Phyco periphyton community structure in embikhah khor at mukalla Coastal zone, Hadhramout-Yemen

A weekly sampling schedule was carried out from January to March, 2019 for studying phycoperiphyton community structure at four stations in Embikhah Khor which receives continuous effluent discharge and solid waste dumping from adjacent areas. A total of 53 phycoperiphyton species were identified under 6 major phyla. The Bacillariophyta made up a large proportion of the species composition contributing to 66.00 %, with 13.20 % Dinophyta and 11.30 % Cyanophyta followed by 5.70 % for Chlorophyta and 1.90 % for both Chrysophyta and Rhodophyta. Although Baillariophytic (diatom) species representation was higher than other classified phyla species, but all together provide information concerning the general nature of the microalgal composition and the formation of phycoperiphyton community structure. These results indicated the relatively pristine nature of Embikhah Khor water. Among the four stations, lowest number of species of 36 were recorded at stations 1 and 2 which affected by wastewater discharge while the highest number (43) of species were recorded at control station (station 4). Vaucheria and Batrachospermum genera are a new recorded in this study. A small non-significant fluctuation (P > 0.05) of phycoperiphyton showed the levels of dissimilarities between the stations in richness and α-diversity. The results of α-diversity and the dominance of diatoms indicate that Embikhah Khor nature is an oligotrophic waterbody.