Phytoplankton community dynamics in the western Arabian Gulf: Spatial and seasonal trends

The spatial and temporal variations in the phytoplankton abundance, composition, and community structure were investigated in the Western Arabian Gulf between 2002-2003 on a seasonal basis. A total of 490 phytoplankton species were identified, of which more than 65% were diatoms, and nearly 30% were dinoflagellates. The maximum number of species were identified during the onset of summer and the least during late fall. The highest abundance was observed in the northern waters during the onset of summer. Among the diatoms, pennate species dominated in abundance over centric, suggesting that they have better tolerance against environmental variables. The cyanophyte Trichodesmium erythraeum bloom was observed during spring and the onset of summer, whereas the dominance of Alexandrium monilatum was noted during summer along the offshore waters. Among the environmental parameters, temperature and nutrient concentration significantly influenced the seasonal variation in the phytoplankton community along the Arabian Gulf.