Phytoplankton community in the Egyptian Mediterranean coastal waters

摘要

Phytoplankton community was investigated quantitatively at three sectors along the Egyptian Mediterranean coast (Rosetta, Abu-Qir and Eastern Harbor) during winter, spring and summer 2008-2009. Phytoplankton count reported wide temporal and spatial variability between a minimum of 72 units/l and a maximum of 5.77x10(6) units/l. Chlorophyceae and Bacillariophyceae were the main components. More than 207 phytoplankton species were identified, but a fevi only demonstrated active contribution to total standing crop, such as the green algae Carteria sp. and marine Chlorella vulgaris, the diatoms Asterionella glacialis, Cylindrotheca closterium, Melosira granulata, Navicula cryptocephala, Pseudo-Nitzschia palea, Pseudo-Nitzschia sigma, Pseudo-Nitzschia delicatissima, Skeletonema costatum, and the dinoflagellate Gonyaulax spp.. Spring was characterized by the lowest plankton density along the whole area, with a minimum of 317units/l off Rosetta Sector, and summer sustained the highest phytoplankton count (2.075 x 10(6) units/l) also at Rosetta Sector. The species diversity of phytoplankton community was quite high, being the most diversified (117 species) off Rosetta. Shannon index sustained values mostly less than 2, except off Rosetta during summer (2 -2.94 nats).