Phytoplankton and some abiotic features of El-Bardawil Lake, Sinai, Egypt

El-Bardawil Lake is a large coastal lagoon on the Mediterranean coast of Sinai, Egypt. Although it is shallow and oligotrophic, it is one of the most important lakes in Egypt as a source of good quality fish and a habitat for wildlife. Phytoplankton biomass is generally low but is highest in summer when dinoflagellates are most abundant and lowest in fall when diatoms dominate the plankton. Green and blue-green algae are relatively unimportant in the plankton. The light environment is always good, although transparency is lowest in summer when chlorophyll-a was highest, up to about 2µg/l. Nutrient limitation, as indicated by dissolved nutrient concentrations, shifted from N-limitation in spring and summer to P-limitation in summer and fall. Nutrient-cycles are probably driven by the winter influx of seawater from the Mediterranean and the growth cycle of the sea grass, Ruppia. This coastal lagoon is currently oligotrophic, but trophic status and the phytoplankton community composition should be monitored if the drainage basin becomes developed. Keywords: phytoplankton; nutrients; Mediterranean; coastal lagoons (Afr J Aqua Sci: 2002 27(2): 97-105