflow should be stopped so as to reduce nutrient loading into the basin; (2) the growth of rooted macrophytes should be encouraged so as to increase water transparency by reducing phytoplankton biomass through competition for nutrients; and (3) piscivorous fish should be introduced to control zooplanktivorous fish in the lake and thus promote the growth of large filter-feeding zooplankton.
African Journal of Aquatic Science 2007, 32(2): 185–192