Phytoplankton community within Al-Auda marsh in maysan province southern Iraq

Abstract

Phytoplankton assemblage in relation to physical and chemical characteristics of water in Al-Auda marsh of Maysan province southern Iraq was assessed from November 2012 to July 2013. Six sampling sites were chosen to examine all phytoplankton species in the study area. A total of 246 species and seventy-five genera have been recognized belonging to twelve phytoplankton classes as follows: Bacillariophyceae (106 taxa), Chlorophyceae (34 taxa), Euglenophyceae (29 taxa), Cyanophyceae (29 taxa), Conjugatophyceae (19 taxa), Mediophyceae (10 taxa), Cryptophyceas (5 taxa), Coscinodiscophyceae (4 taxa), Chrysophyceae (4 taxa), Dinophyceae (3 taxa), Trebouxiophyceae (2 taxa) whereas Compsopogonophyceae recorded only (one taxon).The finding showed class Bacillariophyceae dominated with (43.09%), followed by Chlorophyceae of (13.82%), then (11.79%) for each of Cyanophycean and Euglenophyceae. Mean ± standard deviation for water temperature was ranged between (14.3±1.6°C) during winter to (35.6±1.81°C) during summer, electrical Conductivity (2020±186μ.s/cm) during autumn to (6390±875μ.s/cm) during summer, total Phosphate 0.01±0.0 µg/l during winter to 0.3±0.08 µg/l during spring, and total nitrogen varied from 1.8±0.8 µg/l during winter to 6.9±0.5 µg/l during autumn. Seasonal distribution indicated that phytoplankton flourished predominantly during the summer and spring. The diversity index (H) recorded the highest value in spring and lowest value in autumn, Richness (D) and Evenness (E) indices achieved the highest values in spring, the lowest values in autumn. The Jaccard index (Ss%) recorded the highest similarity between autumn and winter, the lowest similarity was between autumn and spring. The results revealed Al-Auda marsh is mesotrophic according to phytoplankton composition.