on the distribution of zooplankton assemblaces in abu-qir bay, alexandria, egypt

Abstract

Abu Qir Bay is a shallow semi-circular basin lying 35 Km east of Alexandria city. The bay is facing the problem of pollution which discharged into the bay from different sources; El-Tabia Pumping Station (TPS), the outlet of Idku Lake and the Rosetta mouth of the Nile River. Quantitative and qualitative studies of zooplankton community in Abu Qir Bay were performed seasonally during 2004. Fourteen stations were selected to represent the different habitats in the bay.The seasonal variations of zooplankton standing stock in Abu Qir Bay indicated that, the highest count (average 87.1x103 ind/m3) occurred during spring, while the lowest (average 44.2x103 ind/m3) was recorded in summer. The average zooplankton count during the period of study amounted to 60.5x103 ind/m3. The minimum zooplankton crop (average 2.5x103 ind/m3) in front of El-Tabia Pumping Station reflects the effect of wastes discharged into the bay. The zooplankton assemblages in Abu Qir Bay were dominated by Protozoa, Copepoda and meroplanktonic Mollusca which contributed 51.19%, 27.90% and 12.10% respectively to the total zooplankton count. A total of 85 zooplankton species were identified during the period of investigation. The zooplankton organisms recorded in Abu Qir Bay live under a range of water temperature 16.1-28.5ºC and water salinity 34.807–38.658 ppt. 18 species (i.e. 22.35% of the species recorded) are euryhaline species.