PHYTOPLANKTON DYNAMICS IN ESTUARY OF ROSETTA BRANCH OF RIVER NILE, EGYPT | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 12, Volume 10, Issue 3, July 2006, Pages 201-232 PDF (1.61 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2006.1871 | ||
| Author | ||
| Samiha Gharib | ||
| National Institute of Oceanography and Fisheries, Kayet Bay, Alexandria, Egypt | ||
| Abstract | ||
| Phytoplankton biomass and species composition in Rosetta Estuary was analyzed at seven stations based on a programme of monthly sampling from February 2004 to January 2005 and supported by measurements of limnologicar parameters* Variations in water salinity appeared to be the key to all changes in water quality and phytoplankton biomass in Rosetta Estuary. Salinity ranged between 2.8 and 38.0 PSU. Water transparency showed a relatively low values with Secchi disc readings varying from 20 to 100 cm- The pH values are ranging between 7.3 and 9.3. Dissolved oxygen levels indicated good aeration conditions (4.0 - 13.2 mg f1). Nutrient salts varied widely, often occurring in high concentrations, with ranges of 0.2-19.9 \xg at.1"1 for nitrate, 0.1-8.0 ng at.l" 1 for nitrite, 0.0-4.9 ug at.l*1 for ammonia, 0.08-3.2 \ig at.l"1 for phosphate and L2-46.0 tig at.l for silicate. The phytoplankton community consisted of 152 species; Bacillariophyceae comprised the highest number of species (67) followed by Chlorophyceae (41), Cyanophyceae (18), Dinophyceae (16), Euglenophyceae (8), while Rhodophyceae and Dictyochophyceae were represented by only one species each. Chlorophyceae was the dominant group, forming 36.2% of the total phytoplankton biomass followed by Dinophyceae and Bacillariophyceae which ranked, respectively, 31.9% and 20.8% of the total phytoplankton biomass. The phytoplankton biomass ranged between 0.05 and 5.73 mg l"1, with an annual average of 2.06 mg l"1 .Highest biomasses were recorded in May and January due to the prevailing of freshvyater species Scenedesmus quadricauda, Selenastrum gracile, Actinastrum hantzchii, Schroederia sp., AnUstrodesmus setigera and Pediastrum simplex. | ||
| Keywords | ||
| Phytoplankton biomass; physico-chemical parameters; River Nile Rosetta Estuary* | ||
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